1 /* crypto/rsa/rsa_pk1.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59 #include <stdio.h>
60 #include "cryptlib.h"
61 #include <openssl/bn.h>
62 #include <openssl/rsa.h>
63 #include <openssl/rand.h>
64
65 int RSA_padding_add_PKCS1_type_1(unsigned char *to, int tlen,
66 const unsigned char *from, int flen)
67 {
68 int j;
69 unsigned char *p;
70
71 if (flen > (tlen-RSA_PKCS1_PADDING_SIZE))
72 {
73 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_1,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
74 return(0);
75 }
76
77 p=(unsigned char *)to;
78
79 *(p++)=0;
80 *(p++)=1; /* Private Key BT (Block Type) */
81
82 /* pad out with 0xff data */
83 j=tlen-3-flen;
84 memset(p,0xff,j);
85 p+=j;
86 *(p++)='\0';
87 memcpy(p,from,(unsigned int)flen);
88 return(1);
89 }
90
91 int RSA_padding_check_PKCS1_type_1(unsigned char *to, int tlen,
92 const unsigned char *from, int flen, int num)
93 {
94 int i,j;
95 const unsigned char *p;
96
97 p=from;
98 if ((num != (flen+1)) || (*(p++) != 01))
99 {
100 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_BLOCK_TYPE_IS_NOT_01);
101 return(-1);
102 }
103
104 /* scan over padding data */
105 j=flen-1; /* one for type. */
106 for (i=0; i<j; i++)
107 {
108 if (*p != 0xff) /* should decrypt to 0xff */
109 {
110 if (*p == 0)
111 { p++; break; }
112 else {
113 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_BAD_FIXED_HEADER_DECRYPT);
114 return(-1);
115 }
116 }
117 p++;
118 }
119
120 if (i == j)
121 {
122 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_NULL_BEFORE_BLOCK_MISSING);
123 return(-1);
124 }
125
126 if (i < 8)
127 {
128 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_BAD_PAD_BYTE_COUNT);
129 return(-1);
130 }
131 i++; /* Skip over the '\0' */
132 j-=i;
133 if (j > tlen)
134 {
135 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_1,RSA_R_DATA_TOO_LARGE);
136 return(-1);
137 }
138 memcpy(to,p,(unsigned int)j);
139
140 return(j);
141 }
142
143 int RSA_padding_add_PKCS1_type_2(unsigned char *to, int tlen,
144 const unsigned char *from, int flen)
145 {
146 int i,j;
147 unsigned char *p;
148
149 if (flen > (tlen-11))
150 {
151 RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_TYPE_2,RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
152 return(0);
153 }
154
155 p=(unsigned char *)to;
156
157 *(p++)=0;
158 *(p++)=2; /* Public Key BT (Block Type) */
159
160 /* pad out with non-zero random data */
161 j=tlen-3-flen;
162
163 if (RAND_bytes(p,j) <= 0)
164 return(0);
165 for (i=0; i<j; i++)
166 {
167 if (*p == '\0')
168 do {
169 if (RAND_bytes(p,1) <= 0)
170 return(0);
171 } while (*p == '\0');
172 p++;
173 }
174
175 *(p++)='\0';
176
177 memcpy(p,from,(unsigned int)flen);
178 return(1);
179 }
180
181 int RSA_padding_check_PKCS1_type_2(unsigned char *to, int tlen,
182 const unsigned char *from, int flen, int num)
183 {
184 int i,j;
185 const unsigned char *p;
186
187 p=from;
188 if ((num != (flen+1)) || (*(p++) != 02))
189 {
190 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,RSA_R_BLOCK_TYPE_IS_NOT_02);
191 return(-1);
192 }
193 #ifdef PKCS1_CHECK
194 return(num-11);
195 #endif
196
197 /* scan over padding data */
198 j=flen-1; /* one for type. */
199 for (i=0; i<j; i++)
200 if (*(p++) == 0) break;
201
202 if (i == j)
203 {
204 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,RSA_R_NULL_BEFORE_BLOCK_MISSING);
205 return(-1);
206 }
207
208 if (i < 8)
209 {
210 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,RSA_R_BAD_PAD_BYTE_COUNT);
211 return(-1);
212 }
213 i++; /* Skip over the '\0' */
214 j-=i;
215 if (j > tlen)
216 {
217 RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_TYPE_2,RSA_R_DATA_TOO_LARGE);
218 return(-1);
219 }
220 memcpy(to,p,(unsigned int)j);
221
222 return(j);
223 }