/*
 * Copyright (c) 1999, 2000, 2001, 2002, 2004 Beeyond Software Holding BV
 *
 * This library 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.
 *
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/*!\file beecrypt.c
 * \brief BeeCrypt API.
 * \author Bob Deblier <bob.deblier@pandora.be>
 * \ingroup ES_m PRNG_m HASH_m HMAC_m BC_m
 */

#define BEECRYPT_DLL_EXPORT

#if HAVE_CONFIG_H
# include "config.h"
#endif

#include "beecrypt/beecrypt.h"

#include "beecrypt/entropy.h"

#include "beecrypt/fips186.h"
#include "beecrypt/mtprng.h"

#include "beecrypt/md5.h"
#include "beecrypt/sha1.h"
#include "beecrypt/sha256.h"
#include "beecrypt/sha384.h"
#include "beecrypt/sha512.h"

#include "beecrypt/hmacmd5.h"
#include "beecrypt/hmacsha1.h"
#include "beecrypt/hmacsha256.h"
#include "beecrypt/hmacsha384.h"
#include "beecrypt/hmacsha512.h"

#include "beecrypt/aes.h"
#include "beecrypt/blowfish.h"
#include "beecrypt/blockmode.h"

static entropySource entropySourceList[] =
{
#if WIN32
	{ "wincrypt", entropy_wincrypt },
	{ "console", entropy_console },
	{ "wavein", entropy_wavein },
#else
# if HAVE_DEV_URANDOM
	{ "urandom", entropy_dev_urandom },
# endif
# if HAVE_DEV_RANDOM
	{ "random", entropy_dev_random },
# endif
# if HAVE_DEV_TTY
	{ "tty", entropy_dev_tty },
# endif
# if HAVE_DEV_AUDIO
	{ "audio", entropy_dev_audio },
# endif
# if HAVE_DEV_DSP
	{ "dsp", entropy_dev_dsp },
# endif
#endif
};

#define ENTROPYSOURCES (sizeof(entropySourceList) / sizeof(entropySource))

int entropySourceCount()
{
	return ENTROPYSOURCES;
}

const entropySource* entropySourceGet(int n)
{
	if ((n < 0) || (n >= ENTROPYSOURCES))
		return (const entropySource*) 0;

	return entropySourceList+n;
}

const entropySource* entropySourceFind(const char* name)
{
	register int index;

	for (index = 0; index < ENTROPYSOURCES; index++)
	{
		if (strcmp(name, entropySourceList[index].name) == 0)
			return entropySourceList+index;
	}
	return (const entropySource*) 0;
}

const entropySource* entropySourceDefault()
{
	const char* selection = getenv("BEECRYPT_ENTROPY");

	if (selection)
	{
		return entropySourceFind(selection);
	}
	else if (ENTROPYSOURCES)
	{
		return entropySourceList+0;
	}
	return (const entropySource*) 0;
}

int entropyGatherNext(byte* data, size_t size)
{
	const char* selection = getenv("BEECRYPT_ENTROPY");

	if (selection)
	{
		const entropySource* ptr = entropySourceFind(selection);

		if (ptr)
			return ptr->next(data, size);
	}
	else
	{
		register int index;

		for (index = 0; index < ENTROPYSOURCES; index++)
		{
			if (entropySourceList[index].next(data, size) == 0)
				return 0;
		}
	}
	return -1;
}

static const randomGenerator* randomGeneratorList[] =
{
	&fips186prng,
	&mtprng
};

#define RANDOMGENERATORS	(sizeof(randomGeneratorList) / sizeof(randomGenerator*))

int randomGeneratorCount()
{
	return RANDOMGENERATORS;
}

const randomGenerator* randomGeneratorGet(int index)
{
	if ((index < 0) || (index >= RANDOMGENERATORS))
		return (const randomGenerator*) 0;

	return randomGeneratorList[index];
}

const randomGenerator* randomGeneratorFind(const char* name)
{
	register int index;

	for (index = 0; index < RANDOMGENERATORS; index++)
	{
		if (strcmp(name, randomGeneratorList[index]->name) == 0)
			return randomGeneratorList[index];
	}
	return (const randomGenerator*) 0;
}

const randomGenerator* randomGeneratorDefault()
{
	char* selection = getenv("BEECRYPT_RANDOM");

	if (selection)
		return randomGeneratorFind(selection);
	else
		return &fips186prng;
}

int randomGeneratorContextInit(randomGeneratorContext* ctxt, const randomGenerator* rng)
{
	if (ctxt == (randomGeneratorContext*) 0)
		return -1;

	if (rng == (randomGenerator*) 0)
		return -1;

	ctxt->rng = rng;

	if (rng->paramsize)
	{
		ctxt->param = (randomGeneratorParam*) calloc(rng->paramsize, 1);
		if (ctxt->param == (randomGeneratorParam*) 0)
			return -1;
	}
	else
		ctxt->param = (randomGeneratorParam*) 0;

	return ctxt->rng->setup(ctxt->param);
}

int randomGeneratorContextFree(randomGeneratorContext* ctxt)
{
	register int rc = 0;

	if (ctxt == (randomGeneratorContext*) 0)
		return -1;

	if (ctxt->rng == (randomGenerator*) 0)
		return -1;

	if (ctxt->rng->paramsize)
	{
		if (ctxt->param == (randomGeneratorParam*) 0)
			return -1;
	
		rc = ctxt->rng->cleanup(ctxt->param);

		free(ctxt->param);

		ctxt->param = (randomGeneratorParam*) 0;
	}

	return rc;
}

int randomGeneratorContextNext(randomGeneratorContext* ctxt, byte* data, size_t size)
{
	return ctxt->rng->next(ctxt->param, data, size);
}

int randomGeneratorContextSeed(randomGeneratorContext* ctxt, const byte* data, size_t size)
{
	return ctxt->rng->seed(ctxt->param, data, size);
}

static const hashFunction* hashFunctionList[] =
{
	&md5,
	&sha1,
	&sha256,
	&sha384,
	&sha512
};

#define HASHFUNCTIONS (sizeof(hashFunctionList) / sizeof(hashFunction*))

int hashFunctionCount()
{
	return HASHFUNCTIONS;
}

const hashFunction* hashFunctionDefault()
{
	char* selection = getenv("BEECRYPT_HASH");

	if (selection)
		return hashFunctionFind(selection);
	else
		return &sha1;
}

const hashFunction* hashFunctionGet(int index)
{
	if ((index < 0) || (index >= HASHFUNCTIONS))
		return (const hashFunction*) 0;

	return hashFunctionList[index];
}

const hashFunction* hashFunctionFind(const char* name)
{
	register int index;

	for (index = 0; index < HASHFUNCTIONS; index++)
	{
		if (strcmp(name, hashFunctionList[index]->name) == 0)
			return hashFunctionList[index];
	}
	return (const hashFunction*) 0;
}

int hashFunctionContextInit(hashFunctionContext* ctxt, const hashFunction* hash)
{
	if (ctxt == (hashFunctionContext*) 0)
		return -1;

	if (hash == (hashFunction*) 0)
		return -1;

	ctxt->algo = hash;
	ctxt->param = (hashFunctionParam*) calloc(hash->paramsize, 1);

	if (ctxt->param == (hashFunctionParam*) 0)
		return -1;

	return ctxt->algo->reset(ctxt->param);
}

int hashFunctionContextFree(hashFunctionContext* ctxt)
{
	if (ctxt == (hashFunctionContext*) 0)
		return -1;

	if (ctxt->param == (hashFunctionParam*) 0)
		return -1;

	free(ctxt->param);

	ctxt->param = (hashFunctionParam*) 0;

	return 0;
}

int hashFunctionContextReset(hashFunctionContext* ctxt)
{
	if (ctxt == (hashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (hashFunction*) 0)
		return -1;

	if (ctxt->param == (hashFunctionParam*) 0)
		return -1;

	return ctxt->algo->reset(ctxt->param);
}

int hashFunctionContextUpdate(hashFunctionContext* ctxt, const byte* data, size_t size)
{
	if (ctxt == (hashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (hashFunction*) 0)
		return -1;

	if (ctxt->param == (hashFunctionParam*) 0)
		return -1;

	if (data == (const byte*) 0)
		return -1;

	return ctxt->algo->update(ctxt->param, data, size);
}

int hashFunctionContextUpdateMC(hashFunctionContext* ctxt, const memchunk* m)
{
	if (ctxt == (hashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (hashFunction*) 0)
		return -1;

	if (ctxt->param == (hashFunctionParam*) 0)
		return -1;

	if (m == (memchunk*) 0)
		return -1;

	return ctxt->algo->update(ctxt->param, m->data, m->size);
}

int hashFunctionContextUpdateMP(hashFunctionContext* ctxt, const mpnumber* n)
{
	if (ctxt == (hashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (hashFunction*) 0)
		return -1;

	if (ctxt->param == (hashFunctionParam*) 0)
		return -1;

	if (n != (mpnumber*) 0)
	{
		int rc;

		/* get the number of significant bits in the number */
		size_t sig = mpbits(n->size, n->data);

		/* calculate how many bytes we need for a java-style encoding;
		 * if the most significant bit of the most significant byte
		 * is set, then we need to prefix a zero byte.
		 */
		size_t req = ((sig+7) >> 3) + (((sig&7) == 0) ? 1 : 0);

		byte* tmp = (byte*) malloc(req);

		if (tmp == (byte*) 0)
			return -1;

		i2osp(tmp, req, n->data, n->size);

		rc = ctxt->algo->update(ctxt->param, tmp, req);

		free(tmp);

		return rc;
	}
	return -1;
}

int hashFunctionContextDigest(hashFunctionContext* ctxt, byte *digest)
{
	if (ctxt == (hashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (hashFunction*) 0)
		return -1;

	if (ctxt->param == (hashFunctionParam*) 0)
		return -1;

	if (digest == (byte*) 0)
		return -1;

	return ctxt->algo->digest(ctxt->param, digest);
}

int hashFunctionContextDigestMP(hashFunctionContext* ctxt, mpnumber* d)
{
	if (ctxt == (hashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (hashFunction*) 0)
		return -1;

	if (ctxt->param == (hashFunctionParam*) 0)
		return -1;

	if (d != (mpnumber*) 0)
	{
		int rc;

		byte *digest = (byte*) malloc(ctxt->algo->digestsize);

		if (digest == (byte*) 0)
			return -1;

		if (ctxt->algo->digest(ctxt->param, digest))
		{
			free(digest);
			return -1;
		}

		rc = mpnsetbin(d, digest, ctxt->algo->digestsize);

		free(digest);

		return rc;
	}
	return -1;
}

int hashFunctionContextDigestMatch(hashFunctionContext* ctxt, const mpnumber* d)
{
	int rc = 0;

	mpnumber match;

	mpnzero(&match);

	if (hashFunctionContextDigestMP(ctxt, &match) == 0)
		rc = mpeqx(d->size, d->data, match.size, match.data);

	mpnfree(&match);

	return rc;
}

static const keyedHashFunction* keyedHashFunctionList[] =
{
	&hmacmd5,
	&hmacsha1,
	&hmacsha256,
	&hmacsha384,
	&hmacsha512
};

#define KEYEDHASHFUNCTIONS 	(sizeof(keyedHashFunctionList) / sizeof(keyedHashFunction*))

int keyedHashFunctionCount()
{
	return KEYEDHASHFUNCTIONS;
}

const keyedHashFunction* keyedHashFunctionDefault()
{
	char* selection = getenv("BEECRYPT_KEYEDHASH");

	if (selection)
		return keyedHashFunctionFind(selection);
	else
		return &hmacsha1;
}

const keyedHashFunction* keyedHashFunctionGet(int index)
{
	if ((index < 0) || (index >= KEYEDHASHFUNCTIONS))
		return (const keyedHashFunction*) 0;

	return keyedHashFunctionList[index];
}

const keyedHashFunction* keyedHashFunctionFind(const char* name)
{
	register int index;

	for (index = 0; index < KEYEDHASHFUNCTIONS; index++)
	{
		if (strcmp(name, keyedHashFunctionList[index]->name) == 0)
			return keyedHashFunctionList[index];
	}
	return (const keyedHashFunction*) 0;
}

int keyedHashFunctionContextInit(keyedHashFunctionContext* ctxt, const keyedHashFunction* mac)
{
	if (ctxt == (keyedHashFunctionContext*) 0)
		return -1;

	if (mac == (keyedHashFunction*) 0)
		return -1;

	ctxt->algo = mac;
	ctxt->param = (keyedHashFunctionParam*) calloc(mac->paramsize, 1);

	if (ctxt->param == (keyedHashFunctionParam*) 0)
		return -1;

	return ctxt->algo->reset(ctxt->param);
}

int keyedHashFunctionContextFree(keyedHashFunctionContext* ctxt)
{
	if (ctxt == (keyedHashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (keyedHashFunction*) 0)
		return -1;

	if (ctxt->param == (keyedHashFunctionParam*) 0)
		return -1;

	free(ctxt->param);

	ctxt->param = (keyedHashFunctionParam*) 0;

	return 0;
}

int keyedHashFunctionContextSetup(keyedHashFunctionContext* ctxt, const byte* key, size_t keybits)
{
	if (ctxt == (keyedHashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (keyedHashFunction*) 0)
		return -1;

	if (ctxt->param == (keyedHashFunctionParam*) 0)
		return -1;

	if (key == (byte*) 0)
		return -1;

	return ctxt->algo->setup(ctxt->param, key, keybits);
}

int keyedHashFunctionContextReset(keyedHashFunctionContext* ctxt)
{
	if (ctxt == (keyedHashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (keyedHashFunction*) 0)
		return -1;

	if (ctxt->param == (keyedHashFunctionParam*) 0)
		return -1;

	return ctxt->algo->reset(ctxt->param);
}

int keyedHashFunctionContextUpdate(keyedHashFunctionContext* ctxt, const byte* data, size_t size)
{
	if (ctxt == (keyedHashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (keyedHashFunction*) 0)
		return -1;

	if (ctxt->param == (keyedHashFunctionParam*) 0)
		return -1;

	if (data == (byte*) 0)
		return -1;

	return ctxt->algo->update(ctxt->param, data, size);
}

int keyedHashFunctionContextUpdateMC(keyedHashFunctionContext* ctxt, const memchunk* m)
{
	if (ctxt == (keyedHashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (keyedHashFunction*) 0)
		return -1;

	if (ctxt->param == (keyedHashFunctionParam*) 0)
		return -1;

	if (m == (memchunk*) 0)
		return -1;

	return ctxt->algo->update(ctxt->param, m->data, m->size);
}

int keyedHashFunctionContextUpdateMP(keyedHashFunctionContext* ctxt, const mpnumber* n)
{
	if (ctxt == (keyedHashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (keyedHashFunction*) 0)
		return -1;

	if (ctxt->param == (keyedHashFunctionParam*) 0)
		return -1;

	if (n != (mpnumber*) 0)
	{
		int rc;

		/* get the number of significant bits in the number */
		size_t sig = mpbits(n->size, n->data);

		/* calculate how many bytes we need a java-style encoding; if the
		 * most significant bit of the most significant byte is set, then
		 * we need to prefix a zero byte.
		 */
		size_t req = ((sig+7) >> 3) + (((sig&7) == 0) ? 1 : 0);

		byte* tmp = (byte*) malloc(req);

		if (tmp == (byte*) 0)
			return -1;

		i2osp(tmp, req, n->data, n->size);

		rc = ctxt->algo->update(ctxt->param, tmp, req);

		free(tmp);

		return rc;
	}
	return -1;
}

int keyedHashFunctionContextDigest(keyedHashFunctionContext* ctxt, byte* digest)
{
	if (ctxt == (keyedHashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (keyedHashFunction*) 0)
		return -1;

	if (ctxt->param == (keyedHashFunctionParam*) 0)
		return -1;

	if (digest == (byte*) 0)
		return -1;

	return ctxt->algo->digest(ctxt->param, digest);
}

int keyedHashFunctionContextDigestMP(keyedHashFunctionContext* ctxt, mpnumber* d)
{
	if (ctxt == (keyedHashFunctionContext*) 0)
		return -1;

	if (ctxt->algo == (keyedHashFunction*) 0)
		return -1;

	if (ctxt->param == (keyedHashFunctionParam*) 0)
		return -1;

	if (d != (mpnumber*) 0)
	{
		int rc;

		byte *digest = (byte*) malloc(ctxt->algo->digestsize);

		if (digest == (byte*) 0)
			return -1;

		if (ctxt->algo->digest(ctxt->param, digest))
		{
			free(digest);
			return -1;
		}

		rc = os2ip(d->data, d->size, digest, ctxt->algo->digestsize);

		free(digest);

		return rc;
	}
	return -1;
}

int keyedHashFunctionContextDigestMatch(keyedHashFunctionContext* ctxt, const mpnumber* d)
{
	int rc = 0;

	mpnumber match;

	mpnzero(&match);

	if (keyedHashFunctionContextDigestMP(ctxt, &match) == 0)
		rc = mpeqx(d->size, d->data, match.size, match.data);

	mpnfree(&match);

	return rc;
}

static const blockCipher* blockCipherList[] =
{
	&aes,
	&blowfish
};

#define BLOCKCIPHERS (sizeof(blockCipherList) / sizeof(blockCipher*))

int blockCipherCount()
{
	return BLOCKCIPHERS;
}

const blockCipher* blockCipherDefault()
{
	char* selection = getenv("BEECRYPT_CIPHER");

	if (selection)
		return blockCipherFind(selection);
	else
		return &aes;
}

const blockCipher* blockCipherGet(int index)
{
	if ((index < 0) || (index >= BLOCKCIPHERS))
		return (const blockCipher*) 0;

	return blockCipherList[index];
}

const blockCipher* blockCipherFind(const char* name)
{
	register int index;

	for (index = 0; index < BLOCKCIPHERS; index++)
	{
		if (strcmp(name, blockCipherList[index]->name) == 0)
			return blockCipherList[index];
	}

	return (const blockCipher*) 0;
}

int blockCipherContextInit(blockCipherContext* ctxt, const blockCipher* ciph)
{
	if (ctxt == (blockCipherContext*) 0)
		return -1;

	if (ciph == (blockCipher*) 0)
		return -1;

	ctxt->algo = ciph;
	ctxt->param = (blockCipherParam*) calloc(ciph->paramsize, 1);
	ctxt->op = NOCRYPT;

	if (ctxt->param == (blockCipherParam*) 0)
		return -1;

	return 0;
}

int blockCipherContextSetup(blockCipherContext* ctxt, const byte* key, size_t keybits, cipherOperation op)
{
	if (ctxt == (blockCipherContext*) 0)
		return -1;

	if (ctxt->algo == (blockCipher*) 0)
		return -1;

	if (ctxt->param == (blockCipherParam*) 0)
		return -1;

	ctxt->op = op;

	if (key == (byte*) 0)
		return -1;

	return ctxt->algo->setup(ctxt->param, key, keybits, op);
}

int blockCipherContextSetIV(blockCipherContext* ctxt, const byte* iv)
{
	if (ctxt == (blockCipherContext*) 0)
		return -1;

	if (ctxt->algo == (blockCipher*) 0)
		return -1;

	if (ctxt->param == (blockCipherParam*) 0)
		return -1;

	/* null is an allowed value for iv, so don't test it */

	return ctxt->algo->setiv(ctxt->param, iv);
}

int blockCipherContextFree(blockCipherContext* ctxt)
{
	if (ctxt == (blockCipherContext*) 0)
		return -1;

	if (ctxt->param == (blockCipherParam*) 0)
		return -1;

	free(ctxt->param);

	ctxt->param = (blockCipherParam*) 0;

	return 0;
}

int blockCipherContextValidKeylen(blockCipherContext* ctxt, size_t bits)
{
	if (ctxt == (blockCipherContext*) 0)
		return -1;

	if (ctxt->algo == (blockCipher*) 0)
		return -1;

	if (bits < ctxt->algo->keybitsmin || bits > ctxt->algo->keybitsmax)
		return 0;

	return ((bits - ctxt->algo->keybitsmin) % ctxt->algo->keybitsinc) == 0;
}

int blockCipherContextECB(blockCipherContext* ctxt, uint32_t* dst, const uint32_t* src, int nblocks)
{
	switch (ctxt->op)
	{
	case NOCRYPT:
		memcpy(dst, src, nblocks * ctxt->algo->blocksize);
		return 0;
	case ENCRYPT:
		return (ctxt->algo->ecb.encrypt) ?
			ctxt->algo->ecb.encrypt(ctxt->param, dst, src, nblocks) :
			blockEncryptECB(ctxt->algo, ctxt->param, dst, src, nblocks);
	case DECRYPT:
		return (ctxt->algo->ecb.decrypt) ?
			ctxt->algo->ecb.decrypt(ctxt->param, dst, src, nblocks) :
			blockDecryptECB(ctxt->algo, ctxt->param, dst, src, nblocks);
	}
	return -1;
}

int blockCipherContextCBC(blockCipherContext* ctxt, uint32_t* dst, const uint32_t* src, int nblocks)
{
	switch (ctxt->op)
	{
	case NOCRYPT:
		memcpy(dst, src, nblocks * ctxt->algo->blocksize);
		return 0;
	case ENCRYPT:
		return (ctxt->algo->cbc.encrypt) ?
			ctxt->algo->cbc.encrypt(ctxt->param, dst, src, nblocks) :
			blockEncryptCBC(ctxt->algo, ctxt->param, dst, src, nblocks);
	case DECRYPT:
		return (ctxt->algo->cbc.decrypt) ?
			ctxt->algo->cbc.decrypt(ctxt->param, dst, src, nblocks) :
			blockDecryptCBC(ctxt->algo, ctxt->param, dst, src, nblocks);
	}
	return -1;
}

#if WIN32
__declspec(dllexport)
BOOL WINAPI DllMain(HINSTANCE hInst, DWORD fdwReason, LPVOID lpReserved)
{
	switch (fdwReason)
	{
   	case DLL_PROCESS_ATTACH:
   		entropy_provider_setup(hInst);
   		break;
	case DLL_PROCESS_DETACH:
		entropy_provider_cleanup();
		break;
   	}

	return TRUE;
}
#endif