[CRYPTO] api: Add type-safe spawns

This patch allows spawns of specific types (e.g., cipher) to be allocated.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

7 files changed, 42 insertions, 27 deletions

diff --git a/crypto/algapi.c b/crypto/algapi.c
index 69eb504721a4..0f1abca1b98c 100644
--- a/crypto/algapi.c
+++ b/crypto/algapi.c
@@ -377,7 +377,8 @@ void crypto_drop_spawn(struct crypto_spawn *spawn)
 }
 EXPORT_SYMBOL_GPL(crypto_drop_spawn);
 
-struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn)
+struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
+                                    u32 mask)
 {
         struct crypto_alg *alg;
         struct crypto_alg *alg2;
@@ -396,10 +397,18 @@ struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn)
                 return ERR_PTR(-EAGAIN);
         }
 
+        tfm = ERR_PTR(-EINVAL);
+        if (unlikely((alg->cra_flags ^ type) & mask))
+                goto out_put_alg;
+
         tfm = __crypto_alloc_tfm(alg);
         if (IS_ERR(tfm))
-                crypto_mod_put(alg);
+                goto out_put_alg;
+
+        return tfm;
 
+out_put_alg:
+        crypto_mod_put(alg);
         return tfm;
 }
 EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
diff --git a/crypto/cbc.c b/crypto/cbc.c
index f5542b4db387..136fea7e7000 100644
--- a/crypto/cbc.c
+++ b/crypto/cbc.c
@@ -243,6 +243,7 @@ static int crypto_cbc_init_tfm(struct crypto_tfm *tfm)
         struct crypto_instance *inst = (void *)tfm->__crt_alg;
         struct crypto_spawn *spawn = crypto_instance_ctx(inst);
         struct crypto_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
+        struct crypto_cipher *cipher;
 
         switch (crypto_tfm_alg_blocksize(tfm)) {
         case 8:
@@ -260,11 +261,11 @@ static int crypto_cbc_init_tfm(struct crypto_tfm *tfm)
                         ctx->xor = xor_quad;
         }
 
-        tfm = crypto_spawn_tfm(spawn);
-        if (IS_ERR(tfm))
-                return PTR_ERR(tfm);
+        cipher = crypto_spawn_cipher(spawn);
+        if (IS_ERR(cipher))
+                return PTR_ERR(cipher);
 
-        ctx->child = crypto_cipher_cast(tfm);
+        ctx->child = cipher;
         return 0;
 }
 
diff --git a/crypto/ecb.c b/crypto/ecb.c
index f239aa9c4017..839a0aed8c22 100644
--- a/crypto/ecb.c
+++ b/crypto/ecb.c
@@ -99,12 +99,13 @@ static int crypto_ecb_init_tfm(struct crypto_tfm *tfm)
         struct crypto_instance *inst = (void *)tfm->__crt_alg;
         struct crypto_spawn *spawn = crypto_instance_ctx(inst);
         struct crypto_ecb_ctx *ctx = crypto_tfm_ctx(tfm);
+        struct crypto_cipher *cipher;
 
-        tfm = crypto_spawn_tfm(spawn);
-        if (IS_ERR(tfm))
-                return PTR_ERR(tfm);
+        cipher = crypto_spawn_cipher(spawn);
+        if (IS_ERR(cipher))
+                return PTR_ERR(cipher);
 
-        ctx->child = crypto_cipher_cast(tfm);
+        ctx->child = cipher;
         return 0;
 }
 
diff --git a/crypto/hmac.c b/crypto/hmac.c
index b521bcd2b2c6..44187c5ee593 100644
--- a/crypto/hmac.c
+++ b/crypto/hmac.c
@@ -172,15 +172,16 @@ static int hmac_digest(struct hash_desc *pdesc, struct scatterlist *sg,
 
 static int hmac_init_tfm(struct crypto_tfm *tfm)
 {
+        struct crypto_hash *hash;
         struct crypto_instance *inst = (void *)tfm->__crt_alg;
         struct crypto_spawn *spawn = crypto_instance_ctx(inst);
         struct hmac_ctx *ctx = hmac_ctx(__crypto_hash_cast(tfm));
 
-        tfm = crypto_spawn_tfm(spawn);
-        if (IS_ERR(tfm))
-                return PTR_ERR(tfm);
+        hash = crypto_spawn_hash(spawn);
+        if (IS_ERR(hash))
+                return PTR_ERR(hash);
 
-        ctx->child = crypto_hash_cast(tfm);
+        ctx->child = hash;
         return 0;
 }
 
diff --git a/crypto/lrw.c b/crypto/lrw.c
index 56642586d84f..b4105080ac7a 100644
--- a/crypto/lrw.c
+++ b/crypto/lrw.c
@@ -201,21 +201,22 @@ static int decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 
 static int init_tfm(struct crypto_tfm *tfm)
 {
+        struct crypto_cipher *cipher;
         struct crypto_instance *inst = (void *)tfm->__crt_alg;
         struct crypto_spawn *spawn = crypto_instance_ctx(inst);
         struct priv *ctx = crypto_tfm_ctx(tfm);
         u32 *flags = &tfm->crt_flags;
 
-        tfm = crypto_spawn_tfm(spawn);
-        if (IS_ERR(tfm))
-                return PTR_ERR(tfm);
+        cipher = crypto_spawn_cipher(spawn);
+        if (IS_ERR(cipher))
+                return PTR_ERR(cipher);
 
-        if (crypto_tfm_alg_blocksize(tfm) != 16) {
+        if (crypto_cipher_blocksize(cipher) != 16) {
                 *flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
                 return -EINVAL;
         }
 
-        ctx->child = crypto_cipher_cast(tfm);
+        ctx->child = cipher;
         return 0;
 }
 
diff --git a/crypto/pcbc.c b/crypto/pcbc.c
index 0ffb46eb259f..5174d7fdad6e 100644
--- a/crypto/pcbc.c
+++ b/crypto/pcbc.c
@@ -247,6 +247,7 @@ static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm)
         struct crypto_instance *inst = (void *)tfm->__crt_alg;
         struct crypto_spawn *spawn = crypto_instance_ctx(inst);
         struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(tfm);
+        struct crypto_cipher *cipher;
 
         switch (crypto_tfm_alg_blocksize(tfm)) {
         case 8:
@@ -264,11 +265,11 @@ static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm)
                         ctx->xor = xor_quad;
         }
 
-        tfm = crypto_spawn_tfm(spawn);
-        if (IS_ERR(tfm))
-                return PTR_ERR(tfm);
+        cipher = crypto_spawn_cipher(spawn);
+        if (IS_ERR(cipher))
+                return PTR_ERR(cipher);
 
-        ctx->child = crypto_cipher_cast(tfm);
+        ctx->child = cipher;
         return 0;
 }
 
diff --git a/crypto/xcbc.c b/crypto/xcbc.c
index 317e9f08fc04..d7b4be0a057d 100644
--- a/crypto/xcbc.c
+++ b/crypto/xcbc.c
@@ -254,14 +254,15 @@ static int crypto_xcbc_digest(struct hash_desc *pdesc,
 
 static int xcbc_init_tfm(struct crypto_tfm *tfm)
 {
+        struct crypto_cipher *cipher;
         struct crypto_instance *inst = (void *)tfm->__crt_alg;
         struct crypto_spawn *spawn = crypto_instance_ctx(inst);
         struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
         int bs = crypto_hash_blocksize(__crypto_hash_cast(tfm));
 
-        tfm = crypto_spawn_tfm(spawn);
-        if (IS_ERR(tfm))
-                return PTR_ERR(tfm);
+        cipher = crypto_spawn_cipher(spawn);
+        if (IS_ERR(cipher))
+                return PTR_ERR(cipher);
 
         switch(bs) {
         case 16:
@@ -271,7 +272,7 @@ static int xcbc_init_tfm(struct crypto_tfm *tfm)
                 return -EINVAL;
         }
 
-        ctx->child = crypto_cipher_cast(tfm);
+        ctx->child = cipher;
         ctx->odds = (u8*)(ctx+1);
         ctx->prev = ctx->odds + bs;
         ctx->key = ctx->prev + bs;