async_tx: add support for asynchronous GF multiplication
[linux-2.6.git] / crypto / ctr.c
index b974a9f..2d7425f 100644 (file)
@@ -11,6 +11,7 @@
  */
 
 #include <crypto/algapi.h>
+#include <crypto/ctr.h>
 #include <linux/err.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 
-struct ctr_instance_ctx {
-       struct crypto_spawn alg;
-       unsigned int noncesize;
-       unsigned int ivsize;
-       unsigned int countersize;
-};
-
 struct crypto_ctr_ctx {
        struct crypto_cipher *child;
-       u8 *nonce;
 };
 
-static inline void __ctr_inc_byte(u8 *a, unsigned int size)
-{
-       u8 *b = (a + size);
-       u8 c;
-
-       for (; size; size--) {
-               c = *--b + 1;
-               *b = c;
-               if (c)
-                       break;
-       }
-}
-
-static void ctr_inc_quad(u8 *a, unsigned int size)
-{
-       __be32 *b = (__be32 *)(a + size);
-       u32 c;
-
-       for (; size >= 4; size -=4) {
-               c = be32_to_cpu(*--b) + 1;
-               *b = cpu_to_be32(c);
-               if (c)
-                       return;
-       }
-
-       __ctr_inc_byte(a, size);
-}
-
-static void xor_byte(u8 *a, const u8 *b, unsigned int bs)
-{
-       for (; bs; bs--)
-               *a++ ^= *b++;
-}
-
-static void xor_quad(u8 *dst, const u8 *src, unsigned int bs)
-{
-       u32 *a = (u32 *)dst;
-       u32 *b = (u32 *)src;
-
-       for (; bs >= 4; bs -= 4)
-               *a++ ^= *b++;
-
-       xor_byte((u8 *)a, (u8 *)b, bs);
-}
+struct crypto_rfc3686_ctx {
+       struct crypto_blkcipher *child;
+       u8 nonce[CTR_RFC3686_NONCE_SIZE];
+};
 
 static int crypto_ctr_setkey(struct crypto_tfm *parent, const u8 *key,
                             unsigned int keylen)
 {
        struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(parent);
        struct crypto_cipher *child = ctx->child;
-       struct ctr_instance_ctx *ictx =
-               crypto_instance_ctx(crypto_tfm_alg_instance(parent));
-       unsigned int noncelen = ictx->noncesize;
-       int err = 0;
-
-       /* the nonce is stored in bytes at end of key */
-       if (keylen < noncelen)
-               return  -EINVAL;
-
-       memcpy(ctx->nonce, key + (keylen - noncelen), noncelen);
-
-       keylen -=  noncelen;
+       int err;
 
        crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
        crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
@@ -104,73 +46,76 @@ static int crypto_ctr_setkey(struct crypto_tfm *parent, const u8 *key,
        return err;
 }
 
+static void crypto_ctr_crypt_final(struct blkcipher_walk *walk,
+                                  struct crypto_cipher *tfm)
+{
+       unsigned int bsize = crypto_cipher_blocksize(tfm);
+       unsigned long alignmask = crypto_cipher_alignmask(tfm);
+       u8 *ctrblk = walk->iv;
+       u8 tmp[bsize + alignmask];
+       u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
+       u8 *src = walk->src.virt.addr;
+       u8 *dst = walk->dst.virt.addr;
+       unsigned int nbytes = walk->nbytes;
+
+       crypto_cipher_encrypt_one(tfm, keystream, ctrblk);
+       crypto_xor(keystream, src, nbytes);
+       memcpy(dst, keystream, nbytes);
+
+       crypto_inc(ctrblk, bsize);
+}
+
 static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,
-                                   struct crypto_cipher *tfm, u8 *ctrblk,
-                                   unsigned int countersize)
+                                   struct crypto_cipher *tfm)
 {
        void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
                   crypto_cipher_alg(tfm)->cia_encrypt;
        unsigned int bsize = crypto_cipher_blocksize(tfm);
-       unsigned long alignmask = crypto_cipher_alignmask(tfm);
-       u8 ks[bsize + alignmask];
-       u8 *keystream = (u8 *)ALIGN((unsigned long)ks, alignmask + 1);
+       u8 *ctrblk = walk->iv;
        u8 *src = walk->src.virt.addr;
        u8 *dst = walk->dst.virt.addr;
        unsigned int nbytes = walk->nbytes;
 
        do {
                /* create keystream */
-               fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
-               xor_quad(keystream, src, min(nbytes, bsize));
-
-               /* copy result into dst */
-               memcpy(dst, keystream, min(nbytes, bsize));
+               fn(crypto_cipher_tfm(tfm), dst, ctrblk);
+               crypto_xor(dst, src, bsize);
 
                /* increment counter in counterblock */
-               ctr_inc_quad(ctrblk + (bsize - countersize), countersize);
-
-               if (nbytes < bsize)
-                       break;
+               crypto_inc(ctrblk, bsize);
 
                src += bsize;
                dst += bsize;
-               nbytes -= bsize;
-
-       } while (nbytes);
+       } while ((nbytes -= bsize) >= bsize);
 
-       return 0;
+       return nbytes;
 }
 
 static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,
-                                   struct crypto_cipher *tfm, u8 *ctrblk,
-                                   unsigned int countersize)
+                                   struct crypto_cipher *tfm)
 {
        void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
                   crypto_cipher_alg(tfm)->cia_encrypt;
        unsigned int bsize = crypto_cipher_blocksize(tfm);
        unsigned long alignmask = crypto_cipher_alignmask(tfm);
        unsigned int nbytes = walk->nbytes;
+       u8 *ctrblk = walk->iv;
        u8 *src = walk->src.virt.addr;
-       u8 ks[bsize + alignmask];
-       u8 *keystream = (u8 *)ALIGN((unsigned long)ks, alignmask + 1);
+       u8 tmp[bsize + alignmask];
+       u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
 
        do {
                /* create keystream */
                fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
-               xor_quad(src, keystream, min(nbytes, bsize));
+               crypto_xor(src, keystream, bsize);
 
                /* increment counter in counterblock */
-               ctr_inc_quad(ctrblk + (bsize - countersize), countersize);
-
-               if (nbytes < bsize)
-                       break;
+               crypto_inc(ctrblk, bsize);
 
                src += bsize;
-               nbytes -= bsize;
+       } while ((nbytes -= bsize) >= bsize);
 
-       } while (nbytes);
-
-       return 0;
+       return nbytes;
 }
 
 static int crypto_ctr_crypt(struct blkcipher_desc *desc,
@@ -182,52 +127,36 @@ static int crypto_ctr_crypt(struct blkcipher_desc *desc,
        struct crypto_ctr_ctx *ctx = crypto_blkcipher_ctx(tfm);
        struct crypto_cipher *child = ctx->child;
        unsigned int bsize = crypto_cipher_blocksize(child);
-       struct ctr_instance_ctx *ictx =
-               crypto_instance_ctx(crypto_tfm_alg_instance(&tfm->base));
-       unsigned long alignmask = crypto_cipher_alignmask(child);
-       u8 cblk[bsize + alignmask];
-       u8 *counterblk = (u8 *)ALIGN((unsigned long)cblk, alignmask + 1);
        int err;
 
        blkcipher_walk_init(&walk, dst, src, nbytes);
        err = blkcipher_walk_virt_block(desc, &walk, bsize);
 
-       /* set up counter block */
-       memset(counterblk, 0 , bsize);
-       memcpy(counterblk, ctx->nonce, ictx->noncesize);
-       memcpy(counterblk + ictx->noncesize, walk.iv, ictx->ivsize);
-
-       /* initialize counter portion of counter block */
-       ctr_inc_quad(counterblk + (bsize - ictx->countersize),
-                    ictx->countersize);
-
-       while (walk.nbytes) {
+       while (walk.nbytes >= bsize) {
                if (walk.src.virt.addr == walk.dst.virt.addr)
-                       nbytes = crypto_ctr_crypt_inplace(&walk, child,
-                                                         counterblk,
-                                                         ictx->countersize);
+                       nbytes = crypto_ctr_crypt_inplace(&walk, child);
                else
-                       nbytes = crypto_ctr_crypt_segment(&walk, child,
-                                                         counterblk,
-                                                         ictx->countersize);
+                       nbytes = crypto_ctr_crypt_segment(&walk, child);
 
                err = blkcipher_walk_done(desc, &walk, nbytes);
        }
+
+       if (walk.nbytes) {
+               crypto_ctr_crypt_final(&walk, child);
+               err = blkcipher_walk_done(desc, &walk, 0);
+       }
+
        return err;
 }
 
 static int crypto_ctr_init_tfm(struct crypto_tfm *tfm)
 {
        struct crypto_instance *inst = (void *)tfm->__crt_alg;
-       struct ctr_instance_ctx *ictx = crypto_instance_ctx(inst);
+       struct crypto_spawn *spawn = crypto_instance_ctx(inst);
        struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
        struct crypto_cipher *cipher;
 
-       ctx->nonce = kzalloc(ictx->noncesize, GFP_KERNEL);
-       if (!ctx->nonce)
-               return -ENOMEM;
-
-       cipher = crypto_spawn_cipher(&ictx->alg);
+       cipher = crypto_spawn_cipher(spawn);
        if (IS_ERR(cipher))
                return PTR_ERR(cipher);
 
@@ -240,7 +169,6 @@ static void crypto_ctr_exit_tfm(struct crypto_tfm *tfm)
 {
        struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
 
-       kfree(ctx->nonce);
        crypto_free_cipher(ctx->child);
 }
 
@@ -248,10 +176,6 @@ static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb)
 {
        struct crypto_instance *inst;
        struct crypto_alg *alg;
-       struct ctr_instance_ctx *ictx;
-       unsigned int noncesize;
-       unsigned int ivsize;
-       unsigned int countersize;
        int err;
 
        err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
@@ -263,67 +187,28 @@ static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb)
        if (IS_ERR(alg))
                return ERR_PTR(PTR_ERR(alg));
 
-       err = crypto_attr_u32(tb[2], &noncesize);
-       if (err)
-               goto out_put_alg;
-
-       err = crypto_attr_u32(tb[3], &ivsize);
-       if (err)
-               goto out_put_alg;
-
-       err = crypto_attr_u32(tb[4], &countersize);
-       if (err)
-               goto out_put_alg;
-
-       /* verify size of nonce + iv + counter
-        * counter must be >= 4 bytes.
-        */
+       /* Block size must be >= 4 bytes. */
        err = -EINVAL;
-       if (((noncesize + ivsize + countersize) < alg->cra_blocksize) ||
-           ((noncesize + ivsize) > alg->cra_blocksize) ||
-           (countersize > alg->cra_blocksize) || (countersize < 4))
+       if (alg->cra_blocksize < 4)
                goto out_put_alg;
 
-       inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
-       err = -ENOMEM;
-       if (!inst)
+       /* If this is false we'd fail the alignment of crypto_inc. */
+       if (alg->cra_blocksize % 4)
                goto out_put_alg;
 
-       err = -ENAMETOOLONG;
-       if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
-                    "ctr(%s,%u,%u,%u)", alg->cra_name, noncesize,
-                    ivsize, countersize) >= CRYPTO_MAX_ALG_NAME) {
-               goto err_free_inst;
-       }
-
-       if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
-                    "ctr(%s,%u,%u,%u)", alg->cra_driver_name, noncesize,
-                    ivsize, countersize) >= CRYPTO_MAX_ALG_NAME) {
-               goto err_free_inst;
-       }
-
-       ictx = crypto_instance_ctx(inst);
-       ictx->noncesize = noncesize;
-       ictx->ivsize = ivsize;
-       ictx->countersize = countersize;
-
-       err = crypto_init_spawn(&ictx->alg, alg, inst,
-               CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
-       if (err)
-               goto err_free_inst;
+       inst = crypto_alloc_instance("ctr", alg);
+       if (IS_ERR(inst))
+               goto out;
 
-       err = 0;
        inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
        inst->alg.cra_priority = alg->cra_priority;
        inst->alg.cra_blocksize = 1;
-       inst->alg.cra_alignmask = 3;
+       inst->alg.cra_alignmask = alg->cra_alignmask | (__alignof__(u32) - 1);
        inst->alg.cra_type = &crypto_blkcipher_type;
 
-       inst->alg.cra_blkcipher.ivsize = ivsize;
-       inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize
-                                             + noncesize;
-       inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize
-                                             + noncesize;
+       inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
+       inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
+       inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
 
        inst->alg.cra_ctxsize = sizeof(struct crypto_ctr_ctx);
 
@@ -334,24 +219,18 @@ static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb)
        inst->alg.cra_blkcipher.encrypt = crypto_ctr_crypt;
        inst->alg.cra_blkcipher.decrypt = crypto_ctr_crypt;
 
-err_free_inst:
-       if (err)
-               kfree(inst);
-
-out_put_alg:
+out:
        crypto_mod_put(alg);
-
-       if (err)
-               inst = ERR_PTR(err);
-
        return inst;
+
+out_put_alg:
+       inst = ERR_PTR(err);
+       goto out;
 }
 
 static void crypto_ctr_free(struct crypto_instance *inst)
 {
-       struct ctr_instance_ctx *ictx = crypto_instance_ctx(inst);
-
-       crypto_drop_spawn(&ictx->alg);
+       crypto_drop_spawn(crypto_instance_ctx(inst));
        kfree(inst);
 }
 
@@ -362,13 +241,176 @@ static struct crypto_template crypto_ctr_tmpl = {
        .module = THIS_MODULE,
 };
 
+static int crypto_rfc3686_setkey(struct crypto_tfm *parent, const u8 *key,
+                                unsigned int keylen)
+{
+       struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(parent);
+       struct crypto_blkcipher *child = ctx->child;
+       int err;
+
+       /* the nonce is stored in bytes at end of key */
+       if (keylen < CTR_RFC3686_NONCE_SIZE)
+               return -EINVAL;
+
+       memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
+              CTR_RFC3686_NONCE_SIZE);
+
+       keylen -= CTR_RFC3686_NONCE_SIZE;
+
+       crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
+       crypto_blkcipher_set_flags(child, crypto_tfm_get_flags(parent) &
+                                         CRYPTO_TFM_REQ_MASK);
+       err = crypto_blkcipher_setkey(child, key, keylen);
+       crypto_tfm_set_flags(parent, crypto_blkcipher_get_flags(child) &
+                                    CRYPTO_TFM_RES_MASK);
+
+       return err;
+}
+
+static int crypto_rfc3686_crypt(struct blkcipher_desc *desc,
+                               struct scatterlist *dst,
+                               struct scatterlist *src, unsigned int nbytes)
+{
+       struct crypto_blkcipher *tfm = desc->tfm;
+       struct crypto_rfc3686_ctx *ctx = crypto_blkcipher_ctx(tfm);
+       struct crypto_blkcipher *child = ctx->child;
+       unsigned long alignmask = crypto_blkcipher_alignmask(tfm);
+       u8 ivblk[CTR_RFC3686_BLOCK_SIZE + alignmask];
+       u8 *iv = PTR_ALIGN(ivblk + 0, alignmask + 1);
+       u8 *info = desc->info;
+       int err;
+
+       /* set up counter block */
+       memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
+       memcpy(iv + CTR_RFC3686_NONCE_SIZE, info, CTR_RFC3686_IV_SIZE);
+
+       /* initialize counter portion of counter block */
+       *(__be32 *)(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
+               cpu_to_be32(1);
+
+       desc->tfm = child;
+       desc->info = iv;
+       err = crypto_blkcipher_encrypt_iv(desc, dst, src, nbytes);
+       desc->tfm = tfm;
+       desc->info = info;
+
+       return err;
+}
+
+static int crypto_rfc3686_init_tfm(struct crypto_tfm *tfm)
+{
+       struct crypto_instance *inst = (void *)tfm->__crt_alg;
+       struct crypto_spawn *spawn = crypto_instance_ctx(inst);
+       struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);
+       struct crypto_blkcipher *cipher;
+
+       cipher = crypto_spawn_blkcipher(spawn);
+       if (IS_ERR(cipher))
+               return PTR_ERR(cipher);
+
+       ctx->child = cipher;
+
+       return 0;
+}
+
+static void crypto_rfc3686_exit_tfm(struct crypto_tfm *tfm)
+{
+       struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);
+
+       crypto_free_blkcipher(ctx->child);
+}
+
+static struct crypto_instance *crypto_rfc3686_alloc(struct rtattr **tb)
+{
+       struct crypto_instance *inst;
+       struct crypto_alg *alg;
+       int err;
+
+       err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
+       if (err)
+               return ERR_PTR(err);
+
+       alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_BLKCIPHER,
+                                 CRYPTO_ALG_TYPE_MASK);
+       err = PTR_ERR(alg);
+       if (IS_ERR(alg))
+               return ERR_PTR(err);
+
+       /* We only support 16-byte blocks. */
+       err = -EINVAL;
+       if (alg->cra_blkcipher.ivsize != CTR_RFC3686_BLOCK_SIZE)
+               goto out_put_alg;
+
+       /* Not a stream cipher? */
+       if (alg->cra_blocksize != 1)
+               goto out_put_alg;
+
+       inst = crypto_alloc_instance("rfc3686", alg);
+       if (IS_ERR(inst))
+               goto out;
+
+       inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
+       inst->alg.cra_priority = alg->cra_priority;
+       inst->alg.cra_blocksize = 1;
+       inst->alg.cra_alignmask = alg->cra_alignmask;
+       inst->alg.cra_type = &crypto_blkcipher_type;
+
+       inst->alg.cra_blkcipher.ivsize = CTR_RFC3686_IV_SIZE;
+       inst->alg.cra_blkcipher.min_keysize = alg->cra_blkcipher.min_keysize
+                                             + CTR_RFC3686_NONCE_SIZE;
+       inst->alg.cra_blkcipher.max_keysize = alg->cra_blkcipher.max_keysize
+                                             + CTR_RFC3686_NONCE_SIZE;
+
+       inst->alg.cra_blkcipher.geniv = "seqiv";
+
+       inst->alg.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
+
+       inst->alg.cra_init = crypto_rfc3686_init_tfm;
+       inst->alg.cra_exit = crypto_rfc3686_exit_tfm;
+
+       inst->alg.cra_blkcipher.setkey = crypto_rfc3686_setkey;
+       inst->alg.cra_blkcipher.encrypt = crypto_rfc3686_crypt;
+       inst->alg.cra_blkcipher.decrypt = crypto_rfc3686_crypt;
+
+out:
+       crypto_mod_put(alg);
+       return inst;
+
+out_put_alg:
+       inst = ERR_PTR(err);
+       goto out;
+}
+
+static struct crypto_template crypto_rfc3686_tmpl = {
+       .name = "rfc3686",
+       .alloc = crypto_rfc3686_alloc,
+       .free = crypto_ctr_free,
+       .module = THIS_MODULE,
+};
+
 static int __init crypto_ctr_module_init(void)
 {
-       return crypto_register_template(&crypto_ctr_tmpl);
+       int err;
+
+       err = crypto_register_template(&crypto_ctr_tmpl);
+       if (err)
+               goto out;
+
+       err = crypto_register_template(&crypto_rfc3686_tmpl);
+       if (err)
+               goto out_drop_ctr;
+
+out:
+       return err;
+
+out_drop_ctr:
+       crypto_unregister_template(&crypto_ctr_tmpl);
+       goto out;
 }
 
 static void __exit crypto_ctr_module_exit(void)
 {
+       crypto_unregister_template(&crypto_rfc3686_tmpl);
        crypto_unregister_template(&crypto_ctr_tmpl);
 }
 
@@ -377,3 +419,4 @@ module_exit(crypto_ctr_module_exit);
 
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("CTR Counter block mode");
+MODULE_ALIAS("rfc3686");