1 files changed, 1059 insertions, 0 deletions

diff --git a/crypto/skcipher.c b/crypto/skcipher.c
new file mode 100644
index 000000000..a8750b4eb
--- /dev/null
+++ b/crypto/skcipher.c
@@ -0,0 +1,1059 @@
+/*
+ * 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);
+}
+
+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);
+}
+
+static inline void skcipher_map_src(struct skcipher_walk *walk)
+{
+	walk->src.virt.addr = skcipher_map(&walk->in);
+}
+
+static inline void skcipher_map_dst(struct skcipher_walk *walk)
+{
+	walk->dst.virt.addr = skcipher_map(&walk->out);
+}
+
+static inline void skcipher_unmap_src(struct skcipher_walk *walk)
+{
+	skcipher_unmap(&walk->in, walk->src.virt.addr);
+}
+
+static inline void skcipher_unmap_dst(struct skcipher_walk *walk)
+{
+	skcipher_unmap(&walk->out, walk->dst.virt.addr);
+}
+
+static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk)
+{
+	return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
+}
+
+/* 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);
+}
+
+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;
+}
+
+int skcipher_walk_done(struct skcipher_walk *walk, int err)
+{
+	unsigned int n = walk->nbytes;
+	unsigned int nbytes = 0;
+
+	if (!n)
+		goto finish;
+
+	if (likely(err >= 0)) {
+		n -= err;
+		nbytes = walk->total - n;
+	}
+
+	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 (err > 0) {
+			/*
+			 * Didn't process all bytes.  Either the algorithm is
+			 * broken, or this was the last step and it turned out
+			 * the message wasn't evenly divisible into blocks but
+			 * the algorithm requires it.
+			 */
+			err = -EINVAL;
+			nbytes = 0;
+		} else
+			n = skcipher_done_slow(walk, n);
+	}
+
+	if (err > 0)
+		err = 0;
+
+	walk->total = nbytes;
+	walk->nbytes = 0;
+
+	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);
+	}
+
+finish:
+	/* 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;
+}
+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);
+}
+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);
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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 + 1);
+
+	/* 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;
+}
+
+static int skcipher_walk_first(struct skcipher_walk *walk)
+{
+	if (WARN_ON_ONCE(in_irq()))
+		return -EDEADLK;
+
+	walk->buffer = NULL;
+	if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
+		int err = skcipher_copy_iv(walk);
+		if (err)
+			return err;
+	}
+
+	walk->page = NULL;
+
+	return skcipher_walk_next(walk);
+}
+
+static int skcipher_walk_skcipher(struct skcipher_walk *walk,
+				  struct skcipher_request *req)
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+
+	walk->total = req->cryptlen;
+	walk->nbytes = 0;
+	walk->iv = req->iv;
+	walk->oiv = req->iv;
+
+	if (unlikely(!walk->total))
+		return 0;
+
+	scatterwalk_start(&walk->in, req->src);
+	scatterwalk_start(&walk->out, req->dst);
+
+	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);
+}
+
+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;
+}
+EXPORT_SYMBOL_GPL(skcipher_walk_virt);
+
+void skcipher_walk_atomise(struct skcipher_walk *walk)
+{
+	walk->flags &= ~SKCIPHER_WALK_SLEEP;
+}
+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);
+}
+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->nbytes = 0;
+	walk->iv = req->iv;
+	walk->oiv = req->iv;
+
+	if (unlikely(!walk->total))
+		return 0;
+
+	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);
+
+	scatterwalk_done(&walk->in, 0, walk->total);
+	scatterwalk_done(&walk->out, 0, walk->total);
+
+	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;
+}
+
+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);
+}
+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);
+}
+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);
+}
+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);
+}
+
+static void skcipher_set_needkey(struct crypto_skcipher *tfm)
+{
+	if (tfm->keysize)
+		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
+}
+
+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, ~0);
+	crypto_blkcipher_set_flags(blkcipher, crypto_skcipher_get_flags(tfm) &
+					      CRYPTO_TFM_REQ_MASK);
+	err = crypto_blkcipher_setkey(blkcipher, key, keylen);
+	crypto_skcipher_set_flags(tfm, crypto_blkcipher_get_flags(blkcipher) &
+				       CRYPTO_TFM_RES_MASK);
+	if (unlikely(err)) {
+		skcipher_set_needkey(tfm);
+		return err;
+	}
+
+	crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
+	return 0;
+}
+
+static int skcipher_crypt_blkcipher(struct skcipher_request *req,
+				    int (*crypt)(struct blkcipher_desc *,
+						 struct scatterlist *,
+						 struct scatterlist *,
+						 unsigned int))
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	struct crypto_blkcipher **ctx = crypto_skcipher_ctx(tfm);
+	struct blkcipher_desc desc = {
+		.tfm = *ctx,
+		.info = req->iv,
+		.flags = req->base.flags,
+	};
+
+
+	return crypt(&desc, req->dst, req->src, req->cryptlen);
+}
+
+static int skcipher_encrypt_blkcipher(struct skcipher_request *req)
+{
+	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
+	struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
+	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
+
+	return skcipher_crypt_blkcipher(req, alg->encrypt);
+}
+
+static int skcipher_decrypt_blkcipher(struct skcipher_request *req)
+{
+	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
+	struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
+	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
+
+	return skcipher_crypt_blkcipher(req, alg->decrypt);
+}
+
+static void crypto_exit_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
+{
+	struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
+
+	crypto_free_blkcipher(*ctx);
+}
+
+static int crypto_init_skcipher_ops_blkcipher(struct crypto_tfm *tfm)
+{
+	struct crypto_alg *calg = tfm->__crt_alg;
+	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
+	struct crypto_blkcipher **ctx = crypto_tfm_ctx(tfm);
+	struct crypto_blkcipher *blkcipher;
+	struct crypto_tfm *btfm;
+
+	if (!crypto_mod_get(calg))
+		return -EAGAIN;
+
+	btfm = __crypto_alloc_tfm(calg, CRYPTO_ALG_TYPE_BLKCIPHER,
+					CRYPTO_ALG_TYPE_MASK);
+	if (IS_ERR(btfm)) {
+		crypto_mod_put(calg);
+		return PTR_ERR(btfm);
+	}
+
+	blkcipher = __crypto_blkcipher_cast(btfm);
+	*ctx = blkcipher;
+	tfm->exit = crypto_exit_skcipher_ops_blkcipher;
+
+	skcipher->setkey = skcipher_setkey_blkcipher;
+	skcipher->encrypt = skcipher_encrypt_blkcipher;
+	skcipher->decrypt = skcipher_decrypt_blkcipher;
+
+	skcipher->ivsize = crypto_blkcipher_ivsize(blkcipher);
+	skcipher->keysize = calg->cra_blkcipher.max_keysize;
+
+	skcipher_set_needkey(skcipher);
+
+	return 0;
+}
+
+static int skcipher_setkey_ablkcipher(struct crypto_skcipher *tfm,
+				      const u8 *key, unsigned int keylen)
+{
+	struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
+	struct crypto_ablkcipher *ablkcipher = *ctx;
+	int err;
+
+	crypto_ablkcipher_clear_flags(ablkcipher, ~0);
+	crypto_ablkcipher_set_flags(ablkcipher,
+				    crypto_skcipher_get_flags(tfm) &
+				    CRYPTO_TFM_REQ_MASK);
+	err = crypto_ablkcipher_setkey(ablkcipher, key, keylen);
+	crypto_skcipher_set_flags(tfm,
+				  crypto_ablkcipher_get_flags(ablkcipher) &
+				  CRYPTO_TFM_RES_MASK);
+	if (unlikely(err)) {
+		skcipher_set_needkey(tfm);
+		return err;
+	}
+
+	crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
+	return 0;
+}
+
+static int skcipher_crypt_ablkcipher(struct skcipher_request *req,
+				     int (*crypt)(struct ablkcipher_request *))
+{
+	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	struct crypto_ablkcipher **ctx = crypto_skcipher_ctx(tfm);
+	struct ablkcipher_request *subreq = skcipher_request_ctx(req);
+
+	ablkcipher_request_set_tfm(subreq, *ctx);
+	ablkcipher_request_set_callback(subreq, skcipher_request_flags(req),
+					req->base.complete, req->base.data);
+	ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
+				     req->iv);
+
+	return crypt(subreq);
+}
+
+static int skcipher_encrypt_ablkcipher(struct skcipher_request *req)
+{
+	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
+	struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
+	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
+
+	return skcipher_crypt_ablkcipher(req, alg->encrypt);
+}
+
+static int skcipher_decrypt_ablkcipher(struct skcipher_request *req)
+{
+	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
+	struct crypto_tfm *tfm = crypto_skcipher_tfm(skcipher);
+	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
+
+	return skcipher_crypt_ablkcipher(req, alg->decrypt);
+}
+
+static void crypto_exit_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
+{
+	struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
+
+	crypto_free_ablkcipher(*ctx);
+}
+
+static int crypto_init_skcipher_ops_ablkcipher(struct crypto_tfm *tfm)
+{
+	struct crypto_alg *calg = tfm->__crt_alg;
+	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
+	struct crypto_ablkcipher **ctx = crypto_tfm_ctx(tfm);
+	struct crypto_ablkcipher *ablkcipher;
+	struct crypto_tfm *abtfm;
+
+	if (!crypto_mod_get(calg))
+		return -EAGAIN;
+
+	abtfm = __crypto_alloc_tfm(calg, 0, 0);
+	if (IS_ERR(abtfm)) {
+		crypto_mod_put(calg);
+		return PTR_ERR(abtfm);
+	}
+
+	ablkcipher = __crypto_ablkcipher_cast(abtfm);
+	*ctx = ablkcipher;
+	tfm->exit = crypto_exit_skcipher_ops_ablkcipher;
+
+	skcipher->setkey = skcipher_setkey_ablkcipher;
+	skcipher->encrypt = skcipher_encrypt_ablkcipher;
+	skcipher->decrypt = skcipher_decrypt_ablkcipher;
+
+	skcipher->ivsize = crypto_ablkcipher_ivsize(ablkcipher);
+	skcipher->reqsize = crypto_ablkcipher_reqsize(ablkcipher) +
+			    sizeof(struct ablkcipher_request);
+	skcipher->keysize = calg->cra_ablkcipher.max_keysize;
+
+	skcipher_set_needkey(skcipher);
+
+	return 0;
+}
+
+static int skcipher_setkey_unaligned(struct crypto_skcipher *tfm,
+				     const u8 *key, unsigned int keylen)
+{
+	unsigned long alignmask = crypto_skcipher_alignmask(tfm);
+	struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
+	u8 *buffer, *alignbuffer;
+	unsigned long absize;
+	int ret;
+
+	absize = keylen + alignmask;
+	buffer = kmalloc(absize, GFP_ATOMIC);
+	if (!buffer)
+		return -ENOMEM;
+
+	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
+	memcpy(alignbuffer, key, keylen);
+	ret = cipher->setkey(tfm, alignbuffer, keylen);
+	kzfree(buffer);
+	return ret;
+}
+
+static int skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
+			   unsigned int keylen)
+{
+	struct skcipher_alg *cipher = crypto_skcipher_alg(tfm);
+	unsigned long alignmask = crypto_skcipher_alignmask(tfm);
+	int err;
+
+	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
+		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+
+	if ((unsigned long)key & alignmask)
+		err = skcipher_setkey_unaligned(tfm, key, keylen);
+	else
+		err = cipher->setkey(tfm, key, keylen);
+
+	if (unlikely(err)) {
+		skcipher_set_needkey(tfm);
+		return err;
+	}
+
+	crypto_skcipher_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
+	return 0;
+}
+
+static void crypto_skcipher_exit_tfm(struct crypto_tfm *tfm)
+{
+	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
+	struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
+
+	alg->exit(skcipher);
+}
+
+static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
+{
+	struct crypto_skcipher *skcipher = __crypto_skcipher_cast(tfm);
+	struct skcipher_alg *alg = crypto_skcipher_alg(skcipher);
+
+	if (tfm->__crt_alg->cra_type == &crypto_blkcipher_type)
+		return crypto_init_skcipher_ops_blkcipher(tfm);
+
+	if (tfm->__crt_alg->cra_type == &crypto_ablkcipher_type ||
+	    tfm->__crt_alg->cra_type == &crypto_givcipher_type)
+		return crypto_init_skcipher_ops_ablkcipher(tfm);
+
+	skcipher->setkey = skcipher_setkey;
+	skcipher->encrypt = alg->encrypt;
+	skcipher->decrypt = alg->decrypt;
+	skcipher->ivsize = alg->ivsize;
+	skcipher->keysize = alg->max_keysize;
+
+	skcipher_set_needkey(skcipher);
+
+	if (alg->exit)
+		skcipher->base.exit = crypto_skcipher_exit_tfm;
+
+	if (alg->init)
+		return alg->init(skcipher);
+
+	return 0;
+}
+
+static void crypto_skcipher_free_instance(struct crypto_instance *inst)
+{
+	struct skcipher_instance *skcipher =
+		container_of(inst, struct skcipher_instance, s.base);
+
+	skcipher->free(skcipher);
+}
+
+static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
+	__maybe_unused;
+static void crypto_skcipher_show(struct seq_file *m, struct crypto_alg *alg)
+{
+	struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
+						     base);
+
+	seq_printf(m, "type         : skcipher\n");
+	seq_printf(m, "async        : %s\n",
+		   alg->cra_flags & CRYPTO_ALG_ASYNC ?  "yes" : "no");
+	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
+	seq_printf(m, "min keysize  : %u\n", skcipher->min_keysize);
+	seq_printf(m, "max keysize  : %u\n", skcipher->max_keysize);
+	seq_printf(m, "ivsize       : %u\n", skcipher->ivsize);
+	seq_printf(m, "chunksize    : %u\n", skcipher->chunksize);
+	seq_printf(m, "walksize     : %u\n", skcipher->walksize);
+}
+
+#ifdef CONFIG_NET
+static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
+{
+	struct crypto_report_blkcipher rblkcipher;
+	struct skcipher_alg *skcipher = container_of(alg, struct skcipher_alg,
+						     base);
+
+	strncpy(rblkcipher.type, "skcipher", sizeof(rblkcipher.type));
+	strncpy(rblkcipher.geniv, "<none>", sizeof(rblkcipher.geniv));
+
+	rblkcipher.blocksize = alg->cra_blocksize;
+	rblkcipher.min_keysize = skcipher->min_keysize;
+	rblkcipher.max_keysize = skcipher->max_keysize;
+	rblkcipher.ivsize = skcipher->ivsize;
+
+	if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
+		    sizeof(struct crypto_report_blkcipher), &rblkcipher))
+		goto nla_put_failure;
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+#else
+static int crypto_skcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
+{
+	return -ENOSYS;
+}
+#endif
+
+static const struct crypto_type crypto_skcipher_type2 = {
+	.extsize = crypto_skcipher_extsize,
+	.init_tfm = crypto_skcipher_init_tfm,
+	.free = crypto_skcipher_free_instance,
+#ifdef CONFIG_PROC_FS
+	.show = crypto_skcipher_show,
+#endif
+	.report = crypto_skcipher_report,
+	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
+	.maskset = CRYPTO_ALG_TYPE_BLKCIPHER_MASK,
+	.type = CRYPTO_ALG_TYPE_SKCIPHER,
+	.tfmsize = offsetof(struct crypto_skcipher, base),
+};
+
+int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn,
+			  const char *name, u32 type, u32 mask)
+{
+	spawn->base.frontend = &crypto_skcipher_type2;
+	return crypto_grab_spawn(&spawn->base, name, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
+
+struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name,
+					      u32 type, u32 mask)
+{
+	return crypto_alloc_tfm(alg_name, &crypto_skcipher_type2, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_alloc_skcipher);
+
+int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask)
+{
+	return crypto_type_has_alg(alg_name, &crypto_skcipher_type2,
+				   type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_has_skcipher2);
+
+static int skcipher_prepare_alg(struct skcipher_alg *alg)
+{
+	struct crypto_alg *base = &alg->base;
+
+	if (alg->ivsize > PAGE_SIZE / 8 || alg->chunksize > PAGE_SIZE / 8 ||
+	    alg->walksize > PAGE_SIZE / 8)
+		return -EINVAL;
+
+	if (!alg->chunksize)
+		alg->chunksize = base->cra_blocksize;
+	if (!alg->walksize)
+		alg->walksize = alg->chunksize;
+
+	base->cra_type = &crypto_skcipher_type2;
+	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
+	base->cra_flags |= CRYPTO_ALG_TYPE_SKCIPHER;
+
+	return 0;
+}
+
+int crypto_register_skcipher(struct skcipher_alg *alg)
+{
+	struct crypto_alg *base = &alg->base;
+	int err;
+
+	err = skcipher_prepare_alg(alg);
+	if (err)
+		return err;
+
+	return crypto_register_alg(base);
+}
+EXPORT_SYMBOL_GPL(crypto_register_skcipher);
+
+void crypto_unregister_skcipher(struct skcipher_alg *alg)
+{
+	crypto_unregister_alg(&alg->base);
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_skcipher);
+
+int crypto_register_skciphers(struct skcipher_alg *algs, int count)
+{
+	int i, ret;
+
+	for (i = 0; i < count; i++) {
+		ret = crypto_register_skcipher(&algs[i]);
+		if (ret)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	for (--i; i >= 0; --i)
+		crypto_unregister_skcipher(&algs[i]);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(crypto_register_skciphers);
+
+void crypto_unregister_skciphers(struct skcipher_alg *algs, int count)
+{
+	int i;
+
+	for (i = count - 1; i >= 0; --i)
+		crypto_unregister_skcipher(&algs[i]);
+}
+EXPORT_SYMBOL_GPL(crypto_unregister_skciphers);
+
+int skcipher_register_instance(struct crypto_template *tmpl,
+			   struct skcipher_instance *inst)
+{
+	int err;
+
+	err = skcipher_prepare_alg(&inst->alg);
+	if (err)
+		return err;
+
+	return crypto_register_instance(tmpl, skcipher_crypto_instance(inst));
+}
+EXPORT_SYMBOL_GPL(skcipher_register_instance);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Symmetric key cipher type");