crypto/dsa/dsa_asn1.c

   1 /* dsa_asn1.c */
   2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
   3  * project 2000.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 2000 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59 #include <stdio.h>
  60 #include "cryptlib.h"
  61 #include <openssl/dsa.h>
  62 #include <openssl/asn1.h>
  63 #include <openssl/asn1t.h>
  64 #include <openssl/bn.h>
  65 #include <openssl/rand.h>
  66 #ifdef OPENSSL_FIPS
  67 #include <openssl/fips.h>
  68 #endif
  69
  70
  71 /* Override the default new methods */
  72 static int sig_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it)
  73 {
  74         if(operation == ASN1_OP_NEW_PRE) {
  75                 DSA_SIG *sig;
  76                 sig = OPENSSL_malloc(sizeof(DSA_SIG));
  77                 sig->r = NULL;
  78                 sig->s = NULL;
  79                 *pval = (ASN1_VALUE *)sig;
  80                 if(sig) return 2;
  81                 DSAerr(DSA_F_SIG_CB, ERR_R_MALLOC_FAILURE);
  82                 return 0;
  83         }
  84         return 1;
  85 }
  86
  87 ASN1_SEQUENCE_cb(DSA_SIG, sig_cb) = {
  88         ASN1_SIMPLE(DSA_SIG, r, CBIGNUM),
  89         ASN1_SIMPLE(DSA_SIG, s, CBIGNUM)
  90 } ASN1_SEQUENCE_END_cb(DSA_SIG, DSA_SIG)
  91
  92 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA_SIG,DSA_SIG,DSA_SIG)
  93
  94 /* Override the default free and new methods */
  95 static int dsa_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it)
  96 {
  97         if(operation == ASN1_OP_NEW_PRE) {
  98                 *pval = (ASN1_VALUE *)DSA_new();
  99                 if(*pval) return 2;
 100                 return 0;
 101         } else if(operation == ASN1_OP_FREE_PRE) {
 102                 DSA_free((DSA *)*pval);
 103                 *pval = NULL;
 104                 return 2;
 105         }
 106         return 1;
 107 }
 108
 109 ASN1_SEQUENCE_cb(DSAPrivateKey, dsa_cb) = {
 110         ASN1_SIMPLE(DSA, version, LONG),
 111         ASN1_SIMPLE(DSA, p, BIGNUM),
 112         ASN1_SIMPLE(DSA, q, BIGNUM),
 113         ASN1_SIMPLE(DSA, g, BIGNUM),
 114         ASN1_SIMPLE(DSA, pub_key, BIGNUM),
 115         ASN1_SIMPLE(DSA, priv_key, BIGNUM)
 116 } ASN1_SEQUENCE_END_cb(DSA, DSAPrivateKey)
 117
 118 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAPrivateKey, DSAPrivateKey)
 119
 120 ASN1_SEQUENCE_cb(DSAparams, dsa_cb) = {
 121         ASN1_SIMPLE(DSA, p, BIGNUM),
 122         ASN1_SIMPLE(DSA, q, BIGNUM),
 123         ASN1_SIMPLE(DSA, g, BIGNUM),
 124 } ASN1_SEQUENCE_END_cb(DSA, DSAparams)
 125
 126 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAparams, DSAparams)
 127
 128 /* DSA public key is a bit trickier... its effectively a CHOICE type
 129  * decided by a field called write_params which can either write out
 130  * just the public key as an INTEGER or the parameters and public key
 131  * in a SEQUENCE
 132  */
 133
 134 ASN1_SEQUENCE(dsa_pub_internal) = {
 135         ASN1_SIMPLE(DSA, pub_key, BIGNUM),
 136         ASN1_SIMPLE(DSA, p, BIGNUM),
 137         ASN1_SIMPLE(DSA, q, BIGNUM),
 138         ASN1_SIMPLE(DSA, g, BIGNUM)
 139 } ASN1_SEQUENCE_END_name(DSA, dsa_pub_internal)
 140
 141 ASN1_CHOICE_cb(DSAPublicKey, dsa_cb) = {
 142         ASN1_SIMPLE(DSA, pub_key, BIGNUM),
 143         ASN1_EX_COMBINE(0, 0, dsa_pub_internal)
 144 } ASN1_CHOICE_END_cb(DSA, DSAPublicKey, write_params)
 145
 146 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAPublicKey, DSAPublicKey)
 147
 148 int DSA_sign(int type, const unsigned char *dgst, int dlen, unsigned char *sig,
 149              unsigned int *siglen, DSA *dsa)
 150         {
 151         DSA_SIG *s;
 152 #ifdef OPENSSL_FIPS
 153         if(FIPS_mode() && !(dsa->flags & DSA_FLAG_NON_FIPS_ALLOW))
 154                 {
 155                 DSAerr(DSA_F_DSA_SIGN, DSA_R_OPERATION_NOT_ALLOWED_IN_FIPS_MODE);
 156                 return 0;
 157                 }
 158 #endif
 159         RAND_seed(dgst, dlen);
 160         s=DSA_do_sign(dgst,dlen,dsa);
 161         if (s == NULL)
 162                 {
 163                 *siglen=0;
 164                 return(0);
 165                 }
 166         *siglen=i2d_DSA_SIG(s,&sig);
 167         DSA_SIG_free(s);
 168         return(1);
 169         }
 170
 171 int DSA_size(const DSA *r)
 172         {
 173         int ret,i;
 174         ASN1_INTEGER bs;
 175         unsigned char buf[4];   /* 4 bytes looks really small.
 176                                    However, i2d_ASN1_INTEGER() will not look
 177                                    beyond the first byte, as long as the second
 178                                    parameter is NULL. */
 179
 180         i=BN_num_bits(r->q);
 181         bs.length=(i+7)/8;
 182         bs.data=buf;
 183         bs.type=V_ASN1_INTEGER;
 184         /* If the top bit is set the asn1 encoding is 1 larger. */
 185         buf[0]=0xff;
 186
 187         i=i2d_ASN1_INTEGER(&bs,NULL);
 188         i+=i; /* r and s */
 189         ret=ASN1_object_size(1,i,V_ASN1_SEQUENCE);
 190         return(ret);
 191         }
 192
 193 /* data has already been hashed (probably with SHA or SHA-1). */
 194 /* returns
 195  *      1: correct signature
 196  *      0: incorrect signature
 197  *     -1: error
 198  */
 199 int DSA_verify(int type, const unsigned char *dgst, int dgst_len,
 200              const unsigned char *sigbuf, int siglen, DSA *dsa)
 201         {
 202         DSA_SIG *s;
 203         const unsigned char *p = sigbuf;
 204         unsigned char *der = NULL;
 205         int derlen = -1;
 206         int ret=-1;
 207
 208 #ifdef OPENSSL_FIPS
 209         if(FIPS_mode() && !(dsa->flags & DSA_FLAG_NON_FIPS_ALLOW))
 210                 {
 211                 DSAerr(DSA_F_DSA_VERIFY, DSA_R_OPERATION_NOT_ALLOWED_IN_FIPS_MODE);
 212                 return 0;
 213                 }
 214 #endif
 215
 216         s = DSA_SIG_new();
 217         if (s == NULL) return(ret);
 218         if (d2i_DSA_SIG(&s,&p,siglen) == NULL) goto err;
 219         /* Ensure signature uses DER and doesn't have trailing garbage */
 220         derlen = i2d_DSA_SIG(s, &der);
 221         if (derlen != siglen || memcmp(sigbuf, der, derlen))
 222                 goto err;
 223         ret=DSA_do_verify(dgst,dgst_len,s,dsa);
 224 err:
 225         if (derlen > 0)
 226                 {
 227                 OPENSSL_cleanse(der, derlen);
 228                 OPENSSL_free(der);
 229                 }
 230         DSA_SIG_free(s);
 231         return(ret);
 232         }