crypto: arm64/sha-ce - implement export/import

When an ahash algorithm fallback to another ahash and that fallback is
shaXXX-CE, doing export/import lead to error like this:
alg: ahash: sha1-sun8i-ce export() overran state buffer on test vector 0, cfg=\"import/export\"

This is due to the descsize of shaxxx-ce being larger than struct shaxxx_state
off by an u32.
For fixing this, let's implement export/import which rip the finalize
variant instead of using generic export/import.

Fixes: 6ba6c74d ("arm64/crypto: SHA-224/SHA-256 using ARMv8 Crypto Extensions")
Fixes: 2c98833a ("arm64/crypto: SHA-1 using ARMv8 Crypto Extensions")
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/arm64/crypto/sha1-ce-glue.c

@@ -91,12 +91,32 @@ static int sha1_ce_final(struct shash_desc *desc, u8 *out)
 	return sha1_base_finish(desc, out);
 }
 
+static int sha1_ce_export(struct shash_desc *desc, void *out)
+{
+	struct sha1_ce_state *sctx = shash_desc_ctx(desc);
+
+	memcpy(out, &sctx->sst, sizeof(struct sha1_state));
+	return 0;
+}
+
+static int sha1_ce_import(struct shash_desc *desc, const void *in)
+{
+	struct sha1_ce_state *sctx = shash_desc_ctx(desc);
+
+	memcpy(&sctx->sst, in, sizeof(struct sha1_state));
+	sctx->finalize = 0;
+	return 0;
+}
+
 static struct shash_alg alg = {
 	.init			= sha1_base_init,
 	.update			= sha1_ce_update,
 	.final			= sha1_ce_final,
 	.finup			= sha1_ce_finup,
+	.import			= sha1_ce_import,
+	.export			= sha1_ce_export,
 	.descsize		= sizeof(struct sha1_ce_state),
+	.statesize		= sizeof(struct sha1_state),
 	.digestsize		= SHA1_DIGEST_SIZE,
 	.base			= {
 		.cra_name		= "sha1",

arch/arm64/crypto/sha2-ce-glue.c

@@ -109,12 +109,32 @@ static int sha256_ce_final(struct shash_desc *desc, u8 *out)
 	return sha256_base_finish(desc, out);
 }
 
+static int sha256_ce_export(struct shash_desc *desc, void *out)
+{
+	struct sha256_ce_state *sctx = shash_desc_ctx(desc);
+
+	memcpy(out, &sctx->sst, sizeof(struct sha256_state));
+	return 0;
+}
+
+static int sha256_ce_import(struct shash_desc *desc, const void *in)
+{
+	struct sha256_ce_state *sctx = shash_desc_ctx(desc);
+
+	memcpy(&sctx->sst, in, sizeof(struct sha256_state));
+	sctx->finalize = 0;
+	return 0;
+}
+
 static struct shash_alg algs[] = { {
 	.init			= sha224_base_init,
 	.update			= sha256_ce_update,
 	.final			= sha256_ce_final,
 	.finup			= sha256_ce_finup,
+	.export			= sha256_ce_export,
+	.import			= sha256_ce_import,
 	.descsize		= sizeof(struct sha256_ce_state),
+	.statesize		= sizeof(struct sha256_state),
 	.digestsize		= SHA224_DIGEST_SIZE,
 	.base			= {
 		.cra_name		= "sha224",
@@ -128,7 +148,10 @@ static struct shash_alg algs[] = { {
 	.update			= sha256_ce_update,
 	.final			= sha256_ce_final,
 	.finup			= sha256_ce_finup,
+	.export			= sha256_ce_export,
+	.import			= sha256_ce_import,
 	.descsize		= sizeof(struct sha256_ce_state),
+	.statesize		= sizeof(struct sha256_state),
 	.digestsize		= SHA256_DIGEST_SIZE,
 	.base			= {
 		.cra_name		= "sha256",