/* * 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" 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;	unsigned int n; 	n = scatterwalk_copychunks(src, in, bsize, 0);	scatterwalk_advance(in, n); 	desc->prfn(desc, dst, src, bsize); 	n = scatterwalk_copychunks(dst, out, bsize, 1);	scatterwalk_advance(out, n); 	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; 	src = in->data;	dst = scatterwalk_samebuf(in, out) ? src : out->data; 	if (tmp) {		memcpy(tmp, in->data, nbytes);		src = tmp;		dst = tmp;	} 	nbytes = desc->prfn(desc, dst, src, nbytes); 	if (tmp)		memcpy(out->data, tmp, nbytes); 	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;		} 		scatterwalk_map(&walk_in, 0);		scatterwalk_map(&walk_out, 1); 		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);	} 	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)(void *, u8 *, const u8 *) = desc->crfn;	u8 *iv = desc->info;	unsigned int done = 0; 	nbytes -= bsize; 	do {		xor(iv, src);		fn(crypto_tfm_ctx(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)(void *, u8 *, const u8 *) = desc->crfn;	u8 *iv = desc->info;	unsigned int done = 0; 	nbytes -= bsize; 	do {		u8 *tmp_dst = *dst_p; 		fn(crypto_tfm_ctx(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)(void *, u8 *, const u8 *) = desc->crfn;	unsigned int done = 0; 	nbytes -= bsize; 	do {		fn(crypto_tfm_ctx(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;		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){	struct cipher_desc desc;	struct cipher_alg *cipher = &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 *cipher = &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 *cipher = &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 *cipher = &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 *cipher = &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 *cipher = &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;} 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) {		unsigned long align;		unsigned long addr;	    		    	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);		align = crypto_tfm_alg_alignmask(tfm) + 1;		addr = (unsigned long)crypto_tfm_ctx(tfm);		addr = ALIGN(addr, align);		addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);		ops->cit_iv = (void *)addr;	} out:		return ret;} void crypto_exit_cipher_ops(struct crypto_tfm *tfm){}