EZD1287I TTLS Error RC: 456 Initial Handshake ACF2 CSFPGKP CSFSERV class
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EZD1287I TTLS Error RC: 456 Initial Handshake ACF2 CSFPGKP CSFSERV class

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Article ID: 142850

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Updated On:

Products

ACF2 ACF2 - DB2 Option ACF2 for zVM ACF2 - z/OS ACF2 - MISC

Issue/Introduction

configuring AT-TLS encrypted connection from the mainframe ( client ) to a Linux server.

The linux server is currently configured to use CIPHERS that have not been used before and they require ICSF access.  Rules are in place for all callable services
including CSFPGKP  CSFSERV resource CSF1GKP.

a portion of a GSK TRACE is below

xxxx      MESSAGE   00000004  18:32:08.470434  SSL_ERROR
Job TCPIP     Process 0001030A  Thread 00000003  crypto_ec_token_generate_key_pair
ICSF service failure: CSFPGKP retCode = 0x8, rsnCode = 0x3e88              
xxxx      MESSAGE   00000004  18:32:08.470443  SSL_ERROR                           
Job TCPIP     Process 0001030A  Thread 00000003  send_v3_client_messages
Unable to generate ECDH key pair: Error 0x03353084                                

 

Environment

Release : 16.0

Component : CA ACF2 for z/OS

Resolution

There is a CRYPTO class validation for resource CLEARKEY.SYSTOK-SESSION-ONLY
that needs to allow access to all users for some SSL callable services.

$KEY(CLEARKEY) TYPE(CRY)
SYSTOK-SESSION-ONLY UID(*) SERVICE(READ) ALLOW

without this rule in place, ACF2 would protect the resource by default and would not allow access - thus causing potential problems as described below.

The following statement is in IBM doc

The CLEARKEY.token-name resource within the CRYPTOZ class controls the ICSF
policy for creating a clear key versus a secure key.
When the resource is defined and set to NONE, System SSL's usage of the PKCS #11
callable services to generate keys is restricted to secure keys only.
This causes functions within System SSL to fail.
System SSL uses both explicit tokens and the SYSTOK-SESSION-ONLY omnipresent token.

The following are examples that can fail in this environment in System SSL:
The gskkyman utility or CMS APIs that create ECC or DH (FIPS mode) keys or certificates.
Ephemeral ECDH and Ephemeral DH key exchanges during a SSL/TLS handshake.