Use separate function to get GCM functions

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18835)

(cherry picked from commit 92c9086e5c2b63606cd28a7f13f09b9ff35a0de3)

2 files changed, 13 insertions, 6 deletions

diff --git a/include/crypto/aes_platform.h b/include/crypto/aes_platform.h
index e10c076d87..3e26463f7d 100644
--- a/include/crypto/aes_platform.h
+++ b/include/crypto/aes_platform.h
@@ -92,7 +92,7 @@ size_t ppc_aes_gcm_decrypt_wrap(const unsigned char *in, unsigned char *out,
 #   define AES_gcm_encrypt ppc_aes_gcm_encrypt_wrap
 #   define AES_gcm_decrypt ppc_aes_gcm_decrypt_wrap
 #   define AES_GCM_ASM(gctx) ((gctx)->ctr==aes_p8_ctr32_encrypt_blocks && \
-                              (gctx)->gcm.ghash==gcm_ghash_p8)
+                              (gctx)->gcm.funcs.ghash==gcm_ghash_p8)
 void gcm_ghash_p8(u64 Xi[2],const u128 Htable[16],const u8 *inp, size_t len);
 #  endif /* PPC */
 
@@ -124,7 +124,7 @@ void gcm_ghash_p8(u64 Xi[2],const u128 Htable[16],const u8 *inp, size_t len);
 #     define AES_gcm_encrypt armv8_aes_gcm_encrypt
 #     define AES_gcm_decrypt armv8_aes_gcm_decrypt
 #     define AES_GCM_ASM(gctx) ((gctx)->ctr==aes_v8_ctr32_encrypt_blocks && \
-                                (gctx)->gcm.ghash==gcm_ghash_v8)
+                                (gctx)->gcm.funcs.ghash==gcm_ghash_v8)
 size_t aes_gcm_enc_128_kernel(const uint8_t * plaintext, uint64_t plaintext_length, uint8_t * ciphertext,
                               uint64_t *Xi, unsigned char ivec[16], const void *key);
 size_t aes_gcm_enc_192_kernel(const uint8_t * plaintext, uint64_t plaintext_length, uint8_t * ciphertext,
@@ -258,7 +258,7 @@ void gcm_ghash_avx(u64 Xi[2], const u128 Htable[16], const u8 *in, size_t len);
 #   define AES_gcm_encrypt aesni_gcm_encrypt
 #   define AES_gcm_decrypt aesni_gcm_decrypt
 #   define AES_GCM_ASM(ctx)    (ctx->ctr == aesni_ctr32_encrypt_blocks && \
-                                ctx->gcm.ghash == gcm_ghash_avx)
+                                ctx->gcm.funcs.ghash == gcm_ghash_avx)
 #  endif
 
 
diff --git a/include/crypto/modes.h b/include/crypto/modes.h
index b1179c6357..d5c5c193c7 100644
--- a/include/crypto/modes.h
+++ b/include/crypto/modes.h
@@ -107,6 +107,15 @@ _asm mov eax, val _asm bswap eax}
     u64 hi, lo;
 } u128;
 
+typedef void (*gcm_init_fn)(u128 Htable[16], const u64 H[2]);
+typedef void (*gcm_ghash_fn)(u64 Xi[2], const u128 Htable[16], const u8 *inp, size_t len);
+typedef void (*gcm_gmult_fn)(u64 Xi[2], const u128 Htable[16]);
+struct gcm_funcs_st {
+    gcm_init_fn ginit;
+    gcm_ghash_fn ghash;
+    gcm_gmult_fn gmult;
+};
+
 struct gcm128_context {
     /* Following 6 names follow names in GCM specification */
     union {
@@ -120,9 +129,7 @@ struct gcm128_context {
      * used in some assembler modules, i.e. don't change the order!
      */
     u128 Htable[16];
-    void (*gmult) (u64 Xi[2], const u128 Htable[16]);
-    void (*ghash) (u64 Xi[2], const u128 Htable[16], const u8 *inp,
-                   size_t len);
+    struct gcm_funcs_st funcs;
     unsigned int mres, ares;
     block128_f block;
     void *key;