source: EcnlProtoTool/trunk/openssl-1.1.0e/crypto/rsa/rsa_oaep.c@ 331

Last change on this file since 331 was 331, checked in by coas-nagasima, 6 years ago

prototoolに関連するプロジェクトをnewlibからmuslを使うよう変更・更新
ntshellをnewlibの下位の実装から、muslのsyscallの実装に変更・更新
以下のOSSをアップデート
・mruby-1.3.0
・musl-1.1.18
・onigmo-6.1.3
・tcc-0.9.27
以下のOSSを追加
・openssl-1.1.0e
・curl-7.57.0
・zlib-1.2.11
以下のmrbgemsを追加
・iij/mruby-digest
・iij/mruby-env
・iij/mruby-errno
・iij/mruby-iijson
・iij/mruby-ipaddr
・iij/mruby-mock
・iij/mruby-require
・iij/mruby-tls-openssl
  • Property svn:eol-style set to native
  • Property svn:mime-type set to text/x-csrc
File size: 8.9 KB
Line 
1/*
2 * Copyright 1999-2016 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the OpenSSL license (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/* EME-OAEP as defined in RFC 2437 (PKCS #1 v2.0) */
11
12/*
13 * See Victor Shoup, "OAEP reconsidered," Nov. 2000, <URL:
14 * http://www.shoup.net/papers/oaep.ps.Z> for problems with the security
15 * proof for the original OAEP scheme, which EME-OAEP is based on. A new
16 * proof can be found in E. Fujisaki, T. Okamoto, D. Pointcheval, J. Stern,
17 * "RSA-OEAP is Still Alive!", Dec. 2000, <URL:
18 * http://eprint.iacr.org/2000/061/>. The new proof has stronger requirements
19 * for the underlying permutation: "partial-one-wayness" instead of
20 * one-wayness. For the RSA function, this is an equivalent notion.
21 */
22
23#include "internal/constant_time_locl.h"
24
25#include <stdio.h>
26#include "internal/cryptlib.h"
27#include <openssl/bn.h>
28#include <openssl/evp.h>
29#include <openssl/rand.h>
30#include <openssl/sha.h>
31#include "rsa_locl.h"
32
33int RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen,
34 const unsigned char *from, int flen,
35 const unsigned char *param, int plen)
36{
37 return RSA_padding_add_PKCS1_OAEP_mgf1(to, tlen, from, flen,
38 param, plen, NULL, NULL);
39}
40
41int RSA_padding_add_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
42 const unsigned char *from, int flen,
43 const unsigned char *param, int plen,
44 const EVP_MD *md, const EVP_MD *mgf1md)
45{
46 int i, emlen = tlen - 1;
47 unsigned char *db, *seed;
48 unsigned char *dbmask, seedmask[EVP_MAX_MD_SIZE];
49 int mdlen;
50
51 if (md == NULL)
52 md = EVP_sha1();
53 if (mgf1md == NULL)
54 mgf1md = md;
55
56 mdlen = EVP_MD_size(md);
57
58 if (flen > emlen - 2 * mdlen - 1) {
59 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP_MGF1,
60 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
61 return 0;
62 }
63
64 if (emlen < 2 * mdlen + 1) {
65 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP_MGF1,
66 RSA_R_KEY_SIZE_TOO_SMALL);
67 return 0;
68 }
69
70 to[0] = 0;
71 seed = to + 1;
72 db = to + mdlen + 1;
73
74 if (!EVP_Digest((void *)param, plen, db, NULL, md, NULL))
75 return 0;
76 memset(db + mdlen, 0, emlen - flen - 2 * mdlen - 1);
77 db[emlen - flen - mdlen - 1] = 0x01;
78 memcpy(db + emlen - flen - mdlen, from, (unsigned int)flen);
79 if (RAND_bytes(seed, mdlen) <= 0)
80 return 0;
81#ifdef PKCS_TESTVECT
82 memcpy(seed,
83 "\xaa\xfd\x12\xf6\x59\xca\xe6\x34\x89\xb4\x79\xe5\x07\x6d\xde\xc2\xf0\x6c\xb5\x8f",
84 20);
85#endif
86
87 dbmask = OPENSSL_malloc(emlen - mdlen);
88 if (dbmask == NULL) {
89 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP_MGF1, ERR_R_MALLOC_FAILURE);
90 return 0;
91 }
92
93 if (PKCS1_MGF1(dbmask, emlen - mdlen, seed, mdlen, mgf1md) < 0)
94 goto err;
95 for (i = 0; i < emlen - mdlen; i++)
96 db[i] ^= dbmask[i];
97
98 if (PKCS1_MGF1(seedmask, mdlen, db, emlen - mdlen, mgf1md) < 0)
99 goto err;
100 for (i = 0; i < mdlen; i++)
101 seed[i] ^= seedmask[i];
102
103 OPENSSL_free(dbmask);
104 return 1;
105
106 err:
107 OPENSSL_free(dbmask);
108 return 0;
109}
110
111int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen,
112 const unsigned char *from, int flen, int num,
113 const unsigned char *param, int plen)
114{
115 return RSA_padding_check_PKCS1_OAEP_mgf1(to, tlen, from, flen, num,
116 param, plen, NULL, NULL);
117}
118
119int RSA_padding_check_PKCS1_OAEP_mgf1(unsigned char *to, int tlen,
120 const unsigned char *from, int flen,
121 int num, const unsigned char *param,
122 int plen, const EVP_MD *md,
123 const EVP_MD *mgf1md)
124{
125 int i, dblen, mlen = -1, one_index = 0, msg_index;
126 unsigned int good, found_one_byte;
127 const unsigned char *maskedseed, *maskeddb;
128 /*
129 * |em| is the encoded message, zero-padded to exactly |num| bytes: em =
130 * Y || maskedSeed || maskedDB
131 */
132 unsigned char *db = NULL, *em = NULL, seed[EVP_MAX_MD_SIZE],
133 phash[EVP_MAX_MD_SIZE];
134 int mdlen;
135
136 if (md == NULL)
137 md = EVP_sha1();
138 if (mgf1md == NULL)
139 mgf1md = md;
140
141 mdlen = EVP_MD_size(md);
142
143 if (tlen <= 0 || flen <= 0)
144 return -1;
145 /*
146 * |num| is the length of the modulus; |flen| is the length of the
147 * encoded message. Therefore, for any |from| that was obtained by
148 * decrypting a ciphertext, we must have |flen| <= |num|. Similarly,
149 * num < 2 * mdlen + 2 must hold for the modulus irrespective of
150 * the ciphertext, see PKCS #1 v2.2, section 7.1.2.
151 * This does not leak any side-channel information.
152 */
153 if (num < flen || num < 2 * mdlen + 2)
154 goto decoding_err;
155
156 dblen = num - mdlen - 1;
157 db = OPENSSL_malloc(dblen);
158 em = OPENSSL_malloc(num);
159 if (db == NULL || em == NULL) {
160 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1, ERR_R_MALLOC_FAILURE);
161 goto cleanup;
162 }
163
164 /*
165 * Always do this zero-padding copy (even when num == flen) to avoid
166 * leaking that information. The copy still leaks some side-channel
167 * information, but it's impossible to have a fixed memory access
168 * pattern since we can't read out of the bounds of |from|.
169 *
170 * TODO(emilia): Consider porting BN_bn2bin_padded from BoringSSL.
171 */
172 memset(em, 0, num);
173 memcpy(em + num - flen, from, flen);
174
175 /*
176 * The first byte must be zero, however we must not leak if this is
177 * true. See James H. Manger, "A Chosen Ciphertext Attack on RSA
178 * Optimal Asymmetric Encryption Padding (OAEP) [...]", CRYPTO 2001).
179 */
180 good = constant_time_is_zero(em[0]);
181
182 maskedseed = em + 1;
183 maskeddb = em + 1 + mdlen;
184
185 if (PKCS1_MGF1(seed, mdlen, maskeddb, dblen, mgf1md))
186 goto cleanup;
187 for (i = 0; i < mdlen; i++)
188 seed[i] ^= maskedseed[i];
189
190 if (PKCS1_MGF1(db, dblen, seed, mdlen, mgf1md))
191 goto cleanup;
192 for (i = 0; i < dblen; i++)
193 db[i] ^= maskeddb[i];
194
195 if (!EVP_Digest((void *)param, plen, phash, NULL, md, NULL))
196 goto cleanup;
197
198 good &= constant_time_is_zero(CRYPTO_memcmp(db, phash, mdlen));
199
200 found_one_byte = 0;
201 for (i = mdlen; i < dblen; i++) {
202 /*
203 * Padding consists of a number of 0-bytes, followed by a 1.
204 */
205 unsigned int equals1 = constant_time_eq(db[i], 1);
206 unsigned int equals0 = constant_time_is_zero(db[i]);
207 one_index = constant_time_select_int(~found_one_byte & equals1,
208 i, one_index);
209 found_one_byte |= equals1;
210 good &= (found_one_byte | equals0);
211 }
212
213 good &= found_one_byte;
214
215 /*
216 * At this point |good| is zero unless the plaintext was valid,
217 * so plaintext-awareness ensures timing side-channels are no longer a
218 * concern.
219 */
220 if (!good)
221 goto decoding_err;
222
223 msg_index = one_index + 1;
224 mlen = dblen - msg_index;
225
226 if (tlen < mlen) {
227 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1, RSA_R_DATA_TOO_LARGE);
228 mlen = -1;
229 } else {
230 memcpy(to, db + msg_index, mlen);
231 goto cleanup;
232 }
233
234 decoding_err:
235 /*
236 * To avoid chosen ciphertext attacks, the error message should not
237 * reveal which kind of decoding error happened.
238 */
239 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP_MGF1,
240 RSA_R_OAEP_DECODING_ERROR);
241 cleanup:
242 OPENSSL_free(db);
243 OPENSSL_free(em);
244 return mlen;
245}
246
247int PKCS1_MGF1(unsigned char *mask, long len,
248 const unsigned char *seed, long seedlen, const EVP_MD *dgst)
249{
250 long i, outlen = 0;
251 unsigned char cnt[4];
252 EVP_MD_CTX *c = EVP_MD_CTX_new();
253 unsigned char md[EVP_MAX_MD_SIZE];
254 int mdlen;
255 int rv = -1;
256
257 if (c == NULL)
258 goto err;
259 mdlen = EVP_MD_size(dgst);
260 if (mdlen < 0)
261 goto err;
262 for (i = 0; outlen < len; i++) {
263 cnt[0] = (unsigned char)((i >> 24) & 255);
264 cnt[1] = (unsigned char)((i >> 16) & 255);
265 cnt[2] = (unsigned char)((i >> 8)) & 255;
266 cnt[3] = (unsigned char)(i & 255);
267 if (!EVP_DigestInit_ex(c, dgst, NULL)
268 || !EVP_DigestUpdate(c, seed, seedlen)
269 || !EVP_DigestUpdate(c, cnt, 4))
270 goto err;
271 if (outlen + mdlen <= len) {
272 if (!EVP_DigestFinal_ex(c, mask + outlen, NULL))
273 goto err;
274 outlen += mdlen;
275 } else {
276 if (!EVP_DigestFinal_ex(c, md, NULL))
277 goto err;
278 memcpy(mask + outlen, md, len - outlen);
279 outlen = len;
280 }
281 }
282 rv = 0;
283 err:
284 EVP_MD_CTX_free(c);
285 return rv;
286}
Note: See TracBrowser for help on using the repository browser.