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	/* cipher.c - cipher dispatcher
	* Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003
	* 2005, 2007, 2008, 2009 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, see <http://www.gnu.org/licenses/>.
	*/

	#include <config.h>
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <errno.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

	/* Try to use 16 byte aligned cipher context for better performance.
	We use the aligned attribute, thus it is only possible to implement
	this with gcc. */
	#undef NEED_16BYTE_ALIGNED_CONTEXT
	#if defined (__GNUC__)
	# define NEED_16BYTE_ALIGNED_CONTEXT 1
	#endif

	/* A dummy extraspec so that we do not need to tests the extraspec
	field from the module specification against NULL and instead
	directly test the respective fields of extraspecs. */
	static cipher_extra_spec_t dummy_extra_spec;

	/* This is the list of the default ciphers, which are included in
	libgcrypt. */
	static struct cipher_table_entry
	{
	gcry_cipher_spec_t *cipher;
	cipher_extra_spec_t *extraspec;
	unsigned int algorithm;
	int fips_allowed;
	} cipher_table[] =
	{
	#if USE_BLOWFISH
	{ &_gcry_cipher_spec_blowfish,
	&dummy_extra_spec, GCRY_CIPHER_BLOWFISH },
	#endif
	#if USE_DES
	{ &_gcry_cipher_spec_des,
	&dummy_extra_spec, GCRY_CIPHER_DES },
	{ &_gcry_cipher_spec_tripledes,
	&_gcry_cipher_extraspec_tripledes, GCRY_CIPHER_3DES, 1 },
	#endif
	#if USE_ARCFOUR
	{ &_gcry_cipher_spec_arcfour,
	&dummy_extra_spec, GCRY_CIPHER_ARCFOUR },
	#endif
	#if USE_CAST5
	{ &_gcry_cipher_spec_cast5,
	&dummy_extra_spec, GCRY_CIPHER_CAST5 },
	#endif
	#if USE_AES
	{ &_gcry_cipher_spec_aes,
	&_gcry_cipher_extraspec_aes, GCRY_CIPHER_AES, 1 },
	{ &_gcry_cipher_spec_aes192,
	&_gcry_cipher_extraspec_aes192, GCRY_CIPHER_AES192, 1 },
	{ &_gcry_cipher_spec_aes256,
	&_gcry_cipher_extraspec_aes256, GCRY_CIPHER_AES256, 1 },
	#endif
	#if USE_TWOFISH
	{ &_gcry_cipher_spec_twofish,
	&dummy_extra_spec, GCRY_CIPHER_TWOFISH },
	{ &_gcry_cipher_spec_twofish128,
	&dummy_extra_spec, GCRY_CIPHER_TWOFISH128 },
	#endif
	#if USE_SERPENT
	{ &_gcry_cipher_spec_serpent128,
	&dummy_extra_spec, GCRY_CIPHER_SERPENT128 },
	{ &_gcry_cipher_spec_serpent192,
	&dummy_extra_spec, GCRY_CIPHER_SERPENT192 },
	{ &_gcry_cipher_spec_serpent256,
	&dummy_extra_spec, GCRY_CIPHER_SERPENT256 },
	#endif
	#if USE_RFC2268
	{ &_gcry_cipher_spec_rfc2268_40,
	&dummy_extra_spec, GCRY_CIPHER_RFC2268_40 },
	#endif
	#if USE_SEED
	{ &_gcry_cipher_spec_seed,
	&dummy_extra_spec, GCRY_CIPHER_SEED },
	#endif
	#if USE_CAMELLIA
	{ &_gcry_cipher_spec_camellia128,
	&dummy_extra_spec, GCRY_CIPHER_CAMELLIA128 },
	{ &_gcry_cipher_spec_camellia192,
	&dummy_extra_spec, GCRY_CIPHER_CAMELLIA192 },
	{ &_gcry_cipher_spec_camellia256,
	&dummy_extra_spec, GCRY_CIPHER_CAMELLIA256 },
	#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 whether 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) \
	{ \
	cipher_register_default (); \
	default_ciphers_registered = 1; \
	} \
	ath_mutex_unlock (&ciphers_registered_lock); \
	} \
	while (0)


	/* A VIA processor with the Padlock engine as well as the Intel AES_NI
	instructions require an alignment of most data on a 16 byte
	boundary. Because we trick out the compiler while allocating the
	context, the align attribute as used in rijndael.c does not work on
	its own. Thus we need to make sure that the entire context
	structure is a aligned on that boundary. We achieve this by
	defining a new type and use that instead of our usual alignment
	type. */
	typedef union
	{
	PROPERLY_ALIGNED_TYPE foo;
	#ifdef NEED_16BYTE_ALIGNED_CONTEXT
	char bar[16] __attribute__ ((aligned (16)));
	#endif
	char c[1];
	} cipher_context_alignment_t;


	/* The handle structure. */
	struct gcry_cipher_handle
	{
	int magic;
	size_t actual_handle_size; /* Allocated size of this handle. */
	size_t handle_offset; /* Offset to the malloced block. */
	gcry_cipher_spec_t *cipher;
	cipher_extra_spec_t *extraspec;
	gcry_module_t module;

	/* The algorithm id. This is a hack required because the module
	interface does not easily allow to retrieve this value. */
	int algo;

	/* A structure with function pointers for bulk operations. Due to
	limitations of the module system (we don't want to change the
	API) we need to keep these function pointers here. The cipher
	open function intializes them and the actual encryption routines
	use them if they are not NULL. */
	struct {
	void (cfb_enc)(void context, unsigned char *iv,
	void outbuf_arg, const void inbuf_arg,
	unsigned int nblocks);
	void (cfb_dec)(void context, unsigned char *iv,
	void outbuf_arg, const void inbuf_arg,
	unsigned int nblocks);
	void (cbc_enc)(void context, unsigned char *iv,
	void outbuf_arg, const void inbuf_arg,
	unsigned int nblocks, int cbc_mac);
	void (cbc_dec)(void context, unsigned char *iv,
	void outbuf_arg, const void inbuf_arg,
	unsigned int nblocks);
	} bulk;


	int mode;
	unsigned int flags;

	struct {
	unsigned int key:1; /* Set to 1 if a key has been set. */
	unsigned int iv:1; /* Set to 1 if a IV has been set. */
	} marks;

	/* The initialization vector. For best performance we make sure
	that it is properly aligned. In particular some implementations
	of bulk operations expect an 16 byte aligned IV. */
	union {
	cipher_context_alignment_t iv_align;
	unsigned char iv[MAX_BLOCKSIZE];
	} u_iv;

	unsigned char lastiv[MAX_BLOCKSIZE];
	int unused; /* Number of unused bytes in the IV. */

	unsigned char ctr[MAX_BLOCKSIZE]; /* For Counter (CTR) mode. */


	/* What follows are two contexts of the cipher in use. The first
	one needs to be aligned well enough for the cipher operation
	whereas the second one is a copy created by cipher_setkey and
	used by cipher_reset. That second copy has no need for proper
	aligment because it is only accessed by memcpy. */
	cipher_context_alignment_t 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 int keylen)
	{
	(void)c;
	(void)key;
	(void)keylen;
	return GPG_ERR_NO_ERROR;
	}

	static void
	dummy_encrypt_block (void *c,
	unsigned char outbuf, const unsigned char inbuf)
	{
	(void)c;
	(void)outbuf;
	(void)inbuf;
	BUG();
	}

	static void
	dummy_decrypt_block (void *c,
	unsigned char outbuf, const unsigned char inbuf)
	{
	(void)c;
	(void)outbuf;
	(void)inbuf;
	BUG();
	}

	static void
	dummy_encrypt_stream (void *c,
	unsigned char outbuf, const unsigned char inbuf,
	unsigned int n)
	{
	(void)c;
	(void)outbuf;
	(void)inbuf;
	(void)n;
	BUG();
	}

	static void
	dummy_decrypt_stream (void *c,
	unsigned char outbuf, const unsigned char inbuf,
	unsigned int n)
	{
	(void)c;
	(void)outbuf;
	(void)inbuf;
	(void)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
	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;

	if ( fips_mode () && !cipher_table[i].fips_allowed )
	continue;

	err = _gcry_module_add (&ciphers_registered,
	cipher_table[i].algorithm,
	(void *) cipher_table[i].cipher,
	(void *) cipher_table[i].extraspec,
	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,
	cipher_extra_spec_t *extraspec,
	int *algorithm_id,
	gcry_module_t *module)
	{
	gcry_err_code_t err = 0;
	gcry_module_t mod;

	/* We do not support module loading in fips mode. */
	if (fips_mode ())
	return gpg_error (GPG_ERR_NOT_SUPPORTED);

	ath_mutex_lock (&ciphers_registered_lock);
	err = _gcry_module_add (&ciphers_registered, 0,
	(void *)cipher,
	(void *)(extraspec? extraspec : &dummy_extra_spec),
	&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 whose ID is contained in ALGORITHM to a
	string representation of the algorithm name. For unknown algorithm
	IDs this function returns "?". */
	static const char *
	cipher_algo_to_string (int algorithm)
	{
	gcry_module_t cipher;
	const char *name;

	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);
	}
	else
	name = "?";
	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)
	{
	return cipher_algo_to_string (algorithm);
	}


	/* 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 identifier 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;
	cipher_extra_spec_t *extraspec = 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 whether 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;
	}
	else
	{
	cipher = (gcry_cipher_spec_t *) module->spec;
	extraspec = module->extraspec;
	}
	}
	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_OFB:
	case GCRY_CIPHER_MODE_CTR:
	case GCRY_CIPHER_MODE_AESWRAP:
	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:
	/* This mode may be used for debugging. It copies the main
	text verbatim to the ciphertext. We do not allow this in
	fips mode or if no debug flag has been set. */
	if (fips_mode () \|\| !_gcry_get_debug_flag (0))
	err = GPG_ERR_INV_CIPHER_MODE;
	break;

	default:
	err = GPG_ERR_INV_CIPHER_MODE;
	}

	/* Perform selftest here and mark this with a flag in cipher_table?
	No, we should not do this as it takes too long. Further it does
	not make sense to exclude algorithms with failing selftests at
	runtime: If a selftest fails there is something seriously wrong
	with the system and thus we better die immediately. */

	if (! err)
	{
	size_t size = (sizeof (*h)
	+ 2 * cipher->contextsize
	- sizeof (cipher_context_alignment_t)
	#ifdef NEED_16BYTE_ALIGNED_CONTEXT
	+ 15 /* Space for leading alignment gap. */
	#endif /NEED_16BYTE_ALIGNED_CONTEXT/
	);

	if (secure)
	h = gcry_calloc_secure (1, size);
	else
	h = gcry_calloc (1, size);

	if (! h)
	err = gpg_err_code_from_errno (errno);
	else
	{
	size_t off = 0;

	#ifdef NEED_16BYTE_ALIGNED_CONTEXT
	if ( ((unsigned long)h & 0x0f) )
	{
	/* The malloced block is not aligned on a 16 byte
	boundary. Correct for this. */
	off = 16 - ((unsigned long)h & 0x0f);
	h = (void)((char)h + off);
	}
	#endif /NEED_16BYTE_ALIGNED_CONTEXT/

	h->magic = secure ? CTX_MAGIC_SECURE : CTX_MAGIC_NORMAL;
	h->actual_handle_size = size - off;
	h->handle_offset = off;
	h->cipher = cipher;
	h->extraspec = extraspec;
	h->module = module;
	h->algo = algo;
	h->mode = mode;
	h->flags = flags;

	/* Setup bulk encryption routines. */
	switch (algo)
	{
	#ifdef USE_AES
	case GCRY_CIPHER_AES128:
	case GCRY_CIPHER_AES192:
	case GCRY_CIPHER_AES256:
	h->bulk.cfb_enc = _gcry_aes_cfb_enc;
	h->bulk.cfb_dec = _gcry_aes_cfb_dec;
	h->bulk.cbc_enc = _gcry_aes_cbc_enc;
	h->bulk.cbc_dec = _gcry_aes_cbc_dec;
	break;
	#endif /USE_AES/

	default:
	break;
	}
	}
	}

	/* 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)
	{
	size_t off;

	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. */
	off = h->handle_offset;
	wipememory (h, h->actual_handle_size);

	gcry_free ((char*)h - off);
	}


	/* 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 int 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);
	c->marks.key = 1;
	}
	else
	c->marks.key = 0;

	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->u_iv.iv, 0, c->cipher->blocksize);
	if (iv)
	{
	if (ivlen != c->cipher->blocksize)
	{
	log_info ("WARNING: cipher_setiv: ivlen=%u blklen=%u\n",
	ivlen, (unsigned int)c->cipher->blocksize);
	fips_signal_error ("IV length does not match blocklength");
	}
	if (ivlen > c->cipher->blocksize)
	ivlen = c->cipher->blocksize;
	memcpy (c->u_iv.iv, iv, ivlen);
	c->marks.iv = 1;
	}
	else
	c->marks.iv = 0;
	c->unused = 0;
	}


	/* Reset the cipher context to the initial context. 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->marks, 0, sizeof c->marks);
	memset (c->u_iv.iv, 0, c->cipher->blocksize);
	memset (c->lastiv, 0, c->cipher->blocksize);
	memset (c->ctr, 0, c->cipher->blocksize);
	}



	static gcry_err_code_t
	do_ecb_encrypt (gcry_cipher_hd_t c,
	unsigned char *outbuf, unsigned int outbuflen,
	const unsigned char *inbuf, unsigned int inbuflen)
	{
	unsigned int blocksize = c->cipher->blocksize;
	unsigned int n, nblocks;

	if (outbuflen < inbuflen)
	return GPG_ERR_BUFFER_TOO_SHORT;
	if ((inbuflen % blocksize))
	return GPG_ERR_INV_LENGTH;

	nblocks = inbuflen / c->cipher->blocksize;

	for (n=0; n < nblocks; n++ )
	{
	c->cipher->encrypt (&c->context.c, outbuf, (byte)/arggg*/inbuf);
	inbuf += blocksize;
	outbuf += blocksize;
	}
	return 0;
	}

	static gcry_err_code_t
	do_ecb_decrypt (gcry_cipher_hd_t c,
	unsigned char *outbuf, unsigned int outbuflen,
	const unsigned char *inbuf, unsigned int inbuflen)
	{
	unsigned int blocksize = c->cipher->blocksize;
	unsigned int n, nblocks;

	if (outbuflen < inbuflen)
	return GPG_ERR_BUFFER_TOO_SHORT;
	if ((inbuflen % blocksize))
	return GPG_ERR_INV_LENGTH;
	nblocks = inbuflen / c->cipher->blocksize;

	for (n=0; n < nblocks; n++ )
	{
	c->cipher->decrypt (&c->context.c, outbuf, (byte)/arggg*/inbuf );
	inbuf += blocksize;
	outbuf += blocksize;
	}

	return 0;
	}


	static gcry_err_code_t
	do_cbc_encrypt (gcry_cipher_hd_t c,
	unsigned char *outbuf, unsigned int outbuflen,
	const unsigned char *inbuf, unsigned int inbuflen)
	{
	unsigned int n;
	unsigned char *ivp;
	int i;
	size_t blocksize = c->cipher->blocksize;
	unsigned nblocks = inbuflen / blocksize;

	if (outbuflen < ((c->flags & GCRY_CIPHER_CBC_MAC)? blocksize : inbuflen))
	return GPG_ERR_BUFFER_TOO_SHORT;

	if ((inbuflen % c->cipher->blocksize)
	&& !(inbuflen > c->cipher->blocksize
	&& (c->flags & GCRY_CIPHER_CBC_CTS)))
	return GPG_ERR_INV_LENGTH;

	if ((c->flags & GCRY_CIPHER_CBC_CTS) && inbuflen > blocksize)
	{
	if ((inbuflen % blocksize) == 0)
	nblocks--;
	}

	if (c->bulk.cbc_enc)
	{
	c->bulk.cbc_enc (&c->context.c, c->u_iv.iv, outbuf, inbuf, nblocks,
	(c->flags & GCRY_CIPHER_CBC_MAC));
	inbuf += nblocks * blocksize;
	if (!(c->flags & GCRY_CIPHER_CBC_MAC))
	outbuf += nblocks * blocksize;
	}
	else
	{
	for (n=0; n < nblocks; n++ )
	{
	for (ivp=c->u_iv.iv,i=0; i < blocksize; i++ )
	outbuf[i] = inbuf[i] ^ *ivp++;
	c->cipher->encrypt ( &c->context.c, outbuf, outbuf );
	memcpy (c->u_iv.iv, outbuf, blocksize );
	inbuf += blocksize;
	if (!(c->flags & GCRY_CIPHER_CBC_MAC))
	outbuf += blocksize;
	}
	}

	if ((c->flags & GCRY_CIPHER_CBC_CTS) && inbuflen > blocksize)
	{
	/* We have to be careful here, since outbuf might be equal to
	inbuf. */
	int restbytes;
	unsigned char b;

	if ((inbuflen % blocksize) == 0)
	restbytes = blocksize;
	else
	restbytes = inbuflen % blocksize;

	outbuf -= blocksize;
	for (ivp = c->u_iv.iv, i = 0; i < restbytes; i++)
	{
	b = inbuf[i];
	outbuf[blocksize + i] = outbuf[i];
	outbuf[i] = b ^ *ivp++;
	}
	for (; i < blocksize; i++)
	outbuf[i] = 0 ^ *ivp++;

	c->cipher->encrypt (&c->context.c, outbuf, outbuf);
	memcpy (c->u_iv.iv, outbuf, blocksize);
	}

	return 0;
	}


	static gcry_err_code_t
	do_cbc_decrypt (gcry_cipher_hd_t c,
	unsigned char *outbuf, unsigned int outbuflen,
	const unsigned char *inbuf, unsigned int inbuflen)
	{
	unsigned int n;
	unsigned char *ivp;
	int i;
	size_t blocksize = c->cipher->blocksize;
	unsigned int nblocks = inbuflen / blocksize;

	if (outbuflen < inbuflen)
	return GPG_ERR_BUFFER_TOO_SHORT;

	if ((inbuflen % c->cipher->blocksize)
	&& !(inbuflen > c->cipher->blocksize
	&& (c->flags & GCRY_CIPHER_CBC_CTS)))
	return GPG_ERR_INV_LENGTH;

	if ((c->flags & GCRY_CIPHER_CBC_CTS) && inbuflen > blocksize)
	{
	nblocks--;
	if ((inbuflen % blocksize) == 0)
	nblocks--;
	memcpy (c->lastiv, c->u_iv.iv, blocksize);
	}

	if (c->bulk.cbc_dec)
	{
	c->bulk.cbc_dec (&c->context.c, c->u_iv.iv, outbuf, inbuf, nblocks);
	inbuf += nblocks * blocksize;
	outbuf += nblocks * blocksize;
	}
	else
	{
	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->u_iv.iv,i=0; i < blocksize; i++ )
	outbuf[i] ^= *ivp++;
	memcpy(c->u_iv.iv, c->lastiv, blocksize );
	inbuf += c->cipher->blocksize;
	outbuf += c->cipher->blocksize;
	}
	}

	if ((c->flags & GCRY_CIPHER_CBC_CTS) && inbuflen > blocksize)
	{
	int restbytes;

	if ((inbuflen % blocksize) == 0)
	restbytes = blocksize;
	else
	restbytes = inbuflen % blocksize;

	memcpy (c->lastiv, c->u_iv.iv, blocksize ); /* Save Cn-2. */
	memcpy (c->u_iv.iv, inbuf + blocksize, restbytes ); /* Save Cn. */

	c->cipher->decrypt ( &c->context.c, outbuf, inbuf );
	for (ivp=c->u_iv.iv,i=0; i < restbytes; i++ )
	outbuf[i] ^= *ivp++;

	memcpy(outbuf + blocksize, outbuf, restbytes);
	for(i=restbytes; i < blocksize; i++)
	c->u_iv.iv[i] = outbuf[i];
	c->cipher->decrypt (&c->context.c, outbuf, c->u_iv.iv);
	for(ivp=c->lastiv,i=0; i < blocksize; i++ )
	outbuf[i] ^= *ivp++;
	/* c->lastiv is now really lastlastiv, does this matter? */
	}

	return 0;
	}


	static gcry_err_code_t
	do_cfb_encrypt (gcry_cipher_hd_t c,
	unsigned char *outbuf, unsigned int outbuflen,
	const unsigned char *inbuf, unsigned int inbuflen)
	{
	unsigned char *ivp;
	size_t blocksize = c->cipher->blocksize;
	size_t blocksize_x_2 = blocksize + blocksize;

	if (outbuflen < inbuflen)
	return GPG_ERR_BUFFER_TOO_SHORT;

	if ( inbuflen <= 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->u_iv.iv+c->cipher->blocksize - c->unused;
	inbuflen;
	inbuflen--, c->unused-- )
	outbuf++ = (ivp++ ^= *inbuf++);
	return 0;
	}

	if ( c->unused )
	{
	/* XOR the input with the IV and store input into IV */
	inbuflen -= c->unused;
	for(ivp=c->u_iv.iv+blocksize - c->unused; c->unused; c->unused-- )
	outbuf++ = (ivp++ ^= *inbuf++);
	}

	/* Now we can process complete blocks. We use a loop as long as we
	have at least 2 blocks and use conditions for the rest. This
	also allows to use a bulk encryption function if available. */
	if (inbuflen >= blocksize_x_2 && c->bulk.cfb_enc)
	{
	unsigned int nblocks = inbuflen / blocksize;
	c->bulk.cfb_enc (&c->context.c, c->u_iv.iv, outbuf, inbuf, nblocks);
	outbuf += nblocks * blocksize;
	inbuf += nblocks * blocksize;
	inbuflen -= nblocks * blocksize;
	}
	else
	{
	while ( inbuflen >= blocksize_x_2 )
	{
	int i;
	/* Encrypt the IV. */
	c->cipher->encrypt ( &c->context.c, c->u_iv.iv, c->u_iv.iv );
	/* XOR the input with the IV and store input into IV. */
	for(ivp=c->u_iv.iv,i=0; i < blocksize; i++ )
	outbuf++ = (ivp++ ^= *inbuf++);
	inbuflen -= blocksize;
	}
	}

	if ( inbuflen >= blocksize )
	{
	int i;
	/* Save the current IV and then encrypt the IV. */
	memcpy( c->lastiv, c->u_iv.iv, blocksize );
	c->cipher->encrypt ( &c->context.c, c->u_iv.iv, c->u_iv.iv );
	/* XOR the input with the IV and store input into IV */
	for(ivp=c->u_iv.iv,i=0; i < blocksize; i++ )
	outbuf++ = (ivp++ ^= *inbuf++);
	inbuflen -= blocksize;
	}
	if ( inbuflen )
	{
	/* Save the current IV and then encrypt the IV. */
	memcpy( c->lastiv, c->u_iv.iv, blocksize );
	c->cipher->encrypt ( &c->context.c, c->u_iv.iv, c->u_iv.iv );
	c->unused = blocksize;
	/* Apply the XOR. */
	c->unused -= inbuflen;
	for(ivp=c->u_iv.iv; inbuflen; inbuflen-- )
	outbuf++ = (ivp++ ^= *inbuf++);
	}
	return 0;
	}


	static gcry_err_code_t
	do_cfb_decrypt (gcry_cipher_hd_t c,
	unsigned char *outbuf, unsigned int outbuflen,
	const unsigned char *inbuf, unsigned int inbuflen)
	{
	unsigned char *ivp;
	unsigned long temp;
	int i;
	size_t blocksize = c->cipher->blocksize;
	size_t blocksize_x_2 = blocksize + blocksize;

	if (outbuflen < inbuflen)
	return GPG_ERR_BUFFER_TOO_SHORT;

	if (inbuflen <= 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->u_iv.iv+blocksize - c->unused;
	inbuflen;
	inbuflen--, c->unused--)
	{
	temp = *inbuf++;
	outbuf++ = ivp ^ temp;
	*ivp++ = temp;
	}
	return 0;
	}

	if (c->unused)
	{
	/* XOR the input with the IV and store input into IV. */
	inbuflen -= c->unused;
	for (ivp=c->u_iv.iv+blocksize - c->unused; c->unused; c->unused-- )
	{
	temp = *inbuf++;
	outbuf++ = ivp ^ temp;
	*ivp++ = temp;
	}
	}

	/* Now we can process complete blocks. We use a loop as long as we
	have at least 2 blocks and use conditions for the rest. This
	also allows to use a bulk encryption function if available. */
	if (inbuflen >= blocksize_x_2 && c->bulk.cfb_dec)
	{
	unsigned int nblocks = inbuflen / blocksize;
	c->bulk.cfb_dec (&c->context.c, c->u_iv.iv, outbuf, inbuf, nblocks);
	outbuf += nblocks * blocksize;
	inbuf += nblocks * blocksize;
	inbuflen -= nblocks * blocksize;
	}
	else
	{
	while (inbuflen >= blocksize_x_2 )
	{
	/* Encrypt the IV. */
	c->cipher->encrypt ( &c->context.c, c->u_iv.iv, c->u_iv.iv );
	/* XOR the input with the IV and store input into IV. */
	for (ivp=c->u_iv.iv,i=0; i < blocksize; i++ )
	{
	temp = *inbuf++;
	outbuf++ = ivp ^ temp;
	*ivp++ = temp;
	}
	inbuflen -= blocksize;
	}
	}

	if (inbuflen >= blocksize )
	{
	/* Save the current IV and then encrypt the IV. */
	memcpy ( c->lastiv, c->u_iv.iv, blocksize);
	c->cipher->encrypt ( &c->context.c, c->u_iv.iv, c->u_iv.iv );
	/* XOR the input with the IV and store input into IV */
	for (ivp=c->u_iv.iv,i=0; i < blocksize; i++ )
	{
	temp = *inbuf++;
	outbuf++ = ivp ^ temp;
	*ivp++ = temp;
	}
	inbuflen -= blocksize;
	}

	if (inbuflen)
	{
	/* Save the current IV and then encrypt the IV. */
	memcpy ( c->lastiv, c->u_iv.iv, blocksize );
	c->cipher->encrypt ( &c->context.c, c->u_iv.iv, c->u_iv.iv );
	c->unused = blocksize;
	/* Apply the XOR. */
	c->unused -= inbuflen;
	for (ivp=c->u_iv.iv; inbuflen; inbuflen-- )
	{
	temp = *inbuf++;
	outbuf++ = ivp ^ temp;
	*ivp++ = temp;
	}
	}
	return 0;
	}


	static gcry_err_code_t
	do_ofb_encrypt (gcry_cipher_hd_t c,
	unsigned char *outbuf, unsigned int outbuflen,
	const unsigned char *inbuf, unsigned int inbuflen)
	{
	unsigned char *ivp;
	size_t blocksize = c->cipher->blocksize;

	if (outbuflen < inbuflen)
	return GPG_ERR_BUFFER_TOO_SHORT;

	if ( inbuflen <= c->unused )
	{
	/* Short enough to be encoded by the remaining XOR mask. */
	/* XOR the input with the IV */
	for (ivp=c->u_iv.iv+c->cipher->blocksize - c->unused;
	inbuflen;
	inbuflen--, c->unused-- )
	outbuf++ = (ivp++ ^ *inbuf++);
	return 0;
	}

	if( c->unused )
	{
	inbuflen -= c->unused;
	for(ivp=c->u_iv.iv+blocksize - c->unused; c->unused; c->unused-- )
	outbuf++ = (ivp++ ^ *inbuf++);
	}

	/* Now we can process complete blocks. */
	while ( inbuflen >= blocksize )
	{
	int i;
	/* Encrypt the IV (and save the current one). */
	memcpy( c->lastiv, c->u_iv.iv, blocksize );
	c->cipher->encrypt ( &c->context.c, c->u_iv.iv, c->u_iv.iv );

	for (ivp=c->u_iv.iv,i=0; i < blocksize; i++ )
	outbuf++ = (ivp++ ^ *inbuf++);
	inbuflen -= blocksize;
	}
	if ( inbuflen )
	{ /* process the remaining bytes */
	memcpy( c->lastiv, c->u_iv.iv, blocksize );
	c->cipher->encrypt ( &c->context.c, c->u_iv.iv, c->u_iv.iv );
	c->unused = blocksize;
	c->unused -= inbuflen;
	for(ivp=c->u_iv.iv; inbuflen; inbuflen-- )
	outbuf++ = (ivp++ ^ *inbuf++);
	}
	return 0;
	}

	static gcry_err_code_t
	do_ofb_decrypt (gcry_cipher_hd_t c,
	unsigned char *outbuf, unsigned int outbuflen,
	const unsigned char *inbuf, unsigned int inbuflen)
	{
	unsigned char *ivp;
	size_t blocksize = c->cipher->blocksize;

	if (outbuflen < inbuflen)
	return GPG_ERR_BUFFER_TOO_SHORT;

	if( inbuflen <= c->unused )
	{
	/* Short enough to be encoded by the remaining XOR mask. */
	for (ivp=c->u_iv.iv+blocksize - c->unused; inbuflen; inbuflen--,c->unused--)
	outbuf++ = ivp++ ^ *inbuf++;
	return 0;
	}

	if ( c->unused )
	{
	inbuflen -= c->unused;
	for (ivp=c->u_iv.iv+blocksize - c->unused; c->unused; c->unused-- )
	outbuf++ = ivp++ ^ *inbuf++;
	}

	/* Now we can process complete blocks. */
	while ( inbuflen >= blocksize )
	{
	int i;
	/* Encrypt the IV (and save the current one). */
	memcpy( c->lastiv, c->u_iv.iv, blocksize );
	c->cipher->encrypt ( &c->context.c, c->u_iv.iv, c->u_iv.iv );
	for (ivp=c->u_iv.iv,i=0; i < blocksize; i++ )
	outbuf++ = ivp++ ^ *inbuf++;
	inbuflen -= blocksize;
	}
	if ( inbuflen )
	{ /* Process the remaining bytes. */
	/* Encrypt the IV (and save the current one). */
	memcpy( c->lastiv, c->u_iv.iv, blocksize );
	c->cipher->encrypt ( &c->context.c, c->u_iv.iv, c->u_iv.iv );
	c->unused = blocksize;
	c->unused -= inbuflen;
	for (ivp=c->u_iv.iv; inbuflen; inbuflen-- )
	outbuf++ = ivp++ ^ *inbuf++;
	}
	return 0;
	}


	static gcry_err_code_t
	do_ctr_encrypt (gcry_cipher_hd_t c,
	unsigned char *outbuf, unsigned int outbuflen,
	const unsigned char *inbuf, unsigned int inbuflen)
	{
	unsigned int n;
	unsigned char tmp[MAX_BLOCKSIZE];
	int i;
	unsigned int blocksize = c->cipher->blocksize;

	if (outbuflen < inbuflen)
	return GPG_ERR_BUFFER_TOO_SHORT;

	if ((inbuflen % blocksize))
	return GPG_ERR_INV_LENGTH;

	for (n=0; n < inbuflen; n++)
	{
	if ((n % blocksize) == 0)
	{
	c->cipher->encrypt (&c->context.c, tmp, c->ctr);

	for (i = 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 % blocksize];
	}

	wipememory (tmp, sizeof tmp);
	return 0;
	}

	static gcry_err_code_t
	do_ctr_decrypt (gcry_cipher_hd_t c,
	unsigned char *outbuf, unsigned int outbuflen,
	const unsigned char *inbuf, unsigned int inbuflen)
	{
	return do_ctr_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	}


	/* Perform the AES-Wrap algorithm as specified by RFC3394. We
	implement this as a mode usable with any cipher algorithm of
	blocksize 128. */
	static gcry_err_code_t
	do_aeswrap_encrypt (gcry_cipher_hd_t c, byte *outbuf, unsigned int outbuflen,
	const byte *inbuf, unsigned int inbuflen )
	{
	int j, x;
	unsigned int n, i;
	unsigned char r, a, *b;
	unsigned char t[8];

	#if MAX_BLOCKSIZE < 8
	#error Invalid block size
	#endif
	/* We require a cipher with a 128 bit block length. */
	if (c->cipher->blocksize != 16)
	return GPG_ERR_INV_LENGTH;

	/* The output buffer must be able to hold the input data plus one
	additional block. */
	if (outbuflen < inbuflen + 8)
	return GPG_ERR_BUFFER_TOO_SHORT;
	/* Input data must be multiple of 64 bits. */
	if (inbuflen % 8)
	return GPG_ERR_INV_ARG;

	n = inbuflen / 8;

	/* We need at least two 64 bit blocks. */
	if (n < 2)
	return GPG_ERR_INV_ARG;

	r = outbuf;
	a = outbuf; /* We store A directly in OUTBUF. */
	b = c->ctr; /* B is also used to concatenate stuff. */

	/* If an IV has been set we use that IV as the Alternative Initial
	Value; if it has not been set we use the standard value. */
	if (c->marks.iv)
	memcpy (a, c->u_iv.iv, 8);
	else
	memset (a, 0xa6, 8);

	/* Copy the inbuf to the outbuf. */
	memmove (r+8, inbuf, inbuflen);

	memset (t, 0, sizeof t); /* t := 0. */

	for (j = 0; j <= 5; j++)
	{
	for (i = 1; i <= n; i++)
	{
	/* B := AES_k( A \| R[i] ) */
	memcpy (b, a, 8);
	memcpy (b+8, r+i*8, 8);
	c->cipher->encrypt (&c->context.c, b, b);
	/* t := t + 1 */
	for (x = 7; x >= 0; x--)
	{
	t[x]++;
	if (t[x])
	break;
	}
	/* A := MSB_64(B) ^ t */
	for (x=0; x < 8; x++)
	a[x] = b[x] ^ t[x];
	/* R[i] := LSB_64(B) */
	memcpy (r+i*8, b+8, 8);
	}
	}

	return 0;
	}

	/* Perform the AES-Unwrap algorithm as specified by RFC3394. We
	implement this as a mode usable with any cipher algorithm of
	blocksize 128. */
	static gcry_err_code_t
	do_aeswrap_decrypt (gcry_cipher_hd_t c, byte *outbuf, unsigned int outbuflen,
	const byte *inbuf, unsigned int inbuflen)
	{
	int j, x;
	unsigned int n, i;
	unsigned char r, a, *b;
	unsigned char t[8];

	#if MAX_BLOCKSIZE < 8
	#error Invalid block size
	#endif
	/* We require a cipher with a 128 bit block length. */
	if (c->cipher->blocksize != 16)
	return GPG_ERR_INV_LENGTH;

	/* The output buffer must be able to hold the input data minus one
	additional block. Fixme: The caller has more restrictive checks
	- we may want to fix them for this mode. */
	if (outbuflen + 8 < inbuflen)
	return GPG_ERR_BUFFER_TOO_SHORT;
	/* Input data must be multiple of 64 bits. */
	if (inbuflen % 8)
	return GPG_ERR_INV_ARG;

	n = inbuflen / 8;

	/* We need at least three 64 bit blocks. */
	if (n < 3)
	return GPG_ERR_INV_ARG;

	r = outbuf;
	a = c->lastiv; /* We use c->LASTIV as buffer for A. */
	b = c->ctr; /* B is also used to concatenate stuff. */

	/* Copy the inbuf to the outbuf and save A. */
	memcpy (a, inbuf, 8);
	memmove (r, inbuf+8, inbuflen-8);
	n--; /* Reduce to actual number of data blocks. */

	/* t := 6 * n */
	i = n * 6; /* The range is valid because: n = inbuflen / 8 - 1. */
	for (x=0; x < 8 && x < sizeof (i); x++)
	t[7-x] = i >> (8*x);
	for (; x < 8; x++)
	t[7-x] = 0;

	for (j = 5; j >= 0; j--)
	{
	for (i = n; i >= 1; i--)
	{
	/* B := AES_k^1( (A ^ t)\| R[i] ) */
	for (x = 0; x < 8; x++)
	b[x] = a[x] ^ t[x];
	memcpy (b+8, r+(i-1)*8, 8);
	c->cipher->decrypt (&c->context.c, b, b);
	/* t := t - 1 */
	for (x = 7; x >= 0; x--)
	{
	t[x]--;
	if (t[x] != 0xff)
	break;
	}
	/* A := MSB_64(B) */
	memcpy (a, b, 8);
	/* R[i] := LSB_64(B) */
	memcpy (r+(i-1)*8, b+8, 8);
	}
	}

	/* If an IV has been set we compare against this Alternative Initial
	Value; if it has not been set we compare against the standard IV. */
	if (c->marks.iv)
	j = memcmp (a, c->u_iv.iv, 8);
	else
	{
	for (j=0, x=0; x < 8; x++)
	if (a[x] != 0xa6)
	{
	j=1;
	break;
	}
	}
	return j? GPG_ERR_CHECKSUM : 0;
	}


	/****************
	* Encrypt INBUF to OUTBUF with the mode selected at open.
	* inbuf and outbuf may overlap or be the same.
	* Depending on the mode some constraints apply to INBUFLEN.
	*/
	static gcry_err_code_t
	cipher_encrypt (gcry_cipher_hd_t c, byte *outbuf, unsigned int outbuflen,
	const byte *inbuf, unsigned int inbuflen)
	{
	gcry_err_code_t rc;

	switch (c->mode)
	{
	case GCRY_CIPHER_MODE_ECB:
	rc = do_ecb_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	break;

	case GCRY_CIPHER_MODE_CBC:
	rc = do_cbc_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	break;

	case GCRY_CIPHER_MODE_CFB:
	rc = do_cfb_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	break;

	case GCRY_CIPHER_MODE_OFB:
	rc = do_ofb_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	break;

	case GCRY_CIPHER_MODE_CTR:
	rc = do_ctr_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	break;

	case GCRY_CIPHER_MODE_AESWRAP:
	rc = do_aeswrap_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	break;

	case GCRY_CIPHER_MODE_STREAM:
	c->cipher->stencrypt (&c->context.c,
	outbuf, (byte)/arggg*/inbuf, inbuflen);
	rc = 0;
	break;

	case GCRY_CIPHER_MODE_NONE:
	if (fips_mode () \|\| !_gcry_get_debug_flag (0))
	{
	fips_signal_error ("cipher mode NONE used");
	rc = GPG_ERR_INV_CIPHER_MODE;
	}
	else
	{
	if (inbuf != outbuf)
	memmove (outbuf, inbuf, inbuflen);
	rc = 0;
	}
	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, void *out, size_t outsize,
	const void *in, size_t inlen)
	{
	gcry_err_code_t err;

	if (!in) /* Caller requested in-place encryption. */
	err = cipher_encrypt (h, out, outsize, out, outsize);
	else
	err = cipher_encrypt (h, out, outsize, in, inlen);

	/* Failsafe: Make sure that the plaintext will never make it into
	OUT if the encryption returned an error. */
	if (err && out)
	memset (out, 0x42, outsize);

	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 INBUFLEN.
	*/
	static gcry_err_code_t
	cipher_decrypt (gcry_cipher_hd_t c, byte *outbuf, unsigned int outbuflen,
	const byte *inbuf, unsigned int inbuflen)
	{
	gcry_err_code_t rc;

	switch (c->mode)
	{
	case GCRY_CIPHER_MODE_ECB:
	rc = do_ecb_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	break;

	case GCRY_CIPHER_MODE_CBC:
	rc = do_cbc_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	break;

	case GCRY_CIPHER_MODE_CFB:
	rc = do_cfb_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	break;

	case GCRY_CIPHER_MODE_OFB:
	rc = do_ofb_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	break;

	case GCRY_CIPHER_MODE_CTR:
	rc = do_ctr_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	break;

	case GCRY_CIPHER_MODE_AESWRAP:
	rc = do_aeswrap_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
	break;

	case GCRY_CIPHER_MODE_STREAM:
	c->cipher->stdecrypt (&c->context.c,
	outbuf, (byte)/arggg*/inbuf, inbuflen);
	rc = 0;
	break;

	case GCRY_CIPHER_MODE_NONE:
	if (fips_mode () \|\| !_gcry_get_debug_flag (0))
	{
	fips_signal_error ("cipher mode NONE used");
	rc = GPG_ERR_INV_CIPHER_MODE;
	}
	else
	{
	if (inbuf != outbuf)
	memmove (outbuf, inbuf, inbuflen);
	rc = 0;
	}
	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, void *out, size_t outsize,
	const void *in, size_t inlen)
	{
	gcry_err_code_t err;

	if (!in) /* Caller requested in-place encryption. */
	err = cipher_decrypt (h, out, outsize, out, outsize);
	else
	err = cipher_decrypt (h, out, outsize, 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->u_iv.iv + c->unused,
	c->u_iv.iv, c->cipher->blocksize - c->unused);
	memcpy (c->u_iv.iv,
	c->lastiv + c->cipher->blocksize - c->unused, c->unused);
	c->unused = 0;
	}
	}


	gcry_error_t
	_gcry_cipher_setkey (gcry_cipher_hd_t hd, const void *key, size_t keylen)
	{
	return cipher_setkey (hd, (void*)key, keylen);
	}


	gcry_error_t
	_gcry_cipher_setiv (gcry_cipher_hd_t hd, const void *iv, size_t ivlen)
	{
	cipher_setiv (hd, iv, ivlen);
	return 0;
	}

	/* Set counter for CTR mode. (CTR,CTRLEN) must denote a buffer of
	block size length, or (NULL,0) to set the CTR to the all-zero
	block. */
	gpg_error_t
	_gcry_cipher_setctr (gcry_cipher_hd_t hd, const void *ctr, size_t ctrlen)
	{
	if (ctr && ctrlen == hd->cipher->blocksize)
	memcpy (hd->ctr, ctr, hd->cipher->blocksize);
	else if (!ctr \|\| !ctrlen)
	memset (hd->ctr, 0, hd->cipher->blocksize);
	else
	return gpg_error (GPG_ERR_INV_ARG);
	return 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: /* Deprecated; use gcry_cipher_setkey. */
	rc = cipher_setkey( h, buffer, buflen );
	break;

	case GCRYCTL_SET_IV: /* Deprecated; use gcry_cipher_setiv. */
	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 command expects NULL for H and BUFFER to point 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: /* Deprecated; use gcry_cipher_setctr. */
	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;

	case 61: /* Disable weak key detection (private). */
	if (h->extraspec->set_extra_info)
	rc = h->extraspec->set_extra_info
	(&h->context.c, CIPHER_INFO_NO_WEAK_KEY, NULL, 0);
	else
	rc = GPG_ERR_NOT_SUPPORTED;
	break;

	case 62: /* Return current input vector (private). */
	/* This is the input block as used in CFB and OFB mode which has
	initially been set as IV. The returned format is:
	1 byte Actual length of the block in bytes.
	n byte The block.
	If the provided buffer is too short, an error is returned. */
	if (buflen < (1 + h->cipher->blocksize))
	rc = GPG_ERR_TOO_SHORT;
	else
	{
	unsigned char *ivp;
	unsigned char *dst = buffer;
	int n = h->unused;

	if (!n)
	n = h->cipher->blocksize;
	gcry_assert (n <= h->cipher->blocksize);
	*dst++ = n;
	ivp = h->u_iv.iv + h->cipher->blocksize - n;
	while (n--)
	dst++ = ivp++;
	}
	break;

	default:
	rc = GPG_ERR_INV_OP;
	}

	return gcry_error (rc);
	}


	/* Return information about the cipher handle H. CMD is the kind of
	information requested. BUFFER and NBYTES are reserved for now.

	There are no values for CMD yet defined.

	The function always returns GPG_ERR_INV_OP.

	*/
	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;

	(void)h;
	(void)buffer;
	(void)nbytes;

	switch (cmd)
	{
	default:
	err = GPG_ERR_INV_OP;
	}

	return gcry_error (err);
	}

	/* Return information about the given cipher algorithm ALGO.

	WHAT select the kind of information returned:

	GCRYCTL_GET_KEYLEN:
	Return the length of the key. If the algorithm ALGO
	supports multiple key lengths, the maximum supported key length
	is returned. The key length is returned as number of octets.
	BUFFER and NBYTES must be zero.

	GCRYCTL_GET_BLKLEN:
	Return the blocklength of the algorithm ALGO counted in octets.
	BUFFER and NBYTES must be zero.

	GCRYCTL_TEST_ALGO:
	Returns 0 if the specified algorithm ALGO 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 occurred 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);
	}


	/* This function returns length of the key for algorithm ALGO. If the
	algorithm supports multiple key lengths, the maximum supported key
	length is returned. On error 0 is returned. The key length is
	returned as number of octets.

	This is a convenience functions which should be preferred over
	gcry_cipher_algo_info because it allows for proper type
	checking. */
	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;
	}

	/* This functions returns the blocklength of the algorithm ALGO
	counted in octets. On error 0 is returned.

	This is a convenience functions which should be preferred over
	gcry_cipher_algo_info because it allows for proper type
	checking. */
	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;
	}

	/* Explicitly initialize this module. */
	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;
	}


	/* Run the selftests for cipher algorithm ALGO with optional reporting
	function REPORT. */
	gpg_error_t
	_gcry_cipher_selftest (int algo, int extended, selftest_report_func_t report)
	{
	gcry_module_t module = NULL;
	cipher_extra_spec_t *extraspec = NULL;
	gcry_err_code_t ec = 0;

	REGISTER_DEFAULT_CIPHERS;

	ath_mutex_lock (&ciphers_registered_lock);
	module = _gcry_module_lookup_id (ciphers_registered, algo);
	if (module && !(module->flags & FLAG_MODULE_DISABLED))
	extraspec = module->extraspec;
	ath_mutex_unlock (&ciphers_registered_lock);
	if (extraspec && extraspec->selftest)
	ec = extraspec->selftest (algo, extended, report);
	else
	{
	ec = GPG_ERR_CIPHER_ALGO;
	if (report)
	report ("cipher", algo, "module",
	module && !(module->flags & FLAG_MODULE_DISABLED)?
	"no selftest available" :
	module? "algorithm disabled" : "algorithm not found");
	}

	if (module)
	{
	ath_mutex_lock (&ciphers_registered_lock);
	_gcry_module_release (module);
	ath_mutex_unlock (&ciphers_registered_lock);
	}
	return gpg_error (ec);
	}

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