Release 4.11 crypto/skcipher.c

Directory: crypto
/*
 * Symmetric key 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) 2015 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 <crypto/internal/aead.h>
#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
#include <linux/bug.h>
#include <linux/cryptouser.h>
#include <linux/compiler.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/seq_file.h>
#include <net/netlink.h>

#include "internal.h"

enum {
	
SKCIPHER_WALK_PHYS = 1 << 0,
	
SKCIPHER_WALK_SLOW = 1 << 1,
	
SKCIPHER_WALK_COPY = 1 << 2,
	
SKCIPHER_WALK_DIFF = 1 << 3,
	
SKCIPHER_WALK_SLEEP = 1 << 4,
};


struct skcipher_walk_buffer {
	
struct list_head entry;
	
struct scatter_walk dst;
	
unsigned int len;
	
u8 *data;
	
u8 buffer[];
};

static int skcipher_walk_next(struct skcipher_walk *walk);



static inline void skcipher_unmap(struct scatter_walk *walk, void *vaddr)
{
	if (PageHighMem(scatterwalk_page(walk)))
		kunmap_atomic(vaddr);
}

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Herbert Xu 31 100.00% 1 100.00%
Total 31 100.00% 1 100.00%



static inline void *skcipher_map(struct scatter_walk *walk)
{
	struct page *page = scatterwalk_page(walk);

	return (PageHighMem(page) ? kmap_atomic(page) : page_address(page)) +
	       offset_in_page(walk->offset);
}

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Herbert Xu 48 100.00% 1 100.00%
Total 48 100.00% 1 100.00%



static inline void skcipher_map_src(struct skcipher_walk *walk)
{
	walk->src.virt.addr = skcipher_map(&walk->in);
}

Contributors
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Herbert Xu 28 100.00% 1 100.00%
Total 28 100.00% 1 100.00%



static inline void skcipher_map_dst(struct skcipher_walk *walk)
{
	walk->dst.virt.addr = skcipher_map(&walk->out);
}

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Herbert Xu 28 100.00% 1 100.00%
Total 28 100.00% 1 100.00%



static inline void skcipher_unmap_src(struct skcipher_walk *walk)
{
	skcipher_unmap(&walk->in, walk->src.virt.addr);
}

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static inline void skcipher_unmap_dst(struct skcipher_walk *walk)
{
	skcipher_unmap(&walk->out, walk->dst.virt.addr);
}

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Total 28 100.00% 1 100.00%



static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk)
{
	return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
}

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/* Get a spot of the specified length that does not straddle a page.
 * The caller needs to ensure that there is enough space for this operation.
 */


static inline u8 *skcipher_get_spot(u8 *start, unsigned int len)
{
	u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);

	return max(start, end_page);
}

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Total 50 100.00% 1 100.00%



static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
{
	u8 *addr;

	addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
	addr = skcipher_get_spot(addr, bsize);
	scatterwalk_copychunks(addr, &walk->out, bsize,
			       (walk->flags & SKCIPHER_WALK_PHYS) ? 2 : 1);
	return 0;
}

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Herbert Xu 78 100.00% 1 100.00%
Total 78 100.00% 1 100.00%



int skcipher_walk_done(struct skcipher_walk *walk, int err)
{
	unsigned int n = walk->nbytes - err;
	unsigned int nbytes;

	nbytes = walk->total - n;

	if (unlikely(err < 0)) {
		nbytes = 0;
		n = 0;
	} else if (likely(!(walk->flags & (SKCIPHER_WALK_PHYS |
					   SKCIPHER_WALK_SLOW |
					   SKCIPHER_WALK_COPY |
					   SKCIPHER_WALK_DIFF)))) {
unmap_src:
		skcipher_unmap_src(walk);
	} else if (walk->flags & SKCIPHER_WALK_DIFF) {
		skcipher_unmap_dst(walk);
		goto unmap_src;
	} else if (walk->flags & SKCIPHER_WALK_COPY) {
		skcipher_map_dst(walk);
		memcpy(walk->dst.virt.addr, walk->page, n);
		skcipher_unmap_dst(walk);
	} else if (unlikely(walk->flags & SKCIPHER_WALK_SLOW)) {
		if (WARN_ON(err)) {
			err = -EINVAL;
			nbytes = 0;
		} else
			n = skcipher_done_slow(walk, n);
	}

	if (err > 0)
		err = 0;

	walk->total = nbytes;
	walk->nbytes = nbytes;

	scatterwalk_advance(&walk->in, n);
	scatterwalk_advance(&walk->out, n);
	scatterwalk_done(&walk->in, 0, nbytes);
	scatterwalk_done(&walk->out, 1, nbytes);

	if (nbytes) {
		crypto_yield(walk->flags & SKCIPHER_WALK_SLEEP ?
			     CRYPTO_TFM_REQ_MAY_SLEEP : 0);
		return skcipher_walk_next(walk);
	}

	/* Short-circuit for the common/fast path. */
	if (!((unsigned long)walk->buffer | (unsigned long)walk->page))
		goto out;

	if (walk->flags & SKCIPHER_WALK_PHYS)
		goto out;

	if (walk->iv != walk->oiv)
		memcpy(walk->oiv, walk->iv, walk->ivsize);
	if (walk->buffer != walk->page)
		kfree(walk->buffer);
	if (walk->page)
		free_page((unsigned long)walk->page);

out:
	return err;
}
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Herbert Xu 376 100.00% 1 100.00%
Total 376 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(skcipher_walk_done);



void skcipher_walk_complete(struct skcipher_walk *walk, int err)
{
	struct skcipher_walk_buffer *p, *tmp;

	list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
		u8 *data;

		if (err)
			goto done;

		data = p->data;
		if (!data) {
			data = PTR_ALIGN(&p->buffer[0], walk->alignmask + 1);
			data = skcipher_get_spot(data, walk->stride);
		}

		scatterwalk_copychunks(data, &p->dst, p->len, 1);

		if (offset_in_page(p->data) + p->len + walk->stride >
		    PAGE_SIZE)
			free_page((unsigned long)p->data);

done:
		list_del(&p->entry);
		kfree(p);
	}

	if (!err && walk->iv != walk->oiv)
		memcpy(walk->oiv, walk->iv, walk->ivsize);
	if (walk->buffer != walk->page)
		kfree(walk->buffer);
	if (walk->page)
		free_page((unsigned long)walk->page);
}
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Herbert Xu 208 99.05% 1 50.00%
Ard Biesheuvel 2 0.95% 1 50.00%
Total 210 100.00% 2 100.00%


EXPORT_SYMBOL_GPL(skcipher_walk_complete);



static void skcipher_queue_write(struct skcipher_walk *walk,
				 struct skcipher_walk_buffer *p)
{
	p->dst = walk->out;
	list_add_tail(&p->entry, &walk->buffers);
}

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Herbert Xu 37 100.00% 1 100.00%
Total 37 100.00% 1 100.00%



static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize)
{
	bool phys = walk->flags & SKCIPHER_WALK_PHYS;
	unsigned alignmask = walk->alignmask;
	struct skcipher_walk_buffer *p;
	unsigned a;
	unsigned n;
	u8 *buffer;
	void *v;

	if (!phys) {
		if (!walk->buffer)
			walk->buffer = walk->page;
		buffer = walk->buffer;
		if (buffer)
			goto ok;
	}

	/* Start with the minimum alignment of kmalloc. */
	a = crypto_tfm_ctx_alignment() - 1;
	n = bsize;

	if (phys) {
		/* Calculate the minimum alignment of p->buffer. */
		a &= (sizeof(*p) ^ (sizeof(*p) - 1)) >> 1;
		n += sizeof(*p);
	}

	/* Minimum size to align p->buffer by alignmask. */
	n += alignmask & ~a;

	/* Minimum size to ensure p->buffer does not straddle a page. */
	n += (bsize - 1) & ~(alignmask | a);

	v = kzalloc(n, skcipher_walk_gfp(walk));
	if (!v)
		return skcipher_walk_done(walk, -ENOMEM);

	if (phys) {
		p = v;
		p->len = bsize;
		skcipher_queue_write(walk, p);
		buffer = p->buffer;
	} else {
		walk->buffer = v;
		buffer = v;
	}

ok:
	walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1);
	walk->dst.virt.addr = skcipher_get_spot(walk->dst.virt.addr, bsize);
	walk->src.virt.addr = walk->dst.virt.addr;

	scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);

	walk->nbytes = bsize;
	walk->flags |= SKCIPHER_WALK_SLOW;

	return 0;
}

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Herbert Xu 304 95.90% 1 50.00%
Ard Biesheuvel 13 4.10% 1 50.00%
Total 317 100.00% 2 100.00%



static int skcipher_next_copy(struct skcipher_walk *walk)
{
	struct skcipher_walk_buffer *p;
	u8 *tmp = walk->page;

	skcipher_map_src(walk);
	memcpy(tmp, walk->src.virt.addr, walk->nbytes);
	skcipher_unmap_src(walk);

	walk->src.virt.addr = tmp;
	walk->dst.virt.addr = tmp;

	if (!(walk->flags & SKCIPHER_WALK_PHYS))
		return 0;

	p = kmalloc(sizeof(*p), skcipher_walk_gfp(walk));
	if (!p)
		return -ENOMEM;

	p->data = walk->page;
	p->len = walk->nbytes;
	skcipher_queue_write(walk, p);

	if (offset_in_page(walk->page) + walk->nbytes + walk->stride >
	    PAGE_SIZE)
		walk->page = NULL;
	else
		walk->page += walk->nbytes;

	return 0;
}

Contributors
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Herbert Xu 169 99.41% 1 50.00%
Ard Biesheuvel 1 0.59% 1 50.00%
Total 170 100.00% 2 100.00%



static int skcipher_next_fast(struct skcipher_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 & SKCIPHER_WALK_PHYS)
		return 0;

	diff = walk->src.phys.offset - walk->dst.phys.offset;
	diff |= walk->src.virt.page - walk->dst.virt.page;

	skcipher_map_src(walk);
	walk->dst.virt.addr = walk->src.virt.addr;

	if (diff) {
		walk->flags |= SKCIPHER_WALK_DIFF;
		skcipher_map_dst(walk);
	}

	return 0;
}

Contributors
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Herbert Xu 169 100.00% 1 100.00%
Total 169 100.00% 1 100.00%



static int skcipher_walk_next(struct skcipher_walk *walk)
{
	unsigned int bsize;
	unsigned int n;
	int err;

	walk->flags &= ~(SKCIPHER_WALK_SLOW | SKCIPHER_WALK_COPY |
			 SKCIPHER_WALK_DIFF);

	n = walk->total;
	bsize = min(walk->stride, max(n, walk->blocksize));
	n = scatterwalk_clamp(&walk->in, n);
	n = scatterwalk_clamp(&walk->out, n);

	if (unlikely(n < bsize)) {
		if (unlikely(walk->total < walk->blocksize))
			return skcipher_walk_done(walk, -EINVAL);

slow_path:
		err = skcipher_next_slow(walk, bsize);
		goto set_phys_lowmem;
	}

	if (unlikely((walk->in.offset | walk->out.offset) & walk->alignmask)) {
		if (!walk->page) {
			gfp_t gfp = skcipher_walk_gfp(walk);

			walk->page = (void *)__get_free_page(gfp);
			if (!walk->page)
				goto slow_path;
		}

		walk->nbytes = min_t(unsigned, n,
				     PAGE_SIZE - offset_in_page(walk->page));
		walk->flags |= SKCIPHER_WALK_COPY;
		err = skcipher_next_copy(walk);
		goto set_phys_lowmem;
	}

	walk->nbytes = n;

	return skcipher_next_fast(walk);

set_phys_lowmem:
	if (!err && (walk->flags & SKCIPHER_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;
}
Contributors
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Herbert Xu 324 99.69% 1 50.00%
Ard Biesheuvel 1 0.31% 1 50.00%
Total 325 100.00% 2 100.00%


EXPORT_SYMBOL_GPL(skcipher_walk_next);



static int skcipher_copy_iv(struct skcipher_walk *walk)
{
	unsigned a = crypto_tfm_ctx_alignment() - 1;
	unsigned alignmask = walk->alignmask;
	unsigned ivsize = walk->ivsize;
	unsigned bs = walk->stride;
	unsigned aligned_bs;
	unsigned size;
	u8 *iv;

	aligned_bs = ALIGN(bs, alignmask);

	/* Minimum size to align buffer by alignmask. */
	size = alignmask & ~a;

	if (walk->flags & SKCIPHER_WALK_PHYS)
		size += ivsize;
	else {
		size += aligned_bs + ivsize;

		/* Minimum size to ensure buffer does not straddle a page. */
		size += (bs - 1) & ~(alignmask | a);
	}

	walk->buffer = kmalloc(size, skcipher_walk_gfp(walk));
	if (!walk->buffer)
		return -ENOMEM;

	iv = PTR_ALIGN(walk->buffer, alignmask + 1);
	iv = skcipher_get_spot(iv, bs) + aligned_bs;

	walk->iv = memcpy(iv, walk->iv, walk->ivsize);
	return 0;
}

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Herbert Xu 172 99.42% 1 50.00%
Ard Biesheuvel 1 0.58% 1 50.00%
Total 173 100.00% 2 100.00%



static int skcipher_walk_first(struct skcipher_walk *walk)
{
	walk->nbytes = 0;

	if (WARN_ON_ONCE(in_irq()))
		return -EDEADLK;

	if (unlikely(!walk->total))
		return 0;

	walk->buffer = NULL;
	if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
		int err = skcipher_copy_iv(walk);
		if (err)
			return err;
	}

	walk->page = NULL;
	walk->nbytes = walk->total;

	return skcipher_walk_next(walk);
}

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Herbert Xu 104 100.00% 1 100.00%
Total 104 100.00% 1 100.00%



static int skcipher_walk_skcipher(struct skcipher_walk *walk,
				  struct skcipher_request *req)
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);

	scatterwalk_start(&walk->in, req->src);
	scatterwalk_start(&walk->out, req->dst);

	walk->total = req->cryptlen;
	walk->iv = req->iv;
	walk->oiv = req->iv;

	walk->flags &= ~SKCIPHER_WALK_SLEEP;
	walk->flags |= req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ?
		       SKCIPHER_WALK_SLEEP : 0;

	walk->blocksize = crypto_skcipher_blocksize(tfm);
	walk->stride = crypto_skcipher_walksize(tfm);
	walk->ivsize = crypto_skcipher_ivsize(tfm);
	walk->alignmask = crypto_skcipher_alignmask(tfm);

	return skcipher_walk_first(walk);
}

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Herbert Xu 137 98.56% 1 50.00%
Ard Biesheuvel 2 1.44% 1 50.00%
Total 139 100.00% 2 100.00%



int skcipher_walk_virt(struct skcipher_walk *walk,
		       struct skcipher_request *req, bool atomic)
{
	int err;

	walk->flags &= ~SKCIPHER_WALK_PHYS;

	err = skcipher_walk_skcipher(walk, req);

	walk->flags &= atomic ? ~SKCIPHER_WALK_SLEEP : ~0;

	return err;
}
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Herbert Xu 52 100.00% 1 100.00%
Total 52 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(skcipher_walk_virt);



void skcipher_walk_atomise(struct skcipher_walk *walk)
{
	walk->flags &= ~SKCIPHER_WALK_SLEEP;
}
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Herbert Xu 17 100.00% 1 100.00%
Total 17 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(skcipher_walk_atomise);



int skcipher_walk_async(struct skcipher_walk *walk,
			struct skcipher_request *req)
{
	walk->flags |= SKCIPHER_WALK_PHYS;

	INIT_LIST_HEAD(&walk->buffers);

	return skcipher_walk_skcipher(walk, req);
}
Contributors
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Herbert Xu 37 100.00% 1 100.00%
Total 37 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(skcipher_walk_async);



static int skcipher_walk_aead_common(struct skcipher_walk *walk,
				     struct aead_request *req, bool atomic)
{
	struct crypto_aead *tfm = crypto_aead_reqtfm(req);
	int err;

	walk->flags &= ~SKCIPHER_WALK_PHYS;

	scatterwalk_start(&walk->in, req->src);
	scatterwalk_start(&walk->out, req->dst);

	scatterwalk_copychunks(NULL, &walk->in, req->assoclen, 2);
	scatterwalk_copychunks(NULL, &walk->out, req->assoclen, 2);

	walk->iv = req->iv;
	walk->oiv = req->iv;

	if (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP)
		walk->flags |= SKCIPHER_WALK_SLEEP;
	else
		walk->flags &= ~SKCIPHER_WALK_SLEEP;

	walk->blocksize = crypto_aead_blocksize(tfm);
	walk->stride = crypto_aead_chunksize(tfm);
	walk->ivsize = crypto_aead_ivsize(tfm);
	walk->alignmask = crypto_aead_alignmask(tfm);

	err = skcipher_walk_first(walk);

	if (atomic)
		walk->flags &= ~SKCIPHER_WALK_SLEEP;

	return err;
}

Contributors
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Herbert Xu 184 95.83% 2 50.00%
Ard Biesheuvel 8 4.17% 2 50.00%
Total 192 100.00% 4 100.00%



int skcipher_walk_aead(struct skcipher_walk *walk, struct aead_request *req,
		       bool atomic)
{
	walk->total = req->cryptlen;

	return skcipher_walk_aead_common(walk, req, atomic);
}
Contributors
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Herbert Xu 36 100.00% 1 100.00%
Total 36 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(skcipher_walk_aead);



int skcipher_walk_aead_encrypt(struct skcipher_walk *walk,
			       struct aead_request *req, bool atomic)
{
	walk->total = req->cryptlen;

	return skcipher_walk_aead_common(walk, req, atomic);
}
Contributors
Person Tokens Prop Commits CommitProp
Herbert Xu 36 100.00% 1 100.00%
Total 36 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(skcipher_walk_aead_encrypt);



int skcipher_walk_aead_decrypt(struct skcipher_walk *walk,
			       struct aead_request *req, bool atomic)
{
	struct crypto_aead *tfm = crypto_aead_reqtfm(req);

	walk->total = req->cryptlen - crypto_aead_authsize(tfm);

	return skcipher_walk_aead_common(walk, req, atomic);
}
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Herbert Xu 51 100.00% 1 100.00%
Total 51 100.00% 1 100.00%


EXPORT_SYMBOL_GPL(skcipher_walk_aead_decrypt);



static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg)
{
	if (alg->cra_type == &crypto_blkcipher_type)
		return sizeof(struct crypto_blkcipher *);

	if (alg->cra_type == &crypto_ablkcipher_type ||
	    alg->cra_type == &crypto_givcipher_type)
		return sizeof(struct crypto_ablkcipher *);

	return crypto_alg_extsize(alg);
}

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Herbert Xu 59 100.00% 2 100.00%
Total 59 100.00% 2 100.00%



static int skcipher_setkey_blkcipher(struct crypto_skcipher *tfm,
				     const u8 *key, unsigned int keylen)
{
	struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
	struct crypto_blkcipher *blkcipher = *ctx;
	int err;

	crypto_blkcipher_clear_flags(blkcipher,
Person	Tokens	Prop	Commits	CommitProp
Herbert Xu	31	100.00%	1	100.00%
Total	31	100.00%	1	100.00%
cregit-Linux how code gets into the kernel

Release 4.11 crypto/skcipher.c

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