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author | Werner Koch <[email protected]> | 1997-11-24 11:04:11 +0000 |
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committer | Werner Koch <[email protected]> | 1997-11-24 11:04:11 +0000 |
commit | a51cca90b6c8d3628d9b97a08f9370b3e249a9b6 (patch) | |
tree | 093b652e684cef1623777be8ea2b96876f9ee1e7 /cipher/idea.c | |
parent | compress stuff implemented (diff) | |
download | gnupg-a51cca90b6c8d3628d9b97a08f9370b3e249a9b6.tar.gz gnupg-a51cca90b6c8d3628d9b97a08f9370b3e249a9b6.zip |
IDEA removed, signing works
Diffstat (limited to 'cipher/idea.c')
-rw-r--r-- | cipher/idea.c | 352 |
1 files changed, 0 insertions, 352 deletions
diff --git a/cipher/idea.c b/cipher/idea.c deleted file mode 100644 index 3d1b01a98..000000000 --- a/cipher/idea.c +++ /dev/null @@ -1,352 +0,0 @@ -/* idea.c - IDEA function - * Copyright (c) 1997 by Werner Koch (dd9jn) - * - * ATTENTION: This code patented and needs a license for any commercial use. - * - * The code herin is take from: - * Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1996. - * ISBN 0-471-11709-9. . - * - * This file is part of G10. - * - * G10 is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * G10 is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA - */ - -#include <config.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include "util.h" -#include "types.h" -#include "idea.h" - - - -static u16 -mul_inv( u16 x ) -{ - u16 t0, t1; - u16 q, y; - - if( x < 2 ) - return x; - t1 = 0x10001L / x; - y = 0x10001L % x; - if( y == 1 ) - return (1-t1) & 0xffff; - - t0 = 1; - do { - q = x / y; - x = x % y; - t0 += q * t1; - if( x == 1 ) - return t0; - q = y / x; - y = y % x; - t1 += q * t0; - } while( y != 1 ); - return (1-t1) & 0xffff; -} - - - -static void -expand_key( byte *userkey, u16 *ek ) -{ - int i,j; - - for(j=0; j < 8; j++ ) { - ek[j] = (*userkey << 8) + userkey[1]; - userkey += 2; - } - for(i=0; j < IDEA_KEYLEN; j++ ) { - i++; - ek[i+7] = ek[i&7] << 9 | ek[(i+1)&7] >> 7; - ek += i & 8; - i &= 7; - } -} - - -static void -invert_key( u16 *ek, u16 dk[IDEA_KEYLEN] ) -{ - int i; - u16 t1, t2, t3; - u16 temp[IDEA_KEYLEN]; - u16 *p = temp + IDEA_KEYLEN; - - t1 = mul_inv( *ek++ ); - t2 = -*ek++; - t3 = -*ek++; - *--p = mul_inv( *ek++ ); - *--p = t3; - *--p = t2; - *--p = t1; - - for(i=0; i < IDEA_ROUNDS-1; i++ ) { - t1 = *ek++; - *--p = *ek++; - *--p = t1; - - t1 = mul_inv( *ek++ ); - t2 = -*ek++; - t3 = -*ek++; - *--p = mul_inv( *ek++ ); - *--p = t3; - *--p = t2; - *--p = t1; - } - t1 = *ek++; - *--p = *ek++; - *--p = t1; - - t1 = mul_inv( *ek++ ); - t2 = -*ek++; - t3 = -*ek++; - *--p = mul_inv( *ek++ ); - *--p = t3; - *--p = t2; - *--p = t1; - memcpy(dk, temp, sizeof(temp) ); - memset(temp, 0, sizeof(temp) ); /* burn temp */ -} - - -static void -cipher( byte *outbuf, byte *inbuf, u16 *key ) -{ - u16 x1, x2, x3,x4, s2, s3; - u16 *in, *out; - int r = IDEA_ROUNDS; - #define MUL(x,y) \ - do {u16 _t16; u32 _t32; \ - if( (_t16 = (y)) ) { \ - if( (x = (x)&0xffff) ) { \ - _t32 = (u32)x * _t16; \ - x = _t32 & 0xffff; \ - _t16 = _t32 >> 16; \ - x = ((x)-_t16) + (x<_t16?1:0); \ - } \ - else { \ - x = 1 - _t16; \ - } \ - } \ - else { \ - x = 1 - x; \ - } \ - } while(0) - - in = (u16*)inbuf; - x1 = *in++; - x2 = *in++; - x3 = *in++; - x4 = *in; - #ifdef HAVE_LITTLE_ENDIAN - x1 = (x1>>8) | (x1<<8); - x2 = (x2>>8) | (x2<<8); - x3 = (x3>>8) | (x3<<8); - x4 = (x4>>8) | (x4<<8); - #endif - do { - MUL(x1, *key++); - x2 += *key++; - x3 += *key++; - MUL(x4, *key++ ); - - s3 = x3; - x3 ^= x1; - MUL(x3, *key++); - s2 = x2; - x2 ^=x4; - x2 += x3; - MUL(x2, *key++); - x3 += x2; - - x1 ^= x2; - x4 ^= x3; - - x2 ^= s3; - x3 ^= s2; - } while( --r ); - MUL(x1, *key++); - x3 += *key++; - x2 += *key++; - MUL(x4, *key); - - out = (u16*)outbuf; - #ifdef HAVE_LITTLE_ENDIAN - *out++ = (x1>>8) | (x1<<8); - *out++ = (x3>>8) | (x3<<8); - *out++ = (x2>>8) | (x2<<8); - *out = (x4>>8) | (x4<<8); - #else - *out++ = x1; - *out++ = x3; - *out++ = x2; - *out = x4; - #endif - #undef MUL -} - - -void -idea_setkey( IDEA_context *c, byte *key ) -{ - expand_key( key, c->ek ); - invert_key( c->ek, c->dk ); -} - -void -idea_setiv( IDEA_context *c, byte *iv ) -{ - if( iv ) - memcpy( c->iv, iv, IDEA_BLOCKSIZE ); - else - memset( c->iv, 0, IDEA_BLOCKSIZE ); - c->nleft = 0; -} - - -void -idea_encode( IDEA_context *c, byte *outbuf, byte *inbuf, unsigned nblocks ) -{ - unsigned n; - - for(n=0; n < nblocks; n++ ) { - cipher( outbuf, inbuf, c->ek ); - inbuf += 8; - outbuf += 8; - } -} - - -void -idea_decode( IDEA_context *c, byte *outbuf, byte *inbuf, unsigned nblocks ) -{ - unsigned n; - - for(n=0; n < nblocks; n++ ) { - cipher( outbuf, inbuf, c->dk ); - inbuf += 8; - outbuf += 8; - } -} - - -static void -cfbshift( byte *iv, byte *buf, unsigned count) -{ - unsigned n; - - if( count ) { - for( n = IDEA_BLOCKSIZE - count; n; n-- ) - *iv++ = iv[count]; - for( ; count; count-- ) - *iv++ = *buf++; - } -} - - -/**************** - * FIXME: Make use of bigger chunks - */ -static void -xorblock( byte *out, byte *a, byte *b, unsigned count ) -{ - for( ; count ; count--, a++, b++ ) - *out++ = *a ^ *b ; -} - - -void -idea_encode_cfb( IDEA_context *c, byte *outbuf, byte *inbuf, unsigned nbytes) -{ - byte temp[IDEA_BLOCKSIZE]; - - while( nbytes >= IDEA_BLOCKSIZE ) { - cipher( temp, c->iv, c->ek ); - xorblock( outbuf, inbuf, temp, IDEA_BLOCKSIZE); - cfbshift( c->iv, outbuf, IDEA_BLOCKSIZE ); - nbytes -= IDEA_BLOCKSIZE; - inbuf += IDEA_BLOCKSIZE; - outbuf += IDEA_BLOCKSIZE; - } - if( nbytes ) { - cipher( temp, c->iv, c->ek ); - xorblock( outbuf, inbuf, temp, nbytes ); - cfbshift( c->iv, outbuf, nbytes ); - } -} - - -void -idea_decode_cfb( IDEA_context *c, byte *outbuf, byte *inbuf, unsigned nbytes) -{ - byte t, *ivptr; - - ivptr = c->iv + IDEA_BLOCKSIZE - c->nleft; - if( nbytes <= c->nleft ) { - c->nleft -= nbytes; - for( ; nbytes ; nbytes--, ivptr++, inbuf++ ) { - t = *ivptr; - *outbuf++ = t ^ (*ivptr = *inbuf) ; - } - return; - } - - nbytes -= c->nleft; - for( ; c->nleft ; c->nleft--, ivptr++, inbuf++ ) { - t = *ivptr; - *outbuf++ = t ^ (*ivptr = *inbuf) ; - } - - while( nbytes >= IDEA_BLOCKSIZE ) { - memcpy(c->lastcipher, c->iv, IDEA_BLOCKSIZE); - cipher( c->iv, c->iv, c->ek ); - c->nleft = IDEA_BLOCKSIZE; - nbytes -= IDEA_BLOCKSIZE; - ivptr = c->iv; - for( ; c->nleft; c->nleft--, ivptr++, inbuf++ ) { - t = *ivptr; - *outbuf++ = t ^ (*ivptr = *inbuf) ; - } - } - memcpy(c->lastcipher, c->iv, IDEA_BLOCKSIZE); - cipher( c->iv, c->iv, c->ek ); - c->nleft = IDEA_BLOCKSIZE - nbytes; - ivptr = c->iv; - for( ; nbytes; nbytes--, ivptr++, inbuf++ ) { - t = *ivptr; - *outbuf++ = t ^ (*ivptr = *inbuf) ; - } -} - - -/**************** - * This is used for the special way IDEA CFB is used in PGP - */ -void -idea_sync_cfb( IDEA_context *c ) -{ - if( c->nleft ) { - memmove(c->iv + c->nleft, c->iv, IDEA_BLOCKSIZE - c->nleft ); - memcpy(c->iv, c->lastcipher + IDEA_BLOCKSIZE - c->nleft, c->nleft); - c->nleft = 0; - } -} - - |