evp_key.c revision 296465 
1/* crypto/evp/evp_key.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59#include <stdio.h>
60#include "cryptlib.h"
61#include <openssl/x509.h>
62#include <openssl/objects.h>
63#include <openssl/evp.h>
64#include <openssl/ui.h>
65
66/* should be init to zeros. */
67static char prompt_string[80];
68
69void EVP_set_pw_prompt(const char *prompt)
70{
71    if (prompt == NULL)
72        prompt_string[0] = '\0';
73    else {
74        strncpy(prompt_string, prompt, 79);
75        prompt_string[79] = '\0';
76    }
77}
78
79char *EVP_get_pw_prompt(void)
80{
81    if (prompt_string[0] == '\0')
82        return (NULL);
83    else
84        return (prompt_string);
85}
86
87/*
88 * For historical reasons, the standard function for reading passwords is in
89 * the DES library -- if someone ever wants to disable DES, this function
90 * will fail
91 */
92int EVP_read_pw_string(char *buf, int len, const char *prompt, int verify)
93{
94    int ret;
95    char buff[BUFSIZ];
96    UI *ui;
97
98    if ((prompt == NULL) && (prompt_string[0] != '\0'))
99        prompt = prompt_string;
100    ui = UI_new();
101    UI_add_input_string(ui, prompt, 0, buf, 0,
102                        (len >= BUFSIZ) ? BUFSIZ - 1 : len);
103    if (verify)
104        UI_add_verify_string(ui, prompt, 0,
105                             buff, 0, (len >= BUFSIZ) ? BUFSIZ - 1 : len,
106                             buf);
107    ret = UI_process(ui);
108    UI_free(ui);
109    OPENSSL_cleanse(buff, BUFSIZ);
110    return ret;
111}
112
113int EVP_BytesToKey(const EVP_CIPHER *type, const EVP_MD *md,
114                   const unsigned char *salt, const unsigned char *data,
115                   int datal, int count, unsigned char *key,
116                   unsigned char *iv)
117{
118    EVP_MD_CTX c;
119    unsigned char md_buf[EVP_MAX_MD_SIZE];
120    int niv, nkey, addmd = 0;
121    unsigned int mds = 0, i;
122
123    nkey = type->key_len;
124    niv = type->iv_len;
125    OPENSSL_assert(nkey <= EVP_MAX_KEY_LENGTH);
126    OPENSSL_assert(niv <= EVP_MAX_IV_LENGTH);
127
128    if (data == NULL)
129        return (nkey);
130
131    EVP_MD_CTX_init(&c);
132    for (;;) {
133        if (!EVP_DigestInit_ex(&c, md, NULL))
134            return 0;
135        if (addmd++)
136            EVP_DigestUpdate(&c, &(md_buf[0]), mds);
137        EVP_DigestUpdate(&c, data, datal);
138        if (salt != NULL)
139            EVP_DigestUpdate(&c, salt, PKCS5_SALT_LEN);
140        EVP_DigestFinal_ex(&c, &(md_buf[0]), &mds);
141
142        for (i = 1; i < (unsigned int)count; i++) {
143            EVP_DigestInit_ex(&c, md, NULL);
144            EVP_DigestUpdate(&c, &(md_buf[0]), mds);
145            EVP_DigestFinal_ex(&c, &(md_buf[0]), &mds);
146        }
147        i = 0;
148        if (nkey) {
149            for (;;) {
150                if (nkey == 0)
151                    break;
152                if (i == mds)
153                    break;
154                if (key != NULL)
155                    *(key++) = md_buf[i];
156                nkey--;
157                i++;
158            }
159        }
160        if (niv && (i != mds)) {
161            for (;;) {
162                if (niv == 0)
163                    break;
164                if (i == mds)
165                    break;
166                if (iv != NULL)
167                    *(iv++) = md_buf[i];
168                niv--;
169                i++;
170            }
171        }
172        if ((nkey == 0) && (niv == 0))
173            break;
174    }
175    EVP_MD_CTX_cleanup(&c);
176    OPENSSL_cleanse(&(md_buf[0]), EVP_MAX_MD_SIZE);
177    return (type->key_len);
178}
179