providers/common/signature/dsa.c

   1 /*
   2  * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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 <openssl/crypto.h>
  11 #include <openssl/core_numbers.h>
  12 #include <openssl/core_names.h>
  13 #include <openssl/dsa.h>
  14 #include <openssl/params.h>
  15 #include "internal/provider_algs.h"
  16
  17 static OSSL_OP_signature_newctx_fn dsa_newctx;
  18 static OSSL_OP_signature_sign_init_fn dsa_sign_init;
  19 static OSSL_OP_signature_sign_fn dsa_sign;
  20 static OSSL_OP_signature_freectx_fn dsa_freectx;
  21 static OSSL_OP_signature_dupctx_fn dsa_dupctx;
  22 static OSSL_OP_signature_set_params_fn dsa_set_params;
  23
  24 /*
  25  * What's passed as an actual key is defined by the KEYMGMT interface.
  26  * We happen to know that our KEYMGMT simply passes DSA structures, so
  27  * we use that here too.
  28  */
  29
  30 typedef struct {
  31     DSA *dsa;
  32     size_t mdsize;
  33 } PROV_DSA_CTX;
  34
  35 static void *dsa_newctx(void *provctx)
  36 {
  37     return OPENSSL_zalloc(sizeof(PROV_DSA_CTX));
  38 }
  39
  40 static int dsa_sign_init(void *vpdsactx, void *vdsa)
  41 {
  42     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
  43
  44     if (pdsactx == NULL || vdsa == NULL || !DSA_up_ref(vdsa))
  45         return 0;
  46     DSA_free(pdsactx->dsa);
  47     pdsactx->dsa = vdsa;
  48     return 1;
  49 }
  50
  51 static int dsa_sign(void *vpdsactx, unsigned char *sig, size_t *siglen,
  52                     size_t sigsize, const unsigned char *tbs, size_t tbslen)
  53 {
  54     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
  55     int ret;
  56     unsigned int sltmp;
  57     size_t dsasize = DSA_size(pdsactx->dsa);
  58
  59     if (sig == NULL) {
  60         *siglen = dsasize;
  61         return 1;
  62     }
  63
  64     if (sigsize < (size_t)dsasize)
  65         return 0;
  66
  67     if (pdsactx->mdsize != 0 && tbslen != pdsactx->mdsize)
  68         return 0;
  69
  70     ret = DSA_sign(0, tbs, tbslen, sig, &sltmp, pdsactx-> dsa);
  71
  72     if (ret <= 0)
  73         return 0;
  74
  75     *siglen = sltmp;
  76     return 1;
  77 }
  78
  79 static void dsa_freectx(void *vpdsactx)
  80 {
  81     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
  82
  83     DSA_free(pdsactx->dsa);
  84
  85     OPENSSL_free(pdsactx);
  86 }
  87
  88 static void *dsa_dupctx(void *vpdsactx)
  89 {
  90     PROV_DSA_CTX *srcctx = (PROV_DSA_CTX *)vpdsactx;
  91     PROV_DSA_CTX *dstctx;
  92
  93     dstctx = OPENSSL_zalloc(sizeof(*srcctx));
  94     if (dstctx == NULL)
  95         return NULL;
  96
  97     *dstctx = *srcctx;
  98     if (dstctx->dsa != NULL && !DSA_up_ref(dstctx->dsa)) {
  99         OPENSSL_free(dstctx);
 100         return NULL;
 101     }
 102
 103     return dstctx;
 104 }
 105
 106 static int dsa_set_params(void *vpdsactx, const OSSL_PARAM params[])
 107 {
 108     PROV_DSA_CTX *pdsactx = (PROV_DSA_CTX *)vpdsactx;
 109     const OSSL_PARAM *p;
 110     size_t mdsize;
 111
 112     if (pdsactx == NULL || params == NULL)
 113         return 0;
 114
 115     p = OSSL_PARAM_locate_const(params, OSSL_SIGNATURE_PARAM_DIGEST_SIZE);
 116     if (p == NULL || !OSSL_PARAM_get_size_t(p, &mdsize))
 117         return 0;
 118
 119     pdsactx->mdsize = mdsize;
 120
 121     return 1;
 122 }
 123
 124 const OSSL_DISPATCH dsa_signature_functions[] = {
 125     { OSSL_FUNC_SIGNATURE_NEWCTX, (void (*)(void))dsa_newctx },
 126     { OSSL_FUNC_SIGNATURE_SIGN_INIT, (void (*)(void))dsa_sign_init },
 127     { OSSL_FUNC_SIGNATURE_SIGN, (void (*)(void))dsa_sign },
 128     { OSSL_FUNC_SIGNATURE_FREECTX, (void (*)(void))dsa_freectx },
 129     { OSSL_FUNC_SIGNATURE_DUPCTX, (void (*)(void))dsa_dupctx },
 130     { OSSL_FUNC_SIGNATURE_SET_PARAMS, (void (*)(void))dsa_set_params },
 131     { 0, NULL }
 132 };