Add basic support for parsing SSL/TLS cipher suite strings.

BUG=58831
TEST=net_unittests --gtest_filter=CipherSuiteNamesTest.Parse*

Review URL: http://codereview.chromium.org/7396014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@93134 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 57 insertions, 2 deletions

diff --git a/net/base/ssl_cipher_suite_names.cc b/net/base/ssl_cipher_suite_names.cc
index eb6fe46..b91bd0c 100644
--- a/net/base/ssl_cipher_suite_names.cc
+++ b/net/base/ssl_cipher_suite_names.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -7,6 +7,8 @@
 #include <stdlib.h>
 
 #include "base/logging.h"
+#include "base/string_number_conversions.h"
+#include "base/string_util.h"
 #include "net/base/ssl_connection_status_flags.h"
 
 // Rather than storing the names of all the ciphersuites we eliminate the
@@ -372,4 +374,16 @@ void SSLVersionToString(const char** name, int ssl_version) {
   }
 }
 
+bool ParseSSLCipherString(const std::string& cipher_string,
+                          uint16* cipher_suite) {
+  int value = 0;
+  if (cipher_string.size() == 6 &&
+      StartsWithASCII(cipher_string, "0x", false /* case insensitive */) &&
+      base::HexStringToInt(cipher_string, &value)) {
+    *cipher_suite = static_cast<uint16>(value);
+    return true;
+  }
+  return false;
+}
+
 }  // namespace net
diff --git a/net/base/ssl_cipher_suite_names.h b/net/base/ssl_cipher_suite_names.h
index deec529..f97b17f 100644
--- a/net/base/ssl_cipher_suite_names.h
+++ b/net/base/ssl_cipher_suite_names.h
@@ -6,6 +6,8 @@
 #define NET_BASE_SSL_CIPHER_SUITE_NAMES_H_
 #pragma once
 
+#include <string>
+
 #include "base/basictypes.h"
 #include "net/base/net_api.h"
 
@@ -34,6 +36,21 @@ NET_API void SSLCompressionToString(const char** name,
 // If the version is unknown, |name| is set to "???".
 NET_API void SSLVersionToString(const char** name, int ssl_version);
 
+// Parses a string literal that represents a SSL/TLS cipher suite.
+//
+// Supported literal forms:
+//   0xAABB, where AA is cipher_suite[0] and BB is cipher_suite[1], as
+//     defined in RFC 2246, Section 7.4.1.2. Unrecognized but parsable cipher
+//     suites in this form will not return an error.
+//
+// Returns true if the cipher suite was successfully parsed, storing the
+// result in |cipher_suite|.
+//
+// TODO(rsleevi): Support the full strings defined in the IANA TLS parameters
+// list.
+NET_API bool ParseSSLCipherString(const std::string& cipher_string,
+                                  uint16* cipher_suite);
+
 }  // namespace net
 
 #endif  // NET_BASE_SSL_CIPHER_SUITE_NAMES_H_
diff --git a/net/base/ssl_cipher_suite_names_unittest.cc b/net/base/ssl_cipher_suite_names_unittest.cc
index 3a9c2ee..03ceef6 100644
--- a/net/base/ssl_cipher_suite_names_unittest.cc
+++ b/net/base/ssl_cipher_suite_names_unittest.cc
@@ -1,8 +1,10 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/base/ssl_cipher_suite_names.h"
+
+#include "base/basictypes.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace net {
@@ -22,6 +24,28 @@ TEST(CipherSuiteNamesTest, Basic) {
   EXPECT_STREQ(mac, "???");
 }
 
+TEST(CipherSuiteNamesTest, ParseSSLCipherString) {
+  uint16 cipher_suite = 0;
+  EXPECT_TRUE(ParseSSLCipherString("0x0004", &cipher_suite));
+  EXPECT_EQ(0x00004u, cipher_suite);
+
+  EXPECT_TRUE(ParseSSLCipherString("0xBEEF", &cipher_suite));
+  EXPECT_EQ(0xBEEFu, cipher_suite);
+}
+
+TEST(CipherSuiteNamesTest, ParseSSLCipherStringFails) {
+  const char* const cipher_strings[] = {
+    "0004",
+    "0x004",
+    "0xBEEFY",
+  };
+
+  for (size_t i = 0; i < arraysize(cipher_strings); ++i) {
+    uint16 cipher_suite = 0;
+    EXPECT_FALSE(ParseSSLCipherString(cipher_strings[i], &cipher_suite));
+  }
+}
+
 }  // anonymous namespace
 
 }  // namespace net