/* * Block chaining cipher operations. *  * 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. * * Copyright (c) 2006 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/crypto.h>#include <linux/errno.h>#include <linux/hardirq.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/scatterlist.h>#include <linux/seq_file.h>#include <linux/slab.h>#include <linux/string.h> #include "internal.h"#include "scatterwalk.h" enum {	BLKCIPHER_WALK_PHYS = 1 << 0,	BLKCIPHER_WALK_SLOW = 1 << 1,	BLKCIPHER_WALK_COPY = 1 << 2,	BLKCIPHER_WALK_DIFF = 1 << 3,}; static int blkcipher_walk_next(struct blkcipher_desc *desc,			       struct blkcipher_walk *walk);static int blkcipher_walk_first(struct blkcipher_desc *desc,				struct blkcipher_walk *walk); static inline void blkcipher_map_src(struct blkcipher_walk *walk){	walk->src.virt.addr = scatterwalk_map(&walk->in, 0);} static inline void blkcipher_map_dst(struct blkcipher_walk *walk){	walk->dst.virt.addr = scatterwalk_map(&walk->out, 1);} static inline void blkcipher_unmap_src(struct blkcipher_walk *walk){	scatterwalk_unmap(walk->src.virt.addr, 0);} static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk){	scatterwalk_unmap(walk->dst.virt.addr, 1);} static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len){	if (offset_in_page(start + len) < len)		return (u8 *)((unsigned long)(start + len) & PAGE_MASK);	return start;} static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,					       struct blkcipher_walk *walk,					       unsigned int bsize){	u8 *addr;	unsigned int alignmask = crypto_blkcipher_alignmask(tfm); 	addr = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);	addr = blkcipher_get_spot(addr, bsize);	scatterwalk_copychunks(addr, &walk->out, bsize, 1);	return bsize;} static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,					       unsigned int n){	n = walk->nbytes - n; 	if (walk->flags & BLKCIPHER_WALK_COPY) {		blkcipher_map_dst(walk);		memcpy(walk->dst.virt.addr, walk->page, n);		blkcipher_unmap_dst(walk);	} else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {		blkcipher_unmap_src(walk);		if (walk->flags & BLKCIPHER_WALK_DIFF)			blkcipher_unmap_dst(walk);	} 	scatterwalk_advance(&walk->in, n);	scatterwalk_advance(&walk->out, n); 	return n;} int blkcipher_walk_done(struct blkcipher_desc *desc,			struct blkcipher_walk *walk, int err){	struct crypto_blkcipher *tfm = desc->tfm;	unsigned int nbytes = 0; 	if (likely(err >= 0)) {		unsigned int bsize = crypto_blkcipher_blocksize(tfm);		unsigned int n; 		if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))			n = blkcipher_done_fast(walk, err);		else			n = blkcipher_done_slow(tfm, walk, bsize); 		nbytes = walk->total - n;		err = 0;	} 	scatterwalk_done(&walk->in, 0, nbytes);	scatterwalk_done(&walk->out, 1, nbytes); 	walk->total = nbytes;	walk->nbytes = nbytes; 	if (nbytes) {		crypto_yield(desc->flags);		return blkcipher_walk_next(desc, walk);	} 	if (walk->iv != desc->info)		memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));	if (walk->buffer != walk->page)		kfree(walk->buffer);	if (walk->page)		free_page((unsigned long)walk->page); 	return err;}EXPORT_SYMBOL_GPL(blkcipher_walk_done); static inline int blkcipher_next_slow(struct blkcipher_desc *desc,				      struct blkcipher_walk *walk,				      unsigned int bsize,				      unsigned int alignmask){	unsigned int n; 	if (walk->buffer)		goto ok; 	walk->buffer = walk->page;	if (walk->buffer)		goto ok; 	n = bsize * 2 + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));	walk->buffer = kmalloc(n, GFP_ATOMIC);	if (!walk->buffer)		return blkcipher_walk_done(desc, walk, -ENOMEM); ok:	walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,					  alignmask + 1);	walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);	walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr + bsize,						 bsize); 	scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0); 	walk->nbytes = bsize;	walk->flags |= BLKCIPHER_WALK_SLOW; 	return 0;} static inline int blkcipher_next_copy(struct blkcipher_walk *walk){	u8 *tmp = walk->page; 	blkcipher_map_src(walk);	memcpy(tmp, walk->src.virt.addr, walk->nbytes);	blkcipher_unmap_src(walk); 	walk->src.virt.addr = tmp;	walk->dst.virt.addr = tmp; 	return 0;} static inline int blkcipher_next_fast(struct blkcipher_desc *desc,				      struct blkcipher_walk *walk){	unsigned long diff; 	walk->src.phys.page = scatterwalk_page(&walk->in);	walk->src.phys.offset = offset_in_page(walk->in.offset);	walk->dst.phys.page = scatterwalk_page(&walk->out);	walk->dst.phys.offset = offset_in_page(walk->out.offset); 	if (walk->flags & BLKCIPHER_WALK_PHYS)		return 0; 	diff = walk->src.phys.offset - walk->dst.phys.offset;	diff |= walk->src.virt.page - walk->dst.virt.page; 	blkcipher_map_src(walk);	walk->dst.virt.addr = walk->src.virt.addr; 	if (diff) {		walk->flags |= BLKCIPHER_WALK_DIFF;		blkcipher_map_dst(walk);	} 	return 0;} static int blkcipher_walk_next(struct blkcipher_desc *desc,			       struct blkcipher_walk *walk){	struct crypto_blkcipher *tfm = desc->tfm;	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);	unsigned int bsize = crypto_blkcipher_blocksize(tfm);	unsigned int n;	int err; 	n = walk->total;	if (unlikely(n < bsize)) {		desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;		return blkcipher_walk_done(desc, walk, -EINVAL);	} 	walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |			 BLKCIPHER_WALK_DIFF);	if (!scatterwalk_aligned(&walk->in, alignmask) ||	    !scatterwalk_aligned(&walk->out, alignmask)) {		walk->flags |= BLKCIPHER_WALK_COPY;		if (!walk->page) {			walk->page = (void *)__get_free_page(GFP_ATOMIC);			if (!walk->page)				n = 0;		}	} 	n = scatterwalk_clamp(&walk->in, n);	n = scatterwalk_clamp(&walk->out, n); 	if (unlikely(n < bsize)) {		err = blkcipher_next_slow(desc, walk, bsize, alignmask);		goto set_phys_lowmem;	} 	walk->nbytes = n;	if (walk->flags & BLKCIPHER_WALK_COPY) {		err = blkcipher_next_copy(walk);		goto set_phys_lowmem;	} 	return blkcipher_next_fast(desc, walk); set_phys_lowmem:	if (walk->flags & BLKCIPHER_WALK_PHYS) {		walk->src.phys.page = virt_to_page(walk->src.virt.addr);		walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);		walk->src.phys.offset &= PAGE_SIZE - 1;		walk->dst.phys.offset &= PAGE_SIZE - 1;	}	return err;} static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,				    struct crypto_blkcipher *tfm,				    unsigned int alignmask){	unsigned bs = crypto_blkcipher_blocksize(tfm);	unsigned int ivsize = crypto_blkcipher_ivsize(tfm);	unsigned int size = bs * 2 + ivsize + max(bs, ivsize) - (alignmask + 1);	u8 *iv; 	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);	walk->buffer = kmalloc(size, GFP_ATOMIC);	if (!walk->buffer)		return -ENOMEM; 	iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);	iv = blkcipher_get_spot(iv, bs) + bs;	iv = blkcipher_get_spot(iv, bs) + bs;	iv = blkcipher_get_spot(iv, ivsize); 	walk->iv = memcpy(iv, walk->iv, ivsize);	return 0;} int blkcipher_walk_virt(struct blkcipher_desc *desc,			struct blkcipher_walk *walk){	walk->flags &= ~BLKCIPHER_WALK_PHYS;	return blkcipher_walk_first(desc, walk);}EXPORT_SYMBOL_GPL(blkcipher_walk_virt); int blkcipher_walk_phys(struct blkcipher_desc *desc,			struct blkcipher_walk *walk){	walk->flags |= BLKCIPHER_WALK_PHYS;	return blkcipher_walk_first(desc, walk);}EXPORT_SYMBOL_GPL(blkcipher_walk_phys); static int blkcipher_walk_first(struct blkcipher_desc *desc,				struct blkcipher_walk *walk){	struct crypto_blkcipher *tfm = desc->tfm;	unsigned int alignmask = crypto_blkcipher_alignmask(tfm); 	if (WARN_ON_ONCE(in_irq()))		return -EDEADLK; 	walk->nbytes = walk->total;	if (unlikely(!walk->total))		return 0; 	walk->buffer = NULL;	walk->iv = desc->info;	if (unlikely(((unsigned long)walk->iv & alignmask))) {		int err = blkcipher_copy_iv(walk, tfm, alignmask);		if (err)			return err;	} 	scatterwalk_start(&walk->in, walk->in.sg);	scatterwalk_start(&walk->out, walk->out.sg);	walk->page = NULL; 	return blkcipher_walk_next(desc, walk);} static int setkey(struct crypto_tfm *tfm, const u8 *key,		  unsigned int keylen){	struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher; 	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;		return -EINVAL;	} 	return cipher->setkey(tfm, key, keylen);} static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,					     u32 mask){	struct blkcipher_alg *cipher = &alg->cra_blkcipher;	unsigned int len = alg->cra_ctxsize; 	if (cipher->ivsize) {		len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);		len += cipher->ivsize;	} 	return len;} static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask){	struct blkcipher_tfm *crt = &tfm->crt_blkcipher;	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;	unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;	unsigned long addr; 	if (alg->ivsize > PAGE_SIZE / 8)		return -EINVAL; 	crt->setkey = setkey;	crt->encrypt = alg->encrypt;	crt->decrypt = alg->decrypt; 	addr = (unsigned long)crypto_tfm_ctx(tfm);	addr = ALIGN(addr, align);	addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);	crt->iv = (void *)addr; 	return 0;} static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)	__attribute_used__;static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg){	seq_printf(m, "type         : blkcipher\n");	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);	seq_printf(m, "min keysize  : %u\n", alg->cra_blkcipher.min_keysize);	seq_printf(m, "max keysize  : %u\n", alg->cra_blkcipher.max_keysize);	seq_printf(m, "ivsize       : %u\n", alg->cra_blkcipher.ivsize);} const struct crypto_type crypto_blkcipher_type = {	.ctxsize = crypto_blkcipher_ctxsize,	.init = crypto_init_blkcipher_ops,#ifdef CONFIG_PROC_FS	.show = crypto_blkcipher_show,#endif};EXPORT_SYMBOL_GPL(crypto_blkcipher_type); MODULE_LICENSE("GPL");MODULE_DESCRIPTION("Generic block chaining cipher type");