Commit 07f09095 authored by Eric Biggers's avatar Eric Biggers
Browse files

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: default avatarArd Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250630160645.3198-11-ebiggers@kernel.org


Signed-off-by: default avatarEric Biggers <ebiggers@kernel.org>
parent e0cd3716

crypto/sha256.c

+95 −0
Original line number Diff line number Diff line
@@ -13,6 +13,43 @@ 
#include <linux/kernel.h>

#include <linux/module.h>



/*

 * 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,

	},

};