Add functions to allow the mocking of AES hw support for testing.

Bug: 586
Change-Id: I5bc8e6df3a5a14e6b218f41181d06406e835f9c1
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/58605
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Bob Beck <bbe@google.com>

ssl/ssl_lib.cc

diff --git a/ssl/ssl_lib.cc b/ssl/ssl_lib.cc
index 86e8eb3..c035825 100644
--- a/ssl/ssl_lib.cc
+++ b/ssl/ssl_lib.cc
@@ -484,6 +484,17 @@
   return true;
 }
 
+void SSL_CTX_set_aes_hw_override_for_testing(SSL_CTX *ctx,
+                                             bool override_value) {
+  ctx->aes_hw_override = true;
+  ctx->aes_hw_override_value = override_value;
+}
+
+void SSL_set_aes_hw_override_for_testing(SSL *ssl, bool override_value) {
+  ssl->config->aes_hw_override = true;
+  ssl->config->aes_hw_override_value = override_value;
+}
+
 BSSL_NAMESPACE_END
 
 using namespace bssl;
@@ -525,7 +536,9 @@
       false_start_allowed_without_alpn(false),
       handoff(false),
       enable_early_data(false),
-      only_fips_cipher_suites_in_tls13(false) {
+      only_fips_cipher_suites_in_tls13(false),
+      aes_hw_override(false),
+      aes_hw_override_value(false) {
   CRYPTO_MUTEX_init(&lock);
   CRYPTO_new_ex_data(&ex_data);
 }
@@ -647,6 +660,8 @@
   ssl->config->permute_extensions = ctx->permute_extensions;
   ssl->config->only_fips_cipher_suites_in_tls13 =
       ctx->only_fips_cipher_suites_in_tls13;
+  ssl->config->aes_hw_override = ctx->aes_hw_override;
+  ssl->config->aes_hw_override_value = ctx->aes_hw_override_value;
 
   if (!ssl->config->supported_group_list.CopyFrom(ctx->supported_group_list) ||
       !ssl->config->alpn_client_proto_list.CopyFrom(
@@ -2026,18 +2041,27 @@
 }
 
 int SSL_CTX_set_cipher_list(SSL_CTX *ctx, const char *str) {
-  return ssl_create_cipher_list(&ctx->cipher_list, str, false /* not strict */);
+  const bool has_aes_hw = ctx->aes_hw_override ? ctx->aes_hw_override_value
+                                               : EVP_has_aes_hardware();
+  return ssl_create_cipher_list(&ctx->cipher_list, has_aes_hw, str,
+                                false /* not strict */);
 }
 
 int SSL_CTX_set_strict_cipher_list(SSL_CTX *ctx, const char *str) {
-  return ssl_create_cipher_list(&ctx->cipher_list, str, true /* strict */);
+  const bool has_aes_hw = ctx->aes_hw_override ? ctx->aes_hw_override_value
+                                               : EVP_has_aes_hardware();
+  return ssl_create_cipher_list(&ctx->cipher_list, has_aes_hw, str,
+                                true /* strict */);
 }
 
 int SSL_set_cipher_list(SSL *ssl, const char *str) {
   if (!ssl->config) {
     return 0;
   }
-  return ssl_create_cipher_list(&ssl->config->cipher_list, str,
+  const bool has_aes_hw = ssl->config->aes_hw_override
+                              ? ssl->config->aes_hw_override_value
+                              : EVP_has_aes_hardware();
+  return ssl_create_cipher_list(&ssl->config->cipher_list, has_aes_hw, str,
                                 false /* not strict */);
 }
 
@@ -2045,7 +2069,10 @@
   if (!ssl->config) {
     return 0;
   }
-  return ssl_create_cipher_list(&ssl->config->cipher_list, str,
+  const bool has_aes_hw = ssl->config->aes_hw_override
+                              ? ssl->config->aes_hw_override_value
+                              : EVP_has_aes_hardware();
+  return ssl_create_cipher_list(&ssl->config->cipher_list, has_aes_hw, str,
                                 true /* strict */);
 }