Provide method for returning certificate expiration timestamp.

webrtc/base/sslidentity_unittest.cc

Index: webrtc/base/sslidentity_unittest.cc
diff --git a/webrtc/base/sslidentity_unittest.cc b/webrtc/base/sslidentity_unittest.cc
index e8df41506ba90383e9ca89969e75b5b20fe38eeb..cc0f7f8a3cb1cf6c3b1db0a983e042d635bd519b 100644
--- a/webrtc/base/sslidentity_unittest.cc
+++ b/webrtc/base/sslidentity_unittest.cc
@@ -11,6 +11,7 @@
 #include <string>
 
 #include "webrtc/base/gunit.h"
+#include "webrtc/base/helpers.h"
 #include "webrtc/base/ssladapter.h"
 #include "webrtc/base/sslidentity.h"
 
@@ -295,3 +296,33 @@ TEST_F(SSLIdentityTest, PemDerConversion) {
 TEST_F(SSLIdentityTest, GetSignatureDigestAlgorithm) {
   TestGetSignatureDigestAlgorithm();
 }
+
+class SSLIdentityExpirationTest : public testing::Test {
+ public:
+  SSLIdentityExpirationTest() {}
+  ~SSLIdentityExpirationTest() {}
+
+  void TestExpireTime(int times) {
+    for (int i = 0; i < times; i++) {
+      rtc::SSLIdentityParams params;
+      params.common_name = "";
+      params.not_before = 0;
+      // We limit the time to < 2^31 here, i.e., we stay before 2038, since else
+      // we hit time offset limitations in OpenSSL on some 32-bit systems.
+      params.not_after = rtc::CreateRandomId() % 0x80000000;
+      // We test just ECDSA here since what we're out to exercise here is the
+      // code for expiration setting and reading.
+      params.key_params = rtc::KeyParams::ECDSA(rtc::EC_NIST_P256);
+      SSLIdentity* identity = rtc::SSLIdentity::GenerateForTest(params);
+      EXPECT_EQ(params.not_after,
+                identity->certificate().CertificateExpirationTime());
+      delete identity;
+    }
+  }
+};
+
+TEST_F(SSLIdentityExpirationTest, Test) {
+  rtc::SetRandomTestMode(true);
+  TestExpireTime(500);

[hbos, 2015/11/26 16:43:37]

If TestExpireTime(500) fails, will the effects of SetRandomTestMode(true) last
for other tests that might run after it?

I'm thinking maybe the SetRandomTestMode stuff should happen in the
constructor/destructor?

+  rtc::SetRandomTestMode(false);
+}