crypto: sha256: Add mechanism to keep C code as fallback for SHA256_ASM

Currently, architectures have to decide if they want the C code or an
arch-specific implementation. Let's add a macro, that allows to keep the C
code even if SHA256_ASM is defined (but rename it from sha256_block_data_order
to sha256_block_data_order_c). The macro INCLUDE_C_SHA256 can be used by
architectures, that want the C code as fallback code.

Signed-off-by: Charalampos Mitrodimas <charalampos.mitrodimas@vrull.eu>
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Hugo Landau <hlandau@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21923)

diff --git a/crypto/sha/sha256.c b/crypto/sha/sha256.c
index 4017137c270134d2b526057003317be1c53a17c9..6ef218e86e3decb939465e402f03895ab3a3f1f6 100644 (file)
--- a/crypto/sha/sha256.c
+++ b/crypto/sha/sha256.c
@@ -116,12 +116,16 @@ int SHA224_Final(unsigned char *md, SHA256_CTX *c)
 #define HASH_BLOCK_DATA_ORDER   sha256_block_data_order
 #ifndef SHA256_ASM
 static
-#endif
+#else
+# ifdef INCLUDE_C_SHA256
+void sha256_block_data_order_c(SHA256_CTX *ctx, const void *in, size_t num);
+# endif /* INCLUDE_C_SHA256 */
+#endif /* SHA256_ASM */
 void sha256_block_data_order(SHA256_CTX *ctx, const void *in, size_t num);
 
 #include "crypto/md32_common.h"
 
-#ifndef SHA256_ASM
+#if !defined(SHA256_ASM) || defined(INCLUDE_C_SHA256)
 static const SHA_LONG K256[64] = {
     0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,
     0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,
@@ -279,8 +283,12 @@ static void sha256_block_data_order(SHA256_CTX *ctx, const void *in,
         T1 = X[(i)&0x0f] += s0 + s1 + X[(i+9)&0x0f];    \
         ROUND_00_15(i,a,b,c,d,e,f,g,h);         } while (0)
 
+#ifdef INCLUDE_C_SHA256
+void sha256_block_data_order_c(SHA256_CTX *ctx, const void *in, size_t num)
+#else
 static void sha256_block_data_order(SHA256_CTX *ctx, const void *in,
                                     size_t num)
+#endif
 {
     unsigned MD32_REG_T a, b, c, d, e, f, g, h, s0, s1, T1;
     SHA_LONG X[16];