commit 41c10e2b5f37edce8b9f292f7f3bacb7e30e25c4
author David Benjamin <davidben@google.com> Sun Dec 16 00:03:53 2018 -0600
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> Mon Dec 17 17:54:07 2018 +0000
tree 10bb7ed260b06c4f062562a81e9df8166d67ffcb
parent e1b2a65e7f46e7b39df27f09ffa22b6b4021b282

Disable AES-GCM-SIV assembly on Windows.

I'm working on a test harness to check our assembly correctly restores
callee-saved registers. It caught this.

While perlasm tries to smooth over the differences between Windows and SysV
ABIs, it does not capture the difference in xmm registers. All xmm registers
are volatile in SysV, while Windows makes xmm6 through xmm15 callee-saved.

Change-Id: Ia549b0f126885768f7fb330271a590174c483a3d
Reviewed-on: https://boringssl-review.googlesource.com/c/33685
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

crypto/cipher_extra/e_aesgcmsiv.c

diff --git a/crypto/cipher_extra/e_aesgcmsiv.c b/crypto/cipher_extra/e_aesgcmsiv.c
index e3534bb..71a71fa 100644
--- a/crypto/cipher_extra/e_aesgcmsiv.c
+++ b/crypto/cipher_extra/e_aesgcmsiv.c
@@ -27,7 +27,11 @@
 #define EVP_AEAD_AES_GCM_SIV_NONCE_LEN 12
 #define EVP_AEAD_AES_GCM_SIV_TAG_LEN 16
 
-#if defined(OPENSSL_X86_64) && !defined(OPENSSL_NO_ASM)
+// TODO(davidben): AES-GCM-SIV assembly is not correct for Windows. It must save
+// and restore xmm6 through xmm15.
+#if defined(OPENSSL_X86_64) && !defined(OPENSSL_NO_ASM) && \
+    !defined(OPENSSL_WINDOWS)
+#define AES_GCM_SIV_ASM
 
 // Optimised AES-GCM-SIV
 
@@ -549,7 +553,7 @@
     NULL /* tag_len */,
 };
 
-#endif  // X86_64 && !NO_ASM
+#endif  // X86_64 && !NO_ASM && !WINDOWS
 
 struct aead_aes_gcm_siv_ctx {
   union {
@@ -838,7 +842,7 @@
     NULL /* tag_len */,
 };
 
-#if defined(OPENSSL_X86_64) && !defined(OPENSSL_NO_ASM)
+#if defined(AES_GCM_SIV_ASM)
 
 static char avx_aesni_capable(void) {
   const uint32_t ecx = OPENSSL_ia32cap_P[1];
@@ -871,4 +875,4 @@
   return &aead_aes_256_gcm_siv;
 }
 
-#endif  // X86_64 && !NO_ASM
+#endif  // AES_GCM_SIV_ASM