Diffstat (limited to 'pwmanager/libcrypt/cipher/cipher.c') (more/less context) (ignore whitespace changes)
| -rw-r--r-- | pwmanager/libcrypt/cipher/cipher.c | 1391 |
1 files changed, 1391 insertions, 0 deletions
diff --git a/pwmanager/libcrypt/cipher/cipher.c b/pwmanager/libcrypt/cipher/cipher.c new file mode 100644 index 0000000..78ea940 --- a/dev/null +++ b/pwmanager/libcrypt/cipher/cipher.c @@ -0,0 +1,1391 @@ +/* cipher.c - cipher dispatcher + * Copyright (C) 1998,1999,2000,2001,2002,2003 Free Software Foundation, Inc. + * + * This file is part of Libgcrypt. + * + * Libgcrypt is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser general Public License as + * published by the Free Software Foundation; either version 2.1 of + * the License, or (at your option) any later version. + * + * Libgcrypt 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 Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser 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 "g10lib.h" +#include "cipher.h" +#include "ath.h" + +#define MAX_BLOCKSIZE 16 +#define TABLE_SIZE 14 +#define CTX_MAGIC_NORMAL 0x24091964 +#define CTX_MAGIC_SECURE 0x46919042 + +/* This is the list of the default ciphers, which are included in + libgcrypt. */ +static struct cipher_table_entry +{ + gcry_cipher_spec_t *cipher; + unsigned int algorithm; +} cipher_table[] = + { +#if USE_BLOWFISH + { &_gcry_cipher_spec_blowfish, GCRY_CIPHER_BLOWFISH }, +#endif +#if USE_DES + { &_gcry_cipher_spec_des, GCRY_CIPHER_DES }, + { &_gcry_cipher_spec_tripledes, GCRY_CIPHER_3DES }, +#endif +#if USE_ARCFOUR + { &_gcry_cipher_spec_arcfour, GCRY_CIPHER_ARCFOUR }, +#endif +#if USE_CAST5 + { &_gcry_cipher_spec_cast5, GCRY_CIPHER_CAST5 }, +#endif +#if USE_AES + { &_gcry_cipher_spec_aes, GCRY_CIPHER_AES }, + { &_gcry_cipher_spec_aes192, GCRY_CIPHER_AES192 }, + { &_gcry_cipher_spec_aes256, GCRY_CIPHER_AES256 }, +#endif +#if USE_TWOFISH + { &_gcry_cipher_spec_twofish, GCRY_CIPHER_TWOFISH }, + { &_gcry_cipher_spec_twofish128, GCRY_CIPHER_TWOFISH128 }, +#endif +#if USE_SERPENT + { &_gcry_cipher_spec_serpent128, GCRY_CIPHER_SERPENT128 }, + { &_gcry_cipher_spec_serpent192, GCRY_CIPHER_SERPENT192 }, + { &_gcry_cipher_spec_serpent256, GCRY_CIPHER_SERPENT256 }, +#endif +#ifdef USE_RFC2268 + { &_gcry_cipher_spec_rfc2268_40, GCRY_CIPHER_RFC2268_40 }, +#endif + { NULL }, + }; + +/* List of registered ciphers. */ +static gcry_module_t ciphers_registered; + +/* This is the lock protecting CIPHERS_REGISTERED. */ +static ath_mutex_t ciphers_registered_lock = ATH_MUTEX_INITIALIZER; + +/* Flag to check wether the default ciphers have already been + registered. */ +static int default_ciphers_registered; + +/* Convenient macro for registering the default ciphers. */ +#define REGISTER_DEFAULT_CIPHERS \ + do \ + { \ + ath_mutex_lock (&ciphers_registered_lock); \ + if (! default_ciphers_registered) \ + { \ + gcry_cipher_register_default (); \ + default_ciphers_registered = 1; \ + } \ + ath_mutex_unlock (&ciphers_registered_lock); \ + } \ + while (0) + +/* The handle structure. */ +struct gcry_cipher_handle +{ + int magic; + size_t actual_handle_size; /* Allocated size of this handle. */ + gcry_cipher_spec_t *cipher; + gcry_module_t module; + int mode; + unsigned int flags; + unsigned char iv[MAX_BLOCKSIZE]; /* (this should be ulong aligned) */ + unsigned char lastiv[MAX_BLOCKSIZE]; + int unused; /* in IV */ + unsigned char ctr[MAX_BLOCKSIZE]; /* For Counter (CTR) mode. */ + PROPERLY_ALIGNED_TYPE context; +}; + + +/* These dummy functions are used in case a cipher implementation + refuses to provide it's own functions. */ + +static gcry_err_code_t +dummy_setkey (void *c, const unsigned char *key, unsigned keylen) +{ + return GPG_ERR_NO_ERROR; +} + +static void +dummy_encrypt_block (void *c, + unsigned char *outbuf, const unsigned char *inbuf) +{ + BUG(); +} + +static void +dummy_decrypt_block (void *c, + unsigned char *outbuf, const unsigned char *inbuf) +{ + BUG(); +} + +static void +dummy_encrypt_stream (void *c, + unsigned char *outbuf, const unsigned char *inbuf, + unsigned int n) +{ + BUG(); +} + +static void +dummy_decrypt_stream (void *c, + unsigned char *outbuf, const unsigned char *inbuf, + unsigned int n) +{ + BUG(); +} + + +/* Internal function. Register all the ciphers included in + CIPHER_TABLE. Note, that this function gets only used by the macro + REGISTER_DEFAULT_CIPHERS which protects it using a mutex. */ +static void +gcry_cipher_register_default (void) +{ + gcry_err_code_t err = GPG_ERR_NO_ERROR; + int i; + + for (i = 0; !err && cipher_table[i].cipher; i++) + { + if (! cipher_table[i].cipher->setkey) + cipher_table[i].cipher->setkey = dummy_setkey; + if (! cipher_table[i].cipher->encrypt) + cipher_table[i].cipher->encrypt = dummy_encrypt_block; + if (! cipher_table[i].cipher->decrypt) + cipher_table[i].cipher->decrypt = dummy_decrypt_block; + if (! cipher_table[i].cipher->stencrypt) + cipher_table[i].cipher->stencrypt = dummy_encrypt_stream; + if (! cipher_table[i].cipher->stdecrypt) + cipher_table[i].cipher->stdecrypt = dummy_decrypt_stream; + + err = _gcry_module_add (&ciphers_registered, + cipher_table[i].algorithm, + (void *) cipher_table[i].cipher, + NULL); + } + + if (err) + BUG (); +} + +/* Internal callback function. Used via _gcry_module_lookup. */ +static int +gcry_cipher_lookup_func_name (void *spec, void *data) +{ + gcry_cipher_spec_t *cipher = (gcry_cipher_spec_t *) spec; + char *name = (char *) data; + const char **aliases = cipher->aliases; + int i, ret = ! stricmp (name, cipher->name); + + if (aliases) + for (i = 0; aliases[i] && (! ret); i++) + ret = ! stricmp (name, aliases[i]); + + return ret; +} + +/* Internal callback function. Used via _gcry_module_lookup. */ +static int +gcry_cipher_lookup_func_oid (void *spec, void *data) +{ + gcry_cipher_spec_t *cipher = (gcry_cipher_spec_t *) spec; + char *oid = (char *) data; + gcry_cipher_oid_spec_t *oid_specs = cipher->oids; + int ret = 0, i; + + if (oid_specs) + for (i = 0; oid_specs[i].oid && (! ret); i++) + if (! stricmp (oid, oid_specs[i].oid)) + ret = 1; + + return ret; +} + +/* Internal function. Lookup a cipher entry by it's name. */ +static gcry_module_t +gcry_cipher_lookup_name (const char *name) +{ + gcry_module_t cipher; + + cipher = _gcry_module_lookup (ciphers_registered, (void *) name, + gcry_cipher_lookup_func_name); + + return cipher; +} + +/* Internal function. Lookup a cipher entry by it's oid. */ +static gcry_module_t +gcry_cipher_lookup_oid (const char *oid) +{ + gcry_module_t cipher; + + cipher = _gcry_module_lookup (ciphers_registered, (void *) oid, + gcry_cipher_lookup_func_oid); + + return cipher; +} + +/* Register a new cipher module whose specification can be found in + CIPHER. On success, a new algorithm ID is stored in ALGORITHM_ID + and a pointer representhing this module is stored in MODULE. */ +gcry_error_t +gcry_cipher_register (gcry_cipher_spec_t *cipher, + unsigned int *algorithm_id, + gcry_module_t *module) +{ + gcry_err_code_t err = 0; + gcry_module_t mod; + + ath_mutex_lock (&ciphers_registered_lock); + err = _gcry_module_add (&ciphers_registered, 0, + (void *) cipher, &mod); + ath_mutex_unlock (&ciphers_registered_lock); + + if (! err) + { + *module = mod; + *algorithm_id = mod->mod_id; + } + + return gcry_error (err); +} + +/* Unregister the cipher identified by MODULE, which must have been + registered with gcry_cipher_register. */ +void +gcry_cipher_unregister (gcry_module_t module) +{ + ath_mutex_lock (&ciphers_registered_lock); + _gcry_module_release (module); + ath_mutex_unlock (&ciphers_registered_lock); +} + +/* Locate the OID in the oid table and return the index or -1 when not + found. An opitonal "oid." or "OID." prefix in OID is ignored, the + OID is expected to be in standard IETF dotted notation. The + internal algorithm number is returned in ALGORITHM unless it + ispassed as NULL. A pointer to the specification of the module + implementing this algorithm is return in OID_SPEC unless passed as + NULL.*/ +static int +search_oid (const char *oid, int *algorithm, gcry_cipher_oid_spec_t *oid_spec) +{ + gcry_module_t module; + int ret = 0; + + if (oid && ((! strncmp (oid, "oid.", 4)) + || (! strncmp (oid, "OID.", 4)))) + oid += 4; + + module = gcry_cipher_lookup_oid (oid); + if (module) + { + gcry_cipher_spec_t *cipher = module->spec; + int i; + + for (i = 0; cipher->oids[i].oid && !ret; i++) + if (! stricmp (oid, cipher->oids[i].oid)) + { + if (algorithm) + *algorithm = module->mod_id; + if (oid_spec) + *oid_spec = cipher->oids[i]; + ret = 1; + } + _gcry_module_release (module); + } + + return ret; +} + +/* Map STRING to the cipher algorithm identifier. Returns the + algorithm ID of the cipher for the given name or 0 if the name is + not known. It is valid to pass NULL for STRING which results in a + return value of 0. */ +int +gcry_cipher_map_name (const char *string) +{ + gcry_module_t cipher; + int ret, algorithm = 0; + + if (! string) + return 0; + + REGISTER_DEFAULT_CIPHERS; + + /* If the string starts with a digit (optionally prefixed with + either "OID." or "oid."), we first look into our table of ASN.1 + object identifiers to figure out the algorithm */ + + ath_mutex_lock (&ciphers_registered_lock); + + ret = search_oid (string, &algorithm, NULL); + if (! ret) + { + cipher = gcry_cipher_lookup_name (string); + if (cipher) + { + algorithm = cipher->mod_id; + _gcry_module_release (cipher); + } + } + + ath_mutex_unlock (&ciphers_registered_lock); + + return algorithm; +} + + +/* Given a STRING with an OID in dotted decimal notation, this + function returns the cipher mode (GCRY_CIPHER_MODE_*) associated + with that OID or 0 if no mode is known. Passing NULL for string + yields a return value of 0. */ +int +gcry_cipher_mode_from_oid (const char *string) +{ + gcry_cipher_oid_spec_t oid_spec; + int ret = 0, mode = 0; + + if (!string) + return 0; + + ath_mutex_lock (&ciphers_registered_lock); + ret = search_oid (string, NULL, &oid_spec); + if (ret) + mode = oid_spec.mode; + ath_mutex_unlock (&ciphers_registered_lock); + + return mode; +} + + +/* Map the cipher algorithm identifier ALGORITHM to a string + representing this algorithm. This string is the default name as + used by Libgcrypt. NULL is returned for an unknown algorithm. */ +static const char * +cipher_algo_to_string (int algorithm) +{ + gcry_module_t cipher; + const char *name = NULL; + + REGISTER_DEFAULT_CIPHERS; + + ath_mutex_lock (&ciphers_registered_lock); + cipher = _gcry_module_lookup_id (ciphers_registered, algorithm); + if (cipher) + { + name = ((gcry_cipher_spec_t *) cipher->spec)->name; + _gcry_module_release (cipher); + } + ath_mutex_unlock (&ciphers_registered_lock); + + return name; +} + +/* Map the cipher algorithm identifier ALGORITHM to a string + representing this algorithm. This string is the default name as + used by Libgcrypt. An pointer to an empty string is returned for + an unknown algorithm. NULL is never returned. */ +const char * +gcry_cipher_algo_name (int algorithm) +{ + const char *s = cipher_algo_to_string (algorithm); + return s ? s : ""; +} + + +/* Flag the cipher algorithm with the identifier ALGORITHM as + disabled. There is no error return, the function does nothing for + unknown algorithms. Disabled algorithms are vitually not available + in Libgcrypt. */ +static void +disable_cipher_algo (int algorithm) +{ + gcry_module_t cipher; + + REGISTER_DEFAULT_CIPHERS; + + ath_mutex_lock (&ciphers_registered_lock); + cipher = _gcry_module_lookup_id (ciphers_registered, algorithm); + if (cipher) + { + if (! (cipher->flags & FLAG_MODULE_DISABLED)) + cipher->flags |= FLAG_MODULE_DISABLED; + _gcry_module_release (cipher); + } + ath_mutex_unlock (&ciphers_registered_lock); +} + + +/* Return 0 if the cipher algorithm with indentifier ALGORITHM is + available. Returns a basic error code value if it is not available. */ +static gcry_err_code_t +check_cipher_algo (int algorithm) +{ + gcry_err_code_t err = GPG_ERR_NO_ERROR; + gcry_module_t cipher; + + REGISTER_DEFAULT_CIPHERS; + + ath_mutex_lock (&ciphers_registered_lock); + cipher = _gcry_module_lookup_id (ciphers_registered, algorithm); + if (cipher) + { + if (cipher->flags & FLAG_MODULE_DISABLED) + err = GPG_ERR_CIPHER_ALGO; + _gcry_module_release (cipher); + } + else + err = GPG_ERR_CIPHER_ALGO; + ath_mutex_unlock (&ciphers_registered_lock); + + return err; +} + + +/* Return the standard length of the key for the cipher algorithm with + the identifier ALGORITHM. This function expects a valid algorithm + and will abort if the algorithm is not available or the length of + the key is not known. */ +static unsigned int +cipher_get_keylen (int algorithm) +{ + gcry_module_t cipher; + unsigned len = 0; + + REGISTER_DEFAULT_CIPHERS; + + ath_mutex_lock (&ciphers_registered_lock); + cipher = _gcry_module_lookup_id (ciphers_registered, algorithm); + if (cipher) + { + len = ((gcry_cipher_spec_t *) cipher->spec)->keylen; + if (! len) + log_bug ("cipher %d w/o key length\n", algorithm); + _gcry_module_release (cipher); + } + else + log_bug ("cipher %d not found\n", algorithm); + ath_mutex_unlock (&ciphers_registered_lock); + + return len; +} + +/* Return the block length of the cipher algorithm with the identifier + ALGORITHM. This function expects a valid algorithm and will abort + if the algorithm is not available or the length of the key is not + known. */ +static unsigned int +cipher_get_blocksize (int algorithm) +{ + gcry_module_t cipher; + unsigned len = 0; + + REGISTER_DEFAULT_CIPHERS; + + ath_mutex_lock (&ciphers_registered_lock); + cipher = _gcry_module_lookup_id (ciphers_registered, algorithm); + if (cipher) + { + len = ((gcry_cipher_spec_t *) cipher->spec)->blocksize; + if (! len) + log_bug ("cipher %d w/o blocksize\n", algorithm); + _gcry_module_release (cipher); + } + else + log_bug ("cipher %d not found\n", algorithm); + ath_mutex_unlock (&ciphers_registered_lock); + + return len; +} + + +/* + Open a cipher handle for use with cipher algorithm ALGORITHM, using + the cipher mode MODE (one of the GCRY_CIPHER_MODE_*) and return a + handle in HANDLE. Put NULL into HANDLE and return an error code if + something goes wrong. FLAGS may be used to modify the + operation. The defined flags are: + + GCRY_CIPHER_SECURE: allocate all internal buffers in secure memory. + GCRY_CIPHER_ENABLE_SYNC: Enable the sync operation as used in OpenPGP. + GCRY_CIPHER_CBC_CTS: Enable CTS mode. + GCRY_CIPHER_CBC_MAC: Enable MAC mode. + + Values for these flags may be combined using OR. + */ +gcry_error_t +gcry_cipher_open (gcry_cipher_hd_t *handle, + int algo, int mode, unsigned int flags) +{ + int secure = (flags & GCRY_CIPHER_SECURE); + gcry_cipher_spec_t *cipher = NULL; + gcry_module_t module = NULL; + gcry_cipher_hd_t h = NULL; + gcry_err_code_t err = 0; + + /* If the application missed to call the random poll function, we do + it here to ensure that it is used once in a while. */ + _gcry_fast_random_poll (); + + REGISTER_DEFAULT_CIPHERS; + + /* Fetch the according module and check wether the cipher is marked + available for use. */ + ath_mutex_lock (&ciphers_registered_lock); + module = _gcry_module_lookup_id (ciphers_registered, algo); + if (module) + { + /* Found module. */ + + if (module->flags & FLAG_MODULE_DISABLED) + { + /* Not available for use. */ + err = GPG_ERR_CIPHER_ALGO; + _gcry_module_release (module); + } + else + cipher = (gcry_cipher_spec_t *) module->spec; + } + else + err = GPG_ERR_CIPHER_ALGO; + ath_mutex_unlock (&ciphers_registered_lock); + + /* check flags */ + if ((! err) + && ((flags & ~(0 + | GCRY_CIPHER_SECURE + | GCRY_CIPHER_ENABLE_SYNC + | GCRY_CIPHER_CBC_CTS + | GCRY_CIPHER_CBC_MAC)) + || (flags & GCRY_CIPHER_CBC_CTS & GCRY_CIPHER_CBC_MAC))) + err = GPG_ERR_CIPHER_ALGO; + + /* check that a valid mode has been requested */ + if (! err) + switch (mode) + { + case GCRY_CIPHER_MODE_ECB: + case GCRY_CIPHER_MODE_CBC: + case GCRY_CIPHER_MODE_CFB: + case GCRY_CIPHER_MODE_CTR: + if ((cipher->encrypt == dummy_encrypt_block) + || (cipher->decrypt == dummy_decrypt_block)) + err = GPG_ERR_INV_CIPHER_MODE; + break; + + case GCRY_CIPHER_MODE_STREAM: + if ((cipher->stencrypt == dummy_encrypt_stream) + || (cipher->stdecrypt == dummy_decrypt_stream)) + err = GPG_ERR_INV_CIPHER_MODE; + break; + + case GCRY_CIPHER_MODE_NONE: + /* FIXME: issue a warning when this mode is used */ + break; + + default: + err = GPG_ERR_INV_CIPHER_MODE; + } + + /* ? FIXME: perform selftest here and mark this with a flag in + cipher_table ? */ + + if (! err) + { + size_t size = (sizeof (*h) + + 2 * cipher->contextsize + - sizeof (PROPERLY_ALIGNED_TYPE)); + + if (secure) + h = gcry_calloc_secure (1, size); + else + h = gcry_calloc (1, size); + + if (! h) + err = gpg_err_code_from_errno (errno); + else + { + h->magic = secure ? CTX_MAGIC_SECURE : CTX_MAGIC_NORMAL; + h->actual_handle_size = size; + h->cipher = cipher; + h->module = module; + h->mode = mode; + h->flags = flags; + } + } + + /* Done. */ + + if (err) + { + if (module) + { + /* Release module. */ + ath_mutex_lock (&ciphers_registered_lock); + _gcry_module_release (module); + ath_mutex_unlock (&ciphers_registered_lock); + } + } + + *handle = err ? NULL : h; + + return gcry_error (err); +} + + +/* Release all resources associated with the cipher handle H. H may be + NULL in which case this is a no-operation. */ +void +gcry_cipher_close (gcry_cipher_hd_t h) +{ + if (! h) + return; + + if ((h->magic != CTX_MAGIC_SECURE) + && (h->magic != CTX_MAGIC_NORMAL)) + _gcry_fatal_error(GPG_ERR_INTERNAL, + "gcry_cipher_close: already closed/invalid handle"); + else + h->magic = 0; + + /* Release module. */ + ath_mutex_lock (&ciphers_registered_lock); + _gcry_module_release (h->module); + ath_mutex_unlock (&ciphers_registered_lock); + + /* We always want to wipe out the memory even when the context has + been allocated in secure memory. The user might have disabled + secure memory or is using his own implementation which does not + do the wiping. To accomplish this we need to keep track of the + actual size of this structure because we have no way to known + how large the allocated area was when using a standard malloc. */ + wipememory (h, h->actual_handle_size); + + gcry_free (h); +} + + +/* Set the key to be used for the encryption context C to KEY with + length KEYLEN. The length should match the required length. */ +static gcry_error_t +cipher_setkey (gcry_cipher_hd_t c, byte *key, unsigned keylen) +{ + gcry_err_code_t ret; + + ret = (*c->cipher->setkey) (&c->context.c, key, keylen); + if (! ret) + /* Duplicate initial context. */ + memcpy ((void *) ((char *) &c->context.c + c->cipher->contextsize), + (void *) &c->context.c, + c->cipher->contextsize); + + return gcry_error (ret); +} + + +/* Set the IV to be used for the encryption context C to IV with + length IVLEN. The length should match the required length. */ +static void +cipher_setiv( gcry_cipher_hd_t c, const byte *iv, unsigned ivlen ) +{ + memset( c->iv, 0, c->cipher->blocksize ); + if( iv ) { + if( ivlen != c->cipher->blocksize ) + log_info("WARNING: cipher_setiv: ivlen=%u blklen=%u\n", + ivlen, (unsigned) c->cipher->blocksize ); + if (ivlen > c->cipher->blocksize) + ivlen = c->cipher->blocksize; + memcpy( c->iv, iv, ivlen ); + } + c->unused = 0; +} + + +/* Reset the cipher context to the initial contex. This is basically + the same as an release followed by a new. */ +static void +cipher_reset (gcry_cipher_hd_t c) +{ + memcpy (&c->context.c, + (char *) &c->context.c + c->cipher->contextsize, + c->cipher->contextsize); + memset (c->iv, 0, c->cipher->blocksize); + memset (c->lastiv, 0, c->cipher->blocksize); + memset (c->ctr, 0, c->cipher->blocksize); +} + + +static void +do_ecb_encrypt( gcry_cipher_hd_t c, byte *outbuf, const byte *inbuf, + unsigned int nblocks ) +{ + unsigned int n; + + for(n=0; n < nblocks; n++ ) { + c->cipher->encrypt ( &c->context.c, outbuf, (byte*)/*arggg*/inbuf ); + inbuf += c->cipher->blocksize; + outbuf += c->cipher->blocksize; + } +} + +static void +do_ecb_decrypt( gcry_cipher_hd_t c, byte *outbuf, const byte *inbuf, + unsigned int nblocks ) +{ + unsigned n; + + for(n=0; n < nblocks; n++ ) { + c->cipher->decrypt ( &c->context.c, outbuf, (byte*)/*arggg*/inbuf ); + inbuf += c->cipher->blocksize; + outbuf += c->cipher->blocksize; + } +} + +static void +do_cbc_encrypt( gcry_cipher_hd_t c, byte *outbuf, const byte *inbuf, + unsigned int nbytes ) +{ + unsigned int n; + byte *ivp; + int i; + size_t blocksize = c->cipher->blocksize; + unsigned nblocks = nbytes / blocksize; + + if ((c->flags & GCRY_CIPHER_CBC_CTS) && nbytes > blocksize) { + if ((nbytes % blocksize) == 0) + nblocks--; + } + + for(n=0; n < nblocks; n++ ) { + /* fixme: the xor should work on words and not on + * bytes. Maybe it is a good idea to enhance the cipher backend + * API to allow for CBC handling direct in the backend */ + for(ivp=c->iv,i=0; i < blocksize; i++ ) + outbuf[i] = inbuf[i] ^ *ivp++; + c->cipher->encrypt ( &c->context.c, outbuf, outbuf ); + memcpy(c->iv, outbuf, blocksize ); + inbuf += c->cipher->blocksize; + if (!(c->flags & GCRY_CIPHER_CBC_MAC)) + outbuf += c->cipher->blocksize; + } + + if ((c->flags & GCRY_CIPHER_CBC_CTS) && nbytes > blocksize) + { + int restbytes; + + if ((nbytes % blocksize) == 0) + restbytes = blocksize; + else + restbytes = nbytes % blocksize; + + memcpy(outbuf, outbuf - c->cipher->blocksize, restbytes); + outbuf -= c->cipher->blocksize; + + for(ivp=c->iv,i=0; i < restbytes; i++ ) + outbuf[i] = inbuf[i] ^ *ivp++; + for(; i < blocksize; i++ ) + outbuf[i] = 0 ^ *ivp++; + + c->cipher->encrypt ( &c->context.c, outbuf, outbuf ); + memcpy(c->iv, outbuf, blocksize ); + } +} + +static void +do_cbc_decrypt( gcry_cipher_hd_t c, byte *outbuf, const byte *inbuf, + unsigned int nbytes ) +{ + unsigned int n; + byte *ivp; + int i; + size_t blocksize = c->cipher->blocksize; + unsigned int nblocks = nbytes / blocksize; + + if ((c->flags & GCRY_CIPHER_CBC_CTS) && nbytes > blocksize) { + nblocks--; + if ((nbytes % blocksize) == 0) + nblocks--; + memcpy(c->lastiv, c->iv, blocksize ); + } + + for(n=0; n < nblocks; n++ ) { + /* Because outbuf and inbuf might be the same, we have + * to save the original ciphertext block. We use lastiv + * for this here because it is not used otherwise. */ + memcpy(c->lastiv, inbuf, blocksize ); + c->cipher->decrypt ( &c->context.c, outbuf, inbuf ); + for(ivp=c->iv,i=0; i < blocksize; i++ ) + outbuf[i] ^= *ivp++; + memcpy(c->iv, c->lastiv, blocksize ); + inbuf += c->cipher->blocksize; + outbuf += c->cipher->blocksize; + } + + if ((c->flags & GCRY_CIPHER_CBC_CTS) && nbytes > blocksize) { + int restbytes; + + if ((nbytes % blocksize) == 0) + restbytes = blocksize; + else + restbytes = nbytes % blocksize; + + memcpy(c->lastiv, c->iv, blocksize ); /* save Cn-2 */ + memcpy(c->iv, inbuf + blocksize, restbytes ); /* save Cn */ + + c->cipher->decrypt ( &c->context.c, outbuf, inbuf ); + for(ivp=c->iv,i=0; i < restbytes; i++ ) + outbuf[i] ^= *ivp++; + + memcpy(outbuf + blocksize, outbuf, restbytes); + for(i=restbytes; i < blocksize; i++) + c->iv[i] = outbuf[i]; + c->cipher->decrypt ( &c->context.c, outbuf, c->iv ); + for(ivp=c->lastiv,i=0; i < blocksize; i++ ) + outbuf[i] ^= *ivp++; + /* c->lastiv is now really lastlastiv, does this matter? */ + } +} + + +static void +do_cfb_encrypt( gcry_cipher_hd_t c, + byte *outbuf, const byte *inbuf, unsigned nbytes ) +{ + byte *ivp; + size_t blocksize = c->cipher->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->cipher->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->cipher->encrypt ( &c->context.c, 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->cipher->encrypt ( &c->context.c, 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( gcry_cipher_hd_t c, + byte *outbuf, const byte *inbuf, unsigned int nbytes ) +{ + byte *ivp; + ulong temp; + size_t blocksize = c->cipher->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->cipher->encrypt ( &c->context.c, 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->cipher->encrypt ( &c->context.c, 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; + } + } +} + + +static void +do_ctr_encrypt( gcry_cipher_hd_t c, byte *outbuf, const byte *inbuf, + unsigned int nbytes ) +{ + unsigned int n; + byte tmp[MAX_BLOCKSIZE]; + int i; + + for(n=0; n < nbytes; n++) + { + if ((n % c->cipher->blocksize) == 0) + { + c->cipher->encrypt (&c->context.c, tmp, c->ctr); + + for (i = c->cipher->blocksize; i > 0; i--) + { + c->ctr[i-1]++; + if (c->ctr[i-1] != 0) + break; + } + } + + /* XOR input with encrypted counter and store in output. */ + outbuf[n] = inbuf[n] ^ tmp[n % c->cipher->blocksize]; + } +} + +static void +do_ctr_decrypt( gcry_cipher_hd_t c, byte *outbuf, const byte *inbuf, + unsigned int nbytes ) +{ + do_ctr_encrypt (c, outbuf, inbuf, nbytes); +} + + +/**************** + * Encrypt INBUF to OUTBUF with the mode selected at open. + * inbuf and outbuf may overlap or be the same. + * Depending on the mode some contraints apply to NBYTES. + */ +static gcry_err_code_t +cipher_encrypt (gcry_cipher_hd_t c, byte *outbuf, + const byte *inbuf, unsigned int nbytes) +{ + gcry_err_code_t rc = GPG_ERR_NO_ERROR; + + switch( c->mode ) { + case GCRY_CIPHER_MODE_ECB: + if (!(nbytes%c->cipher->blocksize)) + do_ecb_encrypt(c, outbuf, inbuf, nbytes/c->cipher->blocksize ); + else + rc = GPG_ERR_INV_ARG; + break; + case GCRY_CIPHER_MODE_CBC: + if (!(nbytes%c->cipher->blocksize) + || (nbytes > c->cipher->blocksize + && (c->flags & GCRY_CIPHER_CBC_CTS))) + do_cbc_encrypt(c, outbuf, inbuf, nbytes ); + else + rc = GPG_ERR_INV_ARG; + break; + case GCRY_CIPHER_MODE_CFB: + do_cfb_encrypt(c, outbuf, inbuf, nbytes ); + break; + case GCRY_CIPHER_MODE_CTR: + do_ctr_encrypt(c, outbuf, inbuf, nbytes ); + break; + case GCRY_CIPHER_MODE_STREAM: + c->cipher->stencrypt ( &c->context.c, + outbuf, (byte*)/*arggg*/inbuf, nbytes ); + break; + case GCRY_CIPHER_MODE_NONE: + if( inbuf != outbuf ) + memmove( outbuf, inbuf, nbytes ); + break; + default: + log_fatal("cipher_encrypt: invalid mode %d\n", c->mode ); + rc = GPG_ERR_INV_CIPHER_MODE; + break; + } + return rc; +} + + +/**************** + * Encrypt IN and write it to OUT. If IN is NULL, in-place encryption has + * been requested. + */ +gcry_error_t +gcry_cipher_encrypt (gcry_cipher_hd_t h, byte *out, size_t outsize, + const byte *in, size_t inlen) +{ + gcry_err_code_t err; + + if (!in) + /* Caller requested in-place encryption. */ + /* Actullay cipher_encrypt() does not need to know about it, but + * we may change this to get better performance. */ + err = cipher_encrypt (h, out, out, outsize); + else if (outsize < ((h->flags & GCRY_CIPHER_CBC_MAC) ? + h->cipher->blocksize : inlen)) + err = GPG_ERR_TOO_SHORT; + else if ((h->mode == GCRY_CIPHER_MODE_ECB + || (h->mode == GCRY_CIPHER_MODE_CBC + && (! ((h->flags & GCRY_CIPHER_CBC_CTS) + && (inlen > h->cipher->blocksize))))) + && (inlen % h->cipher->blocksize)) + err = GPG_ERR_INV_ARG; + else + err = cipher_encrypt (h, out, in, inlen); + + if (err && out) + memset (out, 0x42, outsize); /* Failsafe: Make sure that the + plaintext will never make it into + OUT. */ + + return gcry_error (err); +} + + + +/**************** + * 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. + */ +static gcry_err_code_t +cipher_decrypt (gcry_cipher_hd_t c, byte *outbuf, const byte *inbuf, + unsigned int nbytes) +{ + gcry_err_code_t rc = GPG_ERR_NO_ERROR; + + switch( c->mode ) { + case GCRY_CIPHER_MODE_ECB: + if (!(nbytes%c->cipher->blocksize)) + do_ecb_decrypt(c, outbuf, inbuf, nbytes/c->cipher->blocksize ); + else + rc = GPG_ERR_INV_ARG; + break; + case GCRY_CIPHER_MODE_CBC: + if (!(nbytes%c->cipher->blocksize) + || (nbytes > c->cipher->blocksize + && (c->flags & GCRY_CIPHER_CBC_CTS))) + do_cbc_decrypt(c, outbuf, inbuf, nbytes ); + else + rc = GPG_ERR_INV_ARG; + break; + case GCRY_CIPHER_MODE_CFB: + do_cfb_decrypt(c, outbuf, inbuf, nbytes ); + break; + case GCRY_CIPHER_MODE_CTR: + do_ctr_decrypt(c, outbuf, inbuf, nbytes ); + break; + case GCRY_CIPHER_MODE_STREAM: + c->cipher->stdecrypt ( &c->context.c, + outbuf, (byte*)/*arggg*/inbuf, nbytes ); + break; + case GCRY_CIPHER_MODE_NONE: + if( inbuf != outbuf ) + memmove( outbuf, inbuf, nbytes ); + break; + default: + log_fatal ("cipher_decrypt: invalid mode %d\n", c->mode ); + rc = GPG_ERR_INV_CIPHER_MODE; + break; + } + return rc; +} + + +gcry_error_t +gcry_cipher_decrypt (gcry_cipher_hd_t h, byte *out, size_t outsize, + const byte *in, size_t inlen) +{ + gcry_err_code_t err = GPG_ERR_NO_ERROR; + + if (! in) + /* Caller requested in-place encryption. */ + /* Actullay cipher_encrypt() does not need to know about it, but + * we may chnage this to get better performance. */ + err = cipher_decrypt (h, out, out, outsize); + else if (outsize < inlen) + err = GPG_ERR_TOO_SHORT; + else if (((h->mode == GCRY_CIPHER_MODE_ECB) + || ((h->mode == GCRY_CIPHER_MODE_CBC) + && (! ((h->flags & GCRY_CIPHER_CBC_CTS) + && (inlen > h->cipher->blocksize))))) + && (inlen % h->cipher->blocksize) != 0) + err = GPG_ERR_INV_ARG; + else + err = cipher_decrypt (h, out, in, inlen); + + return gcry_error (err); +} + + + +/**************** + * Used for PGP's somewhat strange CFB mode. Only works if + * the corresponding flag is set. + */ +static void +cipher_sync( gcry_cipher_hd_t c ) +{ + if( (c->flags & GCRY_CIPHER_ENABLE_SYNC) && c->unused ) { + memmove(c->iv + c->unused, c->iv, c->cipher->blocksize - c->unused ); + memcpy(c->iv, c->lastiv + c->cipher->blocksize - c->unused, c->unused); + c->unused = 0; + } +} + + +gcry_error_t +gcry_cipher_ctl( gcry_cipher_hd_t h, int cmd, void *buffer, size_t buflen) +{ + gcry_err_code_t rc = GPG_ERR_NO_ERROR; + + switch (cmd) + { + case GCRYCTL_SET_KEY: + rc = cipher_setkey( h, buffer, buflen ); + break; + case GCRYCTL_SET_IV: + cipher_setiv( h, buffer, buflen ); + break; + case GCRYCTL_RESET: + cipher_reset (h); + break; + case GCRYCTL_CFB_SYNC: + cipher_sync( h ); + break; + case GCRYCTL_SET_CBC_CTS: + if (buflen) + if (h->flags & GCRY_CIPHER_CBC_MAC) + rc = GPG_ERR_INV_FLAG; + else + h->flags |= GCRY_CIPHER_CBC_CTS; + else + h->flags &= ~GCRY_CIPHER_CBC_CTS; + break; + case GCRYCTL_SET_CBC_MAC: + if (buflen) + if (h->flags & GCRY_CIPHER_CBC_CTS) + rc = GPG_ERR_INV_FLAG; + else + h->flags |= GCRY_CIPHER_CBC_MAC; + else + h->flags &= ~GCRY_CIPHER_CBC_MAC; + break; + case GCRYCTL_DISABLE_ALGO: + /* this one expects a NULL handle and buffer pointing to an + * integer with the algo number. + */ + if( h || !buffer || buflen != sizeof(int) ) + return gcry_error (GPG_ERR_CIPHER_ALGO); + disable_cipher_algo( *(int*)buffer ); + break; + case GCRYCTL_SET_CTR: + if (buffer && buflen == h->cipher->blocksize) + memcpy (h->ctr, buffer, h->cipher->blocksize); + else if (buffer == NULL || buflen == 0) + memset (h->ctr, 0, h->cipher->blocksize); + else + rc = GPG_ERR_INV_ARG; + break; + + default: + rc = GPG_ERR_INV_OP; + } + + return gcry_error (rc); +} + + +/**************** + * Return information about the cipher handle. + */ +gcry_error_t +gcry_cipher_info( gcry_cipher_hd_t h, int cmd, void *buffer, size_t *nbytes) +{ + gcry_err_code_t err = GPG_ERR_NO_ERROR; + + switch (cmd) + { + default: + err = GPG_ERR_INV_OP; + } + + return gcry_error (err); +} + +/**************** + * Return information about the given cipher algorithm + * WHAT select the kind of information returned: + * GCRYCTL_GET_KEYLEN: + * Return the length of the key, if the algorithm + * supports multiple key length, the maximum supported value + * is returnd. The length is return as number of octets. + * buffer and nbytes must be zero. + * The keylength is returned in _bytes_. + * GCRYCTL_GET_BLKLEN: + * Return the blocklength of the algorithm counted in octets. + * buffer and nbytes must be zero. + * GCRYCTL_TEST_ALGO: + * Returns 0 when the specified algorithm is available for use. + * buffer and nbytes must be zero. + * + * Note: Because this function is in most cases used to return an + * integer value, we can make it easier for the caller to just look at + * the return value. The caller will in all cases consult the value + * and thereby detecting whether a error occured or not (i.e. while checking + * the block size) + */ +gcry_error_t +gcry_cipher_algo_info (int algo, int what, void *buffer, size_t *nbytes) +{ + gcry_err_code_t err = GPG_ERR_NO_ERROR; + unsigned int ui; + + switch (what) + { + case GCRYCTL_GET_KEYLEN: + if (buffer || (! nbytes)) + err = GPG_ERR_CIPHER_ALGO; + else + { + ui = cipher_get_keylen (algo); + if ((ui > 0) && (ui <= 512)) + *nbytes = (size_t) ui / 8; + else + /* The only reason is an invalid algo or a strange + blocksize. */ + err = GPG_ERR_CIPHER_ALGO; + } + break; + + case GCRYCTL_GET_BLKLEN: + if (buffer || (! nbytes)) + err = GPG_ERR_CIPHER_ALGO; + else + { + ui = cipher_get_blocksize (algo); + if ((ui > 0) && (ui < 10000)) + *nbytes = ui; + else + /* The only reason is an invalid algo or a strange + blocksize. */ + err = GPG_ERR_CIPHER_ALGO; + } + break; + + case GCRYCTL_TEST_ALGO: + if (buffer || nbytes) + err = GPG_ERR_INV_ARG; + else + err = check_cipher_algo (algo); + break; + + default: + err = GPG_ERR_INV_OP; + } + + return gcry_error (err); +} + + +size_t +gcry_cipher_get_algo_keylen (int algo) +{ + size_t n; + + if (gcry_cipher_algo_info( algo, GCRYCTL_GET_KEYLEN, NULL, &n)) + n = 0; + return n; +} + + +size_t +gcry_cipher_get_algo_blklen (int algo) +{ + size_t n; + + if (gcry_cipher_algo_info( algo, GCRYCTL_GET_BLKLEN, NULL, &n)) + n = 0; + return n; +} + + +gcry_err_code_t +_gcry_cipher_init (void) +{ + gcry_err_code_t err = GPG_ERR_NO_ERROR; + + REGISTER_DEFAULT_CIPHERS; + + return err; +} + +/* Get a list consisting of the IDs of the loaded cipher modules. If + LIST is zero, write the number of loaded cipher modules to + LIST_LENGTH and return. If LIST is non-zero, the first + *LIST_LENGTH algorithm IDs are stored in LIST, which must be of + according size. In case there are less cipher modules than + *LIST_LENGTH, *LIST_LENGTH is updated to the correct number. */ +gcry_error_t +gcry_cipher_list (int *list, int *list_length) +{ + gcry_err_code_t err = GPG_ERR_NO_ERROR; + + ath_mutex_lock (&ciphers_registered_lock); + err = _gcry_module_list (ciphers_registered, list, list_length); + ath_mutex_unlock (&ciphers_registered_lock); + + return err; +} |