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- /* fips_dsa_sign.c */
- /*
- * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
- * 2007.
- */
- /* ====================================================================
- * Copyright (c) 2007 The OpenSSL Project. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- *
- * 3. All advertising materials mentioning features or use of this
- * software must display the following acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
- *
- * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
- * endorse or promote products derived from this software without
- * prior written permission. For written permission, please contact
- * licensing@OpenSSL.org.
- *
- * 5. Products derived from this software may not be called "OpenSSL"
- * nor may "OpenSSL" appear in their names without prior written
- * permission of the OpenSSL Project.
- *
- * 6. Redistributions of any form whatsoever must retain the following
- * acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
- *
- * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
- * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- * ====================================================================
- *
- * This product includes cryptographic software written by Eric Young
- * (eay@cryptsoft.com). This product includes software written by Tim
- * Hudson (tjh@cryptsoft.com).
- *
- */
- #include <string.h>
- #include <openssl/evp.h>
- #include <openssl/dsa.h>
- #include <openssl/err.h>
- #include <openssl/sha.h>
- #include <openssl/bn.h>
- #ifdef OPENSSL_FIPS
- /*
- * FIPS versions of DSA_sign() and DSA_verify(). These include a tiny ASN1
- * encoder/decoder to handle the specific case of a DSA signature.
- */
- # if 0
- int FIPS_dsa_size(DSA *r)
- {
- int ilen;
- ilen = BN_num_bytes(r->q);
- if (ilen > 20)
- return -1;
- /* If MSB set need padding byte */
- ilen++;
- /*
- * Also need 2 bytes INTEGER header for r and s plus 2 bytes SEQUENCE
- * header making 6 in total.
- */
- return ilen * 2 + 6;
- }
- # endif
- /*
- * Tiny ASN1 encoder for DSA_SIG structure. We can assume r, s smaller than
- * 0x80 octets as by the DSA standards they will be less than 2^160
- */
- int FIPS_dsa_sig_encode(unsigned char *out, DSA_SIG *sig)
- {
- int rlen, slen, rpad, spad, seqlen;
- rlen = BN_num_bytes(sig->r);
- if (rlen > 20)
- return -1;
- if (BN_num_bits(sig->r) & 0x7)
- rpad = 0;
- else
- rpad = 1;
- slen = BN_num_bytes(sig->s);
- if (slen > 20)
- return -1;
- if (BN_num_bits(sig->s) & 0x7)
- spad = 0;
- else
- spad = 1;
- /* Length of SEQUENCE, (1 tag + 1 len octet) * 2 + content octets */
- seqlen = rlen + rpad + slen + spad + 4;
- /* Actual encoded length: include SEQUENCE header */
- if (!out)
- return seqlen + 2;
- /* Output SEQUENCE header */
- *out++ = V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED;
- *out++ = (unsigned char)seqlen;
- /* Output r */
- *out++ = V_ASN1_INTEGER;
- *out++ = (unsigned char)(rlen + rpad);
- if (rpad)
- *out++ = 0;
- BN_bn2bin(sig->r, out);
- out += rlen;
- /* Output s */
- *out++ = V_ASN1_INTEGER;
- *out++ = (unsigned char)(slen + spad);
- if (spad)
- *out++ = 0;
- BN_bn2bin(sig->s, out);
- return seqlen + 2;
- }
- /* Companion DSA_SIG decoder */
- int FIPS_dsa_sig_decode(DSA_SIG *sig, const unsigned char *in, int inlen)
- {
- int seqlen, rlen, slen;
- const unsigned char *rbin;
- /* Sanity check */
- /* Need SEQUENCE tag */
- if (*in++ != (V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED))
- return 0;
- /* Get length octet */
- seqlen = *in++;
- /* Check sensible length value */
- if (seqlen < 4 || seqlen > 0x7F)
- return 0;
- /* Check INTEGER tag */
- if (*in++ != V_ASN1_INTEGER)
- return 0;
- rlen = *in++;
- seqlen -= 2 + rlen;
- /* Check sensible seqlen value */
- if (seqlen < 2)
- return 0;
- rbin = in;
- in += rlen;
- /* Check INTEGER tag */
- if (*in++ != V_ASN1_INTEGER)
- return 0;
- slen = *in++;
- /*
- * Remaining bytes of SEQUENCE should exactly match encoding of s
- */
- if (seqlen != (slen + 2))
- return 0;
- if (!sig->r && !(sig->r = BN_new()))
- return 0;
- if (!sig->s && !(sig->s = BN_new()))
- return 0;
- if (!BN_bin2bn(rbin, rlen, sig->r))
- return 0;
- if (!BN_bin2bn(in, slen, sig->s))
- return 0;
- return 1;
- }
- static int fips_dsa_sign(int type, const unsigned char *x, int y,
- unsigned char *sig, unsigned int *siglen,
- EVP_MD_SVCTX * sv)
- {
- DSA *dsa = sv->key;
- unsigned char dig[EVP_MAX_MD_SIZE];
- unsigned int dlen;
- DSA_SIG *s;
- EVP_DigestFinal_ex(sv->mctx, dig, &dlen);
- s = dsa->meth->dsa_do_sign(dig, dlen, dsa);
- OPENSSL_cleanse(dig, dlen);
- if (s == NULL) {
- *siglen = 0;
- return 0;
- }
- *siglen = FIPS_dsa_sig_encode(sig, s);
- DSA_SIG_free(s);
- if (*siglen < 0)
- return 0;
- return 1;
- }
- static int fips_dsa_verify(int type, const unsigned char *x, int y,
- const unsigned char *sigbuf, unsigned int siglen,
- EVP_MD_SVCTX * sv)
- {
- DSA *dsa = sv->key;
- DSA_SIG *s;
- int ret = -1;
- unsigned char dig[EVP_MAX_MD_SIZE];
- unsigned int dlen;
- s = DSA_SIG_new();
- if (s == NULL)
- return ret;
- if (!FIPS_dsa_sig_decode(s, sigbuf, siglen))
- goto err;
- EVP_DigestFinal_ex(sv->mctx, dig, &dlen);
- ret = dsa->meth->dsa_do_verify(dig, dlen, s, dsa);
- OPENSSL_cleanse(dig, dlen);
- err:
- DSA_SIG_free(s);
- return ret;
- }
- static int init(EVP_MD_CTX *ctx)
- {
- return SHA1_Init(ctx->md_data);
- }
- static int update(EVP_MD_CTX *ctx, const void *data, size_t count)
- {
- return SHA1_Update(ctx->md_data, data, count);
- }
- static int final(EVP_MD_CTX *ctx, unsigned char *md)
- {
- return SHA1_Final(md, ctx->md_data);
- }
- static const EVP_MD dss1_md = {
- NID_dsa,
- NID_dsaWithSHA1,
- SHA_DIGEST_LENGTH,
- EVP_MD_FLAG_FIPS | EVP_MD_FLAG_SVCTX,
- init,
- update,
- final,
- NULL,
- NULL,
- (evp_sign_method *) fips_dsa_sign,
- (evp_verify_method *) fips_dsa_verify,
- {EVP_PKEY_DSA, EVP_PKEY_DSA2, EVP_PKEY_DSA3, EVP_PKEY_DSA4, 0},
- SHA_CBLOCK,
- sizeof(EVP_MD *) + sizeof(SHA_CTX),
- };
- const EVP_MD *EVP_dss1(void)
- {
- return (&dss1_md);
- }
- #endif
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