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
65int 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
91int 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
143int 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
181int 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	}
224
225