From ac7670aa24f4be8b3d1c89db53c6e7c598b86dea Mon Sep 17 00:00:00 2001 From: Peter Dettman Date: Wed, 5 Jul 2023 09:48:49 +0700 Subject: TLS: extra client validation of ServerHello parameters --- crypto/src/tls/TlsClientProtocol.cs | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'crypto/src') diff --git a/crypto/src/tls/TlsClientProtocol.cs b/crypto/src/tls/TlsClientProtocol.cs index 99d088622..cff541db3 100644 --- a/crypto/src/tls/TlsClientProtocol.cs +++ b/crypto/src/tls/TlsClientProtocol.cs @@ -1112,6 +1112,16 @@ namespace Org.BouncyCastle.Tls m_tlsClient.NotifySessionID(selectedSessionID); securityParameters.m_resumedSession = selectedSessionID.Length > 0 && m_tlsSession != null && Arrays.AreEqual(selectedSessionID, m_tlsSession.SessionID); + + if (securityParameters.IsResumedSession) + { + if (serverHello.CipherSuite != m_sessionParameters.CipherSuite || + !securityParameters.NegotiatedVersion.Equals(m_sessionParameters.NegotiatedVersion)) + { + throw new TlsFatalAlert(AlertDescription.illegal_parameter, + "ServerHello parameters do not match resumed session"); + } + } } /* @@ -1124,7 +1134,8 @@ namespace Org.BouncyCastle.Tls if (!TlsUtilities.IsValidCipherSuiteSelection(offeredCipherSuites, cipherSuite) || !TlsUtilities.IsValidVersionForCipherSuite(cipherSuite, securityParameters.NegotiatedVersion)) { - throw new TlsFatalAlert(AlertDescription.illegal_parameter); + throw new TlsFatalAlert(AlertDescription.illegal_parameter, + "ServerHello selected invalid cipher suite"); } TlsUtilities.NegotiatedCipherSuite(securityParameters, cipherSuite); -- cgit 1.4.1