crypto/dsa/dsa_asn1.c

   1 /* dsa_asn1.c */
   2 /*
   3  * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
   4  * 2000.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    licensing@OpenSSL.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59
  60 #include <stdio.h>
  61 #include "cryptlib.h"
  62 #include <openssl/dsa.h>
  63 #include <openssl/asn1.h>
  64 #include <openssl/asn1t.h>
  65 #include <openssl/rand.h>
  66
  67 /* Override the default new methods */
  68 static int sig_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
  69                   void *exarg)
  70 {
  71     if (operation == ASN1_OP_NEW_PRE) {
  72         DSA_SIG *sig;
  73         sig = OPENSSL_malloc(sizeof(DSA_SIG));
  74         if (!sig) {
  75             DSAerr(DSA_F_SIG_CB, ERR_R_MALLOC_FAILURE);
  76             return 0;
  77         }
  78         sig->r = NULL;
  79         sig->s = NULL;
  80         *pval = (ASN1_VALUE *)sig;
  81         return 2;
  82     }
  83     return 1;
  84 }
  85
  86 ASN1_SEQUENCE_cb(DSA_SIG, sig_cb) = {
  87         ASN1_SIMPLE(DSA_SIG, r, CBIGNUM),
  88         ASN1_SIMPLE(DSA_SIG, s, CBIGNUM)
  89 } ASN1_SEQUENCE_END_cb(DSA_SIG, DSA_SIG)
  90
  91 IMPLEMENT_ASN1_FUNCTIONS_const(DSA_SIG)
  92
  93 /* Override the default free and new methods */
  94 static int dsa_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
  95                   void *exarg)
  96 {
  97     if (operation == ASN1_OP_NEW_PRE) {
  98         *pval = (ASN1_VALUE *)DSA_new();
  99         if (*pval)
 100             return 2;
 101         return 0;
 102     } else if (operation == ASN1_OP_FREE_PRE) {
 103         DSA_free((DSA *)*pval);
 104         *pval = NULL;
 105         return 2;
 106     }
 107     return 1;
 108 }
 109
 110 ASN1_SEQUENCE_cb(DSAPrivateKey, dsa_cb) = {
 111         ASN1_SIMPLE(DSA, version, LONG),
 112         ASN1_SIMPLE(DSA, p, BIGNUM),
 113         ASN1_SIMPLE(DSA, q, BIGNUM),
 114         ASN1_SIMPLE(DSA, g, BIGNUM),
 115         ASN1_SIMPLE(DSA, pub_key, BIGNUM),
 116         ASN1_SIMPLE(DSA, priv_key, BIGNUM)
 117 } ASN1_SEQUENCE_END_cb(DSA, DSAPrivateKey)
 118
 119 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAPrivateKey, DSAPrivateKey)
 120
 121 ASN1_SEQUENCE_cb(DSAparams, dsa_cb) = {
 122         ASN1_SIMPLE(DSA, p, BIGNUM),
 123         ASN1_SIMPLE(DSA, q, BIGNUM),
 124         ASN1_SIMPLE(DSA, g, BIGNUM),
 125 } ASN1_SEQUENCE_END_cb(DSA, DSAparams)
 126
 127 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAparams, DSAparams)
 128
 129 /*
 130  * DSA public key is a bit trickier... its effectively a CHOICE type decided
 131  * by a field called write_params which can either write out just the public
 132  * key as an INTEGER or the parameters and public key in a SEQUENCE
 133  */
 134
 135 ASN1_SEQUENCE(DSAPublicKey) = {
 136         ASN1_SIMPLE(DSA, pub_key, BIGNUM),
 137         ASN1_SIMPLE(DSA, p, BIGNUM),
 138         ASN1_SIMPLE(DSA, q, BIGNUM),
 139         ASN1_SIMPLE(DSA, g, BIGNUM)
 140 } ASN1_SEQUENCE_END_name(DSA, DSAPublicKey)
 141
 142 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAPublicKey, DSAPublicKey)
 143
 144 DSA *DSAparams_dup(DSA *dsa)
 145 {
 146     return ASN1_item_dup(ASN1_ITEM_rptr(DSAparams), dsa);
 147 }
 148
 149 int DSA_sign(int type, const unsigned char *dgst, int dlen,
 150              unsigned char *sig, unsigned int *siglen, DSA *dsa)
 151 {
 152     DSA_SIG *s;
 153     RAND_seed(dgst, dlen);
 154     s = DSA_do_sign(dgst, dlen, dsa);
 155     if (s == NULL) {
 156         *siglen = 0;
 157         return (0);
 158     }
 159     *siglen = i2d_DSA_SIG(s, &sig);
 160     DSA_SIG_free(s);
 161     return (1);
 162 }
 163
 164 /* data has already been hashed (probably with SHA or SHA-1). */
 165 /*-
 166  * returns
 167  *      1: correct signature
 168  *      0: incorrect signature
 169  *     -1: error
 170  */
 171 int DSA_verify(int type, const unsigned char *dgst, int dgst_len,
 172                const unsigned char *sigbuf, int siglen, DSA *dsa)
 173 {
 174     DSA_SIG *s;
 175     const unsigned char *p = sigbuf;
 176     unsigned char *der = NULL;
 177     int derlen = -1;
 178     int ret = -1;
 179
 180     s = DSA_SIG_new();
 181     if (s == NULL)
 182         return (ret);
 183     if (d2i_DSA_SIG(&s, &p, siglen) == NULL)
 184         goto err;
 185     /* Ensure signature uses DER and doesn't have trailing garbage */
 186     derlen = i2d_DSA_SIG(s, &der);
 187     if (derlen != siglen || memcmp(sigbuf, der, derlen))
 188         goto err;
 189     ret = DSA_do_verify(dgst, dgst_len, s, dsa);
 190  err:
 191     if (derlen > 0) {
 192         OPENSSL_cleanse(der, derlen);
 193         OPENSSL_free(der);
 194     }
 195     DSA_SIG_free(s);
 196     return (ret);
 197 }