1 /* $OpenBSD: cfb64ede.c,v 1.9 2015/02/07 13:19:15 doug Exp $ */
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 "des_locl.h"
60 
61 /* The input and output encrypted as though 64bit cfb mode is being
62  * used.  The extra state information to record how much of the
63  * 64bit block we have used is contained in *num;
64  */
65 
66 void DES_ede3_cfb64_encrypt(const unsigned char *in, unsigned char *out,
67 			    long length, DES_key_schedule *ks1,
68 			    DES_key_schedule *ks2, DES_key_schedule *ks3,
69 			    DES_cblock *ivec, int *num, int enc)
70 	{
71 	DES_LONG v0,v1;
72 	long l=length;
73 	int n= *num;
74 	DES_LONG ti[2];
75 	unsigned char *iv,c,cc;
76 
77 	iv=&(*ivec)[0];
78 	if (enc)
79 		{
80 		while (l--)
81 			{
82 			if (n == 0)
83 				{
84 				c2l(iv,v0);
85 				c2l(iv,v1);
86 
87 				ti[0]=v0;
88 				ti[1]=v1;
89 				DES_encrypt3(ti,ks1,ks2,ks3);
90 				v0=ti[0];
91 				v1=ti[1];
92 
93 				iv = &(*ivec)[0];
94 				l2c(v0,iv);
95 				l2c(v1,iv);
96 				iv = &(*ivec)[0];
97 				}
98 			c= *(in++)^iv[n];
99 			*(out++)=c;
100 			iv[n]=c;
101 			n=(n+1)&0x07;
102 			}
103 		}
104 	else
105 		{
106 		while (l--)
107 			{
108 			if (n == 0)
109 				{
110 				c2l(iv,v0);
111 				c2l(iv,v1);
112 
113 				ti[0]=v0;
114 				ti[1]=v1;
115 				DES_encrypt3(ti,ks1,ks2,ks3);
116 				v0=ti[0];
117 				v1=ti[1];
118 
119 				iv = &(*ivec)[0];
120 				l2c(v0,iv);
121 				l2c(v1,iv);
122 				iv = &(*ivec)[0];
123 				}
124 			cc= *(in++);
125 			c=iv[n];
126 			iv[n]=cc;
127 			*(out++)=c^cc;
128 			n=(n+1)&0x07;
129 			}
130 		}
131 	v0=v1=ti[0]=ti[1]=c=cc=0;
132 	*num=n;
133 	}
134 
135 /* This is compatible with the single key CFB-r for DES, even thought that's
136  * not what EVP needs.
137  */
138 
139 void DES_ede3_cfb_encrypt(const unsigned char *in,unsigned char *out,
140 			  int numbits,long length,DES_key_schedule *ks1,
141 			  DES_key_schedule *ks2,DES_key_schedule *ks3,
142 			  DES_cblock *ivec,int enc)
143 	{
144 	DES_LONG d0,d1,v0,v1;
145 	unsigned long l=length,n=((unsigned int)numbits+7)/8;
146 	int num=numbits,i;
147 	DES_LONG ti[2];
148 	unsigned char *iv;
149 	unsigned char ovec[16];
150 
151 	if (num > 64) return;
152 	iv = &(*ivec)[0];
153 	c2l(iv,v0);
154 	c2l(iv,v1);
155 	if (enc)
156 		{
157 		while (l >= n)
158 			{
159 			l-=n;
160 			ti[0]=v0;
161 			ti[1]=v1;
162 			DES_encrypt3(ti,ks1,ks2,ks3);
163 			c2ln(in,d0,d1,n);
164 			in+=n;
165 			d0^=ti[0];
166 			d1^=ti[1];
167 			l2cn(d0,d1,out,n);
168 			out+=n;
169 			/* 30-08-94 - eay - changed because l>>32 and
170 			 * l<<32 are bad under gcc :-( */
171 			if (num == 32)
172 				{ v0=v1; v1=d0; }
173 			else if (num == 64)
174 				{ v0=d0; v1=d1; }
175 			else
176 				{
177 				iv=&ovec[0];
178 				l2c(v0,iv);
179 				l2c(v1,iv);
180 				l2c(d0,iv);
181 				l2c(d1,iv);
182 				/* shift ovec left most of the bits... */
183 				memmove(ovec,ovec+num/8,8+(num%8 ? 1 : 0));
184 				/* now the remaining bits */
185 				if(num%8 != 0)
186 					for(i=0 ; i < 8 ; ++i)
187 						{
188 						ovec[i]<<=num%8;
189 						ovec[i]|=ovec[i+1]>>(8-num%8);
190 						}
191 				iv=&ovec[0];
192 				c2l(iv,v0);
193 				c2l(iv,v1);
194 				}
195 			}
196 		}
197 	else
198 		{
199 		while (l >= n)
200 			{
201 			l-=n;
202 			ti[0]=v0;
203 			ti[1]=v1;
204 			DES_encrypt3(ti,ks1,ks2,ks3);
205 			c2ln(in,d0,d1,n);
206 			in+=n;
207 			/* 30-08-94 - eay - changed because l>>32 and
208 			 * l<<32 are bad under gcc :-( */
209 			if (num == 32)
210 				{ v0=v1; v1=d0; }
211 			else if (num == 64)
212 				{ v0=d0; v1=d1; }
213 			else
214 				{
215 				iv=&ovec[0];
216 				l2c(v0,iv);
217 				l2c(v1,iv);
218 				l2c(d0,iv);
219 				l2c(d1,iv);
220 				/* shift ovec left most of the bits... */
221 				memmove(ovec,ovec+num/8,8+(num%8 ? 1 : 0));
222 				/* now the remaining bits */
223 				if(num%8 != 0)
224 					for(i=0 ; i < 8 ; ++i)
225 						{
226 						ovec[i]<<=num%8;
227 						ovec[i]|=ovec[i+1]>>(8-num%8);
228 						}
229 				iv=&ovec[0];
230 				c2l(iv,v0);
231 				c2l(iv,v1);
232 				}
233 			d0^=ti[0];
234 			d1^=ti[1];
235 			l2cn(d0,d1,out,n);
236 			out+=n;
237 			}
238 		}
239 	iv = &(*ivec)[0];
240 	l2c(v0,iv);
241 	l2c(v1,iv);
242 	v0=v1=d0=d1=ti[0]=ti[1]=0;
243 	}
244 
245