rijndael: refactor to reduce number of #ifdefs and branches

* cipher/rijndael-aesni.c (_gcry_aes_aesni_encrypt)
(_gcry_aes_aesni_decrypt): Make return stack burn depth.
* cipher/rijndael-amd64.S (_gcry_aes_amd64_encrypt_block)
(_gcry_aes_amd64_decrypt_block): Ditto.
* cipher/rijndael-arm.S (_gcry_aes_arm_encrypt_block)
(_gcry_aes_arm_decrypt_block): Ditto.
* cipher/rijndael-internal.h (RIJNDAEL_context_s)
(rijndael_cryptfn_t): New.
(RIJNDAEL_context): New members 'encrypt_fn' and 'decrypt_fn'.
* cipher/rijndael.c (_gcry_aes_amd64_encrypt_block)
(_gcry_aes_amd64_decrypt_block, _gcry_aes_aesni_encrypt)
(_gcry_aes_aesni_decrypt, _gcry_aes_arm_encrypt_block)
(_gcry_aes_arm_decrypt_block): Change prototypes.
(do_padlock_encrypt, do_padlock_decrypt): New.
(do_setkey): Separate key-length to rounds conversion from
HW features check; Add selection for ctx->encrypt_fn and
ctx->decrypt_fn.
(do_encrypt_aligned, do_decrypt_aligned): Move inside
'[!USE_AMD64_ASM && !USE_ARM_ASM]'; Move USE_AMD64_ASM and
USE_ARM_ASM to...
(do_encrypt, do_decrypt): ...here; Return stack depth; Remove second
temporary buffer from non-aligned input/output case.
(do_padlock): Move decrypt_flag to last argument; Return stack depth.
(rijndael_encrypt): Remove #ifdefs, just call ctx->encrypt_fn.
(_gcry_aes_cfb_enc, _gcry_aes_cbc_enc): Remove USE_PADLOCK; Call
ctx->encrypt_fn in place of do_encrypt/do_encrypt_aligned.
(_gcry_aes_ctr_enc): Call ctx->encrypt_fn in place of
do_encrypt_aligned; Make tmp buffer 16-byte aligned and wipe buffer
after use.
(rijndael_encrypt): Remove #ifdefs, just call ctx->decrypt_fn.
(_gcry_aes_cfb_dec): Remove USE_PADLOCK; Call ctx->decrypt_fn in place
of do_decrypt/do_decrypt_aligned.
(_gcry_aes_cbc_dec): Ditto; Make savebuf buffer 16-byte aligned.
--

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>

1 files changed, 9 insertions, 2 deletions

diff --git a/cipher/rijndael-internal.h b/cipher/rijndael-internal.h
index 762ea767..9898f0ca 100644
--- a/cipher/rijndael-internal.h
+++ b/cipher/rijndael-internal.h
@@ -74,9 +74,14 @@
 # endif
 #endif /* ENABLE_AESNI_SUPPORT */
 
+struct RIJNDAEL_context_s;
+
+typedef unsigned int (*rijndael_cryptfn_t)(const struct RIJNDAEL_context_s *ctx,
+                                           unsigned char *bx,
+                                           const unsigned char *ax);
 
 /* Our context object.  */
-typedef struct
+typedef struct RIJNDAEL_context_s
 {
   /* The first fields are the keyschedule arrays.  This is so that
      they are aligned on a 16 byte boundary if using gcc.  This
@@ -100,7 +105,7 @@ typedef struct
     PROPERLY_ALIGNED_TYPE dummy;
     byte keyschedule[MAXROUNDS+1][4][4];
   } u2;
-  int rounds;                /* Key-length-dependent number of rounds.  */
+  int rounds;                         /* Key-length-dependent number of rounds.  */
   unsigned int decryption_prepared:1; /* The decryption key schedule is available.  */
 #ifdef USE_PADLOCK
   unsigned int use_padlock:1;         /* Padlock shall be used.  */
@@ -108,6 +113,8 @@ typedef struct
 #ifdef USE_AESNI
   unsigned int use_aesni:1;           /* AES-NI shall be used.  */
 #endif /*USE_AESNI*/
+  rijndael_cryptfn_t encrypt_fn;
+  rijndael_cryptfn_t decrypt_fn;
 } RIJNDAEL_context ATTR_ALIGNED_16;
 
 /* Macros defining alias for the keyschedules.  */