Add tests for PSK cipher suites.

Only the three plain PSK suites for now. ECDHE_PSK_WITH_AES_128_GCM_SHA256 will
be in a follow-up.

Change-Id: Iafc116a5b2798c61d90c139b461cf98897ae23b3
Reviewed-on: https://boringssl-review.googlesource.com/2051
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/test/runner/common.go b/ssl/test/runner/common.go
index 935fd15..4aa21bb 100644
--- a/ssl/test/runner/common.go
+++ b/ssl/test/runner/common.go
@@ -325,6 +325,14 @@
 	// returned in the ConnectionState.
 	RequestChannelID bool
 
+	// PreSharedKey, if not nil, is the pre-shared key to use with
+	// the PSK cipher suites.
+	PreSharedKey []byte
+
+	// PreSharedKeyIdentity, if not empty, is the identity to use
+	// with the PSK cipher suites.
+	PreSharedKeyIdentity string
+
 	// Bugs specifies optional misbehaviour to be used for testing other
 	// implementations.
 	Bugs ProtocolBugs
@@ -737,9 +745,10 @@
 }
 
 func initDefaultCipherSuites() {
-	varDefaultCipherSuites = make([]uint16, len(cipherSuites))
-	for i, suite := range cipherSuites {
-		varDefaultCipherSuites[i] = suite.id
+	for _, suite := range cipherSuites {
+		if suite.flags&suitePSK == 0 {
+			varDefaultCipherSuites = append(varDefaultCipherSuites, suite.id)
+		}
 	}
 }