/* * Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the Apache License 2.0 (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy * in the file LICENSE in the source distribution or at * https://www.openssl.org/source/license.html */ #include "internal/deprecated.h" #include #include #include #include #include "crypto/ctype.h" #include "internal/cryptlib.h" #include #include #include #include #include #include #include #include #include "internal/dane.h" #include "crypto/x509.h" #include "x509_local.h" /* CRL score values */ #define CRL_SCORE_NOCRITICAL 0x100 /* No unhandled critical extensions */ #define CRL_SCORE_SCOPE 0x080 /* certificate is within CRL scope */ #define CRL_SCORE_TIME 0x040 /* CRL times valid */ #define CRL_SCORE_ISSUER_NAME 0x020 /* Issuer name matches certificate */ #define CRL_SCORE_VALID /* If this score or above CRL is probably valid */ \ (CRL_SCORE_NOCRITICAL | CRL_SCORE_TIME | CRL_SCORE_SCOPE) #define CRL_SCORE_ISSUER_CERT 0x018 /* CRL issuer is certificate issuer */ #define CRL_SCORE_SAME_PATH 0x008 /* CRL issuer is on certificate path */ #define CRL_SCORE_AKID 0x004 /* CRL issuer matches CRL AKID */ #define CRL_SCORE_TIME_DELTA 0x002 /* Have a delta CRL with valid times */ static int x509_verify_x509(X509_STORE_CTX *ctx); static int x509_verify_rpk(X509_STORE_CTX *ctx); static int build_chain(X509_STORE_CTX *ctx); static int verify_chain(X509_STORE_CTX *ctx); static int verify_rpk(X509_STORE_CTX *ctx); static int dane_verify(X509_STORE_CTX *ctx); static int dane_verify_rpk(X509_STORE_CTX *ctx); static int null_callback(int ok, X509_STORE_CTX *e); static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer); static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x); static int check_extensions(X509_STORE_CTX *ctx); static int check_name_constraints(X509_STORE_CTX *ctx); static int check_id(X509_STORE_CTX *ctx); static int check_trust(X509_STORE_CTX *ctx, int num_untrusted); static int check_revocation(X509_STORE_CTX *ctx); static int check_cert(X509_STORE_CTX *ctx); static int check_policy(X509_STORE_CTX *ctx); static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x); static int check_dane_issuer(X509_STORE_CTX *ctx, int depth); static int check_cert_key_level(X509_STORE_CTX *ctx, X509 *cert); static int check_key_level(X509_STORE_CTX *ctx, EVP_PKEY *pkey); static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert); static int check_curve(X509 *cert); static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer, unsigned int *preasons, X509_CRL *crl, X509 *x); static int get_crl_delta(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x); static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pcrl_score, X509_CRL *base, STACK_OF(X509_CRL) *crls); static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer, int *pcrl_score); static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score, unsigned int *preasons); static int check_crl_path(X509_STORE_CTX *ctx, X509 *x); static int check_crl_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *cert_path, STACK_OF(X509) *crl_path); static int internal_verify(X509_STORE_CTX *ctx); static int null_callback(int ok, X509_STORE_CTX *e) { return ok; } /*- * Return 1 if given cert is considered self-signed, 0 if not, or -1 on error. * This actually verifies self-signedness only if requested. * It calls ossl_x509v3_cache_extensions() * to match issuer and subject names (i.e., the cert being self-issued) and any * present authority key identifier to match the subject key identifier, etc. */ int X509_self_signed(X509 *cert, int verify_signature) { EVP_PKEY *pkey; if ((pkey = X509_get0_pubkey(cert)) == NULL) { /* handles cert == NULL */ ERR_raise(ERR_LIB_X509, X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY); return -1; } if (!ossl_x509v3_cache_extensions(cert)) return -1; if ((cert->ex_flags & EXFLAG_SS) == 0) return 0; if (!verify_signature) return 1; return X509_verify(cert, pkey); } /* * Given a certificate, try and find an exact match in the store. * Returns 1 on success, 0 on not found, -1 on internal error. */ static int lookup_cert_match(X509 **result, X509_STORE_CTX *ctx, X509 *x) { STACK_OF(X509) *certs; X509 *xtmp = NULL; int i, ret; *result = NULL; /* Lookup all certs with matching subject name */ ERR_set_mark(); certs = ctx->lookup_certs(ctx, X509_get_subject_name(x)); ERR_pop_to_mark(); if (certs == NULL) return -1; /* Look for exact match */ for (i = 0; i < sk_X509_num(certs); i++) { xtmp = sk_X509_value(certs, i); if (X509_cmp(xtmp, x) == 0) break; xtmp = NULL; } ret = xtmp != NULL; if (ret) { if (!X509_up_ref(xtmp)) ret = -1; else *result = xtmp; } OSSL_STACK_OF_X509_free(certs); return ret; } /*- * Inform the verify callback of an error. * The error code is set to |err| if |err| is not X509_V_OK, else * |ctx->error| is left unchanged (under the assumption it is set elsewhere). * The error depth is |depth| if >= 0, else it defaults to |ctx->error_depth|. * The error cert is |x| if not NULL, else the cert in |ctx->chain| at |depth|. * * Returns 0 to abort verification with an error, non-zero to continue. */ static int verify_cb_cert(X509_STORE_CTX *ctx, X509 *x, int depth, int err) { if (depth < 0) depth = ctx->error_depth; else ctx->error_depth = depth; ctx->current_cert = x != NULL ? x : sk_X509_value(ctx->chain, depth); if (err != X509_V_OK) ctx->error = err; return ctx->verify_cb(0, ctx); } #define CB_FAIL_IF(cond, ctx, cert, depth, err) \ if ((cond) && verify_cb_cert(ctx, cert, depth, err) == 0) \ return 0 /*- * Inform the verify callback of an error, CRL-specific variant. Here, the * error depth and certificate are already set, we just specify the error * number. * * Returns 0 to abort verification with an error, non-zero to continue. */ static int verify_cb_crl(X509_STORE_CTX *ctx, int err) { ctx->error = err; return ctx->verify_cb(0, ctx); } /* Sadly, returns 0 also on internal error in ctx->verify_cb(). */ static int check_auth_level(X509_STORE_CTX *ctx) { int i; int num = sk_X509_num(ctx->chain); if (ctx->param->auth_level <= 0) return 1; for (i = 0; i < num; ++i) { X509 *cert = sk_X509_value(ctx->chain, i); /* * We've already checked the security of the leaf key, so here we only * check the security of issuer keys. */ CB_FAIL_IF(i > 0 && !check_cert_key_level(ctx, cert), ctx, cert, i, X509_V_ERR_CA_KEY_TOO_SMALL); /* * We also check the signature algorithm security of all certificates * except those of the trust anchor at index num-1. */ CB_FAIL_IF(i < num - 1 && !check_sig_level(ctx, cert), ctx, cert, i, X509_V_ERR_CA_MD_TOO_WEAK); } return 1; } /*- * Returns -1 on internal error. * Sadly, returns 0 also on internal error in ctx->verify_cb(). */ static int verify_rpk(X509_STORE_CTX *ctx) { /* Not much to verify on a RPK */ if (ctx->verify != NULL) return ctx->verify(ctx); return !!ctx->verify_cb(ctx->error == X509_V_OK, ctx); } /*- * Returns -1 on internal error. * Sadly, returns 0 also on internal error in ctx->verify_cb(). */ static int verify_chain(X509_STORE_CTX *ctx) { int err; int ok; if ((ok = build_chain(ctx)) <= 0 || (ok = check_extensions(ctx)) <= 0 || (ok = check_auth_level(ctx)) <= 0 || (ok = check_id(ctx)) <= 0 || (ok = X509_get_pubkey_parameters(NULL, ctx->chain) ? 1 : -1) <= 0 || (ok = ctx->check_revocation(ctx)) <= 0) return ok; err = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain, ctx->param->flags); CB_FAIL_IF(err != X509_V_OK, ctx, NULL, ctx->error_depth, err); /* Verify chain signatures and expiration times */ ok = ctx->verify != NULL ? ctx->verify(ctx) : internal_verify(ctx); if (ok <= 0) return ok; if ((ok = check_name_constraints(ctx)) <= 0) return ok; #ifndef OPENSSL_NO_RFC3779 /* RFC 3779 path validation, now that CRL check has been done */ if ((ok = X509v3_asid_validate_path(ctx)) <= 0) return ok; if ((ok = X509v3_addr_validate_path(ctx)) <= 0) return ok; #endif /* If we get this far evaluate policies */ if ((ctx->param->flags & X509_V_FLAG_POLICY_CHECK) != 0) ok = ctx->check_policy(ctx); return ok; } int X509_STORE_CTX_verify(X509_STORE_CTX *ctx) { if (ctx == NULL) { ERR_raise(ERR_LIB_X509, ERR_R_PASSED_NULL_PARAMETER); return -1; } if (ctx->rpk != NULL) return x509_verify_rpk(ctx); if (ctx->cert == NULL && sk_X509_num(ctx->untrusted) >= 1) ctx->cert = sk_X509_value(ctx->untrusted, 0); return x509_verify_x509(ctx); } int X509_verify_cert(X509_STORE_CTX *ctx) { if (ctx == NULL) { ERR_raise(ERR_LIB_X509, ERR_R_PASSED_NULL_PARAMETER); return -1; } return (ctx->rpk != NULL) ? x509_verify_rpk(ctx) : x509_verify_x509(ctx); } /*- * Returns -1 on internal error. * Sadly, returns 0 also on internal error in ctx->verify_cb(). */ static int x509_verify_rpk(X509_STORE_CTX *ctx) { int ret; /* If the peer's public key is too weak, we can stop early. */ if (!check_key_level(ctx, ctx->rpk) && verify_cb_cert(ctx, NULL, 0, X509_V_ERR_EE_KEY_TOO_SMALL) == 0) return 0; /* Barring any data to verify the RPK, simply report it as untrusted */ ctx->error = X509_V_ERR_RPK_UNTRUSTED; ret = DANETLS_ENABLED(ctx->dane) ? dane_verify_rpk(ctx) : verify_rpk(ctx); /* * Safety-net. If we are returning an error, we must also set ctx->error, * so that the chain is not considered verified should the error be ignored * (e.g. TLS with SSL_VERIFY_NONE). */ if (ret <= 0 && ctx->error == X509_V_OK) ctx->error = X509_V_ERR_UNSPECIFIED; return ret; } /*- * Returns -1 on internal error. * Sadly, returns 0 also on internal error in ctx->verify_cb(). */ static int x509_verify_x509(X509_STORE_CTX *ctx) { int ret; if (ctx->cert == NULL) { ERR_raise(ERR_LIB_X509, X509_R_NO_CERT_SET_FOR_US_TO_VERIFY); ctx->error = X509_V_ERR_INVALID_CALL; return -1; } if (ctx->chain != NULL) { /* * This X509_STORE_CTX has already been used to verify a cert. We * cannot do another one. */ ERR_raise(ERR_LIB_X509, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); ctx->error = X509_V_ERR_INVALID_CALL; return -1; } if (!ossl_x509_add_cert_new(&ctx->chain, ctx->cert, X509_ADD_FLAG_UP_REF)) { ctx->error = X509_V_ERR_OUT_OF_MEM; return -1; } ctx->num_untrusted = 1; /* If the peer's public key is too weak, we can stop early. */ CB_FAIL_IF(!check_cert_key_level(ctx, ctx->cert), ctx, ctx->cert, 0, X509_V_ERR_EE_KEY_TOO_SMALL); ret = DANETLS_ENABLED(ctx->dane) ? dane_verify(ctx) : verify_chain(ctx); /* * Safety-net. If we are returning an error, we must also set ctx->error, * so that the chain is not considered verified should the error be ignored * (e.g. TLS with SSL_VERIFY_NONE). */ if (ret <= 0 && ctx->error == X509_V_OK) ctx->error = X509_V_ERR_UNSPECIFIED; return ret; } static int sk_X509_contains(STACK_OF(X509) *sk, X509 *cert) { int i, n = sk_X509_num(sk); for (i = 0; i < n; i++) if (X509_cmp(sk_X509_value(sk, i), cert) == 0) return 1; return 0; } /* * Find in given STACK_OF(X509) |sk| an issuer cert (if any) of given cert |x|. * The issuer must not yet be in |ctx->chain|, yet allowing the exception that * |x| is self-issued and |ctx->chain| has just one element. * Prefer the first non-expired one, else take the most recently expired one. */ static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x) { int i; X509 *issuer, *rv = NULL; for (i = 0; i < sk_X509_num(sk); i++) { issuer = sk_X509_value(sk, i); if (ctx->check_issued(ctx, x, issuer) && (((x->ex_flags & EXFLAG_SI) != 0 && sk_X509_num(ctx->chain) == 1) || !sk_X509_contains(ctx->chain, issuer))) { if (ossl_x509_check_cert_time(ctx, issuer, -1)) return issuer; if (rv == NULL || ASN1_TIME_compare(X509_get0_notAfter(issuer), X509_get0_notAfter(rv)) > 0) rv = issuer; } } return rv; } /* Check that the given certificate |x| is issued by the certificate |issuer| */ static int check_issued(ossl_unused X509_STORE_CTX *ctx, X509 *x, X509 *issuer) { int err = ossl_x509_likely_issued(issuer, x); if (err == X509_V_OK) return 1; /* * SUBJECT_ISSUER_MISMATCH just means 'x' is clearly not issued by 'issuer'. * Every other error code likely indicates a real error. */ return 0; } /*- * Alternative get_issuer method: look up from a STACK_OF(X509) in other_ctx. * Returns -1 on internal error. */ static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x) { *issuer = find_issuer(ctx, ctx->other_ctx, x); if (*issuer == NULL) return 0; return X509_up_ref(*issuer) ? 1 : -1; } /*- * Alternative lookup method: look from a STACK stored in other_ctx. * Returns NULL on internal/fatal error, empty stack if not found. */ static STACK_OF(X509) *lookup_certs_sk(X509_STORE_CTX *ctx, const X509_NAME *nm) { STACK_OF(X509) *sk = sk_X509_new_null(); X509 *x; int i; if (sk == NULL) return NULL; for (i = 0; i < sk_X509_num(ctx->other_ctx); i++) { x = sk_X509_value(ctx->other_ctx, i); if (X509_NAME_cmp(nm, X509_get_subject_name(x)) == 0) { if (!X509_add_cert(sk, x, X509_ADD_FLAG_UP_REF)) { OSSL_STACK_OF_X509_free(sk); ctx->error = X509_V_ERR_OUT_OF_MEM; return NULL; } } } return sk; } /* * Check EE or CA certificate purpose. For trusted certificates explicit local * auxiliary trust can be used to override EKU-restrictions. * Sadly, returns 0 also on internal error in ctx->verify_cb(). */ static int check_purpose(X509_STORE_CTX *ctx, X509 *x, int purpose, int depth, int must_be_ca) { int tr_ok = X509_TRUST_UNTRUSTED; /* * For trusted certificates we want to see whether any auxiliary trust * settings trump the purpose constraints. * * This is complicated by the fact that the trust ordinals in * ctx->param->trust are entirely independent of the purpose ordinals in * ctx->param->purpose! * * What connects them is their mutual initialization via calls from * X509_STORE_CTX_set_default() into X509_VERIFY_PARAM_lookup() which sets * related values of both param->trust and param->purpose. It is however * typically possible to infer associated trust values from a purpose value * via the X509_PURPOSE API. * * Therefore, we can only check for trust overrides when the purpose we're * checking is the same as ctx->param->purpose and ctx->param->trust is * also set. */ if (depth >= ctx->num_untrusted && purpose == ctx->param->purpose) tr_ok = X509_check_trust(x, ctx->param->trust, X509_TRUST_NO_SS_COMPAT); switch (tr_ok) { case X509_TRUST_TRUSTED: return 1; case X509_TRUST_REJECTED: break; default: /* can only be X509_TRUST_UNTRUSTED */ switch (X509_check_purpose(x, purpose, must_be_ca > 0)) { case 1: return 1; case 0: break; default: if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) == 0) return 1; } break; } return verify_cb_cert(ctx, x, depth, X509_V_ERR_INVALID_PURPOSE); } /*- * Check extensions of a cert chain for consistency with the supplied purpose. * Sadly, returns 0 also on internal error in ctx->verify_cb(). */ static int check_extensions(X509_STORE_CTX *ctx) { int i, must_be_ca, plen = 0; X509 *x; int ret, proxy_path_length = 0; int purpose, allow_proxy_certs, num = sk_X509_num(ctx->chain); /*- * must_be_ca can have 1 of 3 values: * -1: we accept both CA and non-CA certificates, to allow direct * use of self-signed certificates (which are marked as CA). * 0: we only accept non-CA certificates. This is currently not * used, but the possibility is present for future extensions. * 1: we only accept CA certificates. This is currently used for * all certificates in the chain except the leaf certificate. */ must_be_ca = -1; /* CRL path validation */ if (ctx->parent != NULL) { allow_proxy_certs = 0; purpose = X509_PURPOSE_CRL_SIGN; } else { allow_proxy_certs = (ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS) != 0; purpose = ctx->param->purpose; } for (i = 0; i < num; i++) { x = sk_X509_value(ctx->chain, i); CB_FAIL_IF((ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) == 0 && (x->ex_flags & EXFLAG_CRITICAL) != 0, ctx, x, i, X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION); CB_FAIL_IF(!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY) != 0, ctx, x, i, X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED); ret = X509_check_ca(x); switch (must_be_ca) { case -1: CB_FAIL_IF((ctx->param->flags & X509_V_FLAG_X509_STRICT) != 0 && ret != 1 && ret != 0, ctx, x, i, X509_V_ERR_INVALID_CA); break; case 0: CB_FAIL_IF(ret != 0, ctx, x, i, X509_V_ERR_INVALID_NON_CA); break; default: /* X509_V_FLAG_X509_STRICT is implicit for intermediate CAs */ CB_FAIL_IF(ret == 0 || ((i + 1 < num || (ctx->param->flags & X509_V_FLAG_X509_STRICT) != 0) && ret != 1), ctx, x, i, X509_V_ERR_INVALID_CA); break; } if (num > 1) { /* Check for presence of explicit elliptic curve parameters */ ret = check_curve(x); CB_FAIL_IF(ret < 0, ctx, x, i, X509_V_ERR_UNSPECIFIED); CB_FAIL_IF(ret == 0, ctx, x, i, X509_V_ERR_EC_KEY_EXPLICIT_PARAMS); } /* * Do the following set of checks only if strict checking is requested * and not for self-issued (including self-signed) EE (non-CA) certs * because RFC 5280 does not apply to them according RFC 6818 section 2. */ if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) != 0 && num > 1) { /* * this should imply * !(i == 0 && (x->ex_flags & EXFLAG_CA) == 0 * && (x->ex_flags & EXFLAG_SI) != 0) */ /* Check Basic Constraints according to RFC 5280 section 4.2.1.9 */ if (x->ex_pathlen != -1) { CB_FAIL_IF((x->ex_flags & EXFLAG_CA) == 0, ctx, x, i, X509_V_ERR_PATHLEN_INVALID_FOR_NON_CA); CB_FAIL_IF((x->ex_kusage & KU_KEY_CERT_SIGN) == 0, ctx, x, i, X509_V_ERR_PATHLEN_WITHOUT_KU_KEY_CERT_SIGN); } CB_FAIL_IF((x->ex_flags & EXFLAG_CA) != 0 && (x->ex_flags & EXFLAG_BCONS) != 0 && (x->ex_flags & EXFLAG_BCONS_CRITICAL) == 0, ctx, x, i, X509_V_ERR_CA_BCONS_NOT_CRITICAL); /* Check Key Usage according to RFC 5280 section 4.2.1.3 */ if ((x->ex_flags & EXFLAG_CA) != 0) { CB_FAIL_IF((x->ex_flags & EXFLAG_KUSAGE) == 0, ctx, x, i, X509_V_ERR_CA_CERT_MISSING_KEY_USAGE); } else { CB_FAIL_IF((x->ex_kusage & KU_KEY_CERT_SIGN) != 0, ctx, x, i, X509_V_ERR_KU_KEY_CERT_SIGN_INVALID_FOR_NON_CA); } /* Check issuer is non-empty acc. to RFC 5280 section 4.1.2.4 */ CB_FAIL_IF(X509_NAME_entry_count(X509_get_issuer_name(x)) == 0, ctx, x, i, X509_V_ERR_ISSUER_NAME_EMPTY); /* Check subject is non-empty acc. to RFC 5280 section 4.1.2.6 */ CB_FAIL_IF(((x->ex_flags & EXFLAG_CA) != 0 || (x->ex_kusage & KU_CRL_SIGN) != 0 || x->altname == NULL) && X509_NAME_entry_count(X509_get_subject_name(x)) == 0, ctx, x, i, X509_V_ERR_SUBJECT_NAME_EMPTY); CB_FAIL_IF(X509_NAME_entry_count(X509_get_subject_name(x)) == 0 && x->altname != NULL && (x->ex_flags & EXFLAG_SAN_CRITICAL) == 0, ctx, x, i, X509_V_ERR_EMPTY_SUBJECT_SAN_NOT_CRITICAL); /* Check SAN is non-empty according to RFC 5280 section 4.2.1.6 */ CB_FAIL_IF(x->altname != NULL && sk_GENERAL_NAME_num(x->altname) <= 0, ctx, x, i, X509_V_ERR_EMPTY_SUBJECT_ALT_NAME); /* Check sig alg consistency acc. to RFC 5280 section 4.1.1.2 */ CB_FAIL_IF(X509_ALGOR_cmp(&x->sig_alg, &x->cert_info.signature) != 0, ctx, x, i, X509_V_ERR_SIGNATURE_ALGORITHM_INCONSISTENCY); CB_FAIL_IF(x->akid != NULL && (x->ex_flags & EXFLAG_AKID_CRITICAL) != 0, ctx, x, i, X509_V_ERR_AUTHORITY_KEY_IDENTIFIER_CRITICAL); CB_FAIL_IF(x->skid != NULL && (x->ex_flags & EXFLAG_SKID_CRITICAL) != 0, ctx, x, i, X509_V_ERR_SUBJECT_KEY_IDENTIFIER_CRITICAL); if (X509_get_version(x) >= X509_VERSION_3) { /* Check AKID presence acc. to RFC 5280 section 4.2.1.1 */ CB_FAIL_IF(i + 1 < num /* * this means not last cert in chain, * taken as "generated by conforming CAs" */ && (x->akid == NULL || x->akid->keyid == NULL), ctx, x, i, X509_V_ERR_MISSING_AUTHORITY_KEY_IDENTIFIER); /* Check SKID presence acc. to RFC 5280 section 4.2.1.2 */ CB_FAIL_IF((x->ex_flags & EXFLAG_CA) != 0 && x->skid == NULL, ctx, x, i, X509_V_ERR_MISSING_SUBJECT_KEY_IDENTIFIER); } else { CB_FAIL_IF(sk_X509_EXTENSION_num(X509_get0_extensions(x)) > 0, ctx, x, i, X509_V_ERR_EXTENSIONS_REQUIRE_VERSION_3); } } /* check_purpose() makes the callback as needed */ if (purpose > 0 && !check_purpose(ctx, x, purpose, i, must_be_ca)) return 0; /* Check path length */ CB_FAIL_IF(i > 1 && x->ex_pathlen != -1 && plen > x->ex_pathlen + proxy_path_length, ctx, x, i, X509_V_ERR_PATH_LENGTH_EXCEEDED); /* Increment path length if not a self-issued intermediate CA */ if (i > 0 && (x->ex_flags & EXFLAG_SI) == 0) plen++; /* * If this certificate is a proxy certificate, the next certificate * must be another proxy certificate or a EE certificate. If not, * the next certificate must be a CA certificate. */ if (x->ex_flags & EXFLAG_PROXY) { /* * RFC3820, 4.1.3 (b)(1) stipulates that if pCPathLengthConstraint * is less than max_path_length, the former should be copied to * the latter, and 4.1.4 (a) stipulates that max_path_length * should be verified to be larger than zero and decrement it. * * Because we're checking the certs in the reverse order, we start * with verifying that proxy_path_length isn't larger than pcPLC, * and copy the latter to the former if it is, and finally, * increment proxy_path_length. */ if (x->ex_pcpathlen != -1) { CB_FAIL_IF(proxy_path_length > x->ex_pcpathlen, ctx, x, i, X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED); proxy_path_length = x->ex_pcpathlen; } proxy_path_length++; must_be_ca = 0; } else { must_be_ca = 1; } } return 1; } static int has_san_id(X509 *x, int gtype) { int i; int ret = 0; GENERAL_NAMES *gs = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL); if (gs == NULL) return 0; for (i = 0; i < sk_GENERAL_NAME_num(gs); i++) { GENERAL_NAME *g = sk_GENERAL_NAME_value(gs, i); if (g->type == gtype) { ret = 1; break; } } GENERAL_NAMES_free(gs); return ret; } /*- * Returns -1 on internal error. * Sadly, returns 0 also on internal error in ctx->verify_cb(). */ static int check_name_constraints(X509_STORE_CTX *ctx) { int i; /* Check name constraints for all certificates */ for (i = sk_X509_num(ctx->chain) - 1; i >= 0; i--) { X509 *x = sk_X509_value(ctx->chain, i); int j; /* Ignore self-issued certs unless last in chain */ if (i != 0 && (x->ex_flags & EXFLAG_SI) != 0) continue; /* * Proxy certificates policy has an extra constraint, where the * certificate subject MUST be the issuer with a single CN entry * added. * (RFC 3820: 3.4, 4.1.3 (a)(4)) */ if ((x->ex_flags & EXFLAG_PROXY) != 0) { X509_NAME *tmpsubject = X509_get_subject_name(x); X509_NAME *tmpissuer = X509_get_issuer_name(x); X509_NAME_ENTRY *tmpentry = NULL; int last_nid = 0; int err = X509_V_OK; int last_loc = X509_NAME_entry_count(tmpsubject) - 1; /* Check that there are at least two RDNs */ if (last_loc < 1) { err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; goto proxy_name_done; } /* * Check that there is exactly one more RDN in subject as * there is in issuer. */ if (X509_NAME_entry_count(tmpsubject) != X509_NAME_entry_count(tmpissuer) + 1) { err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; goto proxy_name_done; } /* * Check that the last subject component isn't part of a * multi-valued RDN */ if (X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject, last_loc)) == X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject, last_loc - 1))) { err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; goto proxy_name_done; } /* * Check that the last subject RDN is a commonName, and that * all the previous RDNs match the issuer exactly */ tmpsubject = X509_NAME_dup(tmpsubject); if (tmpsubject == NULL) { ERR_raise(ERR_LIB_X509, ERR_R_ASN1_LIB); ctx->error = X509_V_ERR_OUT_OF_MEM; return -1; } tmpentry = X509_NAME_delete_entry(tmpsubject, last_loc); last_nid = OBJ_obj2nid(X509_NAME_ENTRY_get_object(tmpentry)); if (last_nid != NID_commonName || X509_NAME_cmp(tmpsubject, tmpissuer) != 0) { err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION; } X509_NAME_ENTRY_free(tmpentry); X509_NAME_free(tmpsubject); proxy_name_done: CB_FAIL_IF(err != X509_V_OK, ctx, x, i, err); } /* * Check against constraints for all certificates higher in chain * including trust anchor. Trust anchor not strictly speaking needed * but if it includes constraints it is to be assumed it expects them * to be obeyed. */ for (j = sk_X509_num(ctx->chain) - 1; j > i; j--) { NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc; if (nc) { int rv = NAME_CONSTRAINTS_check(x, nc); int ret = 1; /* If EE certificate check commonName too */ if (rv == X509_V_OK && i == 0 && (ctx->param->hostflags & X509_CHECK_FLAG_NEVER_CHECK_SUBJECT) == 0 && ((ctx->param->hostflags & X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT) != 0 || (ret = has_san_id(x, GEN_DNS)) == 0)) rv = NAME_CONSTRAINTS_check_CN(x, nc); if (ret < 0) return ret; switch (rv) { case X509_V_OK: break; case X509_V_ERR_OUT_OF_MEM: return -1; default: CB_FAIL_IF(1, ctx, x, i, rv); break; } } } } return 1; } static int check_id_error(X509_STORE_CTX *ctx, int errcode) { return verify_cb_cert(ctx, ctx->cert, 0, errcode); } static int check_hosts(X509 *x, X509_VERIFY_PARAM *vpm) { int i; int n = sk_OPENSSL_STRING_num(vpm->hosts); char *name; if (vpm->peername != NULL) { OPENSSL_free(vpm->peername); vpm->peername = NULL; } for (i = 0; i < n; ++i) { name = sk_OPENSSL_STRING_value(vpm->hosts, i); if (X509_check_host(x, name, 0, vpm->hostflags, &vpm->peername) > 0) return 1; } return n == 0; } static int check_id(X509_STORE_CTX *ctx) { X509_VERIFY_PARAM *vpm = ctx->param; X509 *x = ctx->cert; if (vpm->hosts != NULL && check_hosts(x, vpm) <= 0) { if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH)) return 0; } if (vpm->email != NULL && X509_check_email(x, vpm->email, vpm->emaillen, 0) <= 0) { if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH)) return 0; } if (vpm->ip != NULL && X509_check_ip(x, vpm->ip, vpm->iplen, 0) <= 0) { if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH)) return 0; } return 1; } /* Returns -1 on internal error */ static int check_trust(X509_STORE_CTX *ctx, int num_untrusted) { int i, res; X509 *x = NULL; X509 *mx; SSL_DANE *dane = ctx->dane; int num = sk_X509_num(ctx->chain); int trust; /* * Check for a DANE issuer at depth 1 or greater, if it is a DANE-TA(2) * match, we're done, otherwise we'll merely record the match depth. */ if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) { trust = check_dane_issuer(ctx, num_untrusted); if (trust != X509_TRUST_UNTRUSTED) return trust; } /* * Check trusted certificates in chain at depth num_untrusted and up. * Note, that depths 0..num_untrusted-1 may also contain trusted * certificates, but the caller is expected to have already checked those, * and wants to incrementally check just any added since. */ for (i = num_untrusted; i < num; i++) { x = sk_X509_value(ctx->chain, i); trust = X509_check_trust(x, ctx->param->trust, 0); /* If explicitly trusted (so not neutral nor rejected) return trusted */ if (trust == X509_TRUST_TRUSTED) goto trusted; if (trust == X509_TRUST_REJECTED) goto rejected; } /* * If we are looking at a trusted certificate, and accept partial chains, * the chain is PKIX trusted. */ if (num_untrusted < num) { if ((ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) != 0) goto trusted; return X509_TRUST_UNTRUSTED; } if (num_untrusted == num && (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) != 0) { /* * Last-resort call with no new trusted certificates, check the leaf * for a direct trust store match. */ i = 0; x = sk_X509_value(ctx->chain, i); res = lookup_cert_match(&mx, ctx, x); if (res < 0) return res; if (res == 0) return X509_TRUST_UNTRUSTED; /* * Check explicit auxiliary trust/reject settings. If none are set, * we'll accept X509_TRUST_UNTRUSTED when not self-signed. */ trust = X509_check_trust(mx, ctx->param->trust, 0); if (trust == X509_TRUST_REJECTED) { X509_free(mx); goto rejected; } /* Replace leaf with trusted match */ (void)sk_X509_set(ctx->chain, 0, mx); X509_free(x); ctx->num_untrusted = 0; goto trusted; } /* * If no trusted certs in chain at all return untrusted and allow * standard (no issuer cert) etc errors to be indicated. */ return X509_TRUST_UNTRUSTED; rejected: return verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED) == 0 ? X509_TRUST_REJECTED : X509_TRUST_UNTRUSTED; trusted: if (!DANETLS_ENABLED(dane)) return X509_TRUST_TRUSTED; if (dane->pdpth < 0) dane->pdpth = num_untrusted; /* With DANE, PKIX alone is not trusted until we have both */ if (dane->mdpth >= 0) return X509_TRUST_TRUSTED; return X509_TRUST_UNTRUSTED; } /* Sadly, returns 0 also on internal error. */ static int check_revocation(X509_STORE_CTX *ctx) { int i = 0, last = 0, ok = 0; if ((ctx->param->flags & X509_V_FLAG_CRL_CHECK) == 0) return 1; if ((ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL) != 0) { last = sk_X509_num(ctx->chain) - 1; } else { /* If checking CRL paths this isn't the EE certificate */ if (ctx->parent != NULL) return 1; last = 0; } for (i = 0; i <= last; i++) { ctx->error_depth = i; ok = check_cert(ctx); if (!ok) return ok; } return 1; } /* Sadly, returns 0 also on internal error. */ static int check_cert(X509_STORE_CTX *ctx) { X509_CRL *crl = NULL, *dcrl = NULL; int ok = 0; int cnum = ctx->error_depth; X509 *x = sk_X509_value(ctx->chain, cnum); ctx->current_cert = x; ctx->current_issuer = NULL; ctx->current_crl_score = 0; ctx->current_reasons = 0; if ((x->ex_flags & EXFLAG_PROXY) != 0) return 1; while (ctx->current_reasons != CRLDP_ALL_REASONS) { unsigned int last_reasons = ctx->current_reasons; /* Try to retrieve relevant CRL */ if (ctx->get_crl != NULL) ok = ctx->get_crl(ctx, &crl, x); else ok = get_crl_delta(ctx, &crl, &dcrl, x); /* If error looking up CRL, nothing we can do except notify callback */ if (!ok) { ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL); goto done; } ctx->current_crl = crl; ok = ctx->check_crl(ctx, crl); if (!ok) goto done; if (dcrl != NULL) { ok = ctx->check_crl(ctx, dcrl); if (!ok) goto done; ok = ctx->cert_crl(ctx, dcrl, x); if (!ok) goto done; } else { ok = 1; } /* Don't look in full CRL if delta reason is removefromCRL */ if (ok != 2) { ok = ctx->cert_crl(ctx, crl, x); if (!ok) goto done; } X509_CRL_free(crl); X509_CRL_free(dcrl); crl = NULL; dcrl = NULL; /* * If reasons not updated we won't get anywhere by another iteration, * so exit loop. */ if (last_reasons == ctx->current_reasons) { ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL); goto done; } } done: X509_CRL_free(crl); X509_CRL_free(dcrl); ctx->current_crl = NULL; return ok; } /* Check CRL times against values in X509_STORE_CTX */ static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify) { time_t *ptime; int i; if ((ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME) != 0) ptime = &ctx->param->check_time; else if ((ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME) != 0) return 1; else ptime = NULL; if (notify) ctx->current_crl = crl; i = X509_cmp_time(X509_CRL_get0_lastUpdate(crl), ptime); if (i == 0) { if (!notify) return 0; if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD)) return 0; } if (i > 0) { if (!notify) return 0; if (!verify_cb_crl(ctx, X509_V_ERR_CRL_NOT_YET_VALID)) return 0; } if (X509_CRL_get0_nextUpdate(crl)) { i = X509_cmp_time(X509_CRL_get0_nextUpdate(crl), ptime); if (i == 0) { if (!notify) return 0; if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD)) return 0; } /* Ignore expiration of base CRL is delta is valid */ if (i < 0 && (ctx->current_crl_score & CRL_SCORE_TIME_DELTA) == 0) { if (!notify || !verify_cb_crl(ctx, X509_V_ERR_CRL_HAS_EXPIRED)) return 0; } } if (notify) ctx->current_crl = NULL; return 1; } static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl, X509 **pissuer, int *pscore, unsigned int *preasons, STACK_OF(X509_CRL) *crls) { int i, crl_score, best_score = *pscore; unsigned int reasons, best_reasons = 0; X509 *x = ctx->current_cert; X509_CRL *crl, *best_crl = NULL; X509 *crl_issuer = NULL, *best_crl_issuer = NULL; for (i = 0; i < sk_X509_CRL_num(crls); i++) { crl = sk_X509_CRL_value(crls, i); reasons = *preasons; crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x); if (crl_score < best_score || crl_score == 0) continue; /* If current CRL is equivalent use it if it is newer */ if (crl_score == best_score && best_crl != NULL) { int day, sec; if (ASN1_TIME_diff(&day, &sec, X509_CRL_get0_lastUpdate(best_crl), X509_CRL_get0_lastUpdate(crl)) == 0) continue; /* * ASN1_TIME_diff never returns inconsistent signs for |day| * and |sec|. */ if (day <= 0 && sec <= 0) continue; } best_crl = crl; best_crl_issuer = crl_issuer; best_score = crl_score; best_reasons = reasons; } if (best_crl != NULL) { X509_CRL_free(*pcrl); *pcrl = best_crl; *pissuer = best_crl_issuer; *pscore = best_score; *preasons = best_reasons; X509_CRL_up_ref(best_crl); X509_CRL_free(*pdcrl); *pdcrl = NULL; get_delta_sk(ctx, pdcrl, pscore, best_crl, crls); } if (best_score >= CRL_SCORE_VALID) return 1; return 0; } /* * Compare two CRL extensions for delta checking purposes. They should be * both present or both absent. If both present all fields must be identical. */ static int crl_extension_match(X509_CRL *a, X509_CRL *b, int nid) { ASN1_OCTET_STRING *exta = NULL, *extb = NULL; int i = X509_CRL_get_ext_by_NID(a, nid, -1); if (i >= 0) { /* Can't have multiple occurrences */ if (X509_CRL_get_ext_by_NID(a, nid, i) != -1) return 0; exta = X509_EXTENSION_get_data(X509_CRL_get_ext(a, i)); } i = X509_CRL_get_ext_by_NID(b, nid, -1); if (i >= 0) { if (X509_CRL_get_ext_by_NID(b, nid, i) != -1) return 0; extb = X509_EXTENSION_get_data(X509_CRL_get_ext(b, i)); } if (exta == NULL && extb == NULL) return 1; if (exta == NULL || extb == NULL) return 0; return ASN1_OCTET_STRING_cmp(exta, extb) == 0; } /* See if a base and delta are compatible */ static int check_delta_base(X509_CRL *delta, X509_CRL *base) { /* Delta CRL must be a delta */ if (delta->base_crl_number == NULL) return 0; /* Base must have a CRL number */ if (base->crl_number == NULL) return 0; /* Issuer names must match */ if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(delta)) != 0) return 0; /* AKID and IDP must match */ if (!crl_extension_match(delta, base, NID_authority_key_identifier)) return 0; if (!crl_extension_match(delta, base, NID_issuing_distribution_point)) return 0; /* Delta CRL base number must not exceed Full CRL number. */ if (ASN1_INTEGER_cmp(delta->base_crl_number, base->crl_number) > 0) return 0; /* Delta CRL number must exceed full CRL number */ return ASN1_INTEGER_cmp(delta->crl_number, base->crl_number) > 0; } /* * For a given base CRL find a delta... maybe extend to delta scoring or * retrieve a chain of deltas... */ static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl, int *pscore, X509_CRL *base, STACK_OF(X509_CRL) *crls) { X509_CRL *delta; int i; if ((ctx->param->flags & X509_V_FLAG_USE_DELTAS) == 0) return; if (((ctx->current_cert->ex_flags | base->flags) & EXFLAG_FRESHEST) == 0) return; for (i = 0; i < sk_X509_CRL_num(crls); i++) { delta = sk_X509_CRL_value(crls, i); if (check_delta_base(delta, base)) { if (check_crl_time(ctx, delta, 0)) *pscore |= CRL_SCORE_TIME_DELTA; X509_CRL_up_ref(delta); *dcrl = delta; return; } } *dcrl = NULL; } /* * For a given CRL return how suitable it is for the supplied certificate * 'x'. The return value is a mask of several criteria. If the issuer is not * the certificate issuer this is returned in *pissuer. The reasons mask is * also used to determine if the CRL is suitable: if no new reasons the CRL * is rejected, otherwise reasons is updated. */ static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer, unsigned int *preasons, X509_CRL *crl, X509 *x) { int crl_score = 0; unsigned int tmp_reasons = *preasons, crl_reasons; /* First see if we can reject CRL straight away */ /* Invalid IDP cannot be processed */ if ((crl->idp_flags & IDP_INVALID) != 0) return 0; /* Reason codes or indirect CRLs need extended CRL support */ if ((ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT) == 0) { if (crl->idp_flags & (IDP_INDIRECT | IDP_REASONS)) return 0; } else if ((crl->idp_flags & IDP_REASONS) != 0) { /* If no new reasons reject */ if ((crl->idp_reasons & ~tmp_reasons) == 0) return 0; } /* Don't process deltas at this stage */ else if (crl->base_crl_number != NULL) return 0; /* If issuer name doesn't match certificate need indirect CRL */ if (X509_NAME_cmp(X509_get_issuer_name(x), X509_CRL_get_issuer(crl)) != 0) { if ((crl->idp_flags & IDP_INDIRECT) == 0) return 0; } else { crl_score |= CRL_SCORE_ISSUER_NAME; } if ((crl->flags & EXFLAG_CRITICAL) == 0) crl_score |= CRL_SCORE_NOCRITICAL; /* Check expiration */ if (check_crl_time(ctx, crl, 0)) crl_score |= CRL_SCORE_TIME; /* Check authority key ID and locate certificate issuer */ crl_akid_check(ctx, crl, pissuer, &crl_score); /* If we can't locate certificate issuer at this point forget it */ if ((crl_score & CRL_SCORE_AKID) == 0) return 0; /* Check cert for matching CRL distribution points */ if (crl_crldp_check(x, crl, crl_score, &crl_reasons)) { /* If no new reasons reject */ if ((crl_reasons & ~tmp_reasons) == 0) return 0; tmp_reasons |= crl_reasons; crl_score |= CRL_SCORE_SCOPE; } *preasons = tmp_reasons; return crl_score; } static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer, int *pcrl_score) { X509 *crl_issuer = NULL; const X509_NAME *cnm = X509_CRL_get_issuer(crl); int cidx = ctx->error_depth; int i; if (cidx != sk_X509_num(ctx->chain) - 1) cidx++; crl_issuer = sk_X509_value(ctx->chain, cidx); if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { if (*pcrl_score & CRL_SCORE_ISSUER_NAME) { *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_ISSUER_CERT; *pissuer = crl_issuer; return; } } for (cidx++; cidx < sk_X509_num(ctx->chain); cidx++) { crl_issuer = sk_X509_value(ctx->chain, cidx); if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm)) continue; if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { *pcrl_score |= CRL_SCORE_AKID | CRL_SCORE_SAME_PATH; *pissuer = crl_issuer; return; } } /* Anything else needs extended CRL support */ if ((ctx->param->flags & X509_V_FLAG_EXTENDED_CRL_SUPPORT) == 0) return; /* * Otherwise the CRL issuer is not on the path. Look for it in the set of * untrusted certificates. */ for (i = 0; i < sk_X509_num(ctx->untrusted); i++) { crl_issuer = sk_X509_value(ctx->untrusted, i); if (X509_NAME_cmp(X509_get_subject_name(crl_issuer), cnm) != 0) continue; if (X509_check_akid(crl_issuer, crl->akid) == X509_V_OK) { *pissuer = crl_issuer; *pcrl_score |= CRL_SCORE_AKID; return; } } } /* * Check the path of a CRL issuer certificate. This creates a new * X509_STORE_CTX and populates it with most of the parameters from the * parent. This could be optimised somewhat since a lot of path checking will * be duplicated by the parent, but this will rarely be used in practice. */ static int check_crl_path(X509_STORE_CTX *ctx, X509 *x) { X509_STORE_CTX crl_ctx = {0}; int ret; /* Don't allow recursive CRL path validation */ if (ctx->parent != NULL) return 0; if (!X509_STORE_CTX_init(&crl_ctx, ctx->store, x, ctx->untrusted)) return -1; crl_ctx.crls = ctx->crls; /* Copy verify params across */ X509_STORE_CTX_set0_param(&crl_ctx, ctx->param); crl_ctx.parent = ctx; crl_ctx.verify_cb = ctx->verify_cb; /* Verify CRL issuer */ ret = X509_verify_cert(&crl_ctx); if (ret <= 0) goto err; /* Check chain is acceptable */ ret = check_crl_chain(ctx, ctx->chain, crl_ctx.chain); err: X509_STORE_CTX_cleanup(&crl_ctx); return ret; } /* * RFC3280 says nothing about the relationship between CRL path and * certificate path, which could lead to situations where a certificate could * be revoked or validated by a CA not authorized to do so. RFC5280 is more * strict and states that the two paths must end in the same trust anchor, * though some discussions remain... until this is resolved we use the * RFC5280 version */ static int check_crl_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *cert_path, STACK_OF(X509) *crl_path) { X509 *cert_ta = sk_X509_value(cert_path, sk_X509_num(cert_path) - 1); X509 *crl_ta = sk_X509_value(crl_path, sk_X509_num(crl_path) - 1); return X509_cmp(cert_ta, crl_ta) == 0; } /*- * Check for match between two dist point names: three separate cases. * 1. Both are relative names and compare X509_NAME types. * 2. One full, one relative. Compare X509_NAME to GENERAL_NAMES. * 3. Both are full names and compare two GENERAL_NAMES. * 4. One is NULL: automatic match. */ static int idp_check_dp(DIST_POINT_NAME *a, DIST_POINT_NAME *b) { X509_NAME *nm = NULL; GENERAL_NAMES *gens = NULL; GENERAL_NAME *gena, *genb; int i, j; if (a == NULL || b == NULL) return 1; if (a->type == 1) { if (a->dpname == NULL) return 0; /* Case 1: two X509_NAME */ if (b->type == 1) { if (b->dpname == NULL) return 0; return X509_NAME_cmp(a->dpname, b->dpname) == 0; } /* Case 2: set name and GENERAL_NAMES appropriately */ nm = a->dpname; gens = b->name.fullname; } else if (b->type == 1) { if (b->dpname == NULL) return 0; /* Case 2: set name and GENERAL_NAMES appropriately */ gens = a->name.fullname; nm = b->dpname; } /* Handle case 2 with one GENERAL_NAMES and one X509_NAME */ if (nm != NULL) { for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) { gena = sk_GENERAL_NAME_value(gens, i); if (gena->type != GEN_DIRNAME) continue; if (X509_NAME_cmp(nm, gena->d.directoryName) == 0) return 1; } return 0; } /* Else case 3: two GENERAL_NAMES */ for (i = 0; i < sk_GENERAL_NAME_num(a->name.fullname); i++) { gena = sk_GENERAL_NAME_value(a->name.fullname, i); for (j = 0; j < sk_GENERAL_NAME_num(b->name.fullname); j++) { genb = sk_GENERAL_NAME_value(b->name.fullname, j); if (GENERAL_NAME_cmp(gena, genb) == 0) return 1; } } return 0; } static int crldp_check_crlissuer(DIST_POINT *dp, X509_CRL *crl, int crl_score) { int i; const X509_NAME *nm = X509_CRL_get_issuer(crl); /* If no CRLissuer return is successful iff don't need a match */ if (dp->CRLissuer == NULL) return (crl_score & CRL_SCORE_ISSUER_NAME) != 0; for (i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) { GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i); if (gen->type != GEN_DIRNAME) continue; if (X509_NAME_cmp(gen->d.directoryName, nm) == 0) return 1; } return 0; } /* Check CRLDP and IDP */ static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score, unsigned int *preasons) { int i; if ((crl->idp_flags & IDP_ONLYATTR) != 0) return 0; if ((x->ex_flags & EXFLAG_CA) != 0) { if ((crl->idp_flags & IDP_ONLYUSER) != 0) return 0; } else { if ((crl->idp_flags & IDP_ONLYCA) != 0) return 0; } *preasons = crl->idp_reasons; for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++) { DIST_POINT *dp = sk_DIST_POINT_value(x->crldp, i); if (crldp_check_crlissuer(dp, crl, crl_score)) { if (crl->idp == NULL || idp_check_dp(dp->distpoint, crl->idp->distpoint)) { *preasons &= dp->dp_reasons; return 1; } } } return (crl->idp == NULL || crl->idp->distpoint == NULL) && (crl_score & CRL_SCORE_ISSUER_NAME) != 0; } /* * Retrieve CRL corresponding to current certificate. If deltas enabled try * to find a delta CRL too */ static int get_crl_delta(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x) { int ok; X509 *issuer = NULL; int crl_score = 0; unsigned int reasons; X509_CRL *crl = NULL, *dcrl = NULL; STACK_OF(X509_CRL) *skcrl; const X509_NAME *nm = X509_get_issuer_name(x); reasons = ctx->current_reasons; ok = get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, ctx->crls); if (ok) goto done; /* Lookup CRLs from store */ skcrl = ctx->lookup_crls(ctx, nm); /* If no CRLs found and a near match from get_crl_sk use that */ if (skcrl == NULL && crl != NULL) goto done; get_crl_sk(ctx, &crl, &dcrl, &issuer, &crl_score, &reasons, skcrl); sk_X509_CRL_pop_free(skcrl, X509_CRL_free); done: /* If we got any kind of CRL use it and return success */ if (crl != NULL) { ctx->current_issuer = issuer; ctx->current_crl_score = crl_score; ctx->current_reasons = reasons; *pcrl = crl; *pdcrl = dcrl; return 1; } return 0; } /* Check CRL validity */ static int check_crl(X509_STORE_CTX *ctx, X509_CRL *crl) { X509 *issuer = NULL; EVP_PKEY *ikey = NULL; int cnum = ctx->error_depth; int chnum = sk_X509_num(ctx->chain) - 1; /* If we have an alternative CRL issuer cert use that */ if (ctx->current_issuer != NULL) { issuer = ctx->current_issuer; /* * Else find CRL issuer: if not last certificate then issuer is next * certificate in chain. */ } else if (cnum < chnum) { issuer = sk_X509_value(ctx->chain, cnum + 1); } else { issuer = sk_X509_value(ctx->chain, chnum); /* If not self-issued, can't check signature */ if (!ctx->check_issued(ctx, issuer, issuer) && !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER)) return 0; } if (issuer == NULL) return 1; /* * Skip most tests for deltas because they have already been done */ if (crl->base_crl_number == NULL) { /* Check for cRLSign bit if keyUsage present */ if ((issuer->ex_flags & EXFLAG_KUSAGE) != 0 && (issuer->ex_kusage & KU_CRL_SIGN) == 0 && !verify_cb_crl(ctx, X509_V_ERR_KEYUSAGE_NO_CRL_SIGN)) return 0; if ((ctx->current_crl_score & CRL_SCORE_SCOPE) == 0 && !verify_cb_crl(ctx, X509_V_ERR_DIFFERENT_CRL_SCOPE)) return 0; if ((ctx->current_crl_score & CRL_SCORE_SAME_PATH) == 0 && check_crl_path(ctx, ctx->current_issuer) <= 0 && !verify_cb_crl(ctx, X509_V_ERR_CRL_PATH_VALIDATION_ERROR)) return 0; if ((crl->idp_flags & IDP_INVALID) != 0 && !verify_cb_crl(ctx, X509_V_ERR_INVALID_EXTENSION)) return 0; } if ((ctx->current_crl_score & CRL_SCORE_TIME) == 0 && !check_crl_time(ctx, crl, 1)) return 0; /* Attempt to get issuer certificate public key */ ikey = X509_get0_pubkey(issuer); if (ikey == NULL && !verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY)) return 0; if (ikey != NULL) { int rv = X509_CRL_check_suiteb(crl, ikey, ctx->param->flags); if (rv != X509_V_OK && !verify_cb_crl(ctx, rv)) return 0; /* Verify CRL signature */ if (X509_CRL_verify(crl, ikey) <= 0 && !verify_cb_crl(ctx, X509_V_ERR_CRL_SIGNATURE_FAILURE)) return 0; } return 1; } /* Check certificate against CRL */ static int cert_crl(X509_STORE_CTX *ctx, X509_CRL *crl, X509 *x) { X509_REVOKED *rev; /* * The rules changed for this... previously if a CRL contained unhandled * critical extensions it could still be used to indicate a certificate * was revoked. This has since been changed since critical extensions can * change the meaning of CRL entries. */ if ((ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL) == 0 && (crl->flags & EXFLAG_CRITICAL) != 0 && !verify_cb_crl(ctx, X509_V_ERR_UNHANDLED_CRITICAL_CRL_EXTENSION)) return 0; /* * Look for serial number of certificate in CRL. If found, make sure * reason is not removeFromCRL. */ if (X509_CRL_get0_by_cert(crl, &rev, x)) { if (rev->reason == CRL_REASON_REMOVE_FROM_CRL) return 2; if (!verify_cb_crl(ctx, X509_V_ERR_CERT_REVOKED)) return 0; } return 1; } /* Sadly, returns 0 also on internal error in ctx->verify_cb(). */ static int check_policy(X509_STORE_CTX *ctx) { int ret; if (ctx->parent) return 1; /* * With DANE, the trust anchor might be a bare public key, not a * certificate! In that case our chain does not have the trust anchor * certificate as a top-most element. This comports well with RFC5280 * chain verification, since there too, the trust anchor is not part of the * chain to be verified. In particular, X509_policy_check() does not look * at the TA cert, but assumes that it is present as the top-most chain * element. We therefore temporarily push a NULL cert onto the chain if it * was verified via a bare public key, and pop it off right after the * X509_policy_check() call. */ if (ctx->bare_ta_signed && !sk_X509_push(ctx->chain, NULL)) { ERR_raise(ERR_LIB_X509, ERR_R_CRYPTO_LIB); goto memerr; } ret = X509_policy_check(&ctx->tree, &ctx->explicit_policy, ctx->chain, ctx->param->policies, ctx->param->flags); if (ctx->bare_ta_signed) (void)sk_X509_pop(ctx->chain); if (ret == X509_PCY_TREE_INTERNAL) { ERR_raise(ERR_LIB_X509, ERR_R_X509_LIB); goto memerr; } /* Invalid or inconsistent extensions */ if (ret == X509_PCY_TREE_INVALID) { int i, cbcalled = 0; /* Locate certificates with bad extensions and notify callback. */ for (i = 0; i < sk_X509_num(ctx->chain); i++) { X509 *x = sk_X509_value(ctx->chain, i); if ((x->ex_flags & EXFLAG_INVALID_POLICY) != 0) cbcalled = 1; CB_FAIL_IF((x->ex_flags & EXFLAG_INVALID_POLICY) != 0, ctx, x, i, X509_V_ERR_INVALID_POLICY_EXTENSION); } if (!cbcalled) { /* Should not be able to get here */ ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR); return 0; } /* The callback ignored the error so we return success */ return 1; } if (ret == X509_PCY_TREE_FAILURE) { ctx->current_cert = NULL; ctx->error = X509_V_ERR_NO_EXPLICIT_POLICY; return ctx->verify_cb(0, ctx); } if (ret != X509_PCY_TREE_VALID) { ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR); return 0; } if ((ctx->param->flags & X509_V_FLAG_NOTIFY_POLICY) != 0) { ctx->current_cert = NULL; /* * Verification errors need to be "sticky", a callback may have allowed * an SSL handshake to continue despite an error, and we must then * remain in an error state. Therefore, we MUST NOT clear earlier * verification errors by setting the error to X509_V_OK. */ if (!ctx->verify_cb(2, ctx)) return 0; } return 1; memerr: ctx->error = X509_V_ERR_OUT_OF_MEM; return -1; } /*- * Check certificate validity times. * If depth >= 0, invoke verification callbacks on error, otherwise just return * the validation status. * * Return 1 on success, 0 otherwise. * Sadly, returns 0 also on internal error in ctx->verify_cb(). */ int ossl_x509_check_cert_time(X509_STORE_CTX *ctx, X509 *x, int depth) { time_t *ptime; int i; if ((ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME) != 0) ptime = &ctx->param->check_time; else if ((ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME) != 0) return 1; else ptime = NULL; i = X509_cmp_time(X509_get0_notBefore(x), ptime); if (i >= 0 && depth < 0) return 0; CB_FAIL_IF(i == 0, ctx, x, depth, X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD); CB_FAIL_IF(i > 0, ctx, x, depth, X509_V_ERR_CERT_NOT_YET_VALID); i = X509_cmp_time(X509_get0_notAfter(x), ptime); if (i <= 0 && depth < 0) return 0; CB_FAIL_IF(i == 0, ctx, x, depth, X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD); CB_FAIL_IF(i < 0, ctx, x, depth, X509_V_ERR_CERT_HAS_EXPIRED); return 1; } /* * Verify the issuer signatures and cert times of ctx->chain. * Sadly, returns 0 also on internal error in ctx->verify_cb(). */ static int internal_verify(X509_STORE_CTX *ctx) { int n; X509 *xi; X509 *xs; /* For RPK: just do the verify callback */ if (ctx->rpk != NULL) { if (!ctx->verify_cb(ctx->error == X509_V_OK, ctx)) return 0; return 1; } n = sk_X509_num(ctx->chain) - 1; xi = sk_X509_value(ctx->chain, n); xs = xi; ctx->error_depth = n; if (ctx->bare_ta_signed) { /* * With DANE-verified bare public key TA signatures, * on the top certificate we check only the timestamps. * We report the issuer as NULL because all we have is a bare key. */ xi = NULL; } else if (ossl_x509_likely_issued(xi, xi) != X509_V_OK /* exceptional case: last cert in the chain is not self-issued */ && ((ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) == 0)) { if (n > 0) { n--; ctx->error_depth = n; xs = sk_X509_value(ctx->chain, n); } else { CB_FAIL_IF(1, ctx, xi, 0, X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE); } /* * The below code will certainly not do a * self-signature check on xi because it is not self-issued. */ } /* * Do not clear error (by ctx->error = X509_V_OK), it must be "sticky", * only the user's callback is allowed to reset errors (at its own peril). */ while (n >= 0) { /*- * For each iteration of this loop: * n is the subject depth * xs is the subject cert, for which the signature is to be checked * xi is NULL for DANE-verified bare public key TA signatures * else the supposed issuer cert containing the public key to use * Initially xs == xi if the last cert in the chain is self-issued. */ /* * Do signature check for self-signed certificates only if explicitly * asked for because it does not add any security and just wastes time. */ if (xi != NULL && (xs != xi || ((ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE) != 0 && (xi->ex_flags & EXFLAG_SS) != 0))) { EVP_PKEY *pkey; /* * If the issuer's public key is not available or its key usage * does not support issuing the subject cert, report the issuer * cert and its depth (rather than n, the depth of the subject). */ int issuer_depth = n + (xs == xi ? 0 : 1); /* * According to https://tools.ietf.org/html/rfc5280#section-6.1.4 * step (n) we must check any given key usage extension in a CA cert * when preparing the verification of a certificate issued by it. * According to https://tools.ietf.org/html/rfc5280#section-4.2.1.3 * we must not verify a certificate signature if the key usage of * the CA certificate that issued the certificate prohibits signing. * In case the 'issuing' certificate is the last in the chain and is * not a CA certificate but a 'self-issued' end-entity cert (i.e., * xs == xi && !(xi->ex_flags & EXFLAG_CA)) RFC 5280 does not apply * (see https://tools.ietf.org/html/rfc6818#section-2) and thus * we are free to ignore any key usage restrictions on such certs. */ int ret = xs == xi && (xi->ex_flags & EXFLAG_CA) == 0 ? X509_V_OK : ossl_x509_signing_allowed(xi, xs); CB_FAIL_IF(ret != X509_V_OK, ctx, xi, issuer_depth, ret); if ((pkey = X509_get0_pubkey(xi)) == NULL) { CB_FAIL_IF(1, ctx, xi, issuer_depth, X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY); } else { CB_FAIL_IF(X509_verify(xs, pkey) <= 0, ctx, xs, n, X509_V_ERR_CERT_SIGNATURE_FAILURE); } } /* In addition to RFC 5280 requirements do also for trust anchor cert */ /* Calls verify callback as needed */ if (!ossl_x509_check_cert_time(ctx, xs, n)) return 0; /* * Signal success at this depth. However, the previous error (if any) * is retained. */ ctx->current_issuer = xi; ctx->current_cert = xs; ctx->error_depth = n; if (!ctx->verify_cb(1, ctx)) return 0; if (--n >= 0) { xi = xs; xs = sk_X509_value(ctx->chain, n); } } return 1; } int X509_cmp_current_time(const ASN1_TIME *ctm) { return X509_cmp_time(ctm, NULL); } /* returns 0 on error, otherwise 1 if ctm > cmp_time, else -1 */ int X509_cmp_time(const ASN1_TIME *ctm, time_t *cmp_time) { static const size_t utctime_length = sizeof("YYMMDDHHMMSSZ") - 1; static const size_t generalizedtime_length = sizeof("YYYYMMDDHHMMSSZ") - 1; ASN1_TIME *asn1_cmp_time = NULL; int i, day, sec, ret = 0; #ifdef CHARSET_EBCDIC const char upper_z = 0x5A; #else const char upper_z = 'Z'; #endif /*- * Note that ASN.1 allows much more slack in the time format than RFC5280. * In RFC5280, the representation is fixed: * UTCTime: YYMMDDHHMMSSZ * GeneralizedTime: YYYYMMDDHHMMSSZ * * We do NOT currently enforce the following RFC 5280 requirement: * "CAs conforming to this profile MUST always encode certificate * validity dates through the year 2049 as UTCTime; certificate validity * dates in 2050 or later MUST be encoded as GeneralizedTime." */ switch (ctm->type) { case V_ASN1_UTCTIME: if (ctm->length != (int)(utctime_length)) return 0; break; case V_ASN1_GENERALIZEDTIME: if (ctm->length != (int)(generalizedtime_length)) return 0; break; default: return 0; } /** * Verify the format: the ASN.1 functions we use below allow a more * flexible format than what's mandated by RFC 5280. * Digit and date ranges will be verified in the conversion methods. */ for (i = 0; i < ctm->length - 1; i++) { if (!ossl_ascii_isdigit(ctm->data[i])) return 0; } if (ctm->data[ctm->length - 1] != upper_z) return 0; /* * There is ASN1_UTCTIME_cmp_time_t but no * ASN1_GENERALIZEDTIME_cmp_time_t or ASN1_TIME_cmp_time_t, * so we go through ASN.1 */ asn1_cmp_time = X509_time_adj(NULL, 0, cmp_time); if (asn1_cmp_time == NULL) goto err; if (ASN1_TIME_diff(&day, &sec, ctm, asn1_cmp_time) == 0) goto err; /* * X509_cmp_time comparison is <=. * The return value 0 is reserved for errors. */ ret = (day >= 0 && sec >= 0) ? -1 : 1; err: ASN1_TIME_free(asn1_cmp_time); return ret; } /* * Return 0 if time should not be checked or reference time is in range, * or else 1 if it is past the end, or -1 if it is before the start */ int X509_cmp_timeframe(const X509_VERIFY_PARAM *vpm, const ASN1_TIME *start, const ASN1_TIME *end) { time_t ref_time; time_t *time = NULL; unsigned long flags = vpm == NULL ? 0 : X509_VERIFY_PARAM_get_flags(vpm); if ((flags & X509_V_FLAG_USE_CHECK_TIME) != 0) { ref_time = X509_VERIFY_PARAM_get_time(vpm); time = &ref_time; } else if ((flags & X509_V_FLAG_NO_CHECK_TIME) != 0) { return 0; /* this means ok */ } /* else reference time is the current time */ if (end != NULL && X509_cmp_time(end, time) < 0) return 1; if (start != NULL && X509_cmp_time(start, time) > 0) return -1; return 0; } ASN1_TIME *X509_gmtime_adj(ASN1_TIME *s, long adj) { return X509_time_adj(s, adj, NULL); } ASN1_TIME *X509_time_adj(ASN1_TIME *s, long offset_sec, time_t *in_tm) { return X509_time_adj_ex(s, 0, offset_sec, in_tm); } ASN1_TIME *X509_time_adj_ex(ASN1_TIME *s, int offset_day, long offset_sec, time_t *in_tm) { time_t t; if (in_tm) t = *in_tm; else time(&t); if (s != NULL && (s->flags & ASN1_STRING_FLAG_MSTRING) == 0) { if (s->type == V_ASN1_UTCTIME) return ASN1_UTCTIME_adj(s, t, offset_day, offset_sec); if (s->type == V_ASN1_GENERALIZEDTIME) return ASN1_GENERALIZEDTIME_adj(s, t, offset_day, offset_sec); } return ASN1_TIME_adj(s, t, offset_day, offset_sec); } /* Copy any missing public key parameters up the chain towards pkey */ int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain) { EVP_PKEY *ktmp = NULL, *ktmp2; int i, j; if (pkey != NULL && !EVP_PKEY_missing_parameters(pkey)) return 1; for (i = 0; i < sk_X509_num(chain); i++) { ktmp = X509_get0_pubkey(sk_X509_value(chain, i)); if (ktmp == NULL) { ERR_raise(ERR_LIB_X509, X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY); return 0; } if (!EVP_PKEY_missing_parameters(ktmp)) break; ktmp = NULL; } if (ktmp == NULL) { ERR_raise(ERR_LIB_X509, X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN); return 0; } /* first, populate the other certs */ for (j = i - 1; j >= 0; j--) { ktmp2 = X509_get0_pubkey(sk_X509_value(chain, j)); if (!EVP_PKEY_copy_parameters(ktmp2, ktmp)) return 0; } if (pkey != NULL) return EVP_PKEY_copy_parameters(pkey, ktmp); return 1; } /* * Make a delta CRL as the difference between two full CRLs. * Sadly, returns NULL also on internal error. */ X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer, EVP_PKEY *skey, const EVP_MD *md, unsigned int flags) { X509_CRL *crl = NULL; int i; STACK_OF(X509_REVOKED) *revs = NULL; /* CRLs can't be delta already */ if (base->base_crl_number != NULL || newer->base_crl_number != NULL) { ERR_raise(ERR_LIB_X509, X509_R_CRL_ALREADY_DELTA); return NULL; } /* Base and new CRL must have a CRL number */ if (base->crl_number == NULL || newer->crl_number == NULL) { ERR_raise(ERR_LIB_X509, X509_R_NO_CRL_NUMBER); return NULL; } /* Issuer names must match */ if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(newer)) != 0) { ERR_raise(ERR_LIB_X509, X509_R_ISSUER_MISMATCH); return NULL; } /* AKID and IDP must match */ if (!crl_extension_match(base, newer, NID_authority_key_identifier)) { ERR_raise(ERR_LIB_X509, X509_R_AKID_MISMATCH); return NULL; } if (!crl_extension_match(base, newer, NID_issuing_distribution_point)) { ERR_raise(ERR_LIB_X509, X509_R_IDP_MISMATCH); return NULL; } /* Newer CRL number must exceed full CRL number */ if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0) { ERR_raise(ERR_LIB_X509, X509_R_NEWER_CRL_NOT_NEWER); return NULL; } /* CRLs must verify */ if (skey != NULL && (X509_CRL_verify(base, skey) <= 0 || X509_CRL_verify(newer, skey) <= 0)) { ERR_raise(ERR_LIB_X509, X509_R_CRL_VERIFY_FAILURE); return NULL; } /* Create new CRL */ crl = X509_CRL_new_ex(base->libctx, base->propq); if (crl == NULL || !X509_CRL_set_version(crl, X509_CRL_VERSION_2)) { ERR_raise(ERR_LIB_X509, ERR_R_X509_LIB); goto err; } /* Set issuer name */ if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer))) { ERR_raise(ERR_LIB_X509, ERR_R_X509_LIB); goto err; } if (!X509_CRL_set1_lastUpdate(crl, X509_CRL_get0_lastUpdate(newer))) { ERR_raise(ERR_LIB_X509, ERR_R_X509_LIB); goto err; } if (!X509_CRL_set1_nextUpdate(crl, X509_CRL_get0_nextUpdate(newer))) { ERR_raise(ERR_LIB_X509, ERR_R_X509_LIB); goto err; } /* Set base CRL number: must be critical */ if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0)) { ERR_raise(ERR_LIB_X509, ERR_R_X509_LIB); goto err; } /* * Copy extensions across from newest CRL to delta: this will set CRL * number to correct value too. */ for (i = 0; i < X509_CRL_get_ext_count(newer); i++) { X509_EXTENSION *ext = X509_CRL_get_ext(newer, i); if (!X509_CRL_add_ext(crl, ext, -1)) { ERR_raise(ERR_LIB_X509, ERR_R_X509_LIB); goto err; } } /* Go through revoked entries, copying as needed */ revs = X509_CRL_get_REVOKED(newer); for (i = 0; i < sk_X509_REVOKED_num(revs); i++) { X509_REVOKED *rvn, *rvtmp; rvn = sk_X509_REVOKED_value(revs, i); /* * Add only if not also in base. * Need something cleverer here for some more complex CRLs covering * multiple CAs. */ if (!X509_CRL_get0_by_serial(base, &rvtmp, &rvn->serialNumber)) { rvtmp = X509_REVOKED_dup(rvn); if (rvtmp == NULL) { ERR_raise(ERR_LIB_X509, ERR_R_ASN1_LIB); goto err; } if (!X509_CRL_add0_revoked(crl, rvtmp)) { X509_REVOKED_free(rvtmp); ERR_raise(ERR_LIB_X509, ERR_R_X509_LIB); goto err; } } } if (skey != NULL && md != NULL && !X509_CRL_sign(crl, skey, md)) { ERR_raise(ERR_LIB_X509, ERR_R_X509_LIB); goto err; } return crl; err: X509_CRL_free(crl); return NULL; } int X509_STORE_CTX_set_ex_data(X509_STORE_CTX *ctx, int idx, void *data) { return CRYPTO_set_ex_data(&ctx->ex_data, idx, data); } void *X509_STORE_CTX_get_ex_data(const X509_STORE_CTX *ctx, int idx) { return CRYPTO_get_ex_data(&ctx->ex_data, idx); } int X509_STORE_CTX_get_error(const X509_STORE_CTX *ctx) { return ctx->error; } void X509_STORE_CTX_set_error(X509_STORE_CTX *ctx, int err) { ctx->error = err; } int X509_STORE_CTX_get_error_depth(const X509_STORE_CTX *ctx) { return ctx->error_depth; } void X509_STORE_CTX_set_error_depth(X509_STORE_CTX *ctx, int depth) { ctx->error_depth = depth; } X509 *X509_STORE_CTX_get_current_cert(const X509_STORE_CTX *ctx) { return ctx->current_cert; } void X509_STORE_CTX_set_current_cert(X509_STORE_CTX *ctx, X509 *x) { ctx->current_cert = x; } STACK_OF(X509) *X509_STORE_CTX_get0_chain(const X509_STORE_CTX *ctx) { return ctx->chain; } STACK_OF(X509) *X509_STORE_CTX_get1_chain(const X509_STORE_CTX *ctx) { if (ctx->chain == NULL) return NULL; return X509_chain_up_ref(ctx->chain); } X509 *X509_STORE_CTX_get0_current_issuer(const X509_STORE_CTX *ctx) { return ctx->current_issuer; } X509_CRL *X509_STORE_CTX_get0_current_crl(const X509_STORE_CTX *ctx) { return ctx->current_crl; } X509_STORE_CTX *X509_STORE_CTX_get0_parent_ctx(const X509_STORE_CTX *ctx) { return ctx->parent; } void X509_STORE_CTX_set_cert(X509_STORE_CTX *ctx, X509 *x) { ctx->cert = x; } void X509_STORE_CTX_set0_rpk(X509_STORE_CTX *ctx, EVP_PKEY *rpk) { ctx->rpk = rpk; } void X509_STORE_CTX_set0_crls(X509_STORE_CTX *ctx, STACK_OF(X509_CRL) *sk) { ctx->crls = sk; } int X509_STORE_CTX_set_purpose(X509_STORE_CTX *ctx, int purpose) { /* * XXX: Why isn't this function always used to set the associated trust? * Should there even be a VPM->trust field at all? Or should the trust * always be inferred from the purpose by X509_STORE_CTX_init(). */ return X509_STORE_CTX_purpose_inherit(ctx, 0, purpose, 0); } int X509_STORE_CTX_set_trust(X509_STORE_CTX *ctx, int trust) { /* * XXX: See above, this function would only be needed when the default * trust for the purpose needs an override in a corner case. */ return X509_STORE_CTX_purpose_inherit(ctx, 0, 0, trust); } /* * This function is used to set the X509_STORE_CTX purpose and trust values. * This is intended to be used when another structure has its own trust and * purpose values which (if set) will be inherited by the ctx. If they aren't * set then we will usually have a default purpose in mind which should then * be used to set the trust value. An example of this is SSL use: an SSL * structure will have its own purpose and trust settings which the * application can set: if they aren't set then we use the default of SSL * client/server. */ int X509_STORE_CTX_purpose_inherit(X509_STORE_CTX *ctx, int def_purpose, int purpose, int trust) { int idx; /* If purpose not set use default */ if (purpose == 0) purpose = def_purpose; /* * If purpose is set but we don't have a default then set the default to * the current purpose */ else if (def_purpose == 0) def_purpose = purpose; /* If we have a purpose then check it is valid */ if (purpose != 0) { X509_PURPOSE *ptmp; idx = X509_PURPOSE_get_by_id(purpose); if (idx == -1) { ERR_raise(ERR_LIB_X509, X509_R_UNKNOWN_PURPOSE_ID); return 0; } ptmp = X509_PURPOSE_get0(idx); if (ptmp->trust == X509_TRUST_DEFAULT) { idx = X509_PURPOSE_get_by_id(def_purpose); if (idx == -1) { ERR_raise(ERR_LIB_X509, X509_R_UNKNOWN_PURPOSE_ID); return 0; } ptmp = X509_PURPOSE_get0(idx); } /* If trust not set then get from purpose default */ if (trust == 0) trust = ptmp->trust; } if (trust != 0) { idx = X509_TRUST_get_by_id(trust); if (idx == -1) { ERR_raise(ERR_LIB_X509, X509_R_UNKNOWN_TRUST_ID); return 0; } } if (ctx->param->purpose == 0 && purpose != 0) ctx->param->purpose = purpose; if (ctx->param->trust == 0 && trust != 0) ctx->param->trust = trust; return 1; } X509_STORE_CTX *X509_STORE_CTX_new_ex(OSSL_LIB_CTX *libctx, const char *propq) { X509_STORE_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx)); if (ctx == NULL) return NULL; ctx->libctx = libctx; if (propq != NULL) { ctx->propq = OPENSSL_strdup(propq); if (ctx->propq == NULL) { OPENSSL_free(ctx); return NULL; } } return ctx; } X509_STORE_CTX *X509_STORE_CTX_new(void) { return X509_STORE_CTX_new_ex(NULL, NULL); } void X509_STORE_CTX_free(X509_STORE_CTX *ctx) { if (ctx == NULL) return; X509_STORE_CTX_cleanup(ctx); /* libctx and propq survive X509_STORE_CTX_cleanup() */ OPENSSL_free(ctx->propq); OPENSSL_free(ctx); } int X509_STORE_CTX_init_rpk(X509_STORE_CTX *ctx, X509_STORE *store, EVP_PKEY *rpk) { if (!X509_STORE_CTX_init(ctx, store, NULL, NULL)) return 0; ctx->rpk = rpk; return 1; } int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509, STACK_OF(X509) *chain) { if (ctx == NULL) { ERR_raise(ERR_LIB_X509, ERR_R_PASSED_NULL_PARAMETER); return 0; } X509_STORE_CTX_cleanup(ctx); ctx->store = store; ctx->cert = x509; ctx->untrusted = chain; ctx->crls = NULL; ctx->num_untrusted = 0; ctx->other_ctx = NULL; ctx->valid = 0; ctx->chain = NULL; ctx->error = X509_V_OK; ctx->explicit_policy = 0; ctx->error_depth = 0; ctx->current_cert = NULL; ctx->current_issuer = NULL; ctx->current_crl = NULL; ctx->current_crl_score = 0; ctx->current_reasons = 0; ctx->tree = NULL; ctx->parent = NULL; ctx->dane = NULL; ctx->bare_ta_signed = 0; ctx->rpk = NULL; /* Zero ex_data to make sure we're cleanup-safe */ memset(&ctx->ex_data, 0, sizeof(ctx->ex_data)); /* store->cleanup is always 0 in OpenSSL, if set must be idempotent */ if (store != NULL) ctx->cleanup = store->cleanup; else ctx->cleanup = NULL; if (store != NULL && store->check_issued != NULL) ctx->check_issued = store->check_issued; else ctx->check_issued = check_issued; if (store != NULL && store->get_issuer != NULL) ctx->get_issuer = store->get_issuer; else ctx->get_issuer = X509_STORE_CTX_get1_issuer; if (store != NULL && store->verify_cb != NULL) ctx->verify_cb = store->verify_cb; else ctx->verify_cb = null_callback; if (store != NULL && store->verify != NULL) ctx->verify = store->verify; else ctx->verify = internal_verify; if (store != NULL && store->check_revocation != NULL) ctx->check_revocation = store->check_revocation; else ctx->check_revocation = check_revocation; if (store != NULL && store->get_crl != NULL) ctx->get_crl = store->get_crl; else ctx->get_crl = NULL; if (store != NULL && store->check_crl != NULL) ctx->check_crl = store->check_crl; else ctx->check_crl = check_crl; if (store != NULL && store->cert_crl != NULL) ctx->cert_crl = store->cert_crl; else ctx->cert_crl = cert_crl; if (store != NULL && store->check_policy != NULL) ctx->check_policy = store->check_policy; else ctx->check_policy = check_policy; if (store != NULL && store->lookup_certs != NULL) ctx->lookup_certs = store->lookup_certs; else ctx->lookup_certs = X509_STORE_CTX_get1_certs; if (store != NULL && store->lookup_crls != NULL) ctx->lookup_crls = store->lookup_crls; else ctx->lookup_crls = X509_STORE_CTX_get1_crls; ctx->param = X509_VERIFY_PARAM_new(); if (ctx->param == NULL) { ERR_raise(ERR_LIB_X509, ERR_R_ASN1_LIB); goto err; } /* Inherit callbacks and flags from X509_STORE if not set use defaults. */ if (store == NULL) ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT | X509_VP_FLAG_ONCE; else if (X509_VERIFY_PARAM_inherit(ctx->param, store->param) == 0) goto err; if (!X509_STORE_CTX_set_default(ctx, "default")) goto err; /* * XXX: For now, continue to inherit trust from VPM, but infer from the * purpose if this still yields the default value. */ if (ctx->param->trust == X509_TRUST_DEFAULT) { int idx = X509_PURPOSE_get_by_id(ctx->param->purpose); X509_PURPOSE *xp = X509_PURPOSE_get0(idx); if (xp != NULL) ctx->param->trust = X509_PURPOSE_get_trust(xp); } if (CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &ctx->ex_data)) return 1; ERR_raise(ERR_LIB_X509, ERR_R_CRYPTO_LIB); err: /* * On error clean up allocated storage, if the store context was not * allocated with X509_STORE_CTX_new() this is our last chance to do so. */ X509_STORE_CTX_cleanup(ctx); return 0; } /* * Set alternative get_issuer method: just from a STACK of trusted certificates. * This avoids the complexity of X509_STORE where it is not needed. */ void X509_STORE_CTX_set0_trusted_stack(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) { ctx->other_ctx = sk; ctx->get_issuer = get_issuer_sk; ctx->lookup_certs = lookup_certs_sk; } void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx) { /* * We need to be idempotent because, unfortunately, free() also calls * cleanup(), so the natural call sequence new(), init(), cleanup(), free() * calls cleanup() for the same object twice! Thus we must zero the * pointers below after they're freed! */ /* Seems to always be NULL in OpenSSL, do this at most once. */ if (ctx->cleanup != NULL) { ctx->cleanup(ctx); ctx->cleanup = NULL; } if (ctx->param != NULL) { if (ctx->parent == NULL) X509_VERIFY_PARAM_free(ctx->param); ctx->param = NULL; } X509_policy_tree_free(ctx->tree); ctx->tree = NULL; OSSL_STACK_OF_X509_free(ctx->chain); ctx->chain = NULL; CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data)); memset(&ctx->ex_data, 0, sizeof(ctx->ex_data)); } void X509_STORE_CTX_set_depth(X509_STORE_CTX *ctx, int depth) { X509_VERIFY_PARAM_set_depth(ctx->param, depth); } void X509_STORE_CTX_set_flags(X509_STORE_CTX *ctx, unsigned long flags) { X509_VERIFY_PARAM_set_flags(ctx->param, flags); } void X509_STORE_CTX_set_time(X509_STORE_CTX *ctx, unsigned long flags, time_t t) { X509_VERIFY_PARAM_set_time(ctx->param, t); } void X509_STORE_CTX_set_current_reasons(X509_STORE_CTX *ctx, unsigned int current_reasons) { ctx->current_reasons = current_reasons; } X509 *X509_STORE_CTX_get0_cert(const X509_STORE_CTX *ctx) { return ctx->cert; } EVP_PKEY *X509_STORE_CTX_get0_rpk(const X509_STORE_CTX *ctx) { return ctx->rpk; } STACK_OF(X509) *X509_STORE_CTX_get0_untrusted(const X509_STORE_CTX *ctx) { return ctx->untrusted; } void X509_STORE_CTX_set0_untrusted(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) { ctx->untrusted = sk; } void X509_STORE_CTX_set0_verified_chain(X509_STORE_CTX *ctx, STACK_OF(X509) *sk) { OSSL_STACK_OF_X509_free(ctx->chain); ctx->chain = sk; } void X509_STORE_CTX_set_verify_cb(X509_STORE_CTX *ctx, X509_STORE_CTX_verify_cb verify_cb) { ctx->verify_cb = verify_cb; } X509_STORE_CTX_verify_cb X509_STORE_CTX_get_verify_cb(const X509_STORE_CTX *ctx) { return ctx->verify_cb; } void X509_STORE_CTX_set_verify(X509_STORE_CTX *ctx, X509_STORE_CTX_verify_fn verify) { ctx->verify = verify; } X509_STORE_CTX_verify_fn X509_STORE_CTX_get_verify(const X509_STORE_CTX *ctx) { return ctx->verify; } X509_STORE_CTX_get_issuer_fn X509_STORE_CTX_get_get_issuer(const X509_STORE_CTX *ctx) { return ctx->get_issuer; } X509_STORE_CTX_check_issued_fn X509_STORE_CTX_get_check_issued(const X509_STORE_CTX *ctx) { return ctx->check_issued; } X509_STORE_CTX_check_revocation_fn X509_STORE_CTX_get_check_revocation(const X509_STORE_CTX *ctx) { return ctx->check_revocation; } X509_STORE_CTX_get_crl_fn X509_STORE_CTX_get_get_crl(const X509_STORE_CTX *ctx) { return ctx->get_crl; } void X509_STORE_CTX_set_get_crl(X509_STORE_CTX *ctx, X509_STORE_CTX_get_crl_fn get_crl) { ctx->get_crl = get_crl; } X509_STORE_CTX_check_crl_fn X509_STORE_CTX_get_check_crl(const X509_STORE_CTX *ctx) { return ctx->check_crl; } X509_STORE_CTX_cert_crl_fn X509_STORE_CTX_get_cert_crl(const X509_STORE_CTX *ctx) { return ctx->cert_crl; } X509_STORE_CTX_check_policy_fn X509_STORE_CTX_get_check_policy(const X509_STORE_CTX *ctx) { return ctx->check_policy; } X509_STORE_CTX_lookup_certs_fn X509_STORE_CTX_get_lookup_certs(const X509_STORE_CTX *ctx) { return ctx->lookup_certs; } X509_STORE_CTX_lookup_crls_fn X509_STORE_CTX_get_lookup_crls(const X509_STORE_CTX *ctx) { return ctx->lookup_crls; } X509_STORE_CTX_cleanup_fn X509_STORE_CTX_get_cleanup(const X509_STORE_CTX *ctx) { return ctx->cleanup; } X509_POLICY_TREE *X509_STORE_CTX_get0_policy_tree(const X509_STORE_CTX *ctx) { return ctx->tree; } int X509_STORE_CTX_get_explicit_policy(const X509_STORE_CTX *ctx) { return ctx->explicit_policy; } int X509_STORE_CTX_get_num_untrusted(const X509_STORE_CTX *ctx) { return ctx->num_untrusted; } int X509_STORE_CTX_set_default(X509_STORE_CTX *ctx, const char *name) { const X509_VERIFY_PARAM *param; param = X509_VERIFY_PARAM_lookup(name); if (param == NULL) { ERR_raise_data(ERR_LIB_X509, X509_R_UNKNOWN_PURPOSE_ID, "name=%s", name); return 0; } return X509_VERIFY_PARAM_inherit(ctx->param, param); } X509_VERIFY_PARAM *X509_STORE_CTX_get0_param(const X509_STORE_CTX *ctx) { return ctx->param; } void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param) { X509_VERIFY_PARAM_free(ctx->param); ctx->param = param; } void X509_STORE_CTX_set0_dane(X509_STORE_CTX *ctx, SSL_DANE *dane) { ctx->dane = dane; } static unsigned char *dane_i2d(X509 *cert, uint8_t selector, unsigned int *i2dlen) { unsigned char *buf = NULL; int len; /* * Extract ASN.1 DER form of certificate or public key. */ switch (selector) { case DANETLS_SELECTOR_CERT: len = i2d_X509(cert, &buf); break; case DANETLS_SELECTOR_SPKI: len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &buf); break; default: ERR_raise(ERR_LIB_X509, X509_R_BAD_SELECTOR); return NULL; } if (len < 0 || buf == NULL) { ERR_raise(ERR_LIB_X509, ERR_R_ASN1_LIB); return NULL; } *i2dlen = (unsigned int)len; return buf; } #define DANETLS_NONE 256 /* impossible uint8_t */ /* Returns -1 on internal error */ static int dane_match_cert(X509_STORE_CTX *ctx, X509 *cert, int depth) { SSL_DANE *dane = ctx->dane; unsigned usage = DANETLS_NONE; unsigned selector = DANETLS_NONE; unsigned ordinal = DANETLS_NONE; unsigned mtype = DANETLS_NONE; unsigned char *i2dbuf = NULL; unsigned int i2dlen = 0; unsigned char mdbuf[EVP_MAX_MD_SIZE]; unsigned char *cmpbuf = NULL; unsigned int cmplen = 0; int i; int recnum; int matched = 0; danetls_record *t = NULL; uint32_t mask; mask = (depth == 0) ? DANETLS_EE_MASK : DANETLS_TA_MASK; /* The trust store is not applicable with DANE-TA(2) */ if (depth >= ctx->num_untrusted) mask &= DANETLS_PKIX_MASK; /* * If we've previously matched a PKIX-?? record, no need to test any * further PKIX-?? records, it remains to just build the PKIX chain. * Had the match been a DANE-?? record, we'd be done already. */ if (dane->mdpth >= 0) mask &= ~DANETLS_PKIX_MASK; /*- * https://tools.ietf.org/html/rfc7671#section-5.1 * https://tools.ietf.org/html/rfc7671#section-5.2 * https://tools.ietf.org/html/rfc7671#section-5.3 * https://tools.ietf.org/html/rfc7671#section-5.4 * * We handle DANE-EE(3) records first as they require no chain building * and no expiration or hostname checks. We also process digests with * higher ordinals first and ignore lower priorities except Full(0) which * is always processed (last). If none match, we then process PKIX-EE(1). * * NOTE: This relies on DANE usages sorting before the corresponding PKIX * usages in SSL_dane_tlsa_add(), and also on descending sorting of digest * priorities. See twin comment in ssl/ssl_lib.c. * * We expect that most TLSA RRsets will have just a single usage, so we * don't go out of our way to cache multiple selector-specific i2d buffers * across usages, but if the selector happens to remain the same as switch * usages, that's OK. Thus, a set of "3 1 1", "3 0 1", "1 1 1", "1 0 1", * records would result in us generating each of the certificate and public * key DER forms twice, but more typically we'd just see multiple "3 1 1" * or multiple "3 0 1" records. * * As soon as we find a match at any given depth, we stop, because either * we've matched a DANE-?? record and the peer is authenticated, or, after * exhausting all DANE-?? records, we've matched a PKIX-?? record, which is * sufficient for DANE, and what remains to do is ordinary PKIX validation. */ recnum = (dane->umask & mask) != 0 ? sk_danetls_record_num(dane->trecs) : 0; for (i = 0; matched == 0 && i < recnum; ++i) { t = sk_danetls_record_value(dane->trecs, i); if ((DANETLS_USAGE_BIT(t->usage) & mask) == 0) continue; if (t->usage != usage) { usage = t->usage; /* Reset digest agility for each usage/selector pair */ mtype = DANETLS_NONE; ordinal = dane->dctx->mdord[t->mtype]; } if (t->selector != selector) { selector = t->selector; /* Update per-selector state */ OPENSSL_free(i2dbuf); i2dbuf = dane_i2d(cert, selector, &i2dlen); if (i2dbuf == NULL) return -1; /* Reset digest agility for each usage/selector pair */ mtype = DANETLS_NONE; ordinal = dane->dctx->mdord[t->mtype]; } else if (t->mtype != DANETLS_MATCHING_FULL) { /*- * Digest agility: * * * * For a fixed selector, after processing all records with the * highest mtype ordinal, ignore all mtypes with lower ordinals * other than "Full". */ if (dane->dctx->mdord[t->mtype] < ordinal) continue; } /* * Each time we hit a (new selector or) mtype, re-compute the relevant * digest, more complex caching is not worth the code space. */ if (t->mtype != mtype) { const EVP_MD *md = dane->dctx->mdevp[mtype = t->mtype]; cmpbuf = i2dbuf; cmplen = i2dlen; if (md != NULL) { cmpbuf = mdbuf; if (!EVP_Digest(i2dbuf, i2dlen, cmpbuf, &cmplen, md, 0)) { matched = -1; break; } } } /* * Squirrel away the certificate and depth if we have a match. Any * DANE match is dispositive, but with PKIX we still need to build a * full chain. */ if (cmplen == t->dlen && memcmp(cmpbuf, t->data, cmplen) == 0) { if (DANETLS_USAGE_BIT(usage) & DANETLS_DANE_MASK) matched = 1; if (matched || dane->mdpth < 0) { dane->mdpth = depth; dane->mtlsa = t; OPENSSL_free(dane->mcert); dane->mcert = cert; X509_up_ref(cert); } break; } } /* Clear the one-element DER cache */ OPENSSL_free(i2dbuf); return matched; } /* Returns -1 on internal error */ static int check_dane_issuer(X509_STORE_CTX *ctx, int depth) { SSL_DANE *dane = ctx->dane; int matched = 0; X509 *cert; if (!DANETLS_HAS_TA(dane) || depth == 0) return X509_TRUST_UNTRUSTED; /* * Record any DANE trust anchor matches, for the first depth to test, if * there's one at that depth. (This'll be false for length 1 chains looking * for an exact match for the leaf certificate). */ cert = sk_X509_value(ctx->chain, depth); if (cert != NULL && (matched = dane_match_cert(ctx, cert, depth)) < 0) return matched; if (matched > 0) { ctx->num_untrusted = depth - 1; return X509_TRUST_TRUSTED; } return X509_TRUST_UNTRUSTED; } static int check_dane_pkeys(X509_STORE_CTX *ctx) { SSL_DANE *dane = ctx->dane; danetls_record *t; int num = ctx->num_untrusted; X509 *cert = sk_X509_value(ctx->chain, num - 1); int recnum = sk_danetls_record_num(dane->trecs); int i; for (i = 0; i < recnum; ++i) { t = sk_danetls_record_value(dane->trecs, i); if (t->usage != DANETLS_USAGE_DANE_TA || t->selector != DANETLS_SELECTOR_SPKI || t->mtype != DANETLS_MATCHING_FULL || X509_verify(cert, t->spki) <= 0) continue; /* Clear any PKIX-?? matches that failed to extend to a full chain */ X509_free(dane->mcert); dane->mcert = NULL; /* Record match via a bare TA public key */ ctx->bare_ta_signed = 1; dane->mdpth = num - 1; dane->mtlsa = t; /* Prune any excess chain certificates */ num = sk_X509_num(ctx->chain); for (; num > ctx->num_untrusted; --num) X509_free(sk_X509_pop(ctx->chain)); return X509_TRUST_TRUSTED; } return X509_TRUST_UNTRUSTED; } /* * Only DANE-EE and SPKI are supported * Returns -1 on internal error */ static int dane_match_rpk(X509_STORE_CTX *ctx, EVP_PKEY *rpk) { SSL_DANE *dane = ctx->dane; danetls_record *t = NULL; int mtype = DANETLS_MATCHING_FULL; unsigned char *i2dbuf = NULL; unsigned int i2dlen = 0; unsigned char mdbuf[EVP_MAX_MD_SIZE]; unsigned char *cmpbuf; unsigned int cmplen = 0; int len; int recnum = sk_danetls_record_num(dane->trecs); int i; int matched = 0; /* Calculate ASN.1 DER of RPK */ if ((len = i2d_PUBKEY(rpk, &i2dbuf)) <= 0) return -1; cmplen = i2dlen = (unsigned int)len; cmpbuf = i2dbuf; for (i = 0; i < recnum; i++) { t = sk_danetls_record_value(dane->trecs, i); if (t->usage != DANETLS_USAGE_DANE_EE || t->selector != DANETLS_SELECTOR_SPKI) continue; /* Calculate hash - keep only one around */ if (t->mtype != mtype) { const EVP_MD *md = dane->dctx->mdevp[mtype = t->mtype]; cmpbuf = i2dbuf; cmplen = i2dlen; if (md != NULL) { cmpbuf = mdbuf; if (!EVP_Digest(i2dbuf, i2dlen, cmpbuf, &cmplen, md, 0)) { matched = -1; break; } } } if (cmplen == t->dlen && memcmp(cmpbuf, t->data, cmplen) == 0) { matched = 1; dane->mdpth = 0; dane->mtlsa = t; break; } } OPENSSL_free(i2dbuf); return matched; } static void dane_reset(SSL_DANE *dane) { /* Reset state to verify another chain, or clear after failure. */ X509_free(dane->mcert); dane->mcert = NULL; dane->mtlsa = NULL; dane->mdpth = -1; dane->pdpth = -1; } /* Sadly, returns 0 also on internal error in ctx->verify_cb(). */ static int check_leaf_suiteb(X509_STORE_CTX *ctx, X509 *cert) { int err = X509_chain_check_suiteb(NULL, cert, NULL, ctx->param->flags); CB_FAIL_IF(err != X509_V_OK, ctx, cert, 0, err); return 1; } /* Returns -1 on internal error */ static int dane_verify_rpk(X509_STORE_CTX *ctx) { SSL_DANE *dane = ctx->dane; int matched; dane_reset(dane); /* * Look for a DANE record for RPK * If error, return -1 * If found, call ctx->verify_cb(1, ctx) * If not found call ctx->verify_cb(0, ctx) */ matched = dane_match_rpk(ctx, ctx->rpk); ctx->error_depth = 0; if (matched < 0) { ctx->error = X509_V_ERR_UNSPECIFIED; return -1; } if (matched > 0) ctx->error = X509_V_OK; else ctx->error = X509_V_ERR_DANE_NO_MATCH; return verify_rpk(ctx); } /* Returns -1 on internal error */ static int dane_verify(X509_STORE_CTX *ctx) { X509 *cert = ctx->cert; SSL_DANE *dane = ctx->dane; int matched; int done; dane_reset(dane); /*- * When testing the leaf certificate, if we match a DANE-EE(3) record, * dane_match() returns 1 and we're done. If however we match a PKIX-EE(1) * record, the match depth and matching TLSA record are recorded, but the * return value is 0, because we still need to find a PKIX trust anchor. * Therefore, when DANE authentication is enabled (required), we're done * if: * + matched < 0, internal error. * + matched == 1, we matched a DANE-EE(3) record * + matched == 0, mdepth < 0 (no PKIX-EE match) and there are no * DANE-TA(2) or PKIX-TA(0) to test. */ matched = dane_match_cert(ctx, ctx->cert, 0); done = matched != 0 || (!DANETLS_HAS_TA(dane) && dane->mdpth < 0); if (done && !X509_get_pubkey_parameters(NULL, ctx->chain)) return -1; if (matched > 0) { /* Callback invoked as needed */ if (!check_leaf_suiteb(ctx, cert)) return 0; /* Callback invoked as needed */ if ((dane->flags & DANE_FLAG_NO_DANE_EE_NAMECHECKS) == 0 && !check_id(ctx)) return 0; /* Bypass internal_verify(), issue depth 0 success callback */ ctx->error_depth = 0; ctx->current_cert = cert; return ctx->verify_cb(1, ctx); } if (matched < 0) { ctx->error_depth = 0; ctx->current_cert = cert; ctx->error = X509_V_ERR_OUT_OF_MEM; return -1; } if (done) { /* Fail early, TA-based success is not possible */ if (!check_leaf_suiteb(ctx, cert)) return 0; return verify_cb_cert(ctx, cert, 0, X509_V_ERR_DANE_NO_MATCH); } /* * Chain verification for usages 0/1/2. TLSA record matching of depth > 0 * certificates happens in-line with building the rest of the chain. */ return verify_chain(ctx); } /* * Get trusted issuer, without duplicate suppression * Returns -1 on internal error. */ static int get1_trusted_issuer(X509 **issuer, X509_STORE_CTX *ctx, X509 *cert) { STACK_OF(X509) *saved_chain = ctx->chain; int ok; ctx->chain = NULL; ok = ctx->get_issuer(issuer, ctx, cert); ctx->chain = saved_chain; return ok; } /*- * Returns -1 on internal error. * Sadly, returns 0 also on internal error in ctx->verify_cb(). */ static int build_chain(X509_STORE_CTX *ctx) { SSL_DANE *dane = ctx->dane; int num = sk_X509_num(ctx->chain); STACK_OF(X509) *sk_untrusted = NULL; unsigned int search; int may_trusted = 0; int may_alternate = 0; int trust = X509_TRUST_UNTRUSTED; int alt_untrusted = 0; int max_depth; int ok = 0; int i; /* Our chain starts with a single untrusted element. */ if (!ossl_assert(num == 1 && ctx->num_untrusted == num)) goto int_err; #define S_DOUNTRUSTED (1 << 0) /* Search untrusted chain */ #define S_DOTRUSTED (1 << 1) /* Search trusted store */ #define S_DOALTERNATE (1 << 2) /* Retry with pruned alternate chain */ /* * Set up search policy, untrusted if possible, trusted-first if enabled, * which is the default. * If we're doing DANE and not doing PKIX-TA/PKIX-EE, we never look in the * trust_store, otherwise we might look there first. If not trusted-first, * and alternate chains are not disabled, try building an alternate chain * if no luck with untrusted first. */ search = ctx->untrusted != NULL ? S_DOUNTRUSTED : 0; if (DANETLS_HAS_PKIX(dane) || !DANETLS_HAS_DANE(dane)) { if (search == 0 || (ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST) != 0) search |= S_DOTRUSTED; else if (!(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS)) may_alternate = 1; may_trusted = 1; } /* Initialize empty untrusted stack. */ if ((sk_untrusted = sk_X509_new_null()) == NULL) { ERR_raise(ERR_LIB_X509, ERR_R_CRYPTO_LIB); goto memerr; } /* * If we got any "Cert(0) Full(0)" trust anchors from DNS, *prepend* them * to our working copy of the untrusted certificate stack. */ if (DANETLS_ENABLED(dane) && dane->certs != NULL && !X509_add_certs(sk_untrusted, dane->certs, X509_ADD_FLAG_DEFAULT)) { ERR_raise(ERR_LIB_X509, ERR_R_X509_LIB); goto memerr; } /* * Shallow-copy the stack of untrusted certificates (with TLS, this is * typically the content of the peer's certificate message) so we can make * multiple passes over it, while free to remove elements as we go. */ if (!X509_add_certs(sk_untrusted, ctx->untrusted, X509_ADD_FLAG_DEFAULT)) { ERR_raise(ERR_LIB_X509, ERR_R_X509_LIB); goto memerr; } /* * Still absurdly large, but arithmetically safe, a lower hard upper bound * might be reasonable. */ if (ctx->param->depth > INT_MAX / 2) ctx->param->depth = INT_MAX / 2; /* * Try to extend the chain until we reach an ultimately trusted issuer. * Build chains up to one longer the limit, later fail if we hit the limit, * with an X509_V_ERR_CERT_CHAIN_TOO_LONG error code. */ max_depth = ctx->param->depth + 1; while (search != 0) { X509 *curr, *issuer = NULL; num = sk_X509_num(ctx->chain); ctx->error_depth = num - 1; /* * Look in the trust store if enabled for first lookup, or we've run * out of untrusted issuers and search here is not disabled. When we * reach the depth limit, we stop extending the chain, if by that point * we've not found a trust anchor, any trusted chain would be too long. * * The error reported to the application verify callback is at the * maximal valid depth with the current certificate equal to the last * not ultimately-trusted issuer. For example, with verify_depth = 0, * the callback will report errors at depth=1 when the immediate issuer * of the leaf certificate is not a trust anchor. No attempt will be * made to locate an issuer for that certificate, since such a chain * would be a-priori too long. */ if ((search & S_DOTRUSTED) != 0) { i = num; if ((search & S_DOALTERNATE) != 0) { /* * As high up the chain as we can, look for an alternative * trusted issuer of an untrusted certificate that currently * has an untrusted issuer. We use the alt_untrusted variable * to track how far up the chain we find the first match. It * is only if and when we find a match, that we prune the chain * and reset ctx->num_untrusted to the reduced count of * untrusted certificates. While we're searching for such a * match (which may never be found), it is neither safe nor * wise to preemptively modify either the chain or * ctx->num_untrusted. * * Note, like ctx->num_untrusted, alt_untrusted is a count of * untrusted certificates, not a "depth". */ i = alt_untrusted; } curr = sk_X509_value(ctx->chain, i - 1); /* Note: get1_trusted_issuer() must be used even if self-signed. */ ok = num > max_depth ? 0 : get1_trusted_issuer(&issuer, ctx, curr); if (ok < 0) { trust = -1; ctx->error = X509_V_ERR_STORE_LOOKUP; break; } if (ok > 0) { int self_signed = X509_self_signed(curr, 0); if (self_signed < 0) { X509_free(issuer); goto int_err; } /* * Alternative trusted issuer for a mid-chain untrusted cert? * Pop the untrusted cert's successors and retry. We might now * be able to complete a valid chain via the trust store. Note * that despite the current trust store match we might still * fail complete the chain to a suitable trust anchor, in which * case we may prune some more untrusted certificates and try * again. Thus the S_DOALTERNATE bit may yet be turned on * again with an even shorter untrusted chain! * * If in the process we threw away our matching PKIX-TA trust * anchor, reset DANE trust. We might find a suitable trusted * certificate among the ones from the trust store. */ if ((search & S_DOALTERNATE) != 0) { if (!ossl_assert(num > i && i > 0 && !self_signed)) { X509_free(issuer); goto int_err; } search &= ~S_DOALTERNATE; for (; num > i; --num) X509_free(sk_X509_pop(ctx->chain)); ctx->num_untrusted = num; if (DANETLS_ENABLED(dane) && dane->mdpth >= ctx->num_untrusted) { dane->mdpth = -1; X509_free(dane->mcert); dane->mcert = NULL; } if (DANETLS_ENABLED(dane) && dane->pdpth >= ctx->num_untrusted) dane->pdpth = -1; } if (!self_signed) { /* untrusted not self-signed certificate */ /* Grow the chain by trusted issuer */ if (!sk_X509_push(ctx->chain, issuer)) { X509_free(issuer); ERR_raise(ERR_LIB_X509, ERR_R_CRYPTO_LIB); goto memerr; } if ((self_signed = X509_self_signed(issuer, 0)) < 0) goto int_err; } else { /* * We have a self-signed untrusted cert that has the same * subject name (and perhaps keyid and/or serial number) as * a trust anchor. We must have an exact match to avoid * possible impersonation via key substitution etc. */ if (X509_cmp(curr, issuer) != 0) { /* Self-signed untrusted mimic. */ X509_free(issuer); ok = 0; } else { /* curr "==" issuer */ /* * Replace self-signed untrusted certificate * by its trusted matching issuer. */ X509_free(curr); ctx->num_untrusted = --num; (void)sk_X509_set(ctx->chain, num, issuer); } } /* * We've added a new trusted certificate to the chain, re-check * trust. If not done, and not self-signed look deeper. * Whether or not we're doing "trusted first", we no longer * look for untrusted certificates from the peer's chain. * * At this point ctx->num_trusted and num must reflect the * correct number of untrusted certificates, since the DANE * logic in check_trust() depends on distinguishing CAs from * "the wire" from CAs from the trust store. In particular, the * certificate at depth "num" should be the new trusted * certificate with ctx->num_untrusted <= num. */ if (ok) { if (!ossl_assert(ctx->num_untrusted <= num)) goto int_err; search &= ~S_DOUNTRUSTED; trust = check_trust(ctx, num); if (trust != X509_TRUST_UNTRUSTED) break; if (!self_signed) continue; } } /* * No dispositive decision, and either self-signed or no match, if * we were doing untrusted-first, and alt-chains are not disabled, * do that, by repeatedly losing one untrusted element at a time, * and trying to extend the shorted chain. */ if ((search & S_DOUNTRUSTED) == 0) { /* Continue search for a trusted issuer of a shorter chain? */ if ((search & S_DOALTERNATE) != 0 && --alt_untrusted > 0) continue; /* Still no luck and no fallbacks left? */ if (!may_alternate || (search & S_DOALTERNATE) != 0 || ctx->num_untrusted < 2) break; /* Search for a trusted issuer of a shorter chain */ search |= S_DOALTERNATE; alt_untrusted = ctx->num_untrusted - 1; } } /* * Try to extend chain with peer-provided untrusted certificate */ if ((search & S_DOUNTRUSTED) != 0) { num = sk_X509_num(ctx->chain); if (!ossl_assert(num == ctx->num_untrusted)) goto int_err; curr = sk_X509_value(ctx->chain, num - 1); issuer = (X509_self_signed(curr, 0) > 0 || num > max_depth) ? NULL : find_issuer(ctx, sk_untrusted, curr); if (issuer == NULL) { /* * Once we have reached a self-signed cert or num > max_depth * or can't find an issuer in the untrusted list we stop looking * there and start looking only in the trust store if enabled. */ search &= ~S_DOUNTRUSTED; if (may_trusted) search |= S_DOTRUSTED; continue; } /* Drop this issuer from future consideration */ (void)sk_X509_delete_ptr(sk_untrusted, issuer); /* Grow the chain by untrusted issuer */ if (!X509_add_cert(ctx->chain, issuer, X509_ADD_FLAG_UP_REF)) goto int_err; ++ctx->num_untrusted; /* Check for DANE-TA trust of the topmost untrusted certificate. */ trust = check_dane_issuer(ctx, ctx->num_untrusted - 1); if (trust == X509_TRUST_TRUSTED || trust == X509_TRUST_REJECTED) break; } } sk_X509_free(sk_untrusted); if (trust < 0) /* internal error */ return trust; /* * Last chance to make a trusted chain, either bare DANE-TA public-key * signers, or else direct leaf PKIX trust. */ num = sk_X509_num(ctx->chain); if (num <= max_depth) { if (trust == X509_TRUST_UNTRUSTED && DANETLS_HAS_DANE_TA(dane)) trust = check_dane_pkeys(ctx); if (trust == X509_TRUST_UNTRUSTED && num == ctx->num_untrusted) trust = check_trust(ctx, num); } switch (trust) { case X509_TRUST_TRUSTED: return 1; case X509_TRUST_REJECTED: /* Callback already issued */ return 0; case X509_TRUST_UNTRUSTED: default: switch (ctx->error) { case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD: case X509_V_ERR_CERT_NOT_YET_VALID: case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD: case X509_V_ERR_CERT_HAS_EXPIRED: return 0; /* Callback already done by ossl_x509_check_cert_time() */ default: /* A preliminary error has become final */ return verify_cb_cert(ctx, NULL, num - 1, ctx->error); case X509_V_OK: break; } CB_FAIL_IF(num > max_depth, ctx, NULL, num - 1, X509_V_ERR_CERT_CHAIN_TOO_LONG); CB_FAIL_IF(DANETLS_ENABLED(dane) && (!DANETLS_HAS_PKIX(dane) || dane->pdpth >= 0), ctx, NULL, num - 1, X509_V_ERR_DANE_NO_MATCH); if (X509_self_signed(sk_X509_value(ctx->chain, num - 1), 0) > 0) return verify_cb_cert(ctx, NULL, num - 1, num == 1 ? X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT : X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN); return verify_cb_cert(ctx, NULL, num - 1, ctx->num_untrusted < num ? X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT : X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY); } int_err: ERR_raise(ERR_LIB_X509, ERR_R_INTERNAL_ERROR); ctx->error = X509_V_ERR_UNSPECIFIED; sk_X509_free(sk_untrusted); return -1; memerr: ctx->error = X509_V_ERR_OUT_OF_MEM; sk_X509_free(sk_untrusted); return -1; } STACK_OF(X509) *X509_build_chain(X509 *target, STACK_OF(X509) *certs, X509_STORE *store, int with_self_signed, OSSL_LIB_CTX *libctx, const char *propq) { int finish_chain = store != NULL; X509_STORE_CTX *ctx; int flags = X509_ADD_FLAG_UP_REF; STACK_OF(X509) *result = NULL; if (target == NULL) { ERR_raise(ERR_LIB_X509, ERR_R_PASSED_NULL_PARAMETER); return NULL; } if ((ctx = X509_STORE_CTX_new_ex(libctx, propq)) == NULL) return NULL; if (!X509_STORE_CTX_init(ctx, store, target, finish_chain ? certs : NULL)) goto err; if (!finish_chain) X509_STORE_CTX_set0_trusted_stack(ctx, certs); if (!ossl_x509_add_cert_new(&ctx->chain, target, X509_ADD_FLAG_UP_REF)) { ctx->error = X509_V_ERR_OUT_OF_MEM; goto err; } ctx->num_untrusted = 1; if (!build_chain(ctx) && finish_chain) goto err; /* result list to store the up_ref'ed certificates */ if (sk_X509_num(ctx->chain) > 1 && !with_self_signed) flags |= X509_ADD_FLAG_NO_SS; if (!ossl_x509_add_certs_new(&result, ctx->chain, flags)) { sk_X509_free(result); result = NULL; } err: X509_STORE_CTX_free(ctx); return result; } /* * note that there's a corresponding minbits_table in ssl/ssl_cert.c * in ssl_get_security_level_bits that's used for selection of DH parameters */ static const int minbits_table[] = { 80, 112, 128, 192, 256 }; static const int NUM_AUTH_LEVELS = OSSL_NELEM(minbits_table); /*- * Check whether the given public key meets the security level of `ctx`. * Returns 1 on success, 0 otherwise. */ static int check_key_level(X509_STORE_CTX *ctx, EVP_PKEY *pkey) { int level = ctx->param->auth_level; /* * At security level zero, return without checking for a supported public * key type. Some engines support key types not understood outside the * engine, and we only need to understand the key when enforcing a security * floor. */ if (level <= 0) return 1; /* Unsupported or malformed keys are not secure */ if (pkey == NULL) return 0; if (level > NUM_AUTH_LEVELS) level = NUM_AUTH_LEVELS; return EVP_PKEY_get_security_bits(pkey) >= minbits_table[level - 1]; } /*- * Check whether the public key of `cert` meets the security level of `ctx`. * Returns 1 on success, 0 otherwise. */ static int check_cert_key_level(X509_STORE_CTX *ctx, X509 *cert) { return check_key_level(ctx, X509_get0_pubkey(cert)); } /*- * Check whether the public key of ``cert`` does not use explicit params * for an elliptic curve. * * Returns 1 on success, 0 if check fails, -1 for other errors. */ static int check_curve(X509 *cert) { EVP_PKEY *pkey = X509_get0_pubkey(cert); int ret, val; /* Unsupported or malformed key */ if (pkey == NULL) return -1; if (EVP_PKEY_get_id(pkey) != EVP_PKEY_EC) return 1; ret = EVP_PKEY_get_int_param(pkey, OSSL_PKEY_PARAM_EC_DECODED_FROM_EXPLICIT_PARAMS, &val); return ret == 1 ? !val : -1; } /*- * Check whether the signature digest algorithm of ``cert`` meets the security * level of ``ctx``. Should not be checked for trust anchors (whether * self-signed or otherwise). * * Returns 1 on success, 0 otherwise. */ static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert) { int secbits = -1; int level = ctx->param->auth_level; if (level <= 0) return 1; if (level > NUM_AUTH_LEVELS) level = NUM_AUTH_LEVELS; if (!X509_get_signature_info(cert, NULL, NULL, &secbits, NULL)) return 0; return secbits >= minbits_table[level - 1]; }