crypto/ec/ecx_key.c

   1 /*
   2  * Copyright 2020-2021 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 <string.h>
  11 #include <openssl/err.h>
  12 #include <openssl/proverr.h>
  13 #include "crypto/ecx.h"
  14 #include "internal/common.h" /* for ossl_assert() */
  15
  16 #ifdef S390X_EC_ASM
  17 # include "s390x_arch.h"
  18 #endif
  19
  20 ECX_KEY *ossl_ecx_key_new(OSSL_LIB_CTX *libctx, ECX_KEY_TYPE type, int haspubkey,
  21                           const char *propq)
  22 {
  23     ECX_KEY *ret = OPENSSL_zalloc(sizeof(*ret));
  24
  25     if (ret == NULL)
  26         return NULL;
  27
  28     ret->libctx = libctx;
  29     ret->haspubkey = haspubkey;
  30     switch (type) {
  31     case ECX_KEY_TYPE_X25519:
  32         ret->keylen = X25519_KEYLEN;
  33         break;
  34     case ECX_KEY_TYPE_X448:
  35         ret->keylen = X448_KEYLEN;
  36         break;
  37     case ECX_KEY_TYPE_ED25519:
  38         ret->keylen = ED25519_KEYLEN;
  39         break;
  40     case ECX_KEY_TYPE_ED448:
  41         ret->keylen = ED448_KEYLEN;
  42         break;
  43     }
  44     ret->type = type;
  45
  46     if (!CRYPTO_NEW_REF(&ret->references, 1))
  47         goto err;
  48
  49     if (propq != NULL) {
  50         ret->propq = OPENSSL_strdup(propq);
  51         if (ret->propq == NULL)
  52             goto err;
  53     }
  54     return ret;
  55 err:
  56     if (ret != NULL) {
  57         OPENSSL_free(ret->propq);
  58         CRYPTO_FREE_REF(&ret->references);
  59     }
  60     OPENSSL_free(ret);
  61     return NULL;
  62 }
  63
  64 void ossl_ecx_key_free(ECX_KEY *key)
  65 {
  66     int i;
  67
  68     if (key == NULL)
  69         return;
  70
  71     CRYPTO_DOWN_REF(&key->references, &i);
  72     REF_PRINT_COUNT("ECX_KEY", key);
  73     if (i > 0)
  74         return;
  75     REF_ASSERT_ISNT(i < 0);
  76
  77     OPENSSL_free(key->propq);
  78     OPENSSL_secure_clear_free(key->privkey, key->keylen);
  79     CRYPTO_FREE_REF(&key->references);
  80     OPENSSL_free(key);
  81 }
  82
  83 void ossl_ecx_key_set0_libctx(ECX_KEY *key, OSSL_LIB_CTX *libctx)
  84 {
  85     key->libctx = libctx;
  86 }
  87
  88 int ossl_ecx_key_up_ref(ECX_KEY *key)
  89 {
  90     int i;
  91
  92     if (CRYPTO_UP_REF(&key->references, &i) <= 0)
  93         return 0;
  94
  95     REF_PRINT_COUNT("ECX_KEY", key);
  96     REF_ASSERT_ISNT(i < 2);
  97     return ((i > 1) ? 1 : 0);
  98 }
  99
 100 unsigned char *ossl_ecx_key_allocate_privkey(ECX_KEY *key)
 101 {
 102     key->privkey = OPENSSL_secure_zalloc(key->keylen);
 103
 104     return key->privkey;
 105 }
 106
 107 int ossl_ecx_compute_key(ECX_KEY *peer, ECX_KEY *priv, size_t keylen,
 108                          unsigned char *secret, size_t *secretlen, size_t outlen)
 109 {
 110     if (priv == NULL
 111             || priv->privkey == NULL
 112             || peer == NULL) {
 113         ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY);
 114         return 0;
 115     }
 116
 117     if (!ossl_assert(keylen == X25519_KEYLEN
 118             || keylen == X448_KEYLEN)) {
 119         ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
 120         return 0;
 121     }
 122
 123     if (secret == NULL) {
 124         *secretlen = keylen;
 125         return 1;
 126     }
 127     if (outlen < keylen) {
 128         ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL);
 129         return 0;
 130     }
 131
 132     if (keylen == X25519_KEYLEN) {
 133 #ifdef S390X_EC_ASM
 134         if (OPENSSL_s390xcap_P.pcc[1]
 135                 & S390X_CAPBIT(S390X_SCALAR_MULTIPLY_X25519)) {
 136             if (s390x_x25519_mul(secret, peer->pubkey, priv->privkey) == 0) {
 137                 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_DURING_DERIVATION);
 138                 return 0;
 139             }
 140         } else
 141 #endif
 142         if (ossl_x25519(secret, priv->privkey, peer->pubkey) == 0) {
 143             ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_DURING_DERIVATION);
 144             return 0;
 145         }
 146     } else {
 147 #ifdef S390X_EC_ASM
 148         if (OPENSSL_s390xcap_P.pcc[1]
 149                 & S390X_CAPBIT(S390X_SCALAR_MULTIPLY_X448)) {
 150             if (s390x_x448_mul(secret, peer->pubkey, priv->privkey) == 0) {
 151                 ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_DURING_DERIVATION);
 152                 return 0;
 153             }
 154         } else
 155 #endif
 156         if (ossl_x448(secret, priv->privkey, peer->pubkey) == 0) {
 157             ERR_raise(ERR_LIB_PROV, PROV_R_FAILED_DURING_DERIVATION);
 158             return 0;
 159         }
 160     }
 161     *secretlen = keylen;
 162     return 1;
 163 }