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-rw-r--r--src/lib/libcrypto/rsa/rsa_oaep.c206
1 files changed, 0 insertions, 206 deletions
diff --git a/src/lib/libcrypto/rsa/rsa_oaep.c b/src/lib/libcrypto/rsa/rsa_oaep.c
deleted file mode 100644
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--- a/src/lib/libcrypto/rsa/rsa_oaep.c
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1/* crypto/rsa/rsa_oaep.c */
2/* Written by Ulf Moeller. This software is distributed on an "AS IS"
3 basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. */
4
5/* EME-OAEP as defined in RFC 2437 (PKCS #1 v2.0) */
6
7/* See Victor Shoup, "OAEP reconsidered," Nov. 2000,
8 * <URL: http://www.shoup.net/papers/oaep.ps.Z>
9 * for problems with the security proof for the
10 * original OAEP scheme, which EME-OAEP is based on.
11 *
12 * A new proof can be found in E. Fujisaki, T. Okamoto,
13 * D. Pointcheval, J. Stern, "RSA-OEAP is Still Alive!",
14 * Dec. 2000, <URL: http://eprint.iacr.org/2000/061/>.
15 * The new proof has stronger requirements for the
16 * underlying permutation: "partial-one-wayness" instead
17 * of one-wayness. For the RSA function, this is
18 * an equivalent notion.
19 */
20
21
22#if !defined(OPENSSL_NO_SHA) && !defined(OPENSSL_NO_SHA1)
23#include <stdio.h>
24#include "cryptlib.h"
25#include <openssl/bn.h>
26#include <openssl/rsa.h>
27#include <openssl/evp.h>
28#include <openssl/rand.h>
29#include <openssl/sha.h>
30
31int MGF1(unsigned char *mask, long len,
32 const unsigned char *seed, long seedlen);
33
34int RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen,
35 const unsigned char *from, int flen,
36 const unsigned char *param, int plen)
37 {
38 int i, emlen = tlen - 1;
39 unsigned char *db, *seed;
40 unsigned char *dbmask, seedmask[SHA_DIGEST_LENGTH];
41
42 if (flen > emlen - 2 * SHA_DIGEST_LENGTH - 1)
43 {
44 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP,
45 RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
46 return 0;
47 }
48
49 if (emlen < 2 * SHA_DIGEST_LENGTH + 1)
50 {
51 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, RSA_R_KEY_SIZE_TOO_SMALL);
52 return 0;
53 }
54
55 dbmask = OPENSSL_malloc(emlen - SHA_DIGEST_LENGTH);
56 if (dbmask == NULL)
57 {
58 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE);
59 return 0;
60 }
61
62 to[0] = 0;
63 seed = to + 1;
64 db = to + SHA_DIGEST_LENGTH + 1;
65
66 EVP_Digest((void *)param, plen, db, NULL, EVP_sha1(), NULL);
67 memset(db + SHA_DIGEST_LENGTH, 0,
68 emlen - flen - 2 * SHA_DIGEST_LENGTH - 1);
69 db[emlen - flen - SHA_DIGEST_LENGTH - 1] = 0x01;
70 memcpy(db + emlen - flen - SHA_DIGEST_LENGTH, from, (unsigned int) flen);
71 if (RAND_bytes(seed, SHA_DIGEST_LENGTH) <= 0)
72 return 0;
73#ifdef PKCS_TESTVECT
74 memcpy(seed,
75 "\xaa\xfd\x12\xf6\x59\xca\xe6\x34\x89\xb4\x79\xe5\x07\x6d\xde\xc2\xf0\x6c\xb5\x8f",
76 20);
77#endif
78
79 MGF1(dbmask, emlen - SHA_DIGEST_LENGTH, seed, SHA_DIGEST_LENGTH);
80 for (i = 0; i < emlen - SHA_DIGEST_LENGTH; i++)
81 db[i] ^= dbmask[i];
82
83 MGF1(seedmask, SHA_DIGEST_LENGTH, db, emlen - SHA_DIGEST_LENGTH);
84 for (i = 0; i < SHA_DIGEST_LENGTH; i++)
85 seed[i] ^= seedmask[i];
86
87 OPENSSL_free(dbmask);
88 return 1;
89 }
90
91int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen,
92 const unsigned char *from, int flen, int num,
93 const unsigned char *param, int plen)
94 {
95 int i, dblen, mlen = -1;
96 const unsigned char *maskeddb;
97 int lzero;
98 unsigned char *db = NULL, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH];
99 int bad = 0;
100
101 if (--num < 2 * SHA_DIGEST_LENGTH + 1)
102 /* 'num' is the length of the modulus, i.e. does not depend on the
103 * particular ciphertext. */
104 goto decoding_err;
105
106 lzero = num - flen;
107 if (lzero < 0)
108 {
109 /* lzero == -1 */
110
111 /* signalling this error immediately after detection might allow
112 * for side-channel attacks (e.g. timing if 'plen' is huge
113 * -- cf. James H. Manger, "A Chosen Ciphertext Attack on RSA Optimal
114 * Asymmetric Encryption Padding (OAEP) [...]", CRYPTO 2001),
115 * so we use a 'bad' flag */
116 bad = 1;
117 lzero = 0;
118 }
119 maskeddb = from - lzero + SHA_DIGEST_LENGTH;
120
121 dblen = num - SHA_DIGEST_LENGTH;
122 db = OPENSSL_malloc(dblen);
123 if (db == NULL)
124 {
125 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE);
126 return -1;
127 }
128
129 MGF1(seed, SHA_DIGEST_LENGTH, maskeddb, dblen);
130 for (i = lzero; i < SHA_DIGEST_LENGTH; i++)
131 seed[i] ^= from[i - lzero];
132
133 MGF1(db, dblen, seed, SHA_DIGEST_LENGTH);
134 for (i = 0; i < dblen; i++)
135 db[i] ^= maskeddb[i];
136
137 EVP_Digest((void *)param, plen, phash, NULL, EVP_sha1(), NULL);
138
139 if (memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad)
140 goto decoding_err;
141 else
142 {
143 for (i = SHA_DIGEST_LENGTH; i < dblen; i++)
144 if (db[i] != 0x00)
145 break;
146 if (db[i] != 0x01 || i++ >= dblen)
147 goto decoding_err;
148 else
149 {
150 /* everything looks OK */
151
152 mlen = dblen - i;
153 if (tlen < mlen)
154 {
155 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_DATA_TOO_LARGE);
156 mlen = -1;
157 }
158 else
159 memcpy(to, db + i, mlen);
160 }
161 }
162 OPENSSL_free(db);
163 return mlen;
164
165decoding_err:
166 /* to avoid chosen ciphertext attacks, the error message should not reveal
167 * which kind of decoding error happened */
168 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_OAEP_DECODING_ERROR);
169 if (db != NULL) OPENSSL_free(db);
170 return -1;
171 }
172
173int MGF1(unsigned char *mask, long len,
174 const unsigned char *seed, long seedlen)
175 {
176 long i, outlen = 0;
177 unsigned char cnt[4];
178 EVP_MD_CTX c;
179 unsigned char md[SHA_DIGEST_LENGTH];
180
181 EVP_MD_CTX_init(&c);
182 for (i = 0; outlen < len; i++)
183 {
184 cnt[0] = (unsigned char)((i >> 24) & 255);
185 cnt[1] = (unsigned char)((i >> 16) & 255);
186 cnt[2] = (unsigned char)((i >> 8)) & 255;
187 cnt[3] = (unsigned char)(i & 255);
188 EVP_DigestInit_ex(&c,EVP_sha1(), NULL);
189 EVP_DigestUpdate(&c, seed, seedlen);
190 EVP_DigestUpdate(&c, cnt, 4);
191 if (outlen + SHA_DIGEST_LENGTH <= len)
192 {
193 EVP_DigestFinal_ex(&c, mask + outlen, NULL);
194 outlen += SHA_DIGEST_LENGTH;
195 }
196 else
197 {
198 EVP_DigestFinal_ex(&c, md, NULL);
199 memcpy(mask + outlen, md, len - outlen);
200 outlen = len;
201 }
202 }
203 EVP_MD_CTX_cleanup(&c);
204 return 0;
205 }
206#endif
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