1 files changed, 397 insertions, 59 deletions

diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c
index 034c939bf91..0122bec3856 100644
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -14,18 +14,20 @@
  *
  */
 
-#include <linux/crypto.h>
+#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>
 #include <linux/errno.h>
+#include <linux/hardirq.h>
 #include <linux/kernel.h>
-#include <linux/io.h>
 #include <linux/module.h>
 #include <linux/scatterlist.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/string.h>
+#include <linux/cryptouser.h>
+#include <net/netlink.h>
 
 #include "internal.h"
-#include "scatterwalk.h"
 
 enum {
 	BLKCIPHER_WALK_PHYS = 1 << 0,
@@ -41,39 +43,39 @@ static int blkcipher_walk_first(struct blkcipher_desc *desc,
 
 static inline void blkcipher_map_src(struct blkcipher_walk *walk)
 {
-	walk->src.virt.addr = scatterwalk_map(&walk->in, 0);
+	walk->src.virt.addr = scatterwalk_map(&walk->in);
 }
 
 static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
 {
-	walk->dst.virt.addr = scatterwalk_map(&walk->out, 1);
+	walk->dst.virt.addr = scatterwalk_map(&walk->out);
 }
 
 static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
 {
-	scatterwalk_unmap(walk->src.virt.addr, 0);
+	scatterwalk_unmap(walk->src.virt.addr);
 }
 
 static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
 {
-	scatterwalk_unmap(walk->dst.virt.addr, 1);
+	scatterwalk_unmap(walk->dst.virt.addr);
 }
 
+/* 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 *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;
+	u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
+	return max(start, end_page);
 }
 
-static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
-					       struct blkcipher_walk *walk,
+static inline unsigned int blkcipher_done_slow(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 = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
 	addr = blkcipher_get_spot(addr, bsize);
 	scatterwalk_copychunks(addr, &walk->out, bsize, 1);
 	return bsize;
@@ -82,16 +84,14 @@ static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
 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);
+		blkcipher_unmap_src(walk);
 	}
 
 	scatterwalk_advance(&walk->in, n);
@@ -103,17 +103,18 @@ static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
 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;
+		unsigned int n = walk->nbytes - err;
 
 		if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
-			n = blkcipher_done_fast(walk, err);
-		else
-			n = blkcipher_done_slow(tfm, walk, bsize);
+			n = blkcipher_done_fast(walk, n);
+		else if (WARN_ON(err)) {
+			err = -EINVAL;
+			goto err;
+		} else
+			n = blkcipher_done_slow(walk, n);
 
 		nbytes = walk->total - n;
 		err = 0;
@@ -122,6 +123,7 @@ int blkcipher_walk_done(struct blkcipher_desc *desc,
 	scatterwalk_done(&walk->in, 0, nbytes);
 	scatterwalk_done(&walk->out, 1, nbytes);
 
+err:
 	walk->total = nbytes;
 	walk->nbytes = nbytes;
 
@@ -131,7 +133,7 @@ int blkcipher_walk_done(struct blkcipher_desc *desc,
 	}
 
 	if (walk->iv != desc->info)
-		memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
+		memcpy(desc->info, walk->iv, walk->ivsize);
 	if (walk->buffer != walk->page)
 		kfree(walk->buffer);
 	if (walk->page)
@@ -147,6 +149,7 @@ static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
 				      unsigned int alignmask)
 {
 	unsigned int n;
+	unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
 
 	if (walk->buffer)
 		goto ok;
@@ -155,7 +158,8 @@ static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
 	if (walk->buffer)
 		goto ok;
 
-	n = bsize * 2 + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
+	n = aligned_bsize * 3 - (alignmask + 1) +
+	    (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
 	walk->buffer = kmalloc(n, GFP_ATOMIC);
 	if (!walk->buffer)
 		return blkcipher_walk_done(desc, walk, -ENOMEM);
@@ -164,8 +168,8 @@ 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);
+	walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
+						 aligned_bsize, bsize);
 
 	scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
 
@@ -219,22 +223,20 @@ static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
 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 bsize;
 	unsigned int n;
 	int err;
 
 	n = walk->total;
-	if (unlikely(n < bsize)) {
+	if (unlikely(n < walk->cipher_blocksize)) {
 		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)) {
+	if (!scatterwalk_aligned(&walk->in, walk->alignmask) ||
+	    !scatterwalk_aligned(&walk->out, walk->alignmask)) {
 		walk->flags |= BLKCIPHER_WALK_COPY;
 		if (!walk->page) {
 			walk->page = (void *)__get_free_page(GFP_ATOMIC);
@@ -243,11 +245,12 @@ static int blkcipher_walk_next(struct blkcipher_desc *desc,
 		}
 	}
 
+	bsize = min(walk->walk_blocksize, n);
 	n = scatterwalk_clamp(&walk->in, n);
 	n = scatterwalk_clamp(&walk->out, n);
 
 	if (unlikely(n < bsize)) {
-		err = blkcipher_next_slow(desc, walk, bsize, alignmask);
+		err = blkcipher_next_slow(desc, walk, bsize, walk->alignmask);
 		goto set_phys_lowmem;
 	}
 
@@ -269,26 +272,26 @@ set_phys_lowmem:
 	return err;
 }
 
-static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
-				    struct crypto_blkcipher *tfm,
-				    unsigned int alignmask)
+static inline int blkcipher_copy_iv(struct blkcipher_walk *walk)
 {
-	unsigned bs = crypto_blkcipher_blocksize(tfm);
-	unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
-	unsigned int size = bs * 2 + ivsize + max(bs, ivsize) - (alignmask + 1);
+	unsigned bs = walk->walk_blocksize;
+	unsigned aligned_bs = ALIGN(bs, walk->alignmask + 1);
+	unsigned int size = aligned_bs * 2 +
+			    walk->ivsize + max(aligned_bs, walk->ivsize) -
+			    (walk->alignmask + 1);
 	u8 *iv;
 
-	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
+	size += walk->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);
+	iv = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
+	iv = blkcipher_get_spot(iv, bs) + aligned_bs;
+	iv = blkcipher_get_spot(iv, bs) + aligned_bs;
+	iv = blkcipher_get_spot(iv, walk->ivsize);
 
-	walk->iv = memcpy(iv, walk->iv, ivsize);
+	walk->iv = memcpy(iv, walk->iv, walk->ivsize);
 	return 0;
 }
 
@@ -296,6 +299,10 @@ int blkcipher_walk_virt(struct blkcipher_desc *desc,
 			struct blkcipher_walk *walk)
 {
 	walk->flags &= ~BLKCIPHER_WALK_PHYS;
+	walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
+	walk->cipher_blocksize = walk->walk_blocksize;
+	walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
+	walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
 	return blkcipher_walk_first(desc, walk);
 }
 EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
@@ -304,6 +311,10 @@ int blkcipher_walk_phys(struct blkcipher_desc *desc,
 			struct blkcipher_walk *walk)
 {
 	walk->flags |= BLKCIPHER_WALK_PHYS;
+	walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
+	walk->cipher_blocksize = walk->walk_blocksize;
+	walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
+	walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
 	return blkcipher_walk_first(desc, walk);
 }
 EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
@@ -311,8 +322,8 @@ 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))
@@ -320,8 +331,8 @@ static int blkcipher_walk_first(struct blkcipher_desc *desc,
 
 	walk->buffer = NULL;
 	walk->iv = desc->info;
-	if (unlikely(((unsigned long)walk->iv & alignmask))) {
-		int err = blkcipher_copy_iv(walk, tfm, alignmask);
+	if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
+		int err = blkcipher_copy_iv(walk);
 		if (err)
 			return err;
 	}
@@ -333,25 +344,112 @@ static int blkcipher_walk_first(struct blkcipher_desc *desc,
 	return blkcipher_walk_next(desc, walk);
 }
 
-static int setkey(struct crypto_tfm *tfm, const u8 *key,
-		  unsigned int keylen)
+int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
+			      struct blkcipher_walk *walk,
+			      unsigned int blocksize)
+{
+	walk->flags &= ~BLKCIPHER_WALK_PHYS;
+	walk->walk_blocksize = blocksize;
+	walk->cipher_blocksize = crypto_blkcipher_blocksize(desc->tfm);
+	walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
+	walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
+	return blkcipher_walk_first(desc, walk);
+}
+EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
+
+int blkcipher_aead_walk_virt_block(struct blkcipher_desc *desc,
+				   struct blkcipher_walk *walk,
+				   struct crypto_aead *tfm,
+				   unsigned int blocksize)
+{
+	walk->flags &= ~BLKCIPHER_WALK_PHYS;
+	walk->walk_blocksize = blocksize;
+	walk->cipher_blocksize = crypto_aead_blocksize(tfm);
+	walk->ivsize = crypto_aead_ivsize(tfm);
+	walk->alignmask = crypto_aead_alignmask(tfm);
+	return blkcipher_walk_first(desc, walk);
+}
+EXPORT_SYMBOL_GPL(blkcipher_aead_walk_virt_block);
+
+static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
+			    unsigned int keylen)
+{
+	struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
+	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
+	int ret;
+	u8 *buffer, *alignbuffer;
+	unsigned long absize;
+
+	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);
+	memset(alignbuffer, 0, keylen);
+	kfree(buffer);
+	return ret;
+}
+
+static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
 {
 	struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
+	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 
 	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
 		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 		return -EINVAL;
 	}
 
+	if ((unsigned long)key & alignmask)
+		return setkey_unaligned(tfm, key, keylen);
+
 	return cipher->setkey(tfm, key, keylen);
 }
 
-static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg)
+static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
+			unsigned int keylen)
+{
+	return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
+}
+
+static int async_encrypt(struct ablkcipher_request *req)
+{
+	struct crypto_tfm *tfm = req->base.tfm;
+	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
+	struct blkcipher_desc desc = {
+		.tfm = __crypto_blkcipher_cast(tfm),
+		.info = req->info,
+		.flags = req->base.flags,
+	};
+
+
+	return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
+}
+
+static int async_decrypt(struct ablkcipher_request *req)
+{
+	struct crypto_tfm *tfm = req->base.tfm;
+	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
+	struct blkcipher_desc desc = {
+		.tfm = __crypto_blkcipher_cast(tfm),
+		.info = req->info,
+		.flags = req->base.flags,
+	};
+
+	return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
+}
+
+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) {
+	if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK &&
+	    cipher->ivsize) {
 		len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
 		len += cipher->ivsize;
 	}
@@ -359,16 +457,31 @@ static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg)
 	return len;
 }
 
-static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm)
+static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
+{
+	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
+	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
+
+	crt->setkey = async_setkey;
+	crt->encrypt = async_encrypt;
+	crt->decrypt = async_decrypt;
+	if (!alg->ivsize) {
+		crt->givencrypt = skcipher_null_givencrypt;
+		crt->givdecrypt = skcipher_null_givdecrypt;
+	}
+	crt->base = __crypto_ablkcipher_cast(tfm);
+	crt->ivsize = alg->ivsize;
+
+	return 0;
+}
+
+static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
 {
 	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;
@@ -381,8 +494,50 @@ static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm)
 	return 0;
 }
 
+static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
+{
+	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
+
+	if (alg->ivsize > PAGE_SIZE / 8)
+		return -EINVAL;
+
+	if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK)
+		return crypto_init_blkcipher_ops_sync(tfm);
+	else
+		return crypto_init_blkcipher_ops_async(tfm);
+}
+
+#ifdef CONFIG_NET
+static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
+{
+	struct crypto_report_blkcipher rblkcipher;
+
+	strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
+	strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
+		sizeof(rblkcipher.geniv));
+
+	rblkcipher.blocksize = alg->cra_blocksize;
+	rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
+	rblkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
+	rblkcipher.ivsize = alg->cra_blkcipher.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_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
+{
+	return -ENOSYS;
+}
+#endif
+
 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
-	__attribute_used__;
+	__attribute__ ((unused));
 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 {
 	seq_printf(m, "type         : blkcipher\n");
@@ -390,6 +545,8 @@ static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
 	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);
+	seq_printf(m, "geniv        : %s\n", alg->cra_blkcipher.geniv ?:
+					     "<default>");
 }
 
 const struct crypto_type crypto_blkcipher_type = {
@@ -398,8 +555,189 @@ const struct crypto_type crypto_blkcipher_type = {
 #ifdef CONFIG_PROC_FS
 	.show = crypto_blkcipher_show,
 #endif
+	.report = crypto_blkcipher_report,
 };
 EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
 
+static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn,
+				const char *name, u32 type, u32 mask)
+{
+	struct crypto_alg *alg;
+	int err;
+
+	type = crypto_skcipher_type(type);
+	mask = crypto_skcipher_mask(mask)| CRYPTO_ALG_GENIV;
+
+	alg = crypto_alg_mod_lookup(name, type, mask);
+	if (IS_ERR(alg))
+		return PTR_ERR(alg);
+
+	err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
+	crypto_mod_put(alg);
+	return err;
+}
+
+struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl,
+					     struct rtattr **tb, u32 type,
+					     u32 mask)
+{
+	struct {
+		int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key,
+			      unsigned int keylen);
+		int (*encrypt)(struct ablkcipher_request *req);
+		int (*decrypt)(struct ablkcipher_request *req);
+
+		unsigned int min_keysize;
+		unsigned int max_keysize;
+		unsigned int ivsize;
+
+		const char *geniv;
+	} balg;
+	const char *name;
+	struct crypto_skcipher_spawn *spawn;
+	struct crypto_attr_type *algt;
+	struct crypto_instance *inst;
+	struct crypto_alg *alg;
+	int err;
+
+	algt = crypto_get_attr_type(tb);
+	if (IS_ERR(algt))
+		return ERR_CAST(algt);
+
+	if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) &
+	    algt->mask)
+		return ERR_PTR(-EINVAL);
+
+	name = crypto_attr_alg_name(tb[1]);
+	if (IS_ERR(name))
+		return ERR_CAST(name);
+
+	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+	if (!inst)
+		return ERR_PTR(-ENOMEM);
+
+	spawn = crypto_instance_ctx(inst);
+
+	/* Ignore async algorithms if necessary. */
+	mask |= crypto_requires_sync(algt->type, algt->mask);
+
+	crypto_set_skcipher_spawn(spawn, inst);
+	err = crypto_grab_nivcipher(spawn, name, type, mask);
+	if (err)
+		goto err_free_inst;
+
+	alg = crypto_skcipher_spawn_alg(spawn);
+
+	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
+	    CRYPTO_ALG_TYPE_BLKCIPHER) {
+		balg.ivsize = alg->cra_blkcipher.ivsize;
+		balg.min_keysize = alg->cra_blkcipher.min_keysize;
+		balg.max_keysize = alg->cra_blkcipher.max_keysize;
+
+		balg.setkey = async_setkey;
+		balg.encrypt = async_encrypt;
+		balg.decrypt = async_decrypt;
+
+		balg.geniv = alg->cra_blkcipher.geniv;
+	} else {
+		balg.ivsize = alg->cra_ablkcipher.ivsize;
+		balg.min_keysize = alg->cra_ablkcipher.min_keysize;
+		balg.max_keysize = alg->cra_ablkcipher.max_keysize;
+
+		balg.setkey = alg->cra_ablkcipher.setkey;
+		balg.encrypt = alg->cra_ablkcipher.encrypt;
+		balg.decrypt = alg->cra_ablkcipher.decrypt;
+
+		balg.geniv = alg->cra_ablkcipher.geniv;
+	}
+
+	err = -EINVAL;
+	if (!balg.ivsize)
+		goto err_drop_alg;
+
+	/*
+	 * This is only true if we're constructing an algorithm with its
+	 * default IV generator.  For the default generator we elide the
+	 * template name and double-check the IV generator.
+	 */
+	if (algt->mask & CRYPTO_ALG_GENIV) {
+		if (!balg.geniv)
+			balg.geniv = crypto_default_geniv(alg);
+		err = -EAGAIN;
+		if (strcmp(tmpl->name, balg.geniv))
+			goto err_drop_alg;
+
+		memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
+		memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
+		       CRYPTO_MAX_ALG_NAME);
+	} else {
+		err = -ENAMETOOLONG;
+		if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
+			     "%s(%s)", tmpl->name, alg->cra_name) >=
+		    CRYPTO_MAX_ALG_NAME)
+			goto err_drop_alg;
+		if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
+			     "%s(%s)", tmpl->name, alg->cra_driver_name) >=
+		    CRYPTO_MAX_ALG_NAME)
+			goto err_drop_alg;
+	}
+
+	inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV;
+	inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
+	inst->alg.cra_priority = alg->cra_priority;
+	inst->alg.cra_blocksize = alg->cra_blocksize;
+	inst->alg.cra_alignmask = alg->cra_alignmask;
+	inst->alg.cra_type = &crypto_givcipher_type;
+
+	inst->alg.cra_ablkcipher.ivsize = balg.ivsize;
+	inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize;
+	inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize;
+	inst->alg.cra_ablkcipher.geniv = balg.geniv;
+
+	inst->alg.cra_ablkcipher.setkey = balg.setkey;
+	inst->alg.cra_ablkcipher.encrypt = balg.encrypt;
+	inst->alg.cra_ablkcipher.decrypt = balg.decrypt;
+
+out:
+	return inst;
+
+err_drop_alg:
+	crypto_drop_skcipher(spawn);
+err_free_inst:
+	kfree(inst);
+	inst = ERR_PTR(err);
+	goto out;
+}
+EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);
+
+void skcipher_geniv_free(struct crypto_instance *inst)
+{
+	crypto_drop_skcipher(crypto_instance_ctx(inst));
+	kfree(inst);
+}
+EXPORT_SYMBOL_GPL(skcipher_geniv_free);
+
+int skcipher_geniv_init(struct crypto_tfm *tfm)
+{
+	struct crypto_instance *inst = (void *)tfm->__crt_alg;
+	struct crypto_ablkcipher *cipher;
+
+	cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst));
+	if (IS_ERR(cipher))
+		return PTR_ERR(cipher);
+
+	tfm->crt_ablkcipher.base = cipher;
+	tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(skcipher_geniv_init);
+
+void skcipher_geniv_exit(struct crypto_tfm *tfm)
+{
+	crypto_free_ablkcipher(tfm->crt_ablkcipher.base);
+}
+EXPORT_SYMBOL_GPL(skcipher_geniv_exit);
+
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Generic block chaining cipher type");