crypto/evp/evp_key.c

   1 /*
   2  * Copyright 1995-2016 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 <stdio.h>
  11 #include "internal/cryptlib.h"
  12 #include <openssl/x509.h>
  13 #include <openssl/objects.h>
  14 #include <openssl/evp.h>
  15 #include <openssl/ui.h>
  16
  17 #ifndef BUFSIZ
  18 # define BUFSIZ 256
  19 #endif
  20
  21 /* should be init to zeros. */
  22 static char prompt_string[80];
  23
  24 void EVP_set_pw_prompt(const char *prompt)
  25 {
  26     if (prompt == NULL)
  27         prompt_string[0] = '\0';
  28     else {
  29         strncpy(prompt_string, prompt, 79);
  30         prompt_string[79] = '\0';
  31     }
  32 }
  33
  34 char *EVP_get_pw_prompt(void)
  35 {
  36     if (prompt_string[0] == '\0')
  37         return NULL;
  38     else
  39         return prompt_string;
  40 }
  41
  42 /*
  43  * For historical reasons, the standard function for reading passwords is in
  44  * the DES library -- if someone ever wants to disable DES, this function
  45  * will fail
  46  */
  47 int EVP_read_pw_string(char *buf, int len, const char *prompt, int verify)
  48 {
  49     return EVP_read_pw_string_min(buf, 0, len, prompt, verify);
  50 }
  51
  52 int EVP_read_pw_string_min(char *buf, int min, int len, const char *prompt,
  53                            int verify)
  54 {
  55     int ret = -1;
  56     char buff[BUFSIZ];
  57     UI *ui;
  58
  59     if ((prompt == NULL) && (prompt_string[0] != '\0'))
  60         prompt = prompt_string;
  61     ui = UI_new();
  62     if (ui == NULL)
  63         return ret;
  64     if (UI_add_input_string(ui, prompt, 0, buf, min,
  65                             (len >= BUFSIZ) ? BUFSIZ - 1 : len) < 0
  66         || (verify
  67             && UI_add_verify_string(ui, prompt, 0, buff, min,
  68                                     (len >= BUFSIZ) ? BUFSIZ - 1 : len,
  69                                     buf) < 0))
  70         goto end;
  71     ret = UI_process(ui);
  72     OPENSSL_cleanse(buff, BUFSIZ);
  73  end:
  74     UI_free(ui);
  75     return ret;
  76 }
  77
  78 int EVP_BytesToKey(const EVP_CIPHER *type, const EVP_MD *md,
  79                    const unsigned char *salt, const unsigned char *data,
  80                    int datal, int count, unsigned char *key,
  81                    unsigned char *iv)
  82 {
  83     EVP_MD_CTX *c;
  84     unsigned char md_buf[EVP_MAX_MD_SIZE];
  85     int niv, nkey, addmd = 0;
  86     unsigned int mds = 0, i;
  87     int rv = 0;
  88     nkey = EVP_CIPHER_key_length(type);
  89     niv = EVP_CIPHER_iv_length(type);
  90     OPENSSL_assert(nkey <= EVP_MAX_KEY_LENGTH);
  91     OPENSSL_assert(niv <= EVP_MAX_IV_LENGTH);
  92
  93     if (data == NULL)
  94         return nkey;
  95
  96     c = EVP_MD_CTX_new();
  97     if (c == NULL)
  98         goto err;
  99     for (;;) {
 100         if (!EVP_DigestInit_ex(c, md, NULL))
 101             goto err;
 102         if (addmd++)
 103             if (!EVP_DigestUpdate(c, &(md_buf[0]), mds))
 104                 goto err;
 105         if (!EVP_DigestUpdate(c, data, datal))
 106             goto err;
 107         if (salt != NULL)
 108             if (!EVP_DigestUpdate(c, salt, PKCS5_SALT_LEN))
 109                 goto err;
 110         if (!EVP_DigestFinal_ex(c, &(md_buf[0]), &mds))
 111             goto err;
 112
 113         for (i = 1; i < (unsigned int)count; i++) {
 114             if (!EVP_DigestInit_ex(c, md, NULL))
 115                 goto err;
 116             if (!EVP_DigestUpdate(c, &(md_buf[0]), mds))
 117                 goto err;
 118             if (!EVP_DigestFinal_ex(c, &(md_buf[0]), &mds))
 119                 goto err;
 120         }
 121         i = 0;
 122         if (nkey) {
 123             for (;;) {
 124                 if (nkey == 0)
 125                     break;
 126                 if (i == mds)
 127                     break;
 128                 if (key != NULL)
 129                     *(key++) = md_buf[i];
 130                 nkey--;
 131                 i++;
 132             }
 133         }
 134         if (niv && (i != mds)) {
 135             for (;;) {
 136                 if (niv == 0)
 137                     break;
 138                 if (i == mds)
 139                     break;
 140                 if (iv != NULL)
 141                     *(iv++) = md_buf[i];
 142                 niv--;
 143                 i++;
 144             }
 145         }
 146         if ((nkey == 0) && (niv == 0))
 147             break;
 148     }
 149     rv = EVP_CIPHER_key_length(type);
 150  err:
 151     EVP_MD_CTX_free(c);
 152     OPENSSL_cleanse(md_buf, sizeof(md_buf));
 153     return rv;
 154 }