From eb9d4fdf1846e688d51d86a9a50f0312aca2af25 Mon Sep 17 00:00:00 2001 From: Glenn Strauss Date: Sun, 23 Oct 2022 19:48:18 -0400 Subject: [PATCH] x509 crt verify SAN iPAddress Signed-off-by: Glenn Strauss --- include/mbedtls/x509_crt.h | 2 +- library/x509_crt.c | 126 ++++++++++++++++++++++++++++++------- 2 files changed, 103 insertions(+), 25 deletions(-) --- a/include/mbedtls/x509_crt.h +++ b/include/mbedtls/x509_crt.h @@ -608,7 +608,7 @@ int mbedtls_x509_crt_verify_info(char *b * \param cn The expected Common Name. This will be checked to be * present in the certificate's subjectAltNames extension or, * if this extension is absent, as a CN component in its - * Subject name. Currently only DNS names are supported. This + * Subject name. DNS names and IP addresses are supported. This * may be \c NULL if the CN need not be verified. * \param flags The address at which to store the result of the verification. * If the verification couldn't be completed, the flag value is --- a/library/x509_crt.c +++ b/library/x509_crt.c @@ -57,6 +57,10 @@ #if defined(MBEDTLS_HAVE_TIME) #if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32) +#define WIN32_LEAN_AND_MEAN +#ifndef _WIN32_WINNT +#define _WIN32_WINNT 0x0600 +#endif #include #else #include @@ -3002,6 +3006,61 @@ find_parent: } } +#ifdef _WIN32 +#ifdef _MSC_VER +#pragma comment(lib, "ws2_32.lib") +#include +#include +#elif (defined(__MINGW32__) || defined(__MINGW64__)) && _WIN32_WINNT >= 0x0600 +#include +#include +#endif +#elif defined(__sun) +/* Solaris requires -lsocket -lnsl for inet_pton() */ +#elif defined(__has_include) +#if __has_include() +#include +#endif +#if __has_include() +#include +#endif +#endif + +/* Use whether or not AF_INET6 is defined to indicate whether or not to use + * the platform inet_pton() or a local implementation (below). The local + * implementation may be used even in cases where the platform provides + * inet_pton(), e.g. when there are different includes required and/or the + * platform implementation requires dependencies on additional libraries. + * Specifically, Windows requires custom includes and additional link + * dependencies, and Solaris requires additional link dependencies. + * Also, as a coarse heuristic, use the local implementation if the compiler + * does not support __has_include(), or if the definition of AF_INET6 is not + * provided by headers included (or not) via __has_include() above. */ +#ifndef AF_INET6 + +#define x509_cn_inet_pton(cn, dst) (0) + +#else + +static int x509_inet_pton_ipv6(const char *src, void *dst) +{ + return inet_pton(AF_INET6, src, dst) == 1 ? 0 : -1; +} + +static int x509_inet_pton_ipv4(const char *src, void *dst) +{ + return inet_pton(AF_INET, src, dst) == 1 ? 0 : -1; +} + +#endif /* AF_INET6 */ + +static size_t x509_cn_inet_pton(const char *cn, void *dst) +{ + return strchr(cn, ':') == NULL + ? x509_inet_pton_ipv4(cn, dst) == 0 ? 4 : 0 + : x509_inet_pton_ipv6(cn, dst) == 0 ? 16 : 0; +} + /* * Check for CN match */ @@ -3022,24 +3081,51 @@ static int x509_crt_check_cn(const mbedt return -1; } +static int x509_crt_check_san_ip(const mbedtls_x509_sequence *san, + const char *cn, size_t cn_len) +{ + uint32_t ip[4]; + cn_len = x509_cn_inet_pton(cn, ip); + if (cn_len == 0) { + return -1; + } + + for (const mbedtls_x509_sequence *cur = san; cur != NULL; cur = cur->next) { + const unsigned char san_type = (unsigned char) cur->buf.tag & + MBEDTLS_ASN1_TAG_VALUE_MASK; + if (san_type == MBEDTLS_X509_SAN_IP_ADDRESS && + cur->buf.len == cn_len && memcmp(cur->buf.p, ip, cn_len) == 0) { + return 0; + } + } + + return -1; +} + /* * Check for SAN match, see RFC 5280 Section 4.2.1.6 */ -static int x509_crt_check_san(const mbedtls_x509_buf *name, +static int x509_crt_check_san(const mbedtls_x509_sequence *san, const char *cn, size_t cn_len) { - const unsigned char san_type = (unsigned char) name->tag & - MBEDTLS_ASN1_TAG_VALUE_MASK; - - /* dNSName */ - if (san_type == MBEDTLS_X509_SAN_DNS_NAME) { - return x509_crt_check_cn(name, cn, cn_len); + int san_ip = 0; + for (const mbedtls_x509_sequence *cur = san; cur != NULL; cur = cur->next) { + switch ((unsigned char) cur->buf.tag & MBEDTLS_ASN1_TAG_VALUE_MASK) { + case MBEDTLS_X509_SAN_DNS_NAME: /* dNSName */ + if (x509_crt_check_cn(&cur->buf, cn, cn_len) == 0) { + return 0; + } + break; + case MBEDTLS_X509_SAN_IP_ADDRESS: /* iPAddress */ + san_ip = 1; + break; + /* (We may handle other types here later.) */ + default: /* Unrecognized type */ + break; + } } - /* (We may handle other types here later.) */ - - /* Unrecognized type */ - return -1; + return san_ip ? x509_crt_check_san_ip(san, cn, cn_len) : -1; } /* @@ -3050,31 +3136,23 @@ static void x509_crt_verify_name(const m uint32_t *flags) { const mbedtls_x509_name *name; - const mbedtls_x509_sequence *cur; size_t cn_len = strlen(cn); if (crt->ext_types & MBEDTLS_X509_EXT_SUBJECT_ALT_NAME) { - for (cur = &crt->subject_alt_names; cur != NULL; cur = cur->next) { - if (x509_crt_check_san(&cur->buf, cn, cn_len) == 0) { - break; - } - } - - if (cur == NULL) { - *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH; + if (x509_crt_check_san(&crt->subject_alt_names, cn, cn_len) == 0) { + return; } } else { for (name = &crt->subject; name != NULL; name = name->next) { if (MBEDTLS_OID_CMP(MBEDTLS_OID_AT_CN, &name->oid) == 0 && x509_crt_check_cn(&name->val, cn, cn_len) == 0) { - break; + return; } } - if (name == NULL) { - *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH; - } } + + *flags |= MBEDTLS_X509_BADCERT_CN_MISMATCH; } /*