/* * Cryptographic API. * * Cipher operations. * * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.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" struct cipher_alg_compat {	unsigned int cia_min_keysize;	unsigned int cia_max_keysize;	int (*cia_setkey)(struct crypto_tfm *tfm, const u8 *key,	                  unsigned int keylen);	void (*cia_encrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);	void (*cia_decrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src); 	unsigned int (*cia_encrypt_ecb)(const struct cipher_desc *desc,					u8 *dst, const u8 *src,					unsigned int nbytes);	unsigned int (*cia_decrypt_ecb)(const struct cipher_desc *desc,					u8 *dst, const u8 *src,					unsigned int nbytes);	unsigned int (*cia_encrypt_cbc)(const struct cipher_desc *desc,					u8 *dst, const u8 *src,					unsigned int nbytes);	unsigned int (*cia_decrypt_cbc)(const struct cipher_desc *desc,					u8 *dst, const u8 *src,					unsigned int nbytes);}; 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 unsigned int crypt_slow(const struct cipher_desc *desc,			       struct scatter_walk *in,			       struct scatter_walk *out, unsigned int bsize){	unsigned long alignmask = crypto_tfm_alg_alignmask(desc->tfm);	u8 buffer[bsize * 2 + alignmask];	u8 *src = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);	u8 *dst = src + bsize; 	scatterwalk_copychunks(src, in, bsize, 0);	desc->prfn(desc, dst, src, bsize);	scatterwalk_copychunks(dst, out, bsize, 1); 	return bsize;} static inline unsigned int crypt_fast(const struct cipher_desc *desc,				      struct scatter_walk *in,				      struct scatter_walk *out,				      unsigned int nbytes, u8 *tmp){	u8 *src, *dst;	u8 *real_src, *real_dst; 	real_src = scatterwalk_map(in, 0);	real_dst = scatterwalk_map(out, 1); 	src = real_src;	dst = scatterwalk_samebuf(in, out) ? src : real_dst; 	if (tmp) {		memcpy(tmp, src, nbytes);		src = tmp;		dst = tmp;	} 	nbytes = desc->prfn(desc, dst, src, nbytes); 	if (tmp)		memcpy(real_dst, tmp, nbytes); 	scatterwalk_unmap(real_src, 0);	scatterwalk_unmap(real_dst, 1); 	scatterwalk_advance(in, nbytes);	scatterwalk_advance(out, nbytes); 	return nbytes;} /*  * 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 page. */static int crypt(const struct cipher_desc *desc,		 struct scatterlist *dst,		 struct scatterlist *src,		 unsigned int nbytes){	struct scatter_walk walk_in, walk_out;	struct crypto_tfm *tfm = desc->tfm;	const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);	unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);	unsigned long buffer = 0; 	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(;;) {		unsigned int n = nbytes;		u8 *tmp = NULL; 		if (!scatterwalk_aligned(&walk_in, alignmask) ||		    !scatterwalk_aligned(&walk_out, alignmask)) {			if (!buffer) {				buffer = __get_free_page(GFP_ATOMIC);				if (!buffer)					n = 0;			}			tmp = (u8 *)buffer;		} 		n = scatterwalk_clamp(&walk_in, n);		n = scatterwalk_clamp(&walk_out, n); 		if (likely(n >= bsize))			n = crypt_fast(desc, &walk_in, &walk_out, n, tmp);		else			n = crypt_slow(desc, &walk_in, &walk_out, bsize); 		nbytes -= n; 		scatterwalk_done(&walk_in, 0, nbytes);		scatterwalk_done(&walk_out, 1, nbytes); 		if (!nbytes)			break; 		crypto_yield(tfm->crt_flags);	} 	if (buffer)		free_page(buffer); 	return 0;} static int crypt_iv_unaligned(struct cipher_desc *desc,			      struct scatterlist *dst,			      struct scatterlist *src,			      unsigned int nbytes){	struct crypto_tfm *tfm = desc->tfm;	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);	u8 *iv = desc->info; 	if (unlikely(((unsigned long)iv & alignmask))) {		unsigned int ivsize = tfm->crt_cipher.cit_ivsize;		u8 buffer[ivsize + alignmask];		u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);		int err; 		desc->info = memcpy(tmp, iv, ivsize);		err = crypt(desc, dst, src, nbytes);		memcpy(iv, tmp, ivsize); 		return err;	} 	return crypt(desc, dst, src, nbytes);} static unsigned int cbc_process_encrypt(const struct cipher_desc *desc,					u8 *dst, const u8 *src,					unsigned int nbytes){	struct crypto_tfm *tfm = desc->tfm;	void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;	int bsize = crypto_tfm_alg_blocksize(tfm); 	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = desc->crfn;	u8 *iv = desc->info;	unsigned int done = 0; 	nbytes -= bsize; 	do {		xor(iv, src);		fn(tfm, dst, iv);		memcpy(iv, dst, bsize); 		src += bsize;		dst += bsize;	} while ((done += bsize) <= nbytes); 	return done;} static unsigned int cbc_process_decrypt(const struct cipher_desc *desc,					u8 *dst, const u8 *src,					unsigned int nbytes){	struct crypto_tfm *tfm = desc->tfm;	void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;	int bsize = crypto_tfm_alg_blocksize(tfm);	unsigned long alignmask = crypto_tfm_alg_alignmask(desc->tfm); 	u8 stack[src == dst ? bsize + alignmask : 0];	u8 *buf = (u8 *)ALIGN((unsigned long)stack, alignmask + 1);	u8 **dst_p = src == dst ? &buf : &dst; 	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = desc->crfn;	u8 *iv = desc->info;	unsigned int done = 0; 	nbytes -= bsize; 	do {		u8 *tmp_dst = *dst_p; 		fn(tfm, tmp_dst, src);		xor(tmp_dst, iv);		memcpy(iv, src, bsize);		if (tmp_dst != dst)			memcpy(dst, tmp_dst, bsize); 		src += bsize;		dst += bsize;	} while ((done += bsize) <= nbytes); 	return done;} static unsigned int ecb_process(const struct cipher_desc *desc, u8 *dst,				const u8 *src, unsigned int nbytes){	struct crypto_tfm *tfm = desc->tfm;	int bsize = crypto_tfm_alg_blocksize(tfm);	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) = desc->crfn;	unsigned int done = 0; 	nbytes -= bsize; 	do {		fn(tfm, dst, src); 		src += bsize;		dst += bsize;	} while ((done += bsize) <= nbytes); 	return done;} static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen){	struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;		tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;	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(tfm, key, keylen);} static int ecb_encrypt(struct crypto_tfm *tfm,		       struct scatterlist *dst,                       struct scatterlist *src, unsigned int nbytes){	struct cipher_desc desc;	struct cipher_alg_compat *cipher = (void *)&tfm->__crt_alg->cra_cipher; 	desc.tfm = tfm;	desc.crfn = cipher->cia_encrypt;	desc.prfn = cipher->cia_encrypt_ecb ?: ecb_process; 	return crypt(&desc, dst, src, nbytes);} static int ecb_decrypt(struct crypto_tfm *tfm,                       struct scatterlist *dst,                       struct scatterlist *src,		       unsigned int nbytes){	struct cipher_desc desc;	struct cipher_alg_compat *cipher = (void *)&tfm->__crt_alg->cra_cipher; 	desc.tfm = tfm;	desc.crfn = cipher->cia_decrypt;	desc.prfn = cipher->cia_decrypt_ecb ?: ecb_process; 	return crypt(&desc, dst, src, nbytes);} static int cbc_encrypt(struct crypto_tfm *tfm,                       struct scatterlist *dst,                       struct scatterlist *src,		       unsigned int nbytes){	struct cipher_desc desc;	struct cipher_alg_compat *cipher = (void *)&tfm->__crt_alg->cra_cipher; 	desc.tfm = tfm;	desc.crfn = cipher->cia_encrypt;	desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;	desc.info = tfm->crt_cipher.cit_iv; 	return crypt(&desc, dst, src, nbytes);} static int cbc_encrypt_iv(struct crypto_tfm *tfm,                          struct scatterlist *dst,                          struct scatterlist *src,                          unsigned int nbytes, u8 *iv){	struct cipher_desc desc;	struct cipher_alg_compat *cipher = (void *)&tfm->__crt_alg->cra_cipher; 	desc.tfm = tfm;	desc.crfn = cipher->cia_encrypt;	desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;	desc.info = iv; 	return crypt_iv_unaligned(&desc, dst, src, nbytes);} static int cbc_decrypt(struct crypto_tfm *tfm,                       struct scatterlist *dst,                       struct scatterlist *src,		       unsigned int nbytes){	struct cipher_desc desc;	struct cipher_alg_compat *cipher = (void *)&tfm->__crt_alg->cra_cipher; 	desc.tfm = tfm;	desc.crfn = cipher->cia_decrypt;	desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;	desc.info = tfm->crt_cipher.cit_iv; 	return crypt(&desc, dst, src, nbytes);} static int cbc_decrypt_iv(struct crypto_tfm *tfm,                          struct scatterlist *dst,                          struct scatterlist *src,                          unsigned int nbytes, u8 *iv){	struct cipher_desc desc;	struct cipher_alg_compat *cipher = (void *)&tfm->__crt_alg->cra_cipher; 	desc.tfm = tfm;	desc.crfn = cipher->cia_decrypt;	desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;	desc.info = iv; 	return crypt_iv_unaligned(&desc, dst, src, nbytes);} 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;	return 0;} static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,					      const u8 *),				   struct crypto_tfm *tfm,				   u8 *dst, const u8 *src){	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);	unsigned int size = crypto_tfm_alg_blocksize(tfm);	u8 buffer[size + alignmask];	u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 	memcpy(tmp, src, size);	fn(tfm, tmp, tmp);	memcpy(dst, tmp, size);} static void cipher_encrypt_unaligned(struct crypto_tfm *tfm,				     u8 *dst, const u8 *src){	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; 	if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {		cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);		return;	} 	cipher->cia_encrypt(tfm, dst, src);} static void cipher_decrypt_unaligned(struct crypto_tfm *tfm,				     u8 *dst, const u8 *src){	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; 	if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {		cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);		return;	} 	cipher->cia_decrypt(tfm, dst, src);} int crypto_init_cipher_ops(struct crypto_tfm *tfm){	int ret = 0;	struct cipher_tfm *ops = &tfm->crt_cipher;	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher; 	ops->cit_setkey = setkey;	ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ?		cipher_encrypt_unaligned : cipher->cia_encrypt;	ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ?		cipher_decrypt_unaligned : cipher->cia_decrypt; 	switch (tfm->crt_cipher.cit_mode) {	case CRYPTO_TFM_MODE_ECB:		ops->cit_encrypt = ecb_encrypt;		ops->cit_decrypt = ecb_decrypt;		ops->cit_encrypt_iv = nocrypt_iv;		ops->cit_decrypt_iv = nocrypt_iv;		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) {

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