/* 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