crypto/dsa/dsa_asn1.c

   1 /*
   2  * Copyright 1999-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <stdio.h>
  11 #include "internal/cryptlib.h"
  12 #include "dsa_locl.h"
  13 #include <openssl/asn1.h>
  14 #include <openssl/asn1t.h>
  15 #include <openssl/rand.h>
  16
  17 ASN1_SEQUENCE(DSA_SIG) = {
  18         ASN1_SIMPLE(DSA_SIG, r, CBIGNUM),
  19         ASN1_SIMPLE(DSA_SIG, s, CBIGNUM)
  20 } static_ASN1_SEQUENCE_END(DSA_SIG)
  21
  22 IMPLEMENT_ASN1_FUNCTIONS_const(DSA_SIG)
  23
  24 void DSA_SIG_get0(const DSA_SIG *sig, const BIGNUM **pr, const BIGNUM **ps)
  25 {
  26     if (pr != NULL)
  27         *pr = sig->r;
  28     if (ps != NULL)
  29         *ps = sig->s;
  30 }
  31
  32 int DSA_SIG_set0(DSA_SIG *sig, BIGNUM *r, BIGNUM *s)
  33 {
  34     if (r == NULL || s == NULL)
  35         return 0;
  36     BN_clear_free(sig->r);
  37     BN_clear_free(sig->s);
  38     sig->r = r;
  39     sig->s = s;
  40     return 1;
  41 }
  42
  43 /* Override the default free and new methods */
  44 static int dsa_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
  45                   void *exarg)
  46 {
  47     if (operation == ASN1_OP_NEW_PRE) {
  48         *pval = (ASN1_VALUE *)DSA_new();
  49         if (*pval != NULL)
  50             return 2;
  51         return 0;
  52     } else if (operation == ASN1_OP_FREE_PRE) {
  53         DSA_free((DSA *)*pval);
  54         *pval = NULL;
  55         return 2;
  56     }
  57     return 1;
  58 }
  59
  60 ASN1_SEQUENCE_cb(DSAPrivateKey, dsa_cb) = {
  61         ASN1_SIMPLE(DSA, version, LONG),
  62         ASN1_SIMPLE(DSA, p, BIGNUM),
  63         ASN1_SIMPLE(DSA, q, BIGNUM),
  64         ASN1_SIMPLE(DSA, g, BIGNUM),
  65         ASN1_SIMPLE(DSA, pub_key, BIGNUM),
  66         ASN1_SIMPLE(DSA, priv_key, CBIGNUM)
  67 } static_ASN1_SEQUENCE_END_cb(DSA, DSAPrivateKey)
  68
  69 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAPrivateKey, DSAPrivateKey)
  70
  71 ASN1_SEQUENCE_cb(DSAparams, dsa_cb) = {
  72         ASN1_SIMPLE(DSA, p, BIGNUM),
  73         ASN1_SIMPLE(DSA, q, BIGNUM),
  74         ASN1_SIMPLE(DSA, g, BIGNUM),
  75 } static_ASN1_SEQUENCE_END_cb(DSA, DSAparams)
  76
  77 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAparams, DSAparams)
  78
  79 ASN1_SEQUENCE_cb(DSAPublicKey, dsa_cb) = {
  80         ASN1_SIMPLE(DSA, pub_key, BIGNUM),
  81         ASN1_SIMPLE(DSA, p, BIGNUM),
  82         ASN1_SIMPLE(DSA, q, BIGNUM),
  83         ASN1_SIMPLE(DSA, g, BIGNUM)
  84 } static_ASN1_SEQUENCE_END_cb(DSA, DSAPublicKey)
  85
  86 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(DSA, DSAPublicKey, DSAPublicKey)
  87
  88 DSA *DSAparams_dup(DSA *dsa)
  89 {
  90     return ASN1_item_dup(ASN1_ITEM_rptr(DSAparams), dsa);
  91 }
  92
  93 int DSA_sign(int type, const unsigned char *dgst, int dlen,
  94              unsigned char *sig, unsigned int *siglen, DSA *dsa)
  95 {
  96     DSA_SIG *s;
  97     RAND_seed(dgst, dlen);
  98     s = DSA_do_sign(dgst, dlen, dsa);
  99     if (s == NULL) {
 100         *siglen = 0;
 101         return (0);
 102     }
 103     *siglen = i2d_DSA_SIG(s, &sig);
 104     DSA_SIG_free(s);
 105     return (1);
 106 }
 107
 108 /* data has already been hashed (probably with SHA or SHA-1). */
 109 /*-
 110  * returns
 111  *      1: correct signature
 112  *      0: incorrect signature
 113  *     -1: error
 114  */
 115 int DSA_verify(int type, const unsigned char *dgst, int dgst_len,
 116                const unsigned char *sigbuf, int siglen, DSA *dsa)
 117 {
 118     DSA_SIG *s;
 119     const unsigned char *p = sigbuf;
 120     unsigned char *der = NULL;
 121     int derlen = -1;
 122     int ret = -1;
 123
 124     s = DSA_SIG_new();
 125     if (s == NULL)
 126         return (ret);
 127     if (d2i_DSA_SIG(&s, &p, siglen) == NULL)
 128         goto err;
 129     /* Ensure signature uses DER and doesn't have trailing garbage */
 130     derlen = i2d_DSA_SIG(s, &der);
 131     if (derlen != siglen || memcmp(sigbuf, der, derlen))
 132         goto err;
 133     ret = DSA_do_verify(dgst, dgst_len, s, dsa);
 134  err:
 135     OPENSSL_clear_free(der, derlen);
 136     DSA_SIG_free(s);
 137     return (ret);
 138 }