Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / crypto / blkcipher.c
diff --git a/kernel/crypto/blkcipher.c b/kernel/crypto/blkcipher.c
new file mode 100644 (file)
index 0000000..0122bec
--- /dev/null
@@ -0,0 +1,743 @@
+/*
+ * 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 <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.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 <linux/cryptouser.h>
+#include <net/netlink.h>
+
+#include "internal.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);
+}
+
+static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
+{
+       walk->dst.virt.addr = scatterwalk_map(&walk->out);
+}
+
+static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
+{
+       scatterwalk_unmap(walk->src.virt.addr);
+}
+
+static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
+{
+       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)
+{
+       u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
+       return max(start, end_page);
+}
+
+static inline unsigned int blkcipher_done_slow(struct blkcipher_walk *walk,
+                                              unsigned int bsize)
+{
+       u8 *addr;
+
+       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;
+}
+
+static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
+                                              unsigned int 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)) {
+               if (walk->flags & BLKCIPHER_WALK_DIFF)
+                       blkcipher_unmap_dst(walk);
+               blkcipher_unmap_src(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)
+{
+       unsigned int nbytes = 0;
+
+       if (likely(err >= 0)) {
+               unsigned int n = walk->nbytes - err;
+
+               if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
+                       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;
+       }
+
+       scatterwalk_done(&walk->in, 0, nbytes);
+       scatterwalk_done(&walk->out, 1, nbytes);
+
+err:
+       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, walk->ivsize);
+       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;
+       unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
+
+       if (walk->buffer)
+               goto ok;
+
+       walk->buffer = walk->page;
+       if (walk->buffer)
+               goto ok;
+
+       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);
+
+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 +
+                                                aligned_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)
+{
+       unsigned int bsize;
+       unsigned int n;
+       int err;
+
+       n = walk->total;
+       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, walk->alignmask) ||
+           !scatterwalk_aligned(&walk->out, walk->alignmask)) {
+               walk->flags |= BLKCIPHER_WALK_COPY;
+               if (!walk->page) {
+                       walk->page = (void *)__get_free_page(GFP_ATOMIC);
+                       if (!walk->page)
+                               n = 0;
+               }
+       }
+
+       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, walk->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)
+{
+       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 += 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, 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, walk->ivsize);
+       return 0;
+}
+
+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);
+
+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);
+
+static int blkcipher_walk_first(struct blkcipher_desc *desc,
+                               struct blkcipher_walk *walk)
+{
+       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 & walk->alignmask))) {
+               int err = blkcipher_copy_iv(walk);
+               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);
+}
+
+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 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 ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK &&
+           cipher->ivsize) {
+               len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
+               len += cipher->ivsize;
+       }
+
+       return len;
+}
+
+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;
+
+       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 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__ ((unused));
+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);
+       seq_printf(m, "geniv        : %s\n", alg->cra_blkcipher.geniv ?:
+                                            "<default>");
+}
+
+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
+       .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");