Add a few more tests around processing the server PSK extension.

The server acknowledging a non-existent session is a particularly
interesting case since getting it wrong means a NULL crash.

Change-Id: Iabde4955de883595239cfd8e9d84a7711e60a886
Reviewed-on: https://boringssl-review.googlesource.com/11500
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: Steven Valdez <svaldez@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
diff --git a/ssl/test/runner/runner.go b/ssl/test/runner/runner.go
index e164843..248c6eb 100644
--- a/ssl/test/runner/runner.go
+++ b/ssl/test/runner/runner.go
@@ -8559,6 +8559,31 @@
 		shouldFail:    true,
 		expectedError: ":DECODE_ERROR:",
 	})
+
+	testCases = append(testCases, testCase{
+		name: "TLS13-AlwaysSelectPSKIdentity",
+		config: Config{
+			MaxVersion: VersionTLS13,
+			Bugs: ProtocolBugs{
+				AlwaysSelectPSKIdentity: true,
+			},
+		},
+		shouldFail:    true,
+		expectedError: ":UNEXPECTED_EXTENSION:",
+	})
+
+	testCases = append(testCases, testCase{
+		name: "TLS13-InvalidPSKIdentity",
+		config: Config{
+			MaxVersion: VersionTLS13,
+			Bugs: ProtocolBugs{
+				SelectPSKIdentityOnResume: 1,
+			},
+		},
+		resumeSession: true,
+		shouldFail:    true,
+		expectedError: ":PSK_IDENTITY_NOT_FOUND:",
+	})
 }
 
 func addPeekTests() {