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