1/* p5_crpt2.c */
2/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
3 * project 1999.
4 */
5/* ====================================================================
6 * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in
17 *    the documentation and/or other materials provided with the
18 *    distribution.
19 *
20 * 3. All advertising materials mentioning features or use of this
21 *    software must display the following acknowledgment:
22 *    "This product includes software developed by the OpenSSL Project
23 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
24 *
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 *    endorse or promote products derived from this software without
27 *    prior written permission. For written permission, please contact
28 *    licensing@OpenSSL.org.
29 *
30 * 5. Products derived from this software may not be called "OpenSSL"
31 *    nor may "OpenSSL" appear in their names without prior written
32 *    permission of the OpenSSL Project.
33 *
34 * 6. Redistributions of any form whatsoever must retain the following
35 *    acknowledgment:
36 *    "This product includes software developed by the OpenSSL Project
37 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
38 *
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
52 *
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com).  This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
56 *
57 */
58#if !defined(OPENSSL_NO_HMAC) && !defined(OPENSSL_NO_SHA)
59#include <stdio.h>
60#include <stdlib.h>
61#include "cryptlib.h"
62#include <openssl/x509.h>
63#include <openssl/evp.h>
64#include <openssl/hmac.h>
65
66/* set this to print out info about the keygen algorithm */
67/* #define DEBUG_PKCS5V2 */
68
69#ifdef DEBUG_PKCS5V2
70	static void h__dump (const unsigned char *p, int len);
71#endif
72
73/* This is an implementation of PKCS#5 v2.0 password based encryption key
74 * derivation function PBKDF2 using the only currently defined function HMAC
75 * with SHA1. Verified against test vectors posted by Peter Gutmann
76 * <pgut001@cs.auckland.ac.nz> to the PKCS-TNG <pkcs-tng@rsa.com> mailing list.
77 */
78
79int PKCS5_PBKDF2_HMAC_SHA1(const char *pass, int passlen,
80			   unsigned char *salt, int saltlen, int iter,
81			   int keylen, unsigned char *out)
82{
83	unsigned char digtmp[SHA_DIGEST_LENGTH], *p, itmp[4];
84	int cplen, j, k, tkeylen;
85	unsigned long i = 1;
86	HMAC_CTX hctx;
87
88	HMAC_CTX_init(&hctx);
89	p = out;
90	tkeylen = keylen;
91	if(!pass) passlen = 0;
92	else if(passlen == -1) passlen = strlen(pass);
93	while(tkeylen) {
94		if(tkeylen > SHA_DIGEST_LENGTH) cplen = SHA_DIGEST_LENGTH;
95		else cplen = tkeylen;
96		/* We are unlikely to ever use more than 256 blocks (5120 bits!)
97		 * but just in case...
98		 */
99		itmp[0] = (unsigned char)((i >> 24) & 0xff);
100		itmp[1] = (unsigned char)((i >> 16) & 0xff);
101		itmp[2] = (unsigned char)((i >> 8) & 0xff);
102		itmp[3] = (unsigned char)(i & 0xff);
103		HMAC_Init_ex(&hctx, pass, passlen, EVP_sha1(), NULL);
104		HMAC_Update(&hctx, salt, saltlen);
105		HMAC_Update(&hctx, itmp, 4);
106		HMAC_Final(&hctx, digtmp, NULL);
107		memcpy(p, digtmp, cplen);
108		for(j = 1; j < iter; j++) {
109			HMAC(EVP_sha1(), pass, passlen,
110				 digtmp, SHA_DIGEST_LENGTH, digtmp, NULL);
111			for(k = 0; k < cplen; k++) p[k] ^= digtmp[k];
112		}
113		tkeylen-= cplen;
114		i++;
115		p+= cplen;
116	}
117	HMAC_CTX_cleanup(&hctx);
118#ifdef DEBUG_PKCS5V2
119	fprintf(stderr, "Password:\n");
120	h__dump (pass, passlen);
121	fprintf(stderr, "Salt:\n");
122	h__dump (salt, saltlen);
123	fprintf(stderr, "Iteration count %d\n", iter);
124	fprintf(stderr, "Key:\n");
125	h__dump (out, keylen);
126#endif
127	return 1;
128}
129
130#ifdef DO_TEST
131main()
132{
133	unsigned char out[4];
134	unsigned char salt[] = {0x12, 0x34, 0x56, 0x78};
135	PKCS5_PBKDF2_HMAC_SHA1("password", -1, salt, 4, 5, 4, out);
136	fprintf(stderr, "Out %02X %02X %02X %02X\n",
137					 out[0], out[1], out[2], out[3]);
138}
139
140#endif
141
142/* Now the key derivation function itself. This is a bit evil because
143 * it has to check the ASN1 parameters are valid: and there are quite a
144 * few of them...
145 */
146
147int PKCS5_v2_PBE_keyivgen(EVP_CIPHER_CTX *ctx, const char *pass, int passlen,
148                         ASN1_TYPE *param, const EVP_CIPHER *c, const EVP_MD *md,
149                         int en_de)
150{
151	unsigned char *pbuf, *salt, key[EVP_MAX_KEY_LENGTH];
152	int saltlen, keylen, iter, plen;
153	PBE2PARAM *pbe2 = NULL;
154	const EVP_CIPHER *cipher;
155	PBKDF2PARAM *kdf = NULL;
156
157	pbuf = param->value.sequence->data;
158	plen = param->value.sequence->length;
159	if(!param || (param->type != V_ASN1_SEQUENCE) ||
160				   !(pbe2 = d2i_PBE2PARAM(NULL, &pbuf, plen))) {
161		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,EVP_R_DECODE_ERROR);
162		return 0;
163	}
164
165	/* See if we recognise the key derivation function */
166
167	if(OBJ_obj2nid(pbe2->keyfunc->algorithm) != NID_id_pbkdf2) {
168		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,
169				EVP_R_UNSUPPORTED_KEY_DERIVATION_FUNCTION);
170		goto err;
171	}
172
173	/* lets see if we recognise the encryption algorithm.
174	 */
175
176	cipher = EVP_get_cipherbyname(
177			OBJ_nid2sn(OBJ_obj2nid(pbe2->encryption->algorithm)));
178
179	if(!cipher) {
180		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,
181						EVP_R_UNSUPPORTED_CIPHER);
182		goto err;
183	}
184
185	/* Fixup cipher based on AlgorithmIdentifier */
186	EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, en_de);
187	if(EVP_CIPHER_asn1_to_param(ctx, pbe2->encryption->parameter) < 0) {
188		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,
189					EVP_R_CIPHER_PARAMETER_ERROR);
190		goto err;
191	}
192	keylen = EVP_CIPHER_CTX_key_length(ctx);
193	OPENSSL_assert(keylen <= sizeof key);
194
195	/* Now decode key derivation function */
196
197	pbuf = pbe2->keyfunc->parameter->value.sequence->data;
198	plen = pbe2->keyfunc->parameter->value.sequence->length;
199	if(!pbe2->keyfunc->parameter ||
200		 (pbe2->keyfunc->parameter->type != V_ASN1_SEQUENCE) ||
201				!(kdf = d2i_PBKDF2PARAM(NULL, &pbuf, plen)) ) {
202		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,EVP_R_DECODE_ERROR);
203		goto err;
204	}
205
206	PBE2PARAM_free(pbe2);
207	pbe2 = NULL;
208
209	/* Now check the parameters of the kdf */
210
211	if(kdf->keylength && (ASN1_INTEGER_get(kdf->keylength) != keylen)){
212		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,
213						EVP_R_UNSUPPORTED_KEYLENGTH);
214		goto err;
215	}
216
217	if(kdf->prf && (OBJ_obj2nid(kdf->prf->algorithm) != NID_hmacWithSHA1)) {
218		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN, EVP_R_UNSUPPORTED_PRF);
219		goto err;
220	}
221
222	if(kdf->salt->type != V_ASN1_OCTET_STRING) {
223		EVPerr(EVP_F_PKCS5_V2_PBE_KEYIVGEN,
224						EVP_R_UNSUPPORTED_SALT_TYPE);
225		goto err;
226	}
227
228	/* it seems that its all OK */
229	salt = kdf->salt->value.octet_string->data;
230	saltlen = kdf->salt->value.octet_string->length;
231	iter = ASN1_INTEGER_get(kdf->iter);
232	PKCS5_PBKDF2_HMAC_SHA1(pass, passlen, salt, saltlen, iter, keylen, key);
233	EVP_CipherInit_ex(ctx, NULL, NULL, key, NULL, en_de);
234	OPENSSL_cleanse(key, keylen);
235	PBKDF2PARAM_free(kdf);
236	return 1;
237
238	err:
239	PBE2PARAM_free(pbe2);
240	PBKDF2PARAM_free(kdf);
241	return 0;
242}
243
244#ifdef DEBUG_PKCS5V2
245static void h__dump (const unsigned char *p, int len)
246{
247        for (; len --; p++) fprintf(stderr, "%02X ", *p);
248        fprintf(stderr, "\n");
249}
250#endif
251#endif
252