We have been contacted. The "Is initial handshake:" is the start of the handshake
Is initial handshake: true
JsseJCE: Using AlgorithmParameters EC from provider IBMJCE version 1.8
JsseJCE: Using AlgorithmParameters EC from provider IBMJCE version 1.8
JsseJCE: Using AlgorithmParameters EC from provider IBMJCE version 1.8
JsseJCE: Using AlgorithmParameters EC from provider IBMJCE version 1.8
Read the data
Default Executor-thread-14, READ: TLSv1.2 Handshake, length = 280
Display what server has been sent
ClientHello is the name of the first part of the handshake.
Display the data in the handshake
*** ClientHello, TLSv1.2
RandomCookie:
GMT: 1604819291
bytes = {...}
Session ID:{}
The following is the list of cipher suites the client will accept
Cipher Suites: [SSL_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, SSL_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, SSL_ECDHE_RSA_WITH_AES_256_GCM_SHA384, ...}
Compression Methods: { }
Unsupported extension status_request, data: 01:00:00:00:00
Extension elliptic_curves, curve names: {secp256r1, secp384r1, secp521r1, unknown curve 256, unknown curve 257, unknown curve 258, unknown curve 259, unknown curve 260}
Extension ec_point_formats, formats: [uncompressed]
Extension signature_algorithms, signature_algorithms: SHA256withECDSA, SHA384withECDSA, SHA512withECDSA, Unknown (hash:0x8, signature:0x4), Unknown (hash:0x8, signature:0x5), Unknown (hash:0x8, signature:0x6), Unknown (hash:0x8, signature:0x9), Unknown (hash:0x8, signature:0xa), ...
For extension types, see here or look at the midrange trace.
Unsupported extension type_50, data: 00:26:04:03:...
Unsupported extension type_17, data: 00:07:02:00:04:00:00:00:00
Extension extended_master_secret
Unsupported extension type_43, data: 02:03:03
End of the data in the initial handshake
***
ALPN – can be ignored
Application-Layer Protocol Negotiation (ALPN) is a Transport Layer Security (TLS) extension that allows the application layer to negotiate which protocol should be performed over a secure connection in a manner that avoids additional round trips and which is independent of the application-layer protocols. It is needed by secure HTTP/2 connections, which improves the compression of web pages and reduces their latency compared to HTTP/1.x.
ALPN not supported, no protocols set
ALPN will not be negotiated6558e265[SSLEngine[hostname=null port=-1] SSL_NULL_WITH_NULL_NULL]
%% Initialized: [Session-1, SSL_NULL_WITH_NULL_NULL]
End of ALPN
The client sent up TLS 1.3 in the supported_versions of the clientHello message, but the server is only configured for TLS 1.2
Fatal (PROTOCOL_VERSION): The client supported protocol versions [TLSv1.3] are not accepted by server preferences [TLS12]
Fatal (PROTOCOL_VERSION): The client supported protocol
versions [TLSv1.3] are not accepted by server preferences [TLS12]
The first three cipher suites (above) were SSL_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, SSL_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, SSL_ECDHE_RSA_WITH_AES_256_GCM_SHA384.
The first is …_ECDSA…, the second is …_ECDSA.., the third is …_RSA_…
- SSL or TLS,
- the protocol ECDHE
- Key exchange algorithm ECDSA
- Authentication/Digital Signature Algorithm: What sort of certificate can be used. ECDSA the server public key is an Elliptic Curve signifies. ECDSA is Elliptic Curve + Digital Signing Algorithm.
- RSA the server public key is created with RSA public certificate.
- “WITH”
- AES_256_GCM the bulk encryption algorithm: Once the handshake has completed, the encryption of the payload is done using symmetric encryption.
- SHA384 indicates the algorithm for hashing the message
Check to see if the server has a compatible certificate to use. If “Alias” has not been specified
- For each cipher spec in the list,
- Extract the key exchange EC DSA etc
- ..For each certificate in the keystore
- …. get the list of alias names which match both
- …. pick one
For Key exchange we have (from above) EC, EC, RSA
ssl: ServerHandshaker.setupPrivateKeyAndChain EC matching alias: BPECCBPECC matching alias: TBPECC192 matching alias: NISTECC5 matching alias: TBPECC160 matching alias: TBPECC320 matching alias: BPECC matching alias: TBPECC512 matching alias: TBPECC256 matching alias: TNISTECC384 matching alias: TBPECC224 matching alias: NISTECC521 matching alias: TNISTECC224 matching alias: TNISTECC521 matching alias: TNISTECC256 matching alias: NISTECC matching alias: BPECC3 matching alias: TNISTECC192 ssl: ServerHandshaker.setupPrivateKeyAndChain, chooseEngineServerAlias BPECCBPECC None were found matching EC return false I think this is a bug in the z/OS code, it does not seem to recognise the Elliptic curves sent to it. ssl: ServerHandshaker.setupPrivateKeyAndChain, return false 3 curve index -1 They the next cipher spec - EC again ssl: ServerHandshaker.setupPrivateKeyAndChain EC matching alias: BPECCBPECC matching alias: TBPECC192 matching alias: NISTECC5 matching alias: TBPECC160 matching alias: TBPECC320 matching alias: BPECC matching alias: TBPECC512 matching alias: TBPECC256 matching alias: TNISTECC384 matching alias: TBPECC224 matching alias: NISTECC521 matching alias: TNISTECC224 matching alias: TNISTECC521 matching alias: TNISTECC256 matching alias: NISTECC matching alias: BPECC3 matching alias: TNISTECC192 ssl: ServerHandshaker.setupPrivateKeyAndChain, chooseEngineServerAlias BPECCBPECC None found .. return false ssl: ServerHandshaker.setupPrivateKeyAndChain, return false 3 curve index -1 Try the next cipher spec - RSA ssl: ServerHandshaker.setupPrivateKeyAndChain RSA matching alias: ZZZZ ssl: ServerHandshaker.setupPrivateKeyAndChain, chooseEngineServerAlias ZZZZ It found one! ssl: ServerHandshaker.setupPrivateKeyAndChain, return true
If you get
fatal error: 40: no cipher suites in common. Click here for more information
SEND TLSv1.2 ALERT: fatal,
JsseJCE: Using KeyPairGenerator EC from provider TBD via init JsseJCE: Using SecureRandom SHA2DRBG from provider IBMJCE version 1.8 JsseJCE: Using KeyPairGenerator EC from provider TBD via init ECDHCrypt: ECDH KeyPairGenerator from provider from init IBMJCE version 1.8 Use the agreed cipher spec SSL_ECDHE_RSA_WITH_AES_256_GCM_SHA384 %% Negotiating: [Session-1, SSL_ECDHE_RSA_WITH_AES_256_GCM_SHA384] JsseJCE: Using MessageDigest SHA-384 from provider IBMJCE version 1.8 End of processing ClientHello
