1 /* rsa_pss.c */
2 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
3 * project 2005.
4 */
5 /* ====================================================================
6 * Copyright (c) 2005 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
59 #include <stdio.h>
60 #include "cryptlib.h"
61 #include <openssl/bn.h>
62 #include <openssl/rsa.h>
63 #include <openssl/evp.h>
64 #include <openssl/rand.h>
65 #include <openssl/sha.h>
66
67 static const unsigned char zeroes[] = {0,0,0,0,0,0,0,0};
68
69 #if defined(_MSC_VER) && defined(_ARM_)
70 #pragma optimize("g", off)
71 #endif
72
RSA_verify_PKCS1_PSS(RSA * rsa,const unsigned char * mHash,const EVP_MD * Hash,const unsigned char * EM,int sLen)73 int RSA_verify_PKCS1_PSS(RSA *rsa, const unsigned char *mHash,
74 const EVP_MD *Hash, const unsigned char *EM, int sLen)
75 {
76 int i;
77 int ret = 0;
78 int hLen, maskedDBLen, MSBits, emLen;
79 const unsigned char *H;
80 unsigned char *DB = NULL;
81 EVP_MD_CTX ctx;
82 unsigned char H_[EVP_MAX_MD_SIZE];
83
84 hLen = EVP_MD_size(Hash);
85 if (hLen < 0)
86 goto err;
87 /*
88 * Negative sLen has special meanings:
89 * -1 sLen == hLen
90 * -2 salt length is autorecovered from signature
91 * -N reserved
92 */
93 if (sLen == -1) sLen = hLen;
94 else if (sLen == -2) sLen = -2;
95 else if (sLen < -2)
96 {
97 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_SLEN_CHECK_FAILED);
98 goto err;
99 }
100
101 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
102 emLen = RSA_size(rsa);
103 if (EM[0] & (0xFF << MSBits))
104 {
105 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_FIRST_OCTET_INVALID);
106 goto err;
107 }
108 if (MSBits == 0)
109 {
110 EM++;
111 emLen--;
112 }
113 if (emLen < (hLen + sLen + 2)) /* sLen can be small negative */
114 {
115 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_DATA_TOO_LARGE);
116 goto err;
117 }
118 if (EM[emLen - 1] != 0xbc)
119 {
120 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_LAST_OCTET_INVALID);
121 goto err;
122 }
123 maskedDBLen = emLen - hLen - 1;
124 H = EM + maskedDBLen;
125 DB = OPENSSL_malloc(maskedDBLen);
126 if (!DB)
127 {
128 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, ERR_R_MALLOC_FAILURE);
129 goto err;
130 }
131 if (PKCS1_MGF1(DB, maskedDBLen, H, hLen, Hash) < 0)
132 goto err;
133 for (i = 0; i < maskedDBLen; i++)
134 DB[i] ^= EM[i];
135 if (MSBits)
136 DB[0] &= 0xFF >> (8 - MSBits);
137 for (i = 0; DB[i] == 0 && i < (maskedDBLen-1); i++) ;
138 if (DB[i++] != 0x1)
139 {
140 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_SLEN_RECOVERY_FAILED);
141 goto err;
142 }
143 if (sLen >= 0 && (maskedDBLen - i) != sLen)
144 {
145 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_SLEN_CHECK_FAILED);
146 goto err;
147 }
148 EVP_MD_CTX_init(&ctx);
149 EVP_DigestInit_ex(&ctx, Hash, NULL);
150 EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes);
151 EVP_DigestUpdate(&ctx, mHash, hLen);
152 if (maskedDBLen - i)
153 EVP_DigestUpdate(&ctx, DB + i, maskedDBLen - i);
154 EVP_DigestFinal(&ctx, H_, NULL);
155 EVP_MD_CTX_cleanup(&ctx);
156 if (memcmp(H_, H, hLen))
157 {
158 RSAerr(RSA_F_RSA_VERIFY_PKCS1_PSS, RSA_R_BAD_SIGNATURE);
159 ret = 0;
160 }
161 else
162 ret = 1;
163
164 err:
165 if (DB)
166 OPENSSL_free(DB);
167
168 return ret;
169
170 }
171
RSA_padding_add_PKCS1_PSS(RSA * rsa,unsigned char * EM,const unsigned char * mHash,const EVP_MD * Hash,int sLen)172 int RSA_padding_add_PKCS1_PSS(RSA *rsa, unsigned char *EM,
173 const unsigned char *mHash,
174 const EVP_MD *Hash, int sLen)
175 {
176 int i;
177 int ret = 0;
178 int hLen, maskedDBLen, MSBits, emLen;
179 unsigned char *H, *salt = NULL, *p;
180 EVP_MD_CTX ctx;
181
182 hLen = EVP_MD_size(Hash);
183 if (hLen < 0)
184 goto err;
185 /*
186 * Negative sLen has special meanings:
187 * -1 sLen == hLen
188 * -2 salt length is maximized
189 * -N reserved
190 */
191 if (sLen == -1) sLen = hLen;
192 else if (sLen == -2) sLen = -2;
193 else if (sLen < -2)
194 {
195 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS, RSA_R_SLEN_CHECK_FAILED);
196 goto err;
197 }
198
199 MSBits = (BN_num_bits(rsa->n) - 1) & 0x7;
200 emLen = RSA_size(rsa);
201 if (MSBits == 0)
202 {
203 *EM++ = 0;
204 emLen--;
205 }
206 if (sLen == -2)
207 {
208 sLen = emLen - hLen - 2;
209 }
210 else if (emLen < (hLen + sLen + 2))
211 {
212 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS,
213 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
214 goto err;
215 }
216 if (sLen > 0)
217 {
218 salt = OPENSSL_malloc(sLen);
219 if (!salt)
220 {
221 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_PSS,
222 ERR_R_MALLOC_FAILURE);
223 goto err;
224 }
225 if (RAND_bytes(salt, sLen) <= 0)
226 goto err;
227 }
228 maskedDBLen = emLen - hLen - 1;
229 H = EM + maskedDBLen;
230 EVP_MD_CTX_init(&ctx);
231 EVP_DigestInit_ex(&ctx, Hash, NULL);
232 EVP_DigestUpdate(&ctx, zeroes, sizeof zeroes);
233 EVP_DigestUpdate(&ctx, mHash, hLen);
234 if (sLen)
235 EVP_DigestUpdate(&ctx, salt, sLen);
236 EVP_DigestFinal(&ctx, H, NULL);
237 EVP_MD_CTX_cleanup(&ctx);
238
239 /* Generate dbMask in place then perform XOR on it */
240 if (PKCS1_MGF1(EM, maskedDBLen, H, hLen, Hash))
241 goto err;
242
243 p = EM;
244
245 /* Initial PS XORs with all zeroes which is a NOP so just update
246 * pointer. Note from a test above this value is guaranteed to
247 * be non-negative.
248 */
249 p += emLen - sLen - hLen - 2;
250 *p++ ^= 0x1;
251 if (sLen > 0)
252 {
253 for (i = 0; i < sLen; i++)
254 *p++ ^= salt[i];
255 }
256 if (MSBits)
257 EM[0] &= 0xFF >> (8 - MSBits);
258
259 /* H is already in place so just set final 0xbc */
260
261 EM[emLen - 1] = 0xbc;
262
263 ret = 1;
264
265 err:
266 if (salt)
267 OPENSSL_free(salt);
268
269 return ret;
270
271 }
272
273 #if defined(_MSC_VER)
274 #pragma optimize("",on)
275 #endif
276