From 79bd2029874356227b6eeaacf405b3ad74dac03b Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Wed, 3 Jan 2018 11:16:26 -0800 Subject: [PATCH] crypto: hash - annotate algorithms taking optional key commit a208fa8f33031b9e0aba44c7d1b7e68eb0cbd29e upstream. 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. Change-Id: Ie0547047b828f276d967e8979cd9176e57c99ac8 Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu [bwh: Backported to 3.2: - Drop changes to nonexistent drivers - There's no CRYPTO_ALG_INTERNAL flag - Adjust filenames] Signed-off-by: Ben Hutchings --- arch/arm64/crypto/crc32-arm64.c | 2 ++ arch/sparc/crypto/crc32c_glue.c | 1 + arch/x86/crypto/crc32-pclmul_glue.c | 1 + arch/x86/crypto/crc32c-intel_glue.c | 1 + crypto/crc32.c | 1 + crypto/crc32c.c | 1 + crypto/cryptd.c | 3 ++- drivers/crypto/bfin_crc.c | 3 ++- include/linux/crypto.h | 6 ++++++ 9 files changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/arm64/crypto/crc32-arm64.c b/arch/arm64/crypto/crc32-arm64.c index 6a37c3c6b11d..3ec568afd1d3 100644 --- a/arch/arm64/crypto/crc32-arm64.c +++ b/arch/arm64/crypto/crc32-arm64.c @@ -232,6 +232,7 @@ static struct shash_alg crc32_alg = { .cra_name = "crc32", .cra_driver_name = "crc32-arm64-hw", .cra_priority = 300, + .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, .cra_blocksize = CHKSUM_BLOCK_SIZE, .cra_alignmask = 0, .cra_ctxsize = sizeof(struct chksum_ctx), @@ -253,6 +254,7 @@ static struct shash_alg crc32c_alg = { .cra_name = "crc32c", .cra_driver_name = "crc32c-arm64-hw", .cra_priority = 300, + .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, .cra_blocksize = CHKSUM_BLOCK_SIZE, .cra_alignmask = 0, .cra_ctxsize = sizeof(struct chksum_ctx), diff --git a/arch/sparc/crypto/crc32c_glue.c b/arch/sparc/crypto/crc32c_glue.c index d1064e46efe8..8aa664638c3c 100644 --- a/arch/sparc/crypto/crc32c_glue.c +++ b/arch/sparc/crypto/crc32c_glue.c @@ -133,6 +133,7 @@ static struct shash_alg alg = { .cra_name = "crc32c", .cra_driver_name = "crc32c-sparc64", .cra_priority = SPARC_CR_OPCODE_PRIORITY, + .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, .cra_blocksize = CHKSUM_BLOCK_SIZE, .cra_ctxsize = sizeof(u32), .cra_alignmask = 7, diff --git a/arch/x86/crypto/crc32-pclmul_glue.c b/arch/x86/crypto/crc32-pclmul_glue.c index 1937fc1d8763..0072dd30dd12 100644 --- a/arch/x86/crypto/crc32-pclmul_glue.c +++ b/arch/x86/crypto/crc32-pclmul_glue.c @@ -162,6 +162,7 @@ static struct shash_alg alg = { .cra_name = "crc32", .cra_driver_name = "crc32-pclmul", .cra_priority = 200, + .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, .cra_blocksize = CHKSUM_BLOCK_SIZE, .cra_ctxsize = sizeof(u32), .cra_module = THIS_MODULE, diff --git a/arch/x86/crypto/crc32c-intel_glue.c b/arch/x86/crypto/crc32c-intel_glue.c index 28640c3d6af7..c743444b9274 100644 --- a/arch/x86/crypto/crc32c-intel_glue.c +++ b/arch/x86/crypto/crc32c-intel_glue.c @@ -240,6 +240,7 @@ static struct shash_alg alg = { .cra_name = "crc32c", .cra_driver_name = "crc32c-intel", .cra_priority = 200, + .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, .cra_blocksize = CHKSUM_BLOCK_SIZE, .cra_ctxsize = sizeof(u32), .cra_module = THIS_MODULE, diff --git a/crypto/crc32.c b/crypto/crc32.c index 187ded28cb0b..fd20768d95ad 100644 --- a/crypto/crc32.c +++ b/crypto/crc32.c @@ -133,6 +133,7 @@ static struct shash_alg alg = { .cra_name = "crc32", .cra_driver_name = "crc32-table", .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.c b/crypto/crc32c.c index 238f0e627ef3..2f01aae2f6f1 100644 --- a/crypto/crc32c.c +++ b/crypto/crc32c.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 1677ad5a3c07..773c10fc6103 100644 --- a/crypto/cryptd.c +++ b/crypto/cryptd.c @@ -603,7 +603,8 @@ static int cryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb, if (err) goto out_free_inst; - inst->alg.halg.base.cra_flags = CRYPTO_ALG_ASYNC; + inst->alg.halg.base.cra_flags = CRYPTO_ALG_ASYNC | + (alg->cra_flags & CRYPTO_ALG_OPTIONAL_KEY); inst->alg.halg.digestsize = salg->digestsize; inst->alg.halg.statesize = salg->statesize; diff --git a/drivers/crypto/bfin_crc.c b/drivers/crypto/bfin_crc.c index d797f31f5d85..8196dd569f83 100644 --- a/drivers/crypto/bfin_crc.c +++ b/drivers/crypto/bfin_crc.c @@ -516,7 +516,8 @@ static struct ahash_alg algs = { .cra_driver_name = DRIVER_NAME, .cra_priority = 100, .cra_flags = CRYPTO_ALG_TYPE_AHASH | - CRYPTO_ALG_ASYNC, + CRYPTO_ALG_ASYNC | + CRYPTO_ALG_OPTIONAL_KEY, .cra_blocksize = CHKSUM_BLOCK_SIZE, .cra_ctxsize = sizeof(struct bfin_crypto_crc_ctx), .cra_alignmask = 3, diff --git a/include/linux/crypto.h b/include/linux/crypto.h index 61dd0b15d21c..f73ac2237358 100644 --- a/include/linux/crypto.h +++ b/include/linux/crypto.h @@ -94,6 +94,12 @@ */ #define CRYPTO_ALG_KERN_DRIVER_ONLY 0x00001000 +/* + * Set if the algorithm has a ->setkey() method but can be used without + * calling it first, i.e. there is a default key. + */ +#define CRYPTO_ALG_OPTIONAL_KEY 0x00004000 + /* * Transform masks and values (for crt_flags). */