Replace all uses of magic numbers when operating on OPENSSL_ia32_P[] by

meaningful constants in a private header file, so that reviewers can actually
get a chance to figure out what the code is attempting to do without knowing
all cpuid bits.

While there, turn it from an array of two 32-bit ints into a properly aligned
64-bit int.

Use of OPENSSL_ia32_P is now restricted to the assembler parts. C code will
now always use OPENSSL_cpu_caps() and check for the proper bits in the
whole 64-bit word it returns.

i386 tests and ok jsing@

1 files changed, 13 insertions, 6 deletions

diff --git a/src/lib/libcrypto/modes/gcm128.c b/src/lib/libcrypto/modes/gcm128.c
index 6f8a8dd7f4..95ee755f83 100644
--- a/src/lib/libcrypto/modes/gcm128.c
+++ b/src/lib/libcrypto/modes/gcm128.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: gcm128.c,v 1.14 2016/11/04 13:56:05 miod Exp $ */
+/* $OpenBSD: gcm128.c,v 1.15 2016/11/04 17:30:30 miod Exp $ */
 /* ====================================================================
  * Copyright (c) 2010 The OpenSSL Project.  All rights reserved.
  *
@@ -637,13 +637,19 @@ static void gcm_gmult_1bit(u64 Xi[2],const u64 H[2])
 
 #endif
 
+#if     defined(GHASH_ASM) && \
+        (defined(__i386)        || defined(__i386__)    || \
+         defined(__x86_64)      || defined(__x86_64__)  || \
+         defined(_M_IX86)       || defined(_M_AMD64)    || defined(_M_X64))
+#include "x86_arch.h"
+#endif
+
 #if     TABLE_BITS==4 && defined(GHASH_ASM)
 # if    (defined(__i386)        || defined(__i386__)    || \
          defined(__x86_64)      || defined(__x86_64__)  || \
          defined(_M_IX86)       || defined(_M_AMD64)    || defined(_M_X64))
 #  define GHASH_ASM_X86_OR_64
 #  define GCM_FUNCREF_4BIT
-extern unsigned int OPENSSL_ia32cap_P[2];
 
 void gcm_init_clmul(u128 Htable[16],const u64 Xi[2]);
 void gcm_gmult_clmul(u64 Xi[2],const u128 Htable[16]);
@@ -705,8 +711,9 @@ void CRYPTO_gcm128_init(GCM128_CONTEXT *ctx,void *key,block128_f block)
 #elif   TABLE_BITS==4
 # if    defined(GHASH_ASM_X86_OR_64)
 #  if   !defined(GHASH_ASM_X86) || defined(OPENSSL_IA32_SSE2)
-        if (OPENSSL_ia32cap_P[0]&(1<<24) &&     /* check FXSR bit */
-            OPENSSL_ia32cap_P[1]&(1<<1) ) {     /* check PCLMULQDQ bit */
+        /* check FXSR and PCLMULQDQ bits */
+        if ((OPENSSL_cpu_caps() & (CPUCAP_MASK_FXSR | CPUCAP_MASK_PCLMUL)) ==
+            (CPUCAP_MASK_FXSR | CPUCAP_MASK_PCLMUL)) {
                 gcm_init_clmul(ctx->Htable,ctx->H.u);
                 ctx->gmult = gcm_gmult_clmul;
                 ctx->ghash = gcm_ghash_clmul;
@@ -716,9 +723,9 @@ void CRYPTO_gcm128_init(GCM128_CONTEXT *ctx,void *key,block128_f block)
         gcm_init_4bit(ctx->Htable,ctx->H.u);
 #  if   defined(GHASH_ASM_X86)                  /* x86 only */
 #   if  defined(OPENSSL_IA32_SSE2)
-        if (OPENSSL_ia32cap_P[0]&(1<<25)) {     /* check SSE bit */
+        if (OPENSSL_cpu_caps() & CPUCAP_MASK_SSE) {     /* check SSE bit */
 #   else
-        if (OPENSSL_ia32cap_P[0]&(1<<23)) {     /* check MMX bit */
+        if (OPENSSL_cpu_caps() & CPUCAP_MASK_MMX) {     /* check MMX bit */
 #   endif
                 ctx->gmult = gcm_gmult_4bit_mmx;
                 ctx->ghash = gcm_ghash_4bit_mmx;