xref: /openbsd-src/lib/libcrypto/evp/evp_key.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /* $OpenBSD: evp_key.c,v 1.18 2014/07/11 08:44:48 jsing Exp $ */
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 <string.h>
61 
62 #include <openssl/evp.h>
63 #include <openssl/objects.h>
64 #include <openssl/ui.h>
65 #include <openssl/x509.h>
66 
67 /* should be init to zeros. */
68 static char prompt_string[80];
69 
70 void
71 EVP_set_pw_prompt(const char *prompt)
72 {
73 	if (prompt == NULL)
74 		prompt_string[0] = '\0';
75 	else {
76 		strlcpy(prompt_string, prompt, sizeof(prompt_string));
77 	}
78 }
79 
80 char *
81 EVP_get_pw_prompt(void)
82 {
83 	if (prompt_string[0] == '\0')
84 		return (NULL);
85 	else
86 		return (prompt_string);
87 }
88 
89 int
90 EVP_read_pw_string(char *buf, int len, const char *prompt, int verify)
91 {
92 	return EVP_read_pw_string_min(buf, 0, len, prompt, verify);
93 }
94 
95 int
96 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 	UI_add_input_string(ui, prompt, 0, buf, min,
107 	    (len >= BUFSIZ) ? BUFSIZ - 1 : len);
108 	if (verify)
109 		UI_add_verify_string(ui, prompt, 0, buff, min,
110 		    (len >= BUFSIZ) ? BUFSIZ - 1 : len, buf);
111 	ret = UI_process(ui);
112 	UI_free(ui);
113 	OPENSSL_cleanse(buff, BUFSIZ);
114 	return ret;
115 }
116 
117 int
118 EVP_BytesToKey(const EVP_CIPHER *type, const EVP_MD *md,
119     const unsigned char *salt, const unsigned char *data, int datal,
120     int count, unsigned char *key, unsigned char *iv)
121 {
122 	EVP_MD_CTX c;
123 	unsigned char md_buf[EVP_MAX_MD_SIZE];
124 	int niv, nkey, addmd = 0;
125 	unsigned int mds = 0, i;
126 	int rv = 0;
127 	nkey = type->key_len;
128 	niv = type->iv_len;
129 	OPENSSL_assert(nkey <= EVP_MAX_KEY_LENGTH);
130 	OPENSSL_assert(niv <= EVP_MAX_IV_LENGTH);
131 
132 	if (data == NULL)
133 		return (nkey);
134 
135 	EVP_MD_CTX_init(&c);
136 	for (;;) {
137 		if (!EVP_DigestInit_ex(&c, md, NULL))
138 			return 0;
139 		if (addmd++)
140 			if (!EVP_DigestUpdate(&c, &(md_buf[0]), mds))
141 				goto err;
142 		if (!EVP_DigestUpdate(&c, data, datal))
143 			goto err;
144 		if (salt != NULL)
145 			if (!EVP_DigestUpdate(&c, salt, PKCS5_SALT_LEN))
146 				goto err;
147 		if (!EVP_DigestFinal_ex(&c, &(md_buf[0]), &mds))
148 			goto err;
149 
150 		for (i = 1; i < (unsigned int)count; i++) {
151 			if (!EVP_DigestInit_ex(&c, md, NULL))
152 				goto err;
153 			if (!EVP_DigestUpdate(&c, &(md_buf[0]), mds))
154 				goto err;
155 			if (!EVP_DigestFinal_ex(&c, &(md_buf[0]), &mds))
156 				goto err;
157 		}
158 		i = 0;
159 		if (nkey) {
160 			for (;;) {
161 				if (nkey == 0)
162 					break;
163 				if (i == mds)
164 					break;
165 				if (key != NULL)
166 					*(key++) = md_buf[i];
167 				nkey--;
168 				i++;
169 			}
170 		}
171 		if (niv && (i != mds)) {
172 			for (;;) {
173 				if (niv == 0)
174 					break;
175 				if (i == mds)
176 					break;
177 				if (iv != NULL)
178 					*(iv++) = md_buf[i];
179 				niv--;
180 				i++;
181 			}
182 		}
183 		if ((nkey == 0) && (niv == 0))
184 			break;
185 	}
186 	rv = type->key_len;
187 
188 err:
189 	EVP_MD_CTX_cleanup(&c);
190 	OPENSSL_cleanse(&(md_buf[0]), EVP_MAX_MD_SIZE);
191 	return rv;
192 }
193