crypto/cipher.c - linux/kernel/git/davem/net-next - Git at Google

 /*
  * Cryptographic API.
  *
  * Cipher operations.
  *
  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the Free
  * Software Foundation; either version 2 of the License, or (at your option)
  * any later version.
  *
  */
 #include <linux/compiler.h>
 #include <linux/kernel.h>
 #include <linux/crypto.h>
 #include <linux/errno.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <asm/scatterlist.h>
 #include "internal.h"
 #include "scatterwalk.h"

 typedef void (cryptfn_t)(void *, u8 *, const u8 *);
 typedef void (procfn_t)(struct crypto_tfm *, u8 *,
                         u8*, cryptfn_t, void *);

 static inline void xor_64(u8 *a, const u8 *b)
 {
 	((u32 *)a)[0] ^= ((u32 *)b)[0];
 	((u32 *)a)[1] ^= ((u32 *)b)[1];
 }

 static inline void xor_128(u8 *a, const u8 *b)
 {
 	((u32 *)a)[0] ^= ((u32 *)b)[0];
 	((u32 *)a)[1] ^= ((u32 *)b)[1];
 	((u32 *)a)[2] ^= ((u32 *)b)[2];
 	((u32 *)a)[3] ^= ((u32 *)b)[3];
 }

 static inline void *prepare_src(struct scatter_walk *walk, int bsize,
 				void *tmp, int in_place)
 {
 	void *src = walk->data;
 	int n = bsize;

 	if (unlikely(scatterwalk_across_pages(walk, bsize))) {
 		src = tmp;
 		n = scatterwalk_copychunks(src, walk, bsize, 0);
 	}
 	scatterwalk_advance(walk, n);
 	return src;
 }

 static inline void *prepare_dst(struct scatter_walk *walk, int bsize,
 				void *tmp, int in_place)
 {
 	void *dst = walk->data;

 	if (unlikely(scatterwalk_across_pages(walk, bsize)) || in_place)
 		dst = tmp;
 	return dst;
 }

 static inline void complete_src(struct scatter_walk *walk, int bsize,
 				void *src, int in_place)
 {
 }

 static inline void complete_dst(struct scatter_walk *walk, int bsize,
 				void *dst, int in_place)
 {
 	int n = bsize;

 	if (unlikely(scatterwalk_across_pages(walk, bsize)))
 		n = scatterwalk_copychunks(dst, walk, bsize, 1);
 	else if (in_place)
 		memcpy(walk->data, dst, bsize);
 	scatterwalk_advance(walk, n);
 }

 /*
  * Generic encrypt/decrypt wrapper for ciphers, handles operations across
  * multiple page boundaries by using temporary blocks.  In user context,
  * the kernel is given a chance to schedule us once per block.
  */
 static int crypt(struct crypto_tfm *tfm,
 		 struct scatterlist *dst,
 		 struct scatterlist *src,
                  unsigned int nbytes, cryptfn_t crfn,
                  procfn_t prfn, void *info)
 {
 	struct scatter_walk walk_in, walk_out;
 	const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
 	u8 tmp_src[bsize];
 	u8 tmp_dst[bsize];

 	if (!nbytes)
 		return 0;

 	if (nbytes % bsize) {
 		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
 		return -EINVAL;
 	}

 	scatterwalk_start(&walk_in, src);
 	scatterwalk_start(&walk_out, dst);

 	for(;;) {
 		u8 *src_p, *dst_p;
 		int in_place;

 		scatterwalk_map(&walk_in, 0);
 		scatterwalk_map(&walk_out, 1);

 		in_place = scatterwalk_samebuf(&walk_in, &walk_out);

 		do {
 			src_p = prepare_src(&walk_in, bsize, tmp_src,
 					    in_place);
 			dst_p = prepare_dst(&walk_out, bsize, tmp_dst,
 					    in_place);

 			prfn(tfm, dst_p, src_p, crfn, info);

 			complete_src(&walk_in, bsize, src_p, in_place);
 			complete_dst(&walk_out, bsize, dst_p, in_place);

 			nbytes -= bsize;
 		} while (nbytes &&
 			 !scatterwalk_across_pages(&walk_in, bsize) &&
 			 !scatterwalk_across_pages(&walk_out, bsize));

 		scatterwalk_done(&walk_in, 0, nbytes);
 		scatterwalk_done(&walk_out, 1, nbytes);

 		if (!nbytes)
 			return 0;

 		crypto_yield(tfm);
 	}
 }

 static void cbc_process_encrypt(struct crypto_tfm *tfm, u8 *dst, u8 *src,
 				cryptfn_t fn, void *info)
 {
 	u8 *iv = info;

 	tfm->crt_u.cipher.cit_xor_block(iv, src);
 	fn(crypto_tfm_ctx(tfm), dst, iv);
 	memcpy(iv, dst, crypto_tfm_alg_blocksize(tfm));
 }

 static void cbc_process_decrypt(struct crypto_tfm *tfm, u8 *dst, u8 *src,
 				cryptfn_t fn, void *info)
 {
 	u8 *iv = info;

 	fn(crypto_tfm_ctx(tfm), dst, src);
 	tfm->crt_u.cipher.cit_xor_block(dst, iv);
 	memcpy(iv, src, crypto_tfm_alg_blocksize(tfm));
 }

 static void ecb_process(struct crypto_tfm *tfm, u8 *dst, u8 *src,
 			cryptfn_t fn, void *info)
 {
 	fn(crypto_tfm_ctx(tfm), dst, src);
 }

 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
 {
 	struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;

 	if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
 		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 		return -EINVAL;
 	} else
 		return cia->cia_setkey(crypto_tfm_ctx(tfm), key, keylen,
 		                       &tfm->crt_flags);
 }

 static int ecb_encrypt(struct crypto_tfm *tfm,
 		       struct scatterlist *dst,
                        struct scatterlist *src, unsigned int nbytes)
 {
 	return crypt(tfm, dst, src, nbytes,
 	             tfm->__crt_alg->cra_cipher.cia_encrypt,
 	             ecb_process, NULL);
 }

 static int ecb_decrypt(struct crypto_tfm *tfm,
                        struct scatterlist *dst,
                        struct scatterlist *src,
 		       unsigned int nbytes)
 {
 	return crypt(tfm, dst, src, nbytes,
 	             tfm->__crt_alg->cra_cipher.cia_decrypt,
 	             ecb_process, NULL);
 }

 static int cbc_encrypt(struct crypto_tfm *tfm,
                        struct scatterlist *dst,
                        struct scatterlist *src,
 		       unsigned int nbytes)
 {
 	return crypt(tfm, dst, src, nbytes,
 	             tfm->__crt_alg->cra_cipher.cia_encrypt,
 	             cbc_process_encrypt, tfm->crt_cipher.cit_iv);
 }

 static int cbc_encrypt_iv(struct crypto_tfm *tfm,
                           struct scatterlist *dst,
                           struct scatterlist *src,
                           unsigned int nbytes, u8 *iv)
 {
 	return crypt(tfm, dst, src, nbytes,
 	             tfm->__crt_alg->cra_cipher.cia_encrypt,
 	             cbc_process_encrypt, iv);
 }

 static int cbc_decrypt(struct crypto_tfm *tfm,
                        struct scatterlist *dst,
                        struct scatterlist *src,
 		       unsigned int nbytes)
 {
 	return crypt(tfm, dst, src, nbytes,
 	             tfm->__crt_alg->cra_cipher.cia_decrypt,
 	             cbc_process_decrypt, tfm->crt_cipher.cit_iv);
 }

 static int cbc_decrypt_iv(struct crypto_tfm *tfm,
                           struct scatterlist *dst,
                           struct scatterlist *src,
                           unsigned int nbytes, u8 *iv)
 {
 	return crypt(tfm, dst, src, nbytes,
 	             tfm->__crt_alg->cra_cipher.cia_decrypt,
 	             cbc_process_decrypt, iv);
 }

 static int nocrypt(struct crypto_tfm *tfm,
                    struct scatterlist *dst,
                    struct scatterlist *src,
 		   unsigned int nbytes)
 {
 	return -ENOSYS;
 }

 static int nocrypt_iv(struct crypto_tfm *tfm,
                       struct scatterlist *dst,
                       struct scatterlist *src,
                       unsigned int nbytes, u8 *iv)
 {
 	return -ENOSYS;
 }

 int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags)
 {
 	u32 mode = flags & CRYPTO_TFM_MODE_MASK;

 	tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB;
 	if (flags & CRYPTO_TFM_REQ_WEAK_KEY)
 		tfm->crt_flags = CRYPTO_TFM_REQ_WEAK_KEY;

 	return 0;
 }

 int crypto_init_cipher_ops(struct crypto_tfm *tfm)
 {
 	int ret = 0;
 	struct cipher_tfm *ops = &tfm->crt_cipher;

 	ops->cit_setkey = setkey;

 	switch (tfm->crt_cipher.cit_mode) {
 	case CRYPTO_TFM_MODE_ECB:
 		ops->cit_encrypt = ecb_encrypt;
 		ops->cit_decrypt = ecb_decrypt;
 		break;

 	case CRYPTO_TFM_MODE_CBC:
 		ops->cit_encrypt = cbc_encrypt;
 		ops->cit_decrypt = cbc_decrypt;
 		ops->cit_encrypt_iv = cbc_encrypt_iv;
 		ops->cit_decrypt_iv = cbc_decrypt_iv;
 		break;

 	case CRYPTO_TFM_MODE_CFB:
 		ops->cit_encrypt = nocrypt;
 		ops->cit_decrypt = nocrypt;
 		ops->cit_encrypt_iv = nocrypt_iv;
 		ops->cit_decrypt_iv = nocrypt_iv;
 		break;

 	case CRYPTO_TFM_MODE_CTR:
 		ops->cit_encrypt = nocrypt;
 		ops->cit_decrypt = nocrypt;
 		ops->cit_encrypt_iv = nocrypt_iv;
 		ops->cit_decrypt_iv = nocrypt_iv;
 		break;

 	default:
 		BUG();
 	}

 	if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) {

 	    	switch (crypto_tfm_alg_blocksize(tfm)) {
 	    	case 8:
 	    		ops->cit_xor_block = xor_64;
 	    		break;

 	    	case 16:
 	    		ops->cit_xor_block = xor_128;
 	    		break;

 	    	default:
 	    		printk(KERN_WARNING "%s: block size %u not supported\n",
 	    		       crypto_tfm_alg_name(tfm),
 	    		       crypto_tfm_alg_blocksize(tfm));
 	    		ret = -EINVAL;
 	    		goto out;
 	    	}

 		ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm);
 	    	ops->cit_iv = kmalloc(ops->cit_ivsize, GFP_KERNEL);
 		if (ops->cit_iv == NULL)
 			ret = -ENOMEM;
 	}

 out:
 	return ret;
 }

 void crypto_exit_cipher_ops(struct crypto_tfm *tfm)
 {
 	if (tfm->crt_cipher.cit_iv)
 		kfree(tfm->crt_cipher.cit_iv);
 }
	/*
	* Cryptographic API.
	*
	* Cipher operations.
	*
	* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the Free
	* Software Foundation; either version 2 of the License, or (at your option)
	* any later version.
	*
	*/
	#include <linux/compiler.h>
	#include <linux/kernel.h>
	#include <linux/crypto.h>
	#include <linux/errno.h>
	#include <linux/mm.h>
	#include <linux/slab.h>
	#include <linux/string.h>
	#include <asm/scatterlist.h>
	#include "internal.h"
	#include "scatterwalk.h"

	typedef void (cryptfn_t)(void , u8 , const u8 *);
	typedef void (procfn_t)(struct crypto_tfm , u8 ,
	u8, cryptfn_t, void );

	static inline void xor_64(u8 a, const u8 b)
	{
	((u32 )a)[0] ^= ((u32 )b)[0];
	((u32 )a)[1] ^= ((u32 )b)[1];
	}

	static inline void xor_128(u8 a, const u8 b)
	{
	((u32 )a)[0] ^= ((u32 )b)[0];
	((u32 )a)[1] ^= ((u32 )b)[1];
	((u32 )a)[2] ^= ((u32 )b)[2];
	((u32 )a)[3] ^= ((u32 )b)[3];
	}

	static inline void prepare_src(struct scatter_walk walk, int bsize,
	void *tmp, int in_place)
	{
	void *src = walk->data;
	int n = bsize;

	if (unlikely(scatterwalk_across_pages(walk, bsize))) {
	src = tmp;
	n = scatterwalk_copychunks(src, walk, bsize, 0);
	}
	scatterwalk_advance(walk, n);
	return src;
	}

	static inline void prepare_dst(struct scatter_walk walk, int bsize,
	void *tmp, int in_place)
	{
	void *dst = walk->data;

	if (unlikely(scatterwalk_across_pages(walk, bsize)) \|\| in_place)
	dst = tmp;
	return dst;
	}

	static inline void complete_src(struct scatter_walk *walk, int bsize,
	void *src, int in_place)
	{
	}

	static inline void complete_dst(struct scatter_walk *walk, int bsize,
	void *dst, int in_place)
	{
	int n = bsize;

	if (unlikely(scatterwalk_across_pages(walk, bsize)))
	n = scatterwalk_copychunks(dst, walk, bsize, 1);
	else if (in_place)
	memcpy(walk->data, dst, bsize);
	scatterwalk_advance(walk, n);
	}

	/*
	* Generic encrypt/decrypt wrapper for ciphers, handles operations across
	* multiple page boundaries by using temporary blocks. In user context,
	* the kernel is given a chance to schedule us once per block.
	*/
	static int crypt(struct crypto_tfm *tfm,
	struct scatterlist *dst,
	struct scatterlist *src,
	unsigned int nbytes, cryptfn_t crfn,
	procfn_t prfn, void *info)
	{
	struct scatter_walk walk_in, walk_out;
	const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
	u8 tmp_src[bsize];
	u8 tmp_dst[bsize];

	if (!nbytes)
	return 0;

	if (nbytes % bsize) {
	tfm->crt_flags \|= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
	return -EINVAL;
	}

	scatterwalk_start(&walk_in, src);
	scatterwalk_start(&walk_out, dst);

	for(;;) {
	u8 src_p, dst_p;
	int in_place;

	scatterwalk_map(&walk_in, 0);
	scatterwalk_map(&walk_out, 1);

	in_place = scatterwalk_samebuf(&walk_in, &walk_out);

	do {
	src_p = prepare_src(&walk_in, bsize, tmp_src,
	in_place);
	dst_p = prepare_dst(&walk_out, bsize, tmp_dst,
	in_place);

	prfn(tfm, dst_p, src_p, crfn, info);

	complete_src(&walk_in, bsize, src_p, in_place);
	complete_dst(&walk_out, bsize, dst_p, in_place);

	nbytes -= bsize;
	} while (nbytes &&
	!scatterwalk_across_pages(&walk_in, bsize) &&
	!scatterwalk_across_pages(&walk_out, bsize));

	scatterwalk_done(&walk_in, 0, nbytes);
	scatterwalk_done(&walk_out, 1, nbytes);

	if (!nbytes)
	return 0;

	crypto_yield(tfm);
	}
	}

	static void cbc_process_encrypt(struct crypto_tfm tfm, u8 dst, u8 *src,
	cryptfn_t fn, void *info)
	{
	u8 *iv = info;

	tfm->crt_u.cipher.cit_xor_block(iv, src);
	fn(crypto_tfm_ctx(tfm), dst, iv);
	memcpy(iv, dst, crypto_tfm_alg_blocksize(tfm));
	}

	static void cbc_process_decrypt(struct crypto_tfm tfm, u8 dst, u8 *src,
	cryptfn_t fn, void *info)
	{
	u8 *iv = info;

	fn(crypto_tfm_ctx(tfm), dst, src);
	tfm->crt_u.cipher.cit_xor_block(dst, iv);
	memcpy(iv, src, crypto_tfm_alg_blocksize(tfm));
	}

	static void ecb_process(struct crypto_tfm tfm, u8 dst, u8 *src,
	cryptfn_t fn, void *info)
	{
	fn(crypto_tfm_ctx(tfm), dst, src);
	}

	static int setkey(struct crypto_tfm tfm, const u8 key, unsigned int keylen)
	{
	struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;

	if (keylen < cia->cia_min_keysize \|\| keylen > cia->cia_max_keysize) {
	tfm->crt_flags \|= CRYPTO_TFM_RES_BAD_KEY_LEN;
	return -EINVAL;
	} else
	return cia->cia_setkey(crypto_tfm_ctx(tfm), key, keylen,
	&tfm->crt_flags);
	}

	static int ecb_encrypt(struct crypto_tfm *tfm,
	struct scatterlist *dst,
	struct scatterlist *src, unsigned int nbytes)
	{
	return crypt(tfm, dst, src, nbytes,
	tfm->__crt_alg->cra_cipher.cia_encrypt,
	ecb_process, NULL);
	}

	static int ecb_decrypt(struct crypto_tfm *tfm,
	struct scatterlist *dst,
	struct scatterlist *src,
	unsigned int nbytes)
	{
	return crypt(tfm, dst, src, nbytes,
	tfm->__crt_alg->cra_cipher.cia_decrypt,
	ecb_process, NULL);
	}

	static int cbc_encrypt(struct crypto_tfm *tfm,
	struct scatterlist *dst,
	struct scatterlist *src,
	unsigned int nbytes)
	{
	return crypt(tfm, dst, src, nbytes,
	tfm->__crt_alg->cra_cipher.cia_encrypt,
	cbc_process_encrypt, tfm->crt_cipher.cit_iv);
	}

	static int cbc_encrypt_iv(struct crypto_tfm *tfm,
	struct scatterlist *dst,
	struct scatterlist *src,
	unsigned int nbytes, u8 *iv)
	{
	return crypt(tfm, dst, src, nbytes,
	tfm->__crt_alg->cra_cipher.cia_encrypt,
	cbc_process_encrypt, iv);
	}

	static int cbc_decrypt(struct crypto_tfm *tfm,
	struct scatterlist *dst,
	struct scatterlist *src,
	unsigned int nbytes)
	{
	return crypt(tfm, dst, src, nbytes,
	tfm->__crt_alg->cra_cipher.cia_decrypt,
	cbc_process_decrypt, tfm->crt_cipher.cit_iv);
	}

	static int cbc_decrypt_iv(struct crypto_tfm *tfm,
	struct scatterlist *dst,
	struct scatterlist *src,
	unsigned int nbytes, u8 *iv)
	{
	return crypt(tfm, dst, src, nbytes,
	tfm->__crt_alg->cra_cipher.cia_decrypt,
	cbc_process_decrypt, iv);
	}

	static int nocrypt(struct crypto_tfm *tfm,
	struct scatterlist *dst,
	struct scatterlist *src,
	unsigned int nbytes)
	{
	return -ENOSYS;
	}

	static int nocrypt_iv(struct crypto_tfm *tfm,
	struct scatterlist *dst,
	struct scatterlist *src,
	unsigned int nbytes, u8 *iv)
	{
	return -ENOSYS;
	}

	int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags)
	{
	u32 mode = flags & CRYPTO_TFM_MODE_MASK;

	tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB;
	if (flags & CRYPTO_TFM_REQ_WEAK_KEY)
	tfm->crt_flags = CRYPTO_TFM_REQ_WEAK_KEY;

	return 0;
	}

	int crypto_init_cipher_ops(struct crypto_tfm *tfm)
	{
	int ret = 0;
	struct cipher_tfm *ops = &tfm->crt_cipher;

	ops->cit_setkey = setkey;

	switch (tfm->crt_cipher.cit_mode) {
	case CRYPTO_TFM_MODE_ECB:
	ops->cit_encrypt = ecb_encrypt;
	ops->cit_decrypt = ecb_decrypt;
	break;

	case CRYPTO_TFM_MODE_CBC:
	ops->cit_encrypt = cbc_encrypt;
	ops->cit_decrypt = cbc_decrypt;
	ops->cit_encrypt_iv = cbc_encrypt_iv;
	ops->cit_decrypt_iv = cbc_decrypt_iv;
	break;

	case CRYPTO_TFM_MODE_CFB:
	ops->cit_encrypt = nocrypt;
	ops->cit_decrypt = nocrypt;
	ops->cit_encrypt_iv = nocrypt_iv;
	ops->cit_decrypt_iv = nocrypt_iv;
	break;

	case CRYPTO_TFM_MODE_CTR:
	ops->cit_encrypt = nocrypt;
	ops->cit_decrypt = nocrypt;
	ops->cit_encrypt_iv = nocrypt_iv;
	ops->cit_decrypt_iv = nocrypt_iv;
	break;

	default:
	BUG();
	}

	if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) {

	switch (crypto_tfm_alg_blocksize(tfm)) {
	case 8:
	ops->cit_xor_block = xor_64;
	break;

	case 16:
	ops->cit_xor_block = xor_128;
	break;

	default:
	printk(KERN_WARNING "%s: block size %u not supported\n",
	crypto_tfm_alg_name(tfm),
	crypto_tfm_alg_blocksize(tfm));
	ret = -EINVAL;
	goto out;
	}

	ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm);
	ops->cit_iv = kmalloc(ops->cit_ivsize, GFP_KERNEL);
	if (ops->cit_iv == NULL)
	ret = -ENOMEM;
	}

	out:
	return ret;
	}

	void crypto_exit_cipher_ops(struct crypto_tfm *tfm)
	{
	if (tfm->crt_cipher.cit_iv)
	kfree(tfm->crt_cipher.cit_iv);
	}