xref: /illumos-gate/usr/src/common/crypto/rsa/rsa_impl.c (revision a07094369b21309434206d9b3601d162693466fc)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * This file contains RSA helper routines common to
31  * the PKCS11 soft token code and the kernel RSA code.
32  */
33 
34 #include <sys/types.h>
35 #include "rsa_impl.h"
36 
37 #ifdef _KERNEL
38 #include <sys/param.h>
39 #else
40 #include <strings.h>
41 #include "softRandom.h"
42 #endif
43 
44 /*
45  * DER encoding T of the DigestInfo values for MD5, SHA1, and SHA2
46  * from PKCS#1 v2.1: RSA Cryptography Standard Section 9.2 Note 1
47  *
48  * MD5:     (0x)30 20 30 0c 06 08 2a 86 48 86 f7 0d 02 05 05 00 04 10 || H
49  * SHA-1:   (0x)30 21 30 09 06 05 2b 0e 03 02 1a 05 00 04 14 || H
50  * SHA-256: (0x)30 31 30 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04 20 || H.
51  * SHA-384: (0x)30 41 30 0d 06 09 60 86 48 01 65 03 04 02 02 05 00 04 30 || H.
52  * SHA-512: (0x)30 51 30 0d 06 09 60 86 48 01 65 03 04 02 03 05 00 04 40 || H.
53  *
54  * Where H is the digested output from MD5 or SHA1. We define the constant
55  * byte array (the prefix) here and use it rather than doing the DER
56  * encoding of the OID in a separate routine.
57  */
58 const CK_BYTE MD5_DER_PREFIX[MD5_DER_PREFIX_Len] = {0x30, 0x20, 0x30, 0x0c,
59     0x06, 0x08, 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, 0x05, 0x00,
60     0x04, 0x10};
61 
62 const CK_BYTE SHA1_DER_PREFIX[SHA1_DER_PREFIX_Len] = {0x30, 0x21, 0x30,
63     0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14};
64 
65 const CK_BYTE SHA1_DER_PREFIX_OID[SHA1_DER_PREFIX_OID_Len] = {0x30, 0x1f, 0x30,
66     0x07, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x04, 0x14};
67 
68 const CK_BYTE SHA256_DER_PREFIX[SHA2_DER_PREFIX_Len] = {0x30, 0x31, 0x30, 0x0d,
69     0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05,
70     0x00, 0x04, 0x20};
71 
72 const CK_BYTE SHA384_DER_PREFIX[SHA2_DER_PREFIX_Len] = {0x30, 0x41, 0x30, 0x0d,
73     0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, 0x05,
74     0x00, 0x04, 0x30};
75 
76 const CK_BYTE SHA512_DER_PREFIX[SHA2_DER_PREFIX_Len] = {0x30, 0x51, 0x30, 0x0d,
77     0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05,
78     0x00, 0x04, 0x40};
79 
80 BIG_ERR_CODE
81 RSA_key_init(RSAkey *key, int psize, int qsize)
82 {
83 	BIG_ERR_CODE err = BIG_OK;
84 
85 /* EXPORT DELETE START */
86 
87 	int plen, qlen, nlen;
88 
89 	plen = (psize + 31) / 32;
90 	qlen = (qsize + 31) / 32;
91 	nlen = plen + qlen;
92 	key->size = psize + qsize;
93 	if ((err = big_init(&(key->p), plen)) != BIG_OK)
94 		return (err);
95 	if ((err = big_init(&(key->q), qlen)) != BIG_OK)
96 		goto ret1;
97 	if ((err = big_init(&(key->n), nlen)) != BIG_OK)
98 		goto ret2;
99 	if ((err = big_init(&(key->d), nlen)) != BIG_OK)
100 		goto ret3;
101 	if ((err = big_init(&(key->e), nlen)) != BIG_OK)
102 		goto ret4;
103 	if ((err = big_init(&(key->dmodpminus1), plen)) != BIG_OK)
104 		goto ret5;
105 	if ((err = big_init(&(key->dmodqminus1), qlen)) != BIG_OK)
106 		goto ret6;
107 	if ((err = big_init(&(key->pinvmodq), qlen)) != BIG_OK)
108 		goto ret7;
109 	if ((err = big_init(&(key->p_rr), plen)) != BIG_OK)
110 		goto ret8;
111 	if ((err = big_init(&(key->q_rr), qlen)) != BIG_OK)
112 		goto ret9;
113 	if ((err = big_init(&(key->n_rr), nlen)) != BIG_OK)
114 		goto ret10;
115 
116 	return (BIG_OK);
117 
118 ret10:
119 	big_finish(&(key->q_rr));
120 ret9:
121 	big_finish(&(key->p_rr));
122 ret8:
123 	big_finish(&(key->pinvmodq));
124 ret7:
125 	big_finish(&(key->dmodqminus1));
126 ret6:
127 	big_finish(&(key->dmodpminus1));
128 ret5:
129 	big_finish(&(key->e));
130 ret4:
131 	big_finish(&(key->d));
132 ret3:
133 	big_finish(&(key->n));
134 ret2:
135 	big_finish(&(key->q));
136 ret1:
137 	big_finish(&(key->p));
138 
139 /* EXPORT DELETE END */
140 
141 	return (err);
142 }
143 
144 
145 void
146 RSA_key_finish(RSAkey *key)
147 {
148 
149 /* EXPORT DELETE START */
150 
151 	big_finish(&(key->n_rr));
152 	big_finish(&(key->q_rr));
153 	big_finish(&(key->p_rr));
154 	big_finish(&(key->pinvmodq));
155 	big_finish(&(key->dmodqminus1));
156 	big_finish(&(key->dmodpminus1));
157 	big_finish(&(key->e));
158 	big_finish(&(key->d));
159 	big_finish(&(key->n));
160 	big_finish(&(key->q));
161 	big_finish(&(key->p));
162 
163 /* EXPORT DELETE END */
164 
165 }
166 
167 
168 /*
169  * To create a block type "02" encryption block for RSA PKCS encryption
170  * process.
171  *
172  * The RSA PKCS Padding before encryption is in the following format:
173  * +------+--------------------+----+-----------------------------+
174  * |0x0002| 8 bytes or more RN |0x00|       DATA                  |
175  * +------+--------------------+----+-----------------------------+
176  *
177  */
178 CK_RV
179 soft_encrypt_rsa_pkcs_encode(uint8_t *databuf,
180     size_t datalen, uint8_t *padbuf, size_t padbuflen)
181 {
182 
183 /* EXPORT DELETE START */
184 
185 	size_t	padlen;
186 	CK_RV	rv;
187 
188 	padlen = padbuflen - datalen;
189 	if (padlen < MIN_PKCS1_PADLEN) {
190 		return (CKR_DATA_LEN_RANGE);
191 	}
192 
193 	/* Pad with 0x0002+non-zero pseudorandom numbers+0x00. */
194 	padbuf[0] = 0x00;
195 	padbuf[1] = 0x02;
196 #ifdef _KERNEL
197 	rv = knzero_random_generator(padbuf + 2, padbuflen - 3);
198 #else
199 	rv = soft_nzero_random_generator(padbuf + 2, padbuflen - 3);
200 #endif
201 	if (rv != CKR_OK) {
202 		return (rv);
203 	}
204 	padbuf[padlen - 1] = 0x00;
205 
206 	bcopy(databuf, padbuf + padlen, datalen);
207 
208 /* EXPORT DELETE END */
209 
210 	return (CKR_OK);
211 }
212 
213 
214 /*
215  * The RSA PKCS Padding after decryption is in the following format:
216  * +------+--------------------+----+-----------------------------+
217  * |0x0002| 8 bytes or more RN |0x00|       DATA                  |
218  * +------+--------------------+----+-----------------------------+
219  *
220  * 'padbuf' points to the recovered message which is the modulus
221  * length. As a result, 'plen' is changed to hold the actual data length.
222  */
223 CK_RV
224 soft_decrypt_rsa_pkcs_decode(uint8_t *padbuf, int *plen)
225 {
226 
227 /* EXPORT DELETE START */
228 
229 	int	i;
230 
231 	/* Check to see if the recovered data is padded is 0x0002. */
232 	if (padbuf[0] != 0x00 || padbuf[1] != 0x02) {
233 		return (CKR_ENCRYPTED_DATA_INVALID);
234 	}
235 
236 	/* Remove all the random bits up to 0x00 (= NULL char) */
237 	for (i = 2; (*plen - i) > 0; i++) {
238 		if (padbuf[i] == 0x00) {
239 			i++;
240 			if (i < MIN_PKCS1_PADLEN) {
241 				return (CKR_ENCRYPTED_DATA_INVALID);
242 			}
243 			*plen -= i;
244 
245 			return (CKR_OK);
246 		}
247 	}
248 
249 /* EXPORT DELETE END */
250 
251 	return (CKR_ENCRYPTED_DATA_INVALID);
252 }
253 
254 /*
255  * To create a block type "01" block for RSA PKCS signature process.
256  *
257  * The RSA PKCS Padding before Signing is in the following format:
258  * +------+--------------+----+-----------------------------+
259  * |0x0001| 0xFFFF.......|0x00|          DATA               |
260  * +------+--------------+----+-----------------------------+
261  */
262 CK_RV
263 soft_sign_rsa_pkcs_encode(uint8_t *pData, size_t dataLen, uint8_t *data,
264     size_t mbit_l)
265 {
266 
267 /* EXPORT DELETE START */
268 
269 	size_t	padlen;
270 
271 	padlen = mbit_l - dataLen;
272 	if (padlen < MIN_PKCS1_PADLEN) {
273 		return (CKR_DATA_LEN_RANGE);
274 	}
275 
276 	padlen -= 3;
277 	data[0] = 0x00;
278 	data[1] = 0x01;
279 #ifdef _KERNEL
280 	kmemset(data + 2, 0xFF, padlen);
281 #else
282 	(void) memset(data + 2, 0xFF, padlen);
283 #endif
284 	data[padlen + 2] = 0x00;
285 	bcopy(pData, data + padlen + 3, dataLen);
286 
287 /* EXPORT DELETE END */
288 
289 	return (CKR_OK);
290 }
291 
292 
293 CK_RV
294 soft_verify_rsa_pkcs_decode(uint8_t *data, int *mbit_l)
295 {
296 
297 /* EXPORT DELETE START */
298 
299 	int i;
300 
301 	/* Check to see if the padding of recovered data starts with 0x0001. */
302 	if ((data[0] != 0x00) || (data[1] != 0x01)) {
303 		return (CKR_SIGNATURE_INVALID);
304 	}
305 	/* Check to see if the recovered data is padded with 0xFFF...00. */
306 	for (i = 2; i < *mbit_l; i++) {
307 		if (data[i] == 0x00) {
308 			i++;
309 			if (i < MIN_PKCS1_PADLEN) {
310 				return (CKR_SIGNATURE_INVALID);
311 			}
312 			*mbit_l -= i;
313 
314 			return (CKR_OK);
315 		} else if (data[i] != 0xFF) {
316 			return (CKR_SIGNATURE_INVALID);
317 		}
318 	}
319 
320 /* EXPORT DELETE END */
321 
322 	return (CKR_SIGNATURE_INVALID);
323 }
324