Do not distinguish NULL and empty PSK identity hints.
Plain PSK omits the ServerKeyExchange when there is no hint and includes
it otherwise (it should have always sent it), while other PSK ciphers
like ECDHE_PSK cannot omit the hint. Having different capabilities here
is odd and RFC 4279 5.2 suggests that all PSK ciphers are capable of
"[not] provid[ing] an identity hint".
Interpret this to mean no identity hint and empty identity hint are the
same state. Annoyingly, this gives a plain PSK implementation two
options for spelling an empty hint. The spec isn't clear and this is not
really a battle worth fighting, so I've left both acceptable and added a
test for this case.
See also https://android-review.googlesource.com/c/275217/. This is also
consistent with Android's PskKeyManager API, our only consumer anyway.
https://developer.android.com/reference/android/net/PskKeyManager.html
Change-Id: I8a8e6cc1f7dd1b8b202cdaf3d4f151bebfb4a25b
Reviewed-on: https://boringssl-review.googlesource.com/11087
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@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 8e107aa..feef62c 100644
--- a/ssl/test/runner/runner.go
+++ b/ssl/test/runner/runner.go
@@ -2567,6 +2567,32 @@
},
})
+ // Test empty ECDHE_PSK identity hints work as expected.
+ testCases = append(testCases, testCase{
+ name: "EmptyECDHEPSKHint",
+ config: Config{
+ MaxVersion: VersionTLS12,
+ CipherSuites: []uint16{TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA},
+ PreSharedKey: []byte("secret"),
+ },
+ flags: []string{"-psk", "secret"},
+ })
+
+ // Test empty PSK identity hints work as expected, even if an explicit
+ // ServerKeyExchange is sent.
+ testCases = append(testCases, testCase{
+ name: "ExplicitEmptyPSKHint",
+ config: Config{
+ MaxVersion: VersionTLS12,
+ CipherSuites: []uint16{TLS_PSK_WITH_AES_128_CBC_SHA},
+ PreSharedKey: []byte("secret"),
+ Bugs: ProtocolBugs{
+ AlwaysSendPreSharedKeyIdentityHint: true,
+ },
+ },
+ flags: []string{"-psk", "secret"},
+ })
+
// versionSpecificCiphersTest specifies a test for the TLS 1.0 and TLS
// 1.1 specific cipher suite settings. A server is setup with the given
// cipher lists and then a connection is made for each member of