crypto/evp/evp_key.c

   1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   2  * All rights reserved.
   3  *
   4  * This package is an SSL implementation written
   5  * by Eric Young (eay@cryptsoft.com).
   6  * The implementation was written so as to conform with Netscapes SSL.
   7  *
   8  * This library is free for commercial and non-commercial use as long as
   9  * the following conditions are aheared to.  The following conditions
  10  * apply to all code found in this distribution, be it the RC4, RSA,
  11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  12  * included with this distribution is covered by the same copyright terms
  13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  14  *
  15  * Copyright remains Eric Young's, and as such any Copyright notices in
  16  * the code are not to be removed.
  17  * If this package is used in a product, Eric Young should be given attribution
  18  * as the author of the parts of the library used.
  19  * This can be in the form of a textual message at program startup or
  20  * in documentation (online or textual) provided with the package.
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  * 3. All advertising materials mentioning features or use of this software
  31  *    must display the following acknowledgement:
  32  *    "This product includes cryptographic software written by
  33  *     Eric Young (eay@cryptsoft.com)"
  34  *    The word 'cryptographic' can be left out if the rouines from the library
  35  *    being used are not cryptographic related :-).
  36  * 4. If you include any Windows specific code (or a derivative thereof) from
  37  *    the apps directory (application code) you must include an acknowledgement:
  38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50  * SUCH DAMAGE.
  51  *
  52  * The licence and distribution terms for any publically available version or
  53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  54  * copied and put under another distribution licence
  55  * [including the GNU Public Licence.]
  56  */
  57
  58 #include <stdio.h>
  59 #include "internal/cryptlib.h"
  60 #include <openssl/x509.h>
  61 #include <openssl/objects.h>
  62 #include <openssl/evp.h>
  63 #include <openssl/ui.h>
  64
  65 /* should be init to zeros. */
  66 static char prompt_string[80];
  67
  68 void EVP_set_pw_prompt(const char *prompt)
  69 {
  70     if (prompt == NULL)
  71         prompt_string[0] = '\0';
  72     else {
  73         strncpy(prompt_string, prompt, 79);
  74         prompt_string[79] = '\0';
  75     }
  76 }
  77
  78 char *EVP_get_pw_prompt(void)
  79 {
  80     if (prompt_string[0] == '\0')
  81         return (NULL);
  82     else
  83         return (prompt_string);
  84 }
  85
  86 /*
  87  * For historical reasons, the standard function for reading passwords is in
  88  * the DES library -- if someone ever wants to disable DES, this function
  89  * will fail
  90  */
  91 int EVP_read_pw_string(char *buf, int len, const char *prompt, int verify)
  92 {
  93     return EVP_read_pw_string_min(buf, 0, len, prompt, verify);
  94 }
  95
  96 int EVP_read_pw_string_min(char *buf, int min, int len, const char *prompt,
  97                            int verify)
  98 {
  99     int ret;
 100     char buff[BUFSIZ];
 101     UI *ui;
 102
 103     if ((prompt == NULL) && (prompt_string[0] != '\0'))
 104         prompt = prompt_string;
 105     ui = UI_new();
 106     if (ui == NULL)
 107         return -1;
 108     UI_add_input_string(ui, prompt, 0, buf, min,
 109                         (len >= BUFSIZ) ? BUFSIZ - 1 : len);
 110     if (verify)
 111         UI_add_verify_string(ui, prompt, 0,
 112                              buff, min, (len >= BUFSIZ) ? BUFSIZ - 1 : len,
 113                              buf);
 114     ret = UI_process(ui);
 115     UI_free(ui);
 116     OPENSSL_cleanse(buff, BUFSIZ);
 117     return ret;
 118 }
 119
 120 int EVP_BytesToKey(const EVP_CIPHER *type, const EVP_MD *md,
 121                    const unsigned char *salt, const unsigned char *data,
 122                    int datal, int count, unsigned char *key,
 123                    unsigned char *iv)
 124 {
 125     EVP_MD_CTX *c;
 126     unsigned char md_buf[EVP_MAX_MD_SIZE];
 127     int niv, nkey, addmd = 0;
 128     unsigned int mds = 0, i;
 129     int rv = 0;
 130     nkey = EVP_CIPHER_key_length(type);
 131     niv = EVP_CIPHER_iv_length(type);
 132     OPENSSL_assert(nkey <= EVP_MAX_KEY_LENGTH);
 133     OPENSSL_assert(niv <= EVP_MAX_IV_LENGTH);
 134
 135     if (data == NULL)
 136         return (nkey);
 137
 138     c = EVP_MD_CTX_new();
 139     if (c == NULL)
 140         goto err;
 141     for (;;) {
 142         if (!EVP_DigestInit_ex(c, md, NULL))
 143             goto err;
 144         if (addmd++)
 145             if (!EVP_DigestUpdate(c, &(md_buf[0]), mds))
 146                 goto err;
 147         if (!EVP_DigestUpdate(c, data, datal))
 148             goto err;
 149         if (salt != NULL)
 150             if (!EVP_DigestUpdate(c, salt, PKCS5_SALT_LEN))
 151                 goto err;
 152         if (!EVP_DigestFinal_ex(c, &(md_buf[0]), &mds))
 153             goto err;
 154
 155         for (i = 1; i < (unsigned int)count; i++) {
 156             if (!EVP_DigestInit_ex(c, md, NULL))
 157                 goto err;
 158             if (!EVP_DigestUpdate(c, &(md_buf[0]), mds))
 159                 goto err;
 160             if (!EVP_DigestFinal_ex(c, &(md_buf[0]), &mds))
 161                 goto err;
 162         }
 163         i = 0;
 164         if (nkey) {
 165             for (;;) {
 166                 if (nkey == 0)
 167                     break;
 168                 if (i == mds)
 169                     break;
 170                 if (key != NULL)
 171                     *(key++) = md_buf[i];
 172                 nkey--;
 173                 i++;
 174             }
 175         }
 176         if (niv && (i != mds)) {
 177             for (;;) {
 178                 if (niv == 0)
 179                     break;
 180                 if (i == mds)
 181                     break;
 182                 if (iv != NULL)
 183                     *(iv++) = md_buf[i];
 184                 niv--;
 185                 i++;
 186             }
 187         }
 188         if ((nkey == 0) && (niv == 0))
 189             break;
 190     }
 191     rv = EVP_CIPHER_key_length(type);
 192  err:
 193     EVP_MD_CTX_free(c);
 194     OPENSSL_cleanse(md_buf, sizeof(md_buf));
 195     return rv;
 196 }