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libgcrypt-1.9-base
cipher/idea.c
379 строк
10 KB
NIIBE Yutaka
cipher: Fix IDEA cipher for clearing memory.
01 ноя 2016, 08:34
01 ноя 2016, 08:34
bf6d5b1
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/* idea.c - IDEA function * Copyright 1997, 1998, 1999, 2001 Werner Koch (dd9jn) * Copyright 2013 g10 Code GmbH * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * WERNER KOCH BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. * * Except as contained in this notice, the name of Werner Koch shall not be * used in advertising or otherwise to promote the sale, use or other dealings * in this Software without prior written authorization from Werner Koch. * * Patents on IDEA have expired: * Europe: EP0482154 on 2011-05-16, * Japan: JP3225440 on 2011-05-16, * U.S.: 5,214,703 on 2012-01-07. */ /* * Please see http://www.noepatents.org/ to learn why software patents * are bad for society and what you can do to fight them. * * The code herein is based on the one from: * Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1996. * ISBN 0-471-11709-9. */ #include <config.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #include <assert.h> #include "types.h" /* for byte and u32 typedefs */ #include "g10lib.h" #include "cipher.h" #define IDEA_KEYSIZE 16 #define IDEA_BLOCKSIZE 8 #define IDEA_ROUNDS 8 #define IDEA_KEYLEN (6*IDEA_ROUNDS+4) typedef struct { u16 ek[IDEA_KEYLEN]; u16 dk[IDEA_KEYLEN]; int have_dk; } IDEA_context; static const char *selftest(void); static u16 mul_inv( u16 x ) { u16 t0, t1; u16 q, y; if( x < 2 ) return x; t1 = 0x10001UL / x; y = 0x10001UL % 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( const 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 = t2; *--p = t3; *--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) ); wipememory(temp, sizeof(temp)); } static void cipher( byte *outbuf, const byte *inbuf, u16 *key ) { u16 s2, s3; u16 in[4]; int r = IDEA_ROUNDS; #define x1 (in[0]) #define x2 (in[1]) #define x3 (in[2]) #define x4 (in[3]) #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) memcpy (in, inbuf, sizeof in); #ifndef WORDS_BIGENDIAN 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); #ifndef WORDS_BIGENDIAN x1 = (x1>>8) | (x1<<8); x2 = (x2>>8) | (x2<<8); x3 = (x3>>8) | (x3<<8); x4 = (x4>>8) | (x4<<8); #endif memcpy (outbuf+0, &x1, 2); memcpy (outbuf+2, &x3, 2); memcpy (outbuf+4, &x2, 2); memcpy (outbuf+6, &x4, 2); #undef MUL #undef x1 #undef x2 #undef x3 #undef x4 } static int do_setkey( IDEA_context *c, const byte *key, unsigned int keylen ) { static int initialized = 0; static const char *selftest_failed = 0; if( !initialized ) { initialized = 1; selftest_failed = selftest(); if( selftest_failed ) log_error( "%s\n", selftest_failed ); } if( selftest_failed ) return GPG_ERR_SELFTEST_FAILED; assert(keylen == 16); c->have_dk = 0; expand_key( key, c->ek ); invert_key( c->ek, c->dk ); return 0; } static gcry_err_code_t idea_setkey (void *context, const byte *key, unsigned int keylen) { IDEA_context *ctx = context; int rc = do_setkey (ctx, key, keylen); _gcry_burn_stack (23+6*sizeof(void*)); return rc; } static void encrypt_block( IDEA_context *c, byte *outbuf, const byte *inbuf ) { cipher( outbuf, inbuf, c->ek ); } static unsigned int idea_encrypt (void *context, byte *out, const byte *in) { IDEA_context *ctx = context; encrypt_block (ctx, out, in); return /*burn_stack*/ (24+3*sizeof (void*)); } static void decrypt_block( IDEA_context *c, byte *outbuf, const byte *inbuf ) { if( !c->have_dk ) { c->have_dk = 1; invert_key( c->ek, c->dk ); } cipher( outbuf, inbuf, c->dk ); } static unsigned int idea_decrypt (void *context, byte *out, const byte *in) { IDEA_context *ctx = context; decrypt_block (ctx, out, in); return /*burn_stack*/ (24+3*sizeof (void*)); } static const char * selftest( void ) { static struct { byte key[16]; byte plain[8]; byte cipher[8]; } test_vectors[] = { { { 0x00, 0x01, 0x00, 0x02, 0x00, 0x03, 0x00, 0x04, 0x00, 0x05, 0x00, 0x06, 0x00, 0x07, 0x00, 0x08 }, { 0x00, 0x00, 0x00, 0x01, 0x00, 0x02, 0x00, 0x03 }, { 0x11, 0xFB, 0xED, 0x2B, 0x01, 0x98, 0x6D, 0xE5 } }, { { 0x00, 0x01, 0x00, 0x02, 0x00, 0x03, 0x00, 0x04, 0x00, 0x05, 0x00, 0x06, 0x00, 0x07, 0x00, 0x08 }, { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08 }, { 0x54, 0x0E, 0x5F, 0xEA, 0x18, 0xC2, 0xF8, 0xB1 } }, { { 0x00, 0x01, 0x00, 0x02, 0x00, 0x03, 0x00, 0x04, 0x00, 0x05, 0x00, 0x06, 0x00, 0x07, 0x00, 0x08 }, { 0x00, 0x19, 0x32, 0x4B, 0x64, 0x7D, 0x96, 0xAF }, { 0x9F, 0x0A, 0x0A, 0xB6, 0xE1, 0x0C, 0xED, 0x78 } }, { { 0x00, 0x01, 0x00, 0x02, 0x00, 0x03, 0x00, 0x04, 0x00, 0x05, 0x00, 0x06, 0x00, 0x07, 0x00, 0x08 }, { 0xF5, 0x20, 0x2D, 0x5B, 0x9C, 0x67, 0x1B, 0x08 }, { 0xCF, 0x18, 0xFD, 0x73, 0x55, 0xE2, 0xC5, 0xC5 } }, { { 0x00, 0x01, 0x00, 0x02, 0x00, 0x03, 0x00, 0x04, 0x00, 0x05, 0x00, 0x06, 0x00, 0x07, 0x00, 0x08 }, { 0xFA, 0xE6, 0xD2, 0xBE, 0xAA, 0x96, 0x82, 0x6E }, { 0x85, 0xDF, 0x52, 0x00, 0x56, 0x08, 0x19, 0x3D } }, { { 0x00, 0x01, 0x00, 0x02, 0x00, 0x03, 0x00, 0x04, 0x00, 0x05, 0x00, 0x06, 0x00, 0x07, 0x00, 0x08 }, { 0x0A, 0x14, 0x1E, 0x28, 0x32, 0x3C, 0x46, 0x50 }, { 0x2F, 0x7D, 0xE7, 0x50, 0x21, 0x2F, 0xB7, 0x34 } }, { { 0x00, 0x01, 0x00, 0x02, 0x00, 0x03, 0x00, 0x04, 0x00, 0x05, 0x00, 0x06, 0x00, 0x07, 0x00, 0x08 }, { 0x05, 0x0A, 0x0F, 0x14, 0x19, 0x1E, 0x23, 0x28 }, { 0x7B, 0x73, 0x14, 0x92, 0x5D, 0xE5, 0x9C, 0x09 } }, { { 0x00, 0x05, 0x00, 0x0A, 0x00, 0x0F, 0x00, 0x14, 0x00, 0x19, 0x00, 0x1E, 0x00, 0x23, 0x00, 0x28 }, { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08 }, { 0x3E, 0xC0, 0x47, 0x80, 0xBE, 0xFF, 0x6E, 0x20 } }, { { 0x3A, 0x98, 0x4E, 0x20, 0x00, 0x19, 0x5D, 0xB3, 0x2E, 0xE5, 0x01, 0xC8, 0xC4, 0x7C, 0xEA, 0x60 }, { 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08 }, { 0x97, 0xBC, 0xD8, 0x20, 0x07, 0x80, 0xDA, 0x86 } }, { { 0x00, 0x64, 0x00, 0xC8, 0x01, 0x2C, 0x01, 0x90, 0x01, 0xF4, 0x02, 0x58, 0x02, 0xBC, 0x03, 0x20 }, { 0x05, 0x32, 0x0A, 0x64, 0x14, 0xC8, 0x19, 0xFA }, { 0x65, 0xBE, 0x87, 0xE7, 0xA2, 0x53, 0x8A, 0xED } }, { { 0x9D, 0x40, 0x75, 0xC1, 0x03, 0xBC, 0x32, 0x2A, 0xFB, 0x03, 0xE7, 0xBE, 0x6A, 0xB3, 0x00, 0x06 }, { 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08 }, { 0xF5, 0xDB, 0x1A, 0xC4, 0x5E, 0x5E, 0xF9, 0xF9 } } }; IDEA_context c; byte buffer[8]; int i; for(i=0; i < DIM(test_vectors); i++ ) { do_setkey( &c, test_vectors[i].key, 16 ); encrypt_block( &c, buffer, test_vectors[i].plain ); if( memcmp( buffer, test_vectors[i].cipher, 8 ) ) return "IDEA test encryption failed."; decrypt_block( &c, buffer, test_vectors[i].cipher ); if( memcmp( buffer, test_vectors[i].plain, 8 ) ) return "IDEA test decryption failed."; } return NULL; } gcry_cipher_spec_t _gcry_cipher_spec_idea = { GCRY_CIPHER_IDEA, {0, 0}, "IDEA", NULL, NULL, IDEA_BLOCKSIZE, 128, sizeof (IDEA_context), idea_setkey, idea_encrypt, idea_decrypt };