crypto/kdf/pbkdf2.c

   1 /*
   2  * Copyright 2018 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 <stdlib.h>
  11 #include <stdarg.h>
  12 #include <string.h>
  13 #include <openssl/hmac.h>
  14 #include <openssl/evp.h>
  15 #include <openssl/kdf.h>
  16 #include "internal/cryptlib.h"
  17 #include "internal/evp_int.h"
  18 #include "kdf_local.h"
  19
  20 static void kdf_pbkdf2_reset(EVP_KDF_IMPL *impl);
  21 static void kdf_pbkdf2_init(EVP_KDF_IMPL *impl);
  22 static int pkcs5_pbkdf2_alg(const char *pass, size_t passlen,
  23                             const unsigned char *salt, int saltlen, int iter,
  24                             const EVP_MD *digest, unsigned char *key,
  25                             size_t keylen);
  26
  27 struct evp_kdf_impl_st {
  28     unsigned char *pass;
  29     size_t pass_len;
  30     unsigned char *salt;
  31     size_t salt_len;
  32     int iter;
  33     const EVP_MD *md;
  34 };
  35
  36 static EVP_KDF_IMPL *kdf_pbkdf2_new(void)
  37 {
  38     EVP_KDF_IMPL *impl;
  39
  40     impl = OPENSSL_zalloc(sizeof(*impl));
  41     if (impl == NULL) {
  42         KDFerr(KDF_F_KDF_PBKDF2_NEW, ERR_R_MALLOC_FAILURE);
  43         return NULL;
  44     }
  45     kdf_pbkdf2_init(impl);
  46     return impl;
  47 }
  48
  49 static void kdf_pbkdf2_free(EVP_KDF_IMPL *impl)
  50 {
  51     kdf_pbkdf2_reset(impl);
  52     OPENSSL_free(impl);
  53 }
  54
  55 static void kdf_pbkdf2_reset(EVP_KDF_IMPL *impl)
  56 {
  57     OPENSSL_free(impl->salt);
  58     OPENSSL_clear_free(impl->pass, impl->pass_len);
  59     memset(impl, 0, sizeof(*impl));
  60     kdf_pbkdf2_init(impl);
  61 }
  62
  63 static void kdf_pbkdf2_init(EVP_KDF_IMPL *impl)
  64 {
  65     impl->iter = PKCS5_DEFAULT_ITER;
  66     impl->md = EVP_sha1();
  67 }
  68
  69 static int pbkdf2_set_membuf(unsigned char **buffer, size_t *buflen,
  70                              const unsigned char *new_buffer,
  71                              size_t new_buflen)
  72 {
  73     if (new_buffer == NULL)
  74         return 1;
  75
  76     OPENSSL_clear_free(*buffer, *buflen);
  77
  78     if (new_buflen > 0) {
  79         *buffer = OPENSSL_memdup(new_buffer, new_buflen);
  80     } else {
  81         *buffer = OPENSSL_malloc(1);
  82     }
  83     if (*buffer == NULL) {
  84         KDFerr(KDF_F_PBKDF2_SET_MEMBUF, ERR_R_MALLOC_FAILURE);
  85         return 0;
  86     }
  87
  88     *buflen = new_buflen;
  89     return 1;
  90 }
  91
  92 static int kdf_pbkdf2_ctrl(EVP_KDF_IMPL *impl, int cmd, va_list args)
  93 {
  94     int iter;
  95     const unsigned char *p;
  96     size_t len;
  97     const EVP_MD *md;
  98
  99     switch (cmd) {
 100     case EVP_KDF_CTRL_SET_PASS:
 101         p = va_arg(args, const unsigned char *);
 102         len = va_arg(args, size_t);
 103         return pbkdf2_set_membuf(&impl->pass, &impl->pass_len, p, len);
 104
 105     case EVP_KDF_CTRL_SET_SALT:
 106         p = va_arg(args, const unsigned char *);
 107         len = va_arg(args, size_t);
 108         return pbkdf2_set_membuf(&impl->salt, &impl->salt_len, p, len);
 109
 110     case EVP_KDF_CTRL_SET_ITER:
 111         iter = va_arg(args, int);
 112         if (iter < 1)
 113             return 0;
 114
 115         impl->iter = iter;
 116         return 1;
 117
 118     case EVP_KDF_CTRL_SET_MD:
 119         md = va_arg(args, const EVP_MD *);
 120         if (md == NULL)
 121             return 0;
 122
 123         impl->md = md;
 124         return 1;
 125
 126     default:
 127         return -2;
 128     }
 129 }
 130
 131 static int kdf_pbkdf2_ctrl_str(EVP_KDF_IMPL *impl, const char *type,
 132                                const char *value)
 133 {
 134     if (value == NULL) {
 135         KDFerr(KDF_F_KDF_PBKDF2_CTRL_STR, KDF_R_VALUE_MISSING);
 136         return 0;
 137     }
 138
 139     if (strcmp(type, "pass") == 0)
 140         return kdf_str2ctrl(impl, kdf_pbkdf2_ctrl, EVP_KDF_CTRL_SET_PASS,
 141                             value);
 142
 143     if (strcmp(type, "hexpass") == 0)
 144         return kdf_hex2ctrl(impl, kdf_pbkdf2_ctrl, EVP_KDF_CTRL_SET_PASS,
 145                             value);
 146
 147     if (strcmp(type, "salt") == 0)
 148         return kdf_str2ctrl(impl, kdf_pbkdf2_ctrl, EVP_KDF_CTRL_SET_SALT,
 149                             value);
 150
 151     if (strcmp(type, "hexsalt") == 0)
 152         return kdf_hex2ctrl(impl, kdf_pbkdf2_ctrl, EVP_KDF_CTRL_SET_SALT,
 153                             value);
 154
 155     if (strcmp(type, "iter") == 0)
 156         return call_ctrl(kdf_pbkdf2_ctrl, impl, EVP_KDF_CTRL_SET_ITER,
 157                          atoi(value));
 158
 159     if (strcmp(type, "digest") == 0)
 160         return kdf_md2ctrl(impl, kdf_pbkdf2_ctrl, EVP_KDF_CTRL_SET_MD, value);
 161
 162     return -2;
 163 }
 164
 165 static int kdf_pbkdf2_derive(EVP_KDF_IMPL *impl, unsigned char *key,
 166                              size_t keylen)
 167 {
 168     if (impl->pass == NULL) {
 169         KDFerr(KDF_F_KDF_PBKDF2_DERIVE, KDF_R_MISSING_PASS);
 170         return 0;
 171     }
 172
 173     if (impl->salt == NULL) {
 174         KDFerr(KDF_F_KDF_PBKDF2_DERIVE, KDF_R_MISSING_SALT);
 175         return 0;
 176     }
 177
 178     return pkcs5_pbkdf2_alg((char *)impl->pass, impl->pass_len,
 179                             impl->salt, impl->salt_len, impl->iter,
 180                             impl->md, key, keylen);
 181 }
 182
 183 const EVP_KDF_METHOD pbkdf2_kdf_meth = {
 184     EVP_KDF_PBKDF2,
 185     kdf_pbkdf2_new,
 186     kdf_pbkdf2_free,
 187     kdf_pbkdf2_reset,
 188     kdf_pbkdf2_ctrl,
 189     kdf_pbkdf2_ctrl_str,
 190     NULL,
 191     kdf_pbkdf2_derive
 192 };
 193
 194 /*
 195  * This is an implementation of PKCS#5 v2.0 password based encryption key
 196  * derivation function PBKDF2. SHA1 version verified against test vectors
 197  * posted by Peter Gutmann to the PKCS-TNG mailing list.
 198  */
 199
 200 static int pkcs5_pbkdf2_alg(const char *pass, size_t passlen,
 201                             const unsigned char *salt, int saltlen, int iter,
 202                             const EVP_MD *digest, unsigned char *key,
 203                             size_t keylen)
 204 {
 205     int ret = 0;
 206     unsigned char digtmp[EVP_MAX_MD_SIZE], *p, itmp[4];
 207     int cplen, j, k, tkeylen, mdlen;
 208     unsigned long i = 1;
 209     HMAC_CTX *hctx_tpl = NULL, *hctx = NULL;
 210
 211     mdlen = EVP_MD_size(digest);
 212     if (mdlen < 0)
 213         return 0;
 214
 215     hctx_tpl = HMAC_CTX_new();
 216     if (hctx_tpl == NULL)
 217         return 0;
 218     p = key;
 219     tkeylen = keylen;
 220     if (!HMAC_Init_ex(hctx_tpl, pass, passlen, digest, NULL))
 221         goto err;
 222     hctx = HMAC_CTX_new();
 223     if (hctx == NULL)
 224         goto err;
 225     while (tkeylen) {
 226         if (tkeylen > mdlen)
 227             cplen = mdlen;
 228         else
 229             cplen = tkeylen;
 230         /*
 231          * We are unlikely to ever use more than 256 blocks (5120 bits!) but
 232          * just in case...
 233          */
 234         itmp[0] = (unsigned char)((i >> 24) & 0xff);
 235         itmp[1] = (unsigned char)((i >> 16) & 0xff);
 236         itmp[2] = (unsigned char)((i >> 8) & 0xff);
 237         itmp[3] = (unsigned char)(i & 0xff);
 238         if (!HMAC_CTX_copy(hctx, hctx_tpl))
 239             goto err;
 240         if (!HMAC_Update(hctx, salt, saltlen)
 241                 || !HMAC_Update(hctx, itmp, 4)
 242                 || !HMAC_Final(hctx, digtmp, NULL))
 243             goto err;
 244         memcpy(p, digtmp, cplen);
 245         for (j = 1; j < iter; j++) {
 246             if (!HMAC_CTX_copy(hctx, hctx_tpl))
 247                 goto err;
 248             if (!HMAC_Update(hctx, digtmp, mdlen)
 249                     || !HMAC_Final(hctx, digtmp, NULL))
 250                 goto err;
 251             for (k = 0; k < cplen; k++)
 252                 p[k] ^= digtmp[k];
 253         }
 254         tkeylen -= cplen;
 255         i++;
 256         p += cplen;
 257     }
 258     ret = 1;
 259
 260 err:
 261     HMAC_CTX_free(hctx);
 262     HMAC_CTX_free(hctx_tpl);
 263     return ret;
 264 }