[PATCH] crypto: s390/sha3 - Use cpu byte-order when exporting

[Herbert Xu <herbert@gondor.apana.org.au>]

On Fri, May 23, 2025 at 02:03:23PM +0200, Ingo Franzki wrote:
>
> I hope you can sort it out what belongs to what.

Please let me know if this patch works or not:

---8<---
The sha3 partial hash on s390 is in little-endian just like the
final hash.  However the generic implementation produces native
or big-endian partial hashes.

Make s390 sha3 conform to that by doing the byte-swap on export
and import.

Reported-by: Ingo Franzki <ifranzki@linux.ibm.com>
Fixes: 6f90ba706551 ("crypto: s390/sha3 - Use API partial block handling")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/arch/s390/crypto/sha.h b/arch/s390/crypto/sha.h
index d757ccbce2b4..cadb4b13622a 100644
--- a/arch/s390/crypto/sha.h
+++ b/arch/s390/crypto/sha.h
@@ -27,6 +27,9 @@ struct s390_sha_ctx {
 			u64 state[SHA512_DIGEST_SIZE / sizeof(u64)];
 			u64 count_hi;
 		} sha512;
+		struct {
+			__le64 state[SHA3_STATE_SIZE / sizeof(u64)];
+		} sha3;
 	};
 	int func;		/* KIMD function to use */
 	bool first_message_part;
diff --git a/arch/s390/crypto/sha3_256_s390.c b/arch/s390/crypto/sha3_256_s390.c
index 4a7731ac6bcd..03bb4f4bab70 100644
--- a/arch/s390/crypto/sha3_256_s390.c
+++ b/arch/s390/crypto/sha3_256_s390.c
@@ -35,23 +35,33 @@ static int sha3_256_init(struct shash_desc *desc)
 static int sha3_256_export(struct shash_desc *desc, void *out)
 {
 	struct s390_sha_ctx *sctx = shash_desc_ctx(desc);
-	struct sha3_state *octx = out;
+	union {
+		u8 *u8;
+		u64 *u64;
+	} p = { .u8 = out };
+	int i;
 
 	if (sctx->first_message_part) {
-		memset(sctx->state, 0, sizeof(sctx->state));
-		sctx->first_message_part = 0;
+		memset(out, 0, SHA3_STATE_SIZE);
+		return 0;
 	}
-	memcpy(octx->st, sctx->state, sizeof(octx->st));
+	for (i = 0; i < SHA3_STATE_SIZE / 8; i++)
+		put_unaligned(le64_to_cpu(sctx->sha3.state[i]), p.u64++);
 	return 0;
 }
 
 static int sha3_256_import(struct shash_desc *desc, const void *in)
 {
 	struct s390_sha_ctx *sctx = shash_desc_ctx(desc);
-	const struct sha3_state *ictx = in;
+	union {
+		const u8 *u8;
+		const u64 *u64;
+	} p = { .u8 = in };
+	int i;
 
+	for (i = 0; i < SHA3_STATE_SIZE / 8; i++)
+		sctx->sha3.state[i] = cpu_to_le64(get_unaligned(p.u64++));
 	sctx->count = 0;
-	memcpy(sctx->state, ictx->st, sizeof(ictx->st));
 	sctx->first_message_part = 0;
 	sctx->func = CPACF_KIMD_SHA3_256;
 
diff --git a/arch/s390/crypto/sha3_512_s390.c b/arch/s390/crypto/sha3_512_s390.c
index 018f02fff444..a5c9690eecb1 100644
--- a/arch/s390/crypto/sha3_512_s390.c
+++ b/arch/s390/crypto/sha3_512_s390.c
@@ -34,24 +34,33 @@ static int sha3_512_init(struct shash_desc *desc)
 static int sha3_512_export(struct shash_desc *desc, void *out)
 {
 	struct s390_sha_ctx *sctx = shash_desc_ctx(desc);
-	struct sha3_state *octx = out;
-
+	union {
+		u8 *u8;
+		u64 *u64;
+	} p = { .u8 = out };
+	int i;
 
 	if (sctx->first_message_part) {
-		memset(sctx->state, 0, sizeof(sctx->state));
-		sctx->first_message_part = 0;
+		memset(out, 0, SHA3_STATE_SIZE);
+		return 0;
 	}
-	memcpy(octx->st, sctx->state, sizeof(octx->st));
+	for (i = 0; i < SHA3_STATE_SIZE / 8; i++)
+		put_unaligned(le64_to_cpu(sctx->sha3.state[i]), p.u64++);
 	return 0;
 }
 
 static int sha3_512_import(struct shash_desc *desc, const void *in)
 {
 	struct s390_sha_ctx *sctx = shash_desc_ctx(desc);
-	const struct sha3_state *ictx = in;
+	union {
+		const u8 *u8;
+		const u64 *u64;
+	} p = { .u8 = in };
+	int i;
 
+	for (i = 0; i < SHA3_STATE_SIZE / 8; i++)
+		sctx->sha3.state[i] = cpu_to_le64(get_unaligned(p.u64++));
 	sctx->count = 0;
-	memcpy(sctx->state, ictx->st, sizeof(ictx->st));
 	sctx->first_message_part = 0;
 	sctx->func = CPACF_KIMD_SHA3_512;
 
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt