From: Eric Biggers <ebigg...@google.com>

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: sta...@vger.kernel.org
Signed-off-by: Eric Biggers <ebigg...@google.com>
---
 arch/arm/crypto/crc32-ce-glue.c                               | 2 ++
 arch/arm64/crypto/crc32-ce-glue.c                             | 2 ++
 arch/powerpc/crypto/crc32c-vpmsum_glue.c                      | 1 +
 arch/s390/crypto/crc32-vx.c                                   | 3 +++
 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_generic.c                                        | 1 +
 crypto/crc32c_generic.c                                       | 1 +
 crypto/cryptd.c                                               | 7 +++----
 crypto/mcryptd.c                                              | 7 +++----
 drivers/crypto/bfin_crc.c                                     | 3 ++-
 drivers/crypto/stm32/stm32_crc32.c                            | 2 ++
 drivers/staging/lustre/lnet/libcfs/linux/linux-crypto-adler.c | 1 +
 include/linux/crypto.h                                        | 6 ++++++
 15 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/arch/arm/crypto/crc32-ce-glue.c b/arch/arm/crypto/crc32-ce-glue.c
index 1b0e0e86ee9c..96e62ec105d0 100644
--- a/arch/arm/crypto/crc32-ce-glue.c
+++ b/arch/arm/crypto/crc32-ce-glue.c
@@ -188,6 +188,7 @@ static struct shash_alg crc32_pmull_algs[] = { {
        .base.cra_name          = "crc32",
        .base.cra_driver_name   = "crc32-arm-ce",
        .base.cra_priority      = 200,
+       .base.cra_flags         = CRYPTO_ALG_OPTIONAL_KEY,
        .base.cra_blocksize     = 1,
        .base.cra_module        = THIS_MODULE,
 }, {
@@ -203,6 +204,7 @@ static struct shash_alg crc32_pmull_algs[] = { {
        .base.cra_name          = "crc32c",
        .base.cra_driver_name   = "crc32c-arm-ce",
        .base.cra_priority      = 200,
+       .base.cra_flags         = CRYPTO_ALG_OPTIONAL_KEY,
        .base.cra_blocksize     = 1,
        .base.cra_module        = THIS_MODULE,
 } };
diff --git a/arch/arm64/crypto/crc32-ce-glue.c 
b/arch/arm64/crypto/crc32-ce-glue.c
index 624f4137918c..34b4e3d46aab 100644
--- a/arch/arm64/crypto/crc32-ce-glue.c
+++ b/arch/arm64/crypto/crc32-ce-glue.c
@@ -185,6 +185,7 @@ static struct shash_alg crc32_pmull_algs[] = { {
        .base.cra_name          = "crc32",
        .base.cra_driver_name   = "crc32-arm64-ce",
        .base.cra_priority      = 200,
+       .base.cra_flags         = CRYPTO_ALG_OPTIONAL_KEY,
        .base.cra_blocksize     = 1,
        .base.cra_module        = THIS_MODULE,
 }, {
@@ -200,6 +201,7 @@ static struct shash_alg crc32_pmull_algs[] = { {
        .base.cra_name          = "crc32c",
        .base.cra_driver_name   = "crc32c-arm64-ce",
        .base.cra_priority      = 200,
+       .base.cra_flags         = CRYPTO_ALG_OPTIONAL_KEY,
        .base.cra_blocksize     = 1,
        .base.cra_module        = THIS_MODULE,
 } };
diff --git a/arch/powerpc/crypto/crc32c-vpmsum_glue.c 
b/arch/powerpc/crypto/crc32c-vpmsum_glue.c
index f058e0c3e4d4..fd1d6c83f0c0 100644
--- a/arch/powerpc/crypto/crc32c-vpmsum_glue.c
+++ b/arch/powerpc/crypto/crc32c-vpmsum_glue.c
@@ -141,6 +141,7 @@ static struct shash_alg alg = {
                .cra_name               = "crc32c",
                .cra_driver_name        = "crc32c-vpmsum",
                .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/s390/crypto/crc32-vx.c b/arch/s390/crypto/crc32-vx.c
index 436865926c26..423ee05887e6 100644
--- a/arch/s390/crypto/crc32-vx.c
+++ b/arch/s390/crypto/crc32-vx.c
@@ -239,6 +239,7 @@ static struct shash_alg crc32_vx_algs[] = {
                        .cra_name        = "crc32",
                        .cra_driver_name = "crc32-vx",
                        .cra_priority    = 200,
+                       .cra_flags       = CRYPTO_ALG_OPTIONAL_KEY,
                        .cra_blocksize   = CRC32_BLOCK_SIZE,
                        .cra_ctxsize     = sizeof(struct crc_ctx),
                        .cra_module      = THIS_MODULE,
@@ -259,6 +260,7 @@ static struct shash_alg crc32_vx_algs[] = {
                        .cra_name        = "crc32be",
                        .cra_driver_name = "crc32be-vx",
                        .cra_priority    = 200,
+                       .cra_flags       = CRYPTO_ALG_OPTIONAL_KEY,
                        .cra_blocksize   = CRC32_BLOCK_SIZE,
                        .cra_ctxsize     = sizeof(struct crc_ctx),
                        .cra_module      = THIS_MODULE,
@@ -279,6 +281,7 @@ static struct shash_alg crc32_vx_algs[] = {
                        .cra_name        = "crc32c",
                        .cra_driver_name = "crc32c-vx",
                        .cra_priority    = 200,
+                       .cra_flags       = CRYPTO_ALG_OPTIONAL_KEY,
                        .cra_blocksize   = CRC32_BLOCK_SIZE,
                        .cra_ctxsize     = sizeof(struct crc_ctx),
                        .cra_module      = THIS_MODULE,
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 27226df3f7d8..c8d9cdacbf10 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 c194d5717ae5..5773e1161072 100644
--- a/arch/x86/crypto/crc32c-intel_glue.c
+++ b/arch/x86/crypto/crc32c-intel_glue.c
@@ -226,6 +226,7 @@ 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_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;
diff --git a/drivers/crypto/bfin_crc.c b/drivers/crypto/bfin_crc.c
index a118b9bed669..bfbf8bf77f03 100644
--- a/drivers/crypto/bfin_crc.c
+++ b/drivers/crypto/bfin_crc.c
@@ -494,7 +494,8 @@ 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/drivers/crypto/stm32/stm32_crc32.c 
b/drivers/crypto/stm32/stm32_crc32.c
index 090582baecfe..8f09b8430893 100644
--- a/drivers/crypto/stm32/stm32_crc32.c
+++ b/drivers/crypto/stm32/stm32_crc32.c
@@ -208,6 +208,7 @@ static struct shash_alg algs[] = {
                        .cra_name               = "crc32",
                        .cra_driver_name        = DRIVER_NAME,
                        .cra_priority           = 200,
+                       .cra_flags              = CRYPTO_ALG_OPTIONAL_KEY,
                        .cra_blocksize          = CHKSUM_BLOCK_SIZE,
                        .cra_alignmask          = 3,
                        .cra_ctxsize            = sizeof(struct stm32_crc_ctx),
@@ -229,6 +230,7 @@ static struct shash_alg algs[] = {
                        .cra_name               = "crc32c",
                        .cra_driver_name        = DRIVER_NAME,
                        .cra_priority           = 200,
+                       .cra_flags              = CRYPTO_ALG_OPTIONAL_KEY,
                        .cra_blocksize          = CHKSUM_BLOCK_SIZE,
                        .cra_alignmask          = 3,
                        .cra_ctxsize            = sizeof(struct stm32_crc_ctx),
diff --git a/drivers/staging/lustre/lnet/libcfs/linux/linux-crypto-adler.c 
b/drivers/staging/lustre/lnet/libcfs/linux/linux-crypto-adler.c
index 2e5d311d2438..db81ed527452 100644
--- a/drivers/staging/lustre/lnet/libcfs/linux/linux-crypto-adler.c
+++ b/drivers/staging/lustre/lnet/libcfs/linux/linux-crypto-adler.c
@@ -120,6 +120,7 @@ static struct shash_alg alg = {
                .cra_name               = "adler32",
                .cra_driver_name        = "adler32-zlib",
                .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/include/linux/crypto.h b/include/linux/crypto.h
index 78508ca4b108..72e47b3ecdc8 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -106,6 +106,12 @@
  */
 #define CRYPTO_ALG_INTERNAL            0x00002000
 
+/*
+ * 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).
  */
-- 
2.15.1.620.gb9897f4670-goog

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