From: Ard Biesheuvel <ardb@xxxxxxxxxx>
crc32c-generic is currently backed by the architecture's CRC-32c library
code, which may offer a variety of implementations depending on the
capabilities of the platform. These are not covered by the crypto
subsystem's fuzz testing capabilities because crc32c-generic is the
reference driver that the fuzzing logic uses as a source of truth.
Fix this by providing a crc32c-arch implementation which is based on the
arch library code if available, and modify crc32c-generic so it is
always based on the generic C implementation. If the arch has no CRC-32c
library code, this change does nothing.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
crypto/Makefile | 1 +
crypto/crc32c_generic.c | 94 +++++++++++++++-----
lib/crc32.c | 2 +
3 files changed, 75 insertions(+), 22 deletions(-)
diff --git a/crypto/Makefile b/crypto/Makefile
index 2d4a3c0659fa..a1ce3fa5298d 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -152,6 +152,7 @@ obj-$(CONFIG_CRYPTO_DEFLATE) += deflate.o
obj-$(CONFIG_CRYPTO_MICHAEL_MIC) += michael_mic.o
obj-$(CONFIG_CRYPTO_CRC32C) += crc32c_generic.o
obj-$(CONFIG_CRYPTO_CRC32) += crc32_generic.o
+CFLAGS_crc32c_generic.o += -DARCH=$(ARCH)
CFLAGS_crc32_generic.o += -DARCH=$(ARCH)
obj-$(CONFIG_CRYPTO_CRCT10DIF) += crct10dif_common.o crct10dif_generic.o
obj-$(CONFIG_CRYPTO_CRC64_ROCKSOFT) += crc64_rocksoft_generic.o
diff --git a/crypto/crc32c_generic.c b/crypto/crc32c_generic.c
index a8c90b3f4c6c..7c2357c30fdf 100644
--- a/crypto/crc32c_generic.c
+++ b/crypto/crc32c_generic.c
@@ -85,6 +85,15 @@ static int chksum_update(struct shash_desc *desc, const u8 *data,
{
struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
+ ctx->crc = __crc32c_le_base(ctx->crc, data, length);
+ return 0;
+}
+
+static int chksum_update_arch(struct shash_desc *desc, const u8 *data,
+ unsigned int length)
+{
+ struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
+
ctx->crc = __crc32c_le(ctx->crc, data, length);
return 0;
}
@@ -98,6 +107,13 @@ static int chksum_final(struct shash_desc *desc, u8 *out)
}
static int __chksum_finup(u32 *crcp, const u8 *data, unsigned int len, u8 *out)
+{
+ put_unaligned_le32(~__crc32c_le_base(*crcp, data, len), out);
+ return 0;
+}
+
+static int __chksum_finup_arch(u32 *crcp, const u8 *data, unsigned int len,
+ u8 *out)
{
put_unaligned_le32(~__crc32c_le(*crcp, data, len), out);
return 0;
@@ -111,6 +127,14 @@ static int chksum_finup(struct shash_desc *desc, const u8 *data,
return __chksum_finup(&ctx->crc, data, len, out);
}
+static int chksum_finup_arch(struct shash_desc *desc, const u8 *data,
+ unsigned int len, u8 *out)
+{
+ struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
+
+ return __chksum_finup_arch(&ctx->crc, data, len, out);
+}
+
static int chksum_digest(struct shash_desc *desc, const u8 *data,
unsigned int length, u8 *out)
{
@@ -119,6 +143,14 @@ static int chksum_digest(struct shash_desc *desc, const u8 *data,
return __chksum_finup(&mctx->key, data, length, out);
}
+static int chksum_digest_arch(struct shash_desc *desc, const u8 *data,
+ unsigned int length, u8 *out)
+{
+ struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
+
+ return __chksum_finup_arch(&mctx->key, data, length, out);
+}
+
static int crc32c_cra_init(struct crypto_tfm *tfm)
{
struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
@@ -127,35 +159,53 @@ static int crc32c_cra_init(struct crypto_tfm *tfm)
return 0;
}
-static struct shash_alg alg = {
- .digestsize = CHKSUM_DIGEST_SIZE,
- .setkey = chksum_setkey,
- .init = chksum_init,
- .update = chksum_update,
- .final = chksum_final,
- .finup = chksum_finup,
- .digest = chksum_digest,
- .descsize = sizeof(struct chksum_desc_ctx),
- .base = {
- .cra_name = "crc32c",
- .cra_driver_name = "crc32c-generic",
- .cra_priority = 100,
- .cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
- .cra_blocksize = CHKSUM_BLOCK_SIZE,
- .cra_ctxsize = sizeof(struct chksum_ctx),
- .cra_module = THIS_MODULE,
- .cra_init = crc32c_cra_init,
- }
-};
+static struct shash_alg algs[] = {{
+ .digestsize = CHKSUM_DIGEST_SIZE,
+ .setkey = chksum_setkey,
+ .init = chksum_init,
+ .update = chksum_update,
+ .final = chksum_final,
+ .finup = chksum_finup,
+ .digest = chksum_digest,
+ .descsize = sizeof(struct chksum_desc_ctx),
+
+ .base.cra_name = "crc32c",
+ .base.cra_driver_name = "crc32c-generic",
+ .base.cra_priority = 100,
+ .base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
+ .base.cra_blocksize = CHKSUM_BLOCK_SIZE,
+ .base.cra_ctxsize = sizeof(struct chksum_ctx),
+ .base.cra_module = THIS_MODULE,
+ .base.cra_init = crc32c_cra_init,
+}, {
+ .digestsize = CHKSUM_DIGEST_SIZE,
+ .setkey = chksum_setkey,
+ .init = chksum_init,
+ .update = chksum_update_arch,
+ .final = chksum_final,
+ .finup = chksum_finup_arch,
+ .digest = chksum_digest_arch,
+ .descsize = sizeof(struct chksum_desc_ctx),
+
+ .base.cra_name = "crc32c",
+ .base.cra_driver_name = "crc32c-" __stringify(ARCH),
+ .base.cra_priority = 150,
+ .base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
+ .base.cra_blocksize = CHKSUM_BLOCK_SIZE,
+ .base.cra_ctxsize = sizeof(struct chksum_ctx),
+ .base.cra_module = THIS_MODULE,
+ .base.cra_init = crc32c_cra_init,
+}};
static int __init crc32c_mod_init(void)
{
- return crypto_register_shash(&alg);
+ /* register the arch flavor only if it differs from the generic one */
+ return crypto_register_shashes(algs, 1 + (&__crc32c_le != &__crc32c_le_base));
}
static void __exit crc32c_mod_fini(void)
{
- crypto_unregister_shash(&alg);
+ crypto_unregister_shashes(algs, 1 + (&__crc32c_le != &__crc32c_le_base));
}
subsys_initcall(crc32c_mod_init);
diff --git a/lib/crc32.c b/lib/crc32.c
index a54ba87b7073..ff587fee3893 100644
--- a/lib/crc32.c
+++ b/lib/crc32.c
@@ -208,6 +208,8 @@ u32 __pure crc32_le_base(u32, unsigned char const *, size_t) __alias(crc32_le);
EXPORT_SYMBOL(crc32_le_base);
u32 __pure __crc32c_le_base(u32, unsigned char const *, size_t) __alias(__crc32c_le);
+EXPORT_SYMBOL(__crc32c_le_base);
+
u32 __pure crc32_be_base(u32, unsigned char const *, size_t) __alias(crc32_be);
/*
--
2.47.0.rc1.288.g06298d1525-goog
