Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 1 | /* crypto/des/cfb_enc.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 "e_os.h" |
| 60 | #include "des_locl.h" |
| 61 | #include <assert.h> |
| 62 | |
| 63 | /* The input and output are loaded in multiples of 8 bits. |
| 64 | * What this means is that if you hame numbits=12 and length=2 |
| 65 | * the first 12 bits will be retrieved from the first byte and half |
| 66 | * the second. The second 12 bits will come from the 3rd and half the 4th |
| 67 | * byte. |
| 68 | */ |
| 69 | /* Until Aug 1 2003 this function did not correctly implement CFB-r, so it |
| 70 | * will not be compatible with any encryption prior to that date. Ben. */ |
| 71 | void DES_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits, |
| 72 | long length, DES_key_schedule *schedule, DES_cblock *ivec, |
| 73 | int enc) |
| 74 | { |
| 75 | register DES_LONG d0,d1,v0,v1; |
| 76 | register unsigned long l=length; |
| 77 | register int num=numbits/8,n=(numbits+7)/8,i,rem=numbits%8; |
| 78 | DES_LONG ti[2]; |
| 79 | unsigned char *iv; |
| 80 | #ifndef L_ENDIAN |
| 81 | unsigned char ovec[16]; |
| 82 | #else |
| 83 | unsigned int sh[4]; |
| 84 | unsigned char *ovec=(unsigned char *)sh; |
| 85 | |
| 86 | /* I kind of count that compiler optimizes away this assertioni,*/ |
| 87 | assert (sizeof(sh[0])==4); /* as this holds true for all, */ |
| 88 | /* but 16-bit platforms... */ |
| 89 | |
| 90 | #endif |
| 91 | |
| 92 | if (numbits<=0 || numbits > 64) return; |
| 93 | iv = &(*ivec)[0]; |
| 94 | c2l(iv,v0); |
| 95 | c2l(iv,v1); |
| 96 | if (enc) |
| 97 | { |
| 98 | while (l >= (unsigned long)n) |
| 99 | { |
| 100 | l-=n; |
| 101 | ti[0]=v0; |
| 102 | ti[1]=v1; |
| 103 | DES_encrypt1((DES_LONG *)ti,schedule,DES_ENCRYPT); |
| 104 | c2ln(in,d0,d1,n); |
| 105 | in+=n; |
| 106 | d0^=ti[0]; |
| 107 | d1^=ti[1]; |
| 108 | l2cn(d0,d1,out,n); |
| 109 | out+=n; |
| 110 | /* 30-08-94 - eay - changed because l>>32 and |
| 111 | * l<<32 are bad under gcc :-( */ |
| 112 | if (numbits == 32) |
| 113 | { v0=v1; v1=d0; } |
| 114 | else if (numbits == 64) |
| 115 | { v0=d0; v1=d1; } |
| 116 | else |
| 117 | { |
| 118 | #ifndef L_ENDIAN |
| 119 | iv=&ovec[0]; |
| 120 | l2c(v0,iv); |
| 121 | l2c(v1,iv); |
| 122 | l2c(d0,iv); |
| 123 | l2c(d1,iv); |
| 124 | #else |
| 125 | sh[0]=v0, sh[1]=v1, sh[2]=d0, sh[3]=d1; |
| 126 | #endif |
| 127 | if (rem==0) |
| 128 | memmove(ovec,ovec+num,8); |
| 129 | else |
| 130 | for(i=0 ; i < 8 ; ++i) |
| 131 | ovec[i]=ovec[i+num]<<rem | |
| 132 | ovec[i+num+1]>>(8-rem); |
| 133 | #ifdef L_ENDIAN |
| 134 | v0=sh[0], v1=sh[1]; |
| 135 | #else |
| 136 | iv=&ovec[0]; |
| 137 | c2l(iv,v0); |
| 138 | c2l(iv,v1); |
| 139 | #endif |
| 140 | } |
| 141 | } |
| 142 | } |
| 143 | else |
| 144 | { |
| 145 | while (l >= (unsigned long)n) |
| 146 | { |
| 147 | l-=n; |
| 148 | ti[0]=v0; |
| 149 | ti[1]=v1; |
| 150 | DES_encrypt1((DES_LONG *)ti,schedule,DES_ENCRYPT); |
| 151 | c2ln(in,d0,d1,n); |
| 152 | in+=n; |
| 153 | /* 30-08-94 - eay - changed because l>>32 and |
| 154 | * l<<32 are bad under gcc :-( */ |
| 155 | if (numbits == 32) |
| 156 | { v0=v1; v1=d0; } |
| 157 | else if (numbits == 64) |
| 158 | { v0=d0; v1=d1; } |
| 159 | else |
| 160 | { |
| 161 | #ifndef L_ENDIAN |
| 162 | iv=&ovec[0]; |
| 163 | l2c(v0,iv); |
| 164 | l2c(v1,iv); |
| 165 | l2c(d0,iv); |
| 166 | l2c(d1,iv); |
| 167 | #else |
| 168 | sh[0]=v0, sh[1]=v1, sh[2]=d0, sh[3]=d1; |
| 169 | #endif |
| 170 | if (rem==0) |
| 171 | memmove(ovec,ovec+num,8); |
| 172 | else |
| 173 | for(i=0 ; i < 8 ; ++i) |
| 174 | ovec[i]=ovec[i+num]<<rem | |
| 175 | ovec[i+num+1]>>(8-rem); |
| 176 | #ifdef L_ENDIAN |
| 177 | v0=sh[0], v1=sh[1]; |
| 178 | #else |
| 179 | iv=&ovec[0]; |
| 180 | c2l(iv,v0); |
| 181 | c2l(iv,v1); |
| 182 | #endif |
| 183 | } |
| 184 | d0^=ti[0]; |
| 185 | d1^=ti[1]; |
| 186 | l2cn(d0,d1,out,n); |
| 187 | out+=n; |
| 188 | } |
| 189 | } |
| 190 | iv = &(*ivec)[0]; |
| 191 | l2c(v0,iv); |
| 192 | l2c(v1,iv); |
| 193 | v0=v1=d0=d1=ti[0]=ti[1]=0; |
| 194 | } |
| 195 | |