From 07f090959bba437dd531bd2e08440ec6bf588878 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Mon, 30 Jun 2025 09:06:41 -0700 Subject: [PATCH] crypto: sha256 - Use same state format as legacy drivers Make the export and import functions for the sha224, sha256, hmac(sha224), and hmac(sha256) shash algorithms use the same format as the padlock-sha and nx-sha256 drivers, as required by Herbert. Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250630160645.3198-11-ebiggers@kernel.org Signed-off-by: Eric Biggers --- crypto/sha256.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) diff --git a/crypto/sha256.c b/crypto/sha256.c index d81166cbba953..052806559f06c 100644 --- a/crypto/sha256.c +++ b/crypto/sha256.c @@ -13,6 +13,43 @@ #include #include +/* + * Export and import functions. crypto_shash wants a particular format that + * matches that used by some legacy drivers. It currently is the same as the + * library SHA context, except the value in bytecount must be block-aligned and + * the remainder must be stored in an extra u8 appended to the struct. + */ + +#define SHA256_SHASH_STATE_SIZE 105 +static_assert(offsetof(struct __sha256_ctx, state) == 0); +static_assert(offsetof(struct __sha256_ctx, bytecount) == 32); +static_assert(offsetof(struct __sha256_ctx, buf) == 40); +static_assert(sizeof(struct __sha256_ctx) + 1 == SHA256_SHASH_STATE_SIZE); + +static int __crypto_sha256_export(const struct __sha256_ctx *ctx0, void *out) +{ + struct __sha256_ctx ctx = *ctx0; + unsigned int partial; + u8 *p = out; + + partial = ctx.bytecount % SHA256_BLOCK_SIZE; + ctx.bytecount -= partial; + memcpy(p, &ctx, sizeof(ctx)); + p += sizeof(ctx); + *p = partial; + return 0; +} + +static int __crypto_sha256_import(struct __sha256_ctx *ctx, const void *in) +{ + const u8 *p = in; + + memcpy(ctx, p, sizeof(*ctx)); + p += sizeof(*ctx); + ctx->bytecount += *p; + return 0; +} + /* SHA-224 */ const u8 sha224_zero_message_hash[SHA224_DIGEST_SIZE] = { @@ -51,6 +88,16 @@ static int crypto_sha224_digest(struct shash_desc *desc, return 0; } +static int crypto_sha224_export(struct shash_desc *desc, void *out) +{ + return __crypto_sha256_export(&SHA224_CTX(desc)->ctx, out); +} + +static int crypto_sha224_import(struct shash_desc *desc, const void *in) +{ + return __crypto_sha256_import(&SHA224_CTX(desc)->ctx, in); +} + /* SHA-256 */ const u8 sha256_zero_message_hash[SHA256_DIGEST_SIZE] = { @@ -89,6 +136,16 @@ static int crypto_sha256_digest(struct shash_desc *desc, return 0; } +static int crypto_sha256_export(struct shash_desc *desc, void *out) +{ + return __crypto_sha256_export(&SHA256_CTX(desc)->ctx, out); +} + +static int crypto_sha256_import(struct shash_desc *desc, const void *in) +{ + return __crypto_sha256_import(&SHA256_CTX(desc)->ctx, in); +} + /* HMAC-SHA224 */ #define HMAC_SHA224_KEY(tfm) ((struct hmac_sha224_key *)crypto_shash_ctx(tfm)) @@ -128,6 +185,19 @@ static int crypto_hmac_sha224_digest(struct shash_desc *desc, return 0; } +static int crypto_hmac_sha224_export(struct shash_desc *desc, void *out) +{ + return __crypto_sha256_export(&HMAC_SHA224_CTX(desc)->ctx.sha_ctx, out); +} + +static int crypto_hmac_sha224_import(struct shash_desc *desc, const void *in) +{ + struct hmac_sha224_ctx *ctx = HMAC_SHA224_CTX(desc); + + ctx->ctx.ostate = HMAC_SHA224_KEY(desc->tfm)->key.ostate; + return __crypto_sha256_import(&ctx->ctx.sha_ctx, in); +} + /* HMAC-SHA256 */ #define HMAC_SHA256_KEY(tfm) ((struct hmac_sha256_key *)crypto_shash_ctx(tfm)) @@ -167,6 +237,19 @@ static int crypto_hmac_sha256_digest(struct shash_desc *desc, return 0; } +static int crypto_hmac_sha256_export(struct shash_desc *desc, void *out) +{ + return __crypto_sha256_export(&HMAC_SHA256_CTX(desc)->ctx.sha_ctx, out); +} + +static int crypto_hmac_sha256_import(struct shash_desc *desc, const void *in) +{ + struct hmac_sha256_ctx *ctx = HMAC_SHA256_CTX(desc); + + ctx->ctx.ostate = HMAC_SHA256_KEY(desc->tfm)->key.ostate; + return __crypto_sha256_import(&ctx->ctx.sha_ctx, in); +} + /* Algorithm definitions */ static struct shash_alg algs[] = { @@ -181,7 +264,10 @@ static struct shash_alg algs[] = { .update = crypto_sha224_update, .final = crypto_sha224_final, .digest = crypto_sha224_digest, + .export = crypto_sha224_export, + .import = crypto_sha224_import, .descsize = sizeof(struct sha224_ctx), + .statesize = SHA256_SHASH_STATE_SIZE, }, { .base.cra_name = "sha256", @@ -194,7 +280,10 @@ static struct shash_alg algs[] = { .update = crypto_sha256_update, .final = crypto_sha256_final, .digest = crypto_sha256_digest, + .export = crypto_sha256_export, + .import = crypto_sha256_import, .descsize = sizeof(struct sha256_ctx), + .statesize = SHA256_SHASH_STATE_SIZE, }, { .base.cra_name = "hmac(sha224)", @@ -209,7 +298,10 @@ static struct shash_alg algs[] = { .update = crypto_hmac_sha224_update, .final = crypto_hmac_sha224_final, .digest = crypto_hmac_sha224_digest, + .export = crypto_hmac_sha224_export, + .import = crypto_hmac_sha224_import, .descsize = sizeof(struct hmac_sha224_ctx), + .statesize = SHA256_SHASH_STATE_SIZE, }, { .base.cra_name = "hmac(sha256)", @@ -224,7 +316,10 @@ static struct shash_alg algs[] = { .update = crypto_hmac_sha256_update, .final = crypto_hmac_sha256_final, .digest = crypto_hmac_sha256_digest, + .export = crypto_hmac_sha256_export, + .import = crypto_hmac_sha256_import, .descsize = sizeof(struct hmac_sha256_ctx), + .statesize = SHA256_SHASH_STATE_SIZE, }, }; -- 2.47.2