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authorEric Biggers <ebiggers@google.com>2018-01-03 11:16:26 -0800
committerHerbert Xu <herbert@gondor.apana.org.au>2018-01-12 23:03:35 +1100
commita208fa8f33031b9e0aba44c7d1b7e68eb0cbd29e (patch)
treee700ec232c2831a0471ce788552c69db8cc6c949 /crypto
parenta16e772e664b9a261424107784804cffc8894977 (diff)
downloadlinux-a208fa8f33031b9e0aba44c7d1b7e68eb0cbd29e.tar.gz
crypto: hash - annotate algorithms taking optional key
We need to consistently enforce that keyed hashes cannot be used without
setting the key.  To do this we need a reliable way to determine whether
a given hash algorithm is keyed or not.  AF_ALG currently does this by
checking for the presence of a ->setkey() method.  However, this is
actually slightly broken because the CRC-32 algorithms implement
->setkey() but can also be used without a key.  (The CRC-32 "key" is not
actually a cryptographic key but rather represents the initial state.
If not overridden, then a default initial state is used.)

Prepare to fix this by introducing a flag CRYPTO_ALG_OPTIONAL_KEY which
indicates that the algorithm has a ->setkey() method, but it is not
required to be called.  Then set it on all the CRC-32 algorithms.

The same also applies to the Adler-32 implementation in Lustre.

Also, the cryptd and mcryptd templates have to pass through the flag
from their underlying algorithm.

Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto')
-rw-r--r--crypto/crc32_generic.c1
-rw-r--r--crypto/crc32c_generic.c1
-rw-r--r--crypto/cryptd.c7
-rw-r--r--crypto/mcryptd.c7
4 files changed, 8 insertions, 8 deletions
diff --git a/crypto/crc32_generic.c b/crypto/crc32_generic.c
index aa2a25fc7482..718cbce8d169 100644
--- a/crypto/crc32_generic.c
+++ b/crypto/crc32_generic.c
@@ -133,6 +133,7 @@ static struct shash_alg alg = {
 		.cra_name		= "crc32",
 		.cra_driver_name	= "crc32-generic",
 		.cra_priority		= 100,
+		.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
 		.cra_blocksize		= CHKSUM_BLOCK_SIZE,
 		.cra_ctxsize		= sizeof(u32),
 		.cra_module		= THIS_MODULE,
diff --git a/crypto/crc32c_generic.c b/crypto/crc32c_generic.c
index 4c0a0e271876..372320399622 100644
--- a/crypto/crc32c_generic.c
+++ b/crypto/crc32c_generic.c
@@ -146,6 +146,7 @@ static struct shash_alg alg = {
 		.cra_name		=	"crc32c",
 		.cra_driver_name	=	"crc32c-generic",
 		.cra_priority		=	100,
+		.cra_flags		=	CRYPTO_ALG_OPTIONAL_KEY,
 		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
 		.cra_alignmask		=	3,
 		.cra_ctxsize		=	sizeof(struct chksum_ctx),
diff --git a/crypto/cryptd.c b/crypto/cryptd.c
index 457ae3e66a41..addca7bae33f 100644
--- a/crypto/cryptd.c
+++ b/crypto/cryptd.c
@@ -896,10 +896,9 @@ static int cryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb,
 	if (err)
 		goto out_free_inst;
 
-	type = CRYPTO_ALG_ASYNC;
-	if (alg->cra_flags & CRYPTO_ALG_INTERNAL)
-		type |= CRYPTO_ALG_INTERNAL;
-	inst->alg.halg.base.cra_flags = type;
+	inst->alg.halg.base.cra_flags = CRYPTO_ALG_ASYNC |
+		(alg->cra_flags & (CRYPTO_ALG_INTERNAL |
+				   CRYPTO_ALG_OPTIONAL_KEY));
 
 	inst->alg.halg.digestsize = salg->digestsize;
 	inst->alg.halg.statesize = salg->statesize;
diff --git a/crypto/mcryptd.c b/crypto/mcryptd.c
index ace346b976b3..fe5129d6ff4e 100644
--- a/crypto/mcryptd.c
+++ b/crypto/mcryptd.c
@@ -516,10 +516,9 @@ static int mcryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb,
 	if (err)
 		goto out_free_inst;
 
-	type = CRYPTO_ALG_ASYNC;
-	if (alg->cra_flags & CRYPTO_ALG_INTERNAL)
-		type |= CRYPTO_ALG_INTERNAL;
-	inst->alg.halg.base.cra_flags = type;
+	inst->alg.halg.base.cra_flags = CRYPTO_ALG_ASYNC |
+		(alg->cra_flags & (CRYPTO_ALG_INTERNAL |
+				   CRYPTO_ALG_OPTIONAL_KEY));
 
 	inst->alg.halg.digestsize = halg->digestsize;
 	inst->alg.halg.statesize = halg->statesize;