diff options
Diffstat (limited to 'cipher/cipher.c')
| -rw-r--r-- | cipher/cipher.c | 573 |
1 files changed, 0 insertions, 573 deletions
diff --git a/cipher/cipher.c b/cipher/cipher.c deleted file mode 100644 index 601165b7..00000000 --- a/cipher/cipher.c +++ /dev/null @@ -1,573 +0,0 @@ -/* cipher.c - cipher dispatcher - * Copyright (C) 1998 Free Software Foundation, Inc. - * - * This file is part of GnuPG. - * - * GnuPG 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. - * - * GnuPG 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 <errno.h> -#include <assert.h> -#include "util.h" -#include "errors.h" -#include "cipher.h" -#include "des.h" -#include "blowfish.h" -#include "cast5.h" -#include "dynload.h" - - -#define MAX_BLOCKSIZE 16 -#define TABLE_SIZE 10 - -struct cipher_table_s { - const char *name; - int algo; - size_t blocksize; - size_t keylen; - size_t contextsize; /* allocate this amount of context */ - int (*setkey)( void *c, byte *key, unsigned keylen ); - void (*encrypt)( void *c, byte *outbuf, byte *inbuf ); - void (*decrypt)( void *c, byte *outbuf, byte *inbuf ); -}; - -static struct cipher_table_s cipher_table[TABLE_SIZE]; - - -struct cipher_handle_s { - int algo; - int mode; - size_t blocksize; - byte iv[MAX_BLOCKSIZE]; /* (this should be ulong aligned) */ - byte lastiv[MAX_BLOCKSIZE]; - int unused; /* in IV */ - int (*setkey)( void *c, byte *key, unsigned keylen ); - void (*encrypt)( void *c, byte *outbuf, byte *inbuf ); - void (*decrypt)( void *c, byte *outbuf, byte *inbuf ); - byte context[1]; -}; - - -static int -dummy_setkey( void *c, byte *key, unsigned keylen ) { return 0; } -static void -dummy_encrypt_block( void *c, byte *outbuf, byte *inbuf ) { BUG(); } -static void -dummy_decrypt_block( void *c, byte *outbuf, byte *inbuf ) { BUG(); } - - - -/**************** - * Put the static entries into the table. - */ -static void -setup_cipher_table(void) -{ - - int i; - - i = 0; - cipher_table[i].algo = CIPHER_ALGO_BLOWFISH; - cipher_table[i].name = blowfish_get_info( cipher_table[i].algo, - &cipher_table[i].keylen, - &cipher_table[i].blocksize, - &cipher_table[i].contextsize, - &cipher_table[i].setkey, - &cipher_table[i].encrypt, - &cipher_table[i].decrypt ); - if( !cipher_table[i].name ) - BUG(); - i++; - cipher_table[i].algo = CIPHER_ALGO_CAST5; - cipher_table[i].name = cast5_get_info( cipher_table[i].algo, - &cipher_table[i].keylen, - &cipher_table[i].blocksize, - &cipher_table[i].contextsize, - &cipher_table[i].setkey, - &cipher_table[i].encrypt, - &cipher_table[i].decrypt ); - if( !cipher_table[i].name ) - BUG(); - i++; - cipher_table[i].algo = CIPHER_ALGO_3DES; - cipher_table[i].name = des_get_info( cipher_table[i].algo, - &cipher_table[i].keylen, - &cipher_table[i].blocksize, - &cipher_table[i].contextsize, - &cipher_table[i].setkey, - &cipher_table[i].encrypt, - &cipher_table[i].decrypt ); - if( !cipher_table[i].name ) - BUG(); - i++; - cipher_table[i].algo = CIPHER_ALGO_BLOWFISH160; - cipher_table[i].name = blowfish_get_info( cipher_table[i].algo, - &cipher_table[i].keylen, - &cipher_table[i].blocksize, - &cipher_table[i].contextsize, - &cipher_table[i].setkey, - &cipher_table[i].encrypt, - &cipher_table[i].decrypt ); - if( !cipher_table[i].name ) - BUG(); - i++; - cipher_table[i].algo = CIPHER_ALGO_DUMMY; - cipher_table[i].name = "DUMMY"; - cipher_table[i].blocksize = 8; - cipher_table[i].keylen = 128; - cipher_table[i].contextsize = 0; - cipher_table[i].setkey = dummy_setkey; - cipher_table[i].encrypt = dummy_encrypt_block; - cipher_table[i].decrypt = dummy_decrypt_block; - i++; - - for( ; i < TABLE_SIZE; i++ ) - cipher_table[i].name = NULL; -} - - -/**************** - * Try to load all modules and return true if new modules are available - */ -static int -load_cipher_modules(void) -{ - static int done = 0; - static int initialized = 0; - void *context = NULL; - struct cipher_table_s *ct; - int ct_idx; - int i; - const char *name; - int any = 0; - - if( !initialized ) { - cipher_modules_constructor(); - setup_cipher_table(); /* load static modules on the first call */ - initialized = 1; - return 1; - } - - if( done ) - return 0; - done = 1; - - for(ct_idx=0, ct = cipher_table; ct_idx < TABLE_SIZE; ct_idx++,ct++ ) { - if( !ct->name ) - break; - } - if( ct_idx >= TABLE_SIZE-1 ) - BUG(); /* table already full */ - /* now load all extensions */ - while( (name = enum_gnupgext_ciphers( &context, &ct->algo, - &ct->keylen, &ct->blocksize, &ct->contextsize, - &ct->setkey, &ct->encrypt, &ct->decrypt)) ) { - if( ct->blocksize != 8 && ct->blocksize != 16 ) { - log_info("skipping cipher %d: unsupported blocksize\n", ct->algo); - continue; - } - for(i=0; cipher_table[i].name; i++ ) - if( cipher_table[i].algo == ct->algo ) - break; - if( cipher_table[i].name ) { - log_info("skipping cipher %d: already loaded\n", ct->algo ); - continue; - } - /* put it into the table */ - if( g10_opt_verbose > 1 ) - log_info("loaded cipher %d (%s)\n", ct->algo, name); - ct->name = name; - ct_idx++; - ct++; - any = 1; - /* check whether there are more available table slots */ - if( ct_idx >= TABLE_SIZE-1 ) { - log_info("cipher table full; ignoring other extensions\n"); - break; - } - } - enum_gnupgext_ciphers( &context, NULL, NULL, NULL, NULL, - NULL, NULL, NULL ); - return any; -} - - - - - - - -/**************** - * Map a string to the cipher algo - */ -int -string_to_cipher_algo( const char *string ) -{ - int i; - const char *s; - - do { - for(i=0; (s=cipher_table[i].name); i++ ) - if( !stricmp( s, string ) ) - return cipher_table[i].algo; - } while( load_cipher_modules() ); - return 0; -} - -/**************** - * Map a cipher algo to a string - */ -const char * -cipher_algo_to_string( int algo ) -{ - int i; - - do { - for(i=0; cipher_table[i].name; i++ ) - if( cipher_table[i].algo == algo ) - return cipher_table[i].name; - } while( load_cipher_modules() ); - return NULL; -} - -/**************** - * Return 0 if the cipher algo is available - */ -int -check_cipher_algo( int algo ) -{ - int i; - - do { - for(i=0; cipher_table[i].name; i++ ) - if( cipher_table[i].algo == algo ) - return 0; /* okay */ - } while( load_cipher_modules() ); - return G10ERR_CIPHER_ALGO; -} - - -unsigned -cipher_get_keylen( int algo ) -{ - int i; - unsigned len = 0; - - do { - for(i=0; cipher_table[i].name; i++ ) { - if( cipher_table[i].algo == algo ) { - len = cipher_table[i].keylen; - if( !len ) - log_bug("cipher %d w/o key length\n", algo ); - return len; - } - } - } while( load_cipher_modules() ); - log_bug("cipher %d not found\n", algo ); - return 0; -} - -unsigned -cipher_get_blocksize( int algo ) -{ - int i; - unsigned len = 0; - - do { - for(i=0; cipher_table[i].name; i++ ) { - if( cipher_table[i].algo == algo ) { - len = cipher_table[i].blocksize; - if( !len ) - log_bug("cipher %d w/o blocksize\n", algo ); - return len; - } - } - } while( load_cipher_modules() ); - log_bug("cipher %d not found\n", algo ); - return 0; -} - - -/**************** - * Open a cipher handle for use with algorithm ALGO, in mode MODE - * and put it into secure memory if SECURE is true. - */ -CIPHER_HANDLE -cipher_open( int algo, int mode, int secure ) -{ - CIPHER_HANDLE hd; - int i; - - fast_random_poll(); - do { - for(i=0; cipher_table[i].name; i++ ) - if( cipher_table[i].algo == algo ) - break; - } while( !cipher_table[i].name && load_cipher_modules() ); - if( !cipher_table[i].name ) { - log_fatal("cipher_open: algorithm %d not available\n", algo ); - return NULL; - } - - /* ? perform selftest here and mark this with a flag in cipher_table ? */ - - hd = secure ? m_alloc_secure_clear( sizeof *hd - + cipher_table[i].contextsize ) - : m_alloc_clear( sizeof *hd + cipher_table[i].contextsize ); - hd->algo = algo; - hd->blocksize = cipher_table[i].blocksize; - hd->setkey = cipher_table[i].setkey; - hd->encrypt = cipher_table[i].encrypt; - hd->decrypt = cipher_table[i].decrypt; - if( algo == CIPHER_ALGO_DUMMY ) - hd->mode = CIPHER_MODE_DUMMY; - else if( mode == CIPHER_MODE_AUTO_CFB ) { - if( algo == CIPHER_ALGO_BLOWFISH160 || algo >= 100 ) - hd->mode = CIPHER_MODE_CFB; - else - hd->mode = CIPHER_MODE_PHILS_CFB; - } - else - hd->mode = mode; - - return hd; -} - - -void -cipher_close( CIPHER_HANDLE c ) -{ - m_free(c); -} - - -int -cipher_setkey( CIPHER_HANDLE c, byte *key, unsigned keylen ) -{ - return (*c->setkey)( &c->context, key, keylen ); -} - - - -void -cipher_setiv( CIPHER_HANDLE c, const byte *iv ) -{ - if( iv ) - memcpy( c->iv, iv, c->blocksize ); - else - memset( c->iv, 0, c->blocksize ); - c->unused = 0; -} - - - -static void -do_ecb_encrypt( CIPHER_HANDLE c, byte *outbuf, byte *inbuf, unsigned nblocks ) -{ - unsigned n; - - for(n=0; n < nblocks; n++ ) { - (*c->encrypt)( &c->context, outbuf, inbuf ); - inbuf += c->blocksize; - outbuf += c->blocksize; - } -} - -static void -do_ecb_decrypt( CIPHER_HANDLE c, byte *outbuf, byte *inbuf, unsigned nblocks ) -{ - unsigned n; - - for(n=0; n < nblocks; n++ ) { - (*c->decrypt)( &c->context, outbuf, inbuf ); - inbuf += c->blocksize; - outbuf += c->blocksize; - } -} - - -static void -do_cfb_encrypt( CIPHER_HANDLE c, byte *outbuf, byte *inbuf, unsigned nbytes ) -{ - byte *ivp; - size_t blocksize = c->blocksize; - - if( nbytes <= c->unused ) { - /* short enough to be encoded by the remaining XOR mask */ - /* XOR the input with the IV and store input into IV */ - for(ivp=c->iv+c->blocksize - c->unused; nbytes; nbytes--, c->unused-- ) - *outbuf++ = (*ivp++ ^= *inbuf++); - return; - } - - if( c->unused ) { - /* XOR the input with the IV and store input into IV */ - nbytes -= c->unused; - for(ivp=c->iv+blocksize - c->unused; c->unused; c->unused-- ) - *outbuf++ = (*ivp++ ^= *inbuf++); - } - - /* now we can process complete blocks */ - while( nbytes >= blocksize ) { - int i; - /* encrypt the IV (and save the current one) */ - memcpy( c->lastiv, c->iv, blocksize ); - (*c->encrypt)( &c->context, c->iv, c->iv ); - /* XOR the input with the IV and store input into IV */ - for(ivp=c->iv,i=0; i < blocksize; i++ ) - *outbuf++ = (*ivp++ ^= *inbuf++); - nbytes -= blocksize; - } - if( nbytes ) { /* process the remaining bytes */ - /* encrypt the IV (and save the current one) */ - memcpy( c->lastiv, c->iv, blocksize ); - (*c->encrypt)( &c->context, c->iv, c->iv ); - c->unused = blocksize; - /* and apply the xor */ - c->unused -= nbytes; - for(ivp=c->iv; nbytes; nbytes-- ) - *outbuf++ = (*ivp++ ^= *inbuf++); - } -} - -static void -do_cfb_decrypt( CIPHER_HANDLE c, byte *outbuf, byte *inbuf, unsigned nbytes ) -{ - byte *ivp; - ulong temp; - size_t blocksize = c->blocksize; - - if( nbytes <= c->unused ) { - /* short enough to be encoded by the remaining XOR mask */ - /* XOR the input with the IV and store input into IV */ - for(ivp=c->iv+blocksize - c->unused; nbytes; nbytes--,c->unused--){ - temp = *inbuf++; - *outbuf++ = *ivp ^ temp; - *ivp++ = temp; - } - return; - } - - if( c->unused ) { - /* XOR the input with the IV and store input into IV */ - nbytes -= c->unused; - for(ivp=c->iv+blocksize - c->unused; c->unused; c->unused-- ) { - temp = *inbuf++; - *outbuf++ = *ivp ^ temp; - *ivp++ = temp; - } - } - - /* now we can process complete blocks */ - while( nbytes >= blocksize ) { - int i; - /* encrypt the IV (and save the current one) */ - memcpy( c->lastiv, c->iv, blocksize ); - (*c->encrypt)( &c->context, c->iv, c->iv ); - /* XOR the input with the IV and store input into IV */ - for(ivp=c->iv,i=0; i < blocksize; i++ ) { - temp = *inbuf++; - *outbuf++ = *ivp ^ temp; - *ivp++ = temp; - } - nbytes -= blocksize; - } - if( nbytes ) { /* process the remaining bytes */ - /* encrypt the IV (and save the current one) */ - memcpy( c->lastiv, c->iv, blocksize ); - (*c->encrypt)( &c->context, c->iv, c->iv ); - c->unused = blocksize; - /* and apply the xor */ - c->unused -= nbytes; - for(ivp=c->iv; nbytes; nbytes-- ) { - temp = *inbuf++; - *outbuf++ = *ivp ^ temp; - *ivp++ = temp; - } - } -} - - -/**************** - * Encrypt INBUF to OUTBUF with the mode selected at open. - * inbuf and outbuf may overlap or be the same. - * Depending on the mode some some contraints apply to NBYTES. - */ -void -cipher_encrypt( CIPHER_HANDLE c, byte *outbuf, byte *inbuf, unsigned nbytes ) -{ - switch( c->mode ) { - case CIPHER_MODE_ECB: - assert(!(nbytes%8)); - do_ecb_encrypt(c, outbuf, inbuf, nbytes/8 ); - break; - case CIPHER_MODE_CFB: - case CIPHER_MODE_PHILS_CFB: - do_cfb_encrypt(c, outbuf, inbuf, nbytes ); - break; - case CIPHER_MODE_DUMMY: - if( inbuf != outbuf ) - memmove( outbuf, inbuf, nbytes ); - break; - default: log_fatal("cipher_encrypt: invalid mode %d\n", c->mode ); - } -} - - -/**************** - * Decrypt INBUF to OUTBUF with the mode selected at open. - * inbuf and outbuf may overlap or be the same. - * Depending on the mode some some contraints apply to NBYTES. - */ -void -cipher_decrypt( CIPHER_HANDLE c, byte *outbuf, byte *inbuf, unsigned nbytes ) -{ - switch( c->mode ) { - case CIPHER_MODE_ECB: - assert(!(nbytes%8)); - do_ecb_decrypt(c, outbuf, inbuf, nbytes/8 ); - break; - case CIPHER_MODE_CFB: - case CIPHER_MODE_PHILS_CFB: - do_cfb_decrypt(c, outbuf, inbuf, nbytes ); - break; - case CIPHER_MODE_DUMMY: - if( inbuf != outbuf ) - memmove( outbuf, inbuf, nbytes ); - break; - default: log_fatal("cipher_decrypt: invalid mode %d\n", c->mode ); - } -} - - - -/**************** - * Used for PGP's somewhat strange CFB mode. Only works if - * the handle is in PHILS_CFB mode - */ -void -cipher_sync( CIPHER_HANDLE c ) -{ - if( c->mode == CIPHER_MODE_PHILS_CFB && c->unused ) { - memmove(c->iv + c->unused, c->iv, c->blocksize - c->unused ); - memcpy(c->iv, c->lastiv + c->blocksize - c->unused, c->unused); - c->unused = 0; - } -} - |