gsk_attribute_set_enum()--Set enumerated information for a secure session or an SSL environment


  Syntax
 #include <gskssl.h>

 int gsk_attribute_set_enum(gsk_handle my_gsk_handle,
                            GSK_ENUM_ID enumID,
                            GSK_ENUM_VALUE enumValue);
  Service Program Name: QSYS/QSOSSLSR

  Default Public Authority: *USE

  Threadsafe: Yes

The gsk_attribute_set_enum() function is used to set a specified enumerated type attribute to an enumerated value in the secure session or SSL environment.


Parameters

my_gsk_handle  (Input) 
Indicates one of the following handles:
  • The handle for the secure session. (my_session_handle)
  • The handle for the SSL environment. (my_env_handle)

enumID  (Input) 
Indicates one of the following operations:

  • Start of V7R2 changes GSK_PROTOCOL_TLSV12 (438) - Enables or disables the TLS Version 1.2 protocol. enumValue must specify one of the following:

    • GSK_TRUE (1) - Enable TLS Version 1.2.
    • GSK_FALSE (0) - Disable TLS Version 1.2.


  • GSK_PROTOCOL_TLSV11 (437) - Enables or disables the TLS Version 1.1 protocol. enumValue must specify one of the following:

    • GSK_TRUE (1) - Enable TLS Version 1.1.
    • GSK_FALSE (0) - Disable TLS Version 1.1.


  • GSK_PROTOCOL_TLSV10 (436) - Enables or disables the TLS Version 1.0 protocol. enumValue must specify one of the following:

    • GSK_TRUE (1) - Enable TLS Version 1.0.
    • GSK_FALSE (0) - Disable TLS Version 1.0.


  • GSK_PROTOCOL_TLSV1 (407) - Enables or disables all of the TLS Version 1.x protocols. enumValue must specify one of the following:

    • GSK_PROTOCOL_TLSV1_ON (518) - Enable TLS Version 1.x.
    • GSK_PROTOCOL_TLSV1_OFF (519) - Disable TLS Version 1.x.

    For compatibility with previous releases, this value is a master switch for all of the TLS version 1.x protocols. Each of the individual protocol settings (GSK_PROTOCOL_TLSV12, GSK_PROTOCOL_TLSV11, and GSK_PROTOCOL_TLSV10) will override this setting, but those individual settings get their default value from this setting. End of V7R2 changes

  • GSK_PROTOCOL_SSLV3 (404) - Enables or disables the SSL Version 3 protocol. enumValue must specify one of the following:

    • GSK_PROTOCOL_SSLV3_ON (512) - Enable SSL Version 3.
    • GSK_PROTOCOL_SSLV3_OFF (513) - Disable SSL Version 3.


  • GSK_PROTOCOL_SSLV2 (403) - Enables or disables the SSL Version 2 protocol. enumValue must specify one of the following:

    • GSK_PROTOCOL_SSLV2_ON (510) - Enable SSL Version 2.
    • GSK_PROTOCOL_SSLV2_OFF (511) - Disable SSL Version 2.


  • GSK_SESSION_TYPE (402) - Type of handshake to be used for this secure session or SSL environment. enumValue must specify one of the following operations:

    • GSK_CLIENT_SESSION (507) - Secure sessions act as clients.
    • GSK_SERVER_SESSION (508) - Secure sessions act as a server with no client authentication. The client is not asked for a certificate.
    • GSK_SERVER_SESSION_WITH_CL_AUTH (509) - Secure sessions act as a server that requests the client to send a certificate. The value for GSK_CLIENT_AUTH_TYPE will determine what happens if the client certificate is not valid or not provided.
    • Start of V7R2 changes GSK_SERVER_SESSION_WITH_CL_AUTH_CRITICAL (594) - Secure sessions act as a server that requires the client to send a certificate. If the client does not send a certificate, the secure session will not start, and gsk_secure_soc_init() will return GSK_ERROR_NO_CERTIFICATE. This provides the same functionality as setting GSK_SERVER_SESSION_WITH_CL_AUTH and GSK_IBMI_CLIENT_AUTH_REQUIRED. End of V7R2 changes


  • GSK_CLIENT_AUTH_TYPE (401) - Type of client authentication to use for this session. enumValue must specify one of the following:

    • GSK_CLIENT_AUTH_FULL (503) - All received certificates are validated. If an invalid certificate is received, the secure session does not start, and an error code is returned from gsk_secure_soc_init().

      If no certificate is sent by the client, the start of the secure session is successful. Applications can detect this situation by checking the GSK_CERTIFICATE_VALIDATION_CODE enumId through gsk_attribute_get_numeric_value(). A numValue of GSK_ERROR_NO_CERTIFICATE will indicate no certificate was sent by client. In this case, the application is responsible for the authentication of the client.

    • GSK_CLIENT_AUTH_PASSTHRU (505) - All received certificates are validated. If validation is successful or validation fails because the certificate is expired or does not have a trusted root, the secure session will start. For the other validation failure cases the secure session does not start, and an error code is returned from gsk_secure_soc_init(). Applications can detect the situation where the secure session started but validation failed by checking the GSK_CERTIFICATE_VALIDATION_CODE enumId via gsk_attribute_get_numeric_value(). The numValue will indicate the certificate validation return code for client's certificate. In this situation, the application is responsible for the authentication of the client.

      If no certificate is sent by the client, the start of the secure session is successful. Applications can detect this situation by checking the GSK_CERTIFICATE_VALIDATION_CODE enumId as well. A numValue of GSK_ERROR_NO_CERTIFICATE will indicate no certificate was sent by client. In this case, the application is also responsible for the authentication of the client.

      NOTE: If Authentication PassThru is set, and the application set the certificate callback to GSK_VALIDATION_REQUIRED, SSL will reject the call with an error code GSK_CONFLICTING_VALIDATION_SETTING. If a certificate validation callback has been set to GSK_VALIDATION_REQUIRED, and application set authentication to PassThru, SSL will also reject the call with an error code GSK_CONFLICTING_VALIDATION_SETTING.

    • GSK_IBMI_CLIENT_AUTH_REQUIRED (6995) - All received certificates are validated. If a certificate that is not valid is received, the secure session does not start, and an error code is returned from gsk_secure_soc_init(). If no certificate is sent by the client, the secure session does not start, and an error code of GSK_ERROR_NO_CERTIFICATE is returned from gsk_secure_soc_init().

  • Start of V7R2 changes GSK_ALLOW_UNAUTHENTICATED_RESUME (423) - Indicate if a cached handshake can be used if the client did not provide a certificate during the initial handshake. This attribute is only relevant when the server is configured for optional (GSK_CLIENT_AUTH_PASSTHRU or GSK_CLIENT_AUTH_FULL) client authentication. enumValue must specify one of the following:

    • GSK_ALLOW_UNAUTHENTICATED_RESUME_ON (588) - A session resume can use a session ID without an associated client certificate for the cached handshake.
    • GSK_ALLOW_UNAUTHENTICATED_RESUME_OFF (589) - A session resume attempt will force a full SSL handshake if the proposed session ID to resume does not have an associated client certificate. The server will have the opportunity to ask the client for a certificate again.
    End of V7R2 changes

  • GSK_SERVER_AUTH_TYPE (410) - Type of server authentication to use for this session. enumValue must specify one of the following:

    • GSK_SERVER_AUTH_FULL (534) - All received certificates are validated. If a certificate that is not valid is received, the secure session does not start, and an error code is returned from gsk_secure_soc_init(). If no certificate is sent by the server, the secure session does not start, and an error code of GSK_ERROR_NO_CERTIFICATE is returned from gsk_secure_soc_init().

    • GSK_SERVER_AUTH_PASSTHRU (535) - All received certificates are validated. If validation is successful or validation fails because the certificate has expired or does not have a trusted root, the secure session will start. For the other validation failure cases the secure session does not start, and an error code is returned from gsk_secure_soc_init(). Applications can detect the situation where the secure session started but validation failed by checking the GSK_CERTIFICATE_VALIDATION_CODE enumId via gsk_attribute_get_numeric_value(). The numValue will indicate the certificate validation return code for server's certificate. In this situation, the application is responsible for the authentication of the server.

      It is highly recommended that this option only be used if an alternate authentication method is used.

      NOTE: If Authentication PassThru is set, and the application set the certificate callback to GSK_VALIDATION_REQUIRED, SSL will reject the call with an error code GSK_CONFLICTING_VALIDATION_SETTING. If a certificate validation callback has been set to GSK_VALIDATION_REQUIRED, and application set authentication to PassThru, SSL will also reject the call with an error code GSK_CONFLICTING_VALIDATION_SETTING.

  • GSK_ENVIRONMENT_CLOSE_OPTIONS (411) - Type of special close options to use for this environment. If gsk_environment_close() is issued prior to all secure sessions being closed, the active secure sessions will continue to work and the environment close will effectively be delayed. The resources for the SSL environment will not be freed up until after the last secure session closes. No new secure sessions will be allowed to start using the closed SSL environment. enumValue must specify one of the following:

    • GSK_DELAYED_ENVIRONMENT_CLOSE (536) - Enable the environment close callback routine support.
    • GSK_NORMAL_ENVIRONMENT_CLOSE (537) - Field is ignored.


  • Start of V7R2 changes GSK_OCSP_ENABLE (426) - Enable Online Certificate Status Protocol (OCSP) certificate revocation checking using Authority Information Access (AIA) certificate extension information. If the certificate being validated has an AIA extension, the first OCSP responder identified in the AIA extension will be queried for revocation status. See the usage notes for further use of this attribute in conjunction with GSK_OCSP_URL. enumValue must specify one of the following:

    • GSK_TRUE (1) - Enable OCSP certificate revocation checking via AIA extension.
    • GSK_FALSE (0) - Disable OCSP certificate revocation checking via AIA extension.


  • GSK_OCSP_NONCE_GENERATION_ENABLE (428) - Enable OCSP nonce extension generation as part of the OCSP request. enumValue must specify one of the following:

    • GSK_TRUE (1) - Enable OCSP nonce extension generation and send nonce in OCSP requests.
    • GSK_FALSE (0) - Disable OCSP nonce extension generation.


  • GSK_OCSP_NONCE_CHECK_ENABLE (427) - Determine if OCSP nonce extension checking is required. The nonce extension improves security to prevent replay attacks by validating that the request matches the response. enumValue must specify one of the following:

    • GSK_TRUE (1) - Enable OCSP nonce extension validation. If the OCSP response nonce does not match the nonce sent in the OCSP request, the response is rejected.
    • GSK_FALSE (0) - Disable OCSP nonce extension validation.

    Setting GSK_OCSP_NONCE_CHECK_ENABLE to GSK_TRUE will automatically set GSK_OCSP_NONCE_GENERATION_ENABLE to GSK_TRUE.

  • GSK_OCSP_RETRIEVE_VIA_GET (435) - The method with which the OCSP request will be sent. If enumValue is set to GSK_TRUE, the OCSP request will be sent via HTTP GET if the total request size after BASE64 encoding is less than or equal to 255 bytes. If enumValue is GSK_FALSE or the total request size after encoding is greater than 255 bytes the request will be sent via HTTP POST. enumValue must specify one of the following:

    • GSK_TRUE (1) - Send OCSP request via HTTP GET when possible.
    • GSK_FALSE (0) - Always send OCSP request via HTTP POST.

    This option must be set to GSK_TRUE as one of the steps to comply with RFC 5019: The Lightweight Online Certificate Status Protocol (OCSP) Profile for High-Volume Environments.

  • GSK_EXTENDED_RENEGOTIATION_CRITICAL_CLIENT (451) - Client session RFC 5746 renegotiation indication requirement level. The initial system SSL default is GSK_FALSE however that default can be changed using System Service Tools (SST) Advanced Analysis Command SSLCONFIG. enumValue must specify one of the following:

    • GSK_TRUE (1) - The server must provide RFC 5746 renegotiation indication during the initial handshake in order for the handshake to be successful. Warning - The client will no longer be able to handshake with servers that have not or can not be updated to support RFC 5746.
    • GSK_FALSE (0) - RFC 5746 renegotiation indication from the server is not required on initial handshake. RFC 5746 renegotiation indication will still be required for all renegotiated handshakes.


  • GSK_EXTENDED_RENEGOTIATION_CRITICAL_SERVER (452) - Server session RFC 5746 renegotiation indication requirement level. The initial system SSL default is GSK_FALSE however that default can be changed using System Service Tools (SST) Advanced Analysis Command SSLCONFIG. enumValue must specify one of the following:

    • GSK_TRUE (1) - The client must provide RFC 5746 renegotiation indication during the initial handshake in order for the handshake to be successful. Warning - The server will no longer be able to handshake with clients that have not or can not be updated to support RFC 5746.
    • GSK_FALSE (0) - RFC 5746 renegotiation indication from the client is not required on initial handshake. RFC 5746 renegotiation indication will still be required for all renegotiated handshakes.


  • GSK_CERTREQ_DNLIST_ENABLE (457) - Enables the sending of the distinguished name (DN) list in the CertificateRequest message. This attribute only applies to a server. enumValue must specify one of the following:

    • GSK_TRUE (1) - The DN list is sent.
    • GSK_FALSE (0) - The DN list is not sent.
    End of V7R2 changes


enumValue  (Input) 
An enumerated type appropiate to the enumID.

Authorities

No authorization is required.


Return Value

gsk_attribute_set_enum() returns an integer. Possible values are:

[GSK_OK]
gsk_attribute_set_enum() was successful.

[GSK_ATTRIBUTE_INVALID_ENUMERATION]
The enumeration specified for the enumValue was not valid.

[GSK_ATTRIBUTE_INVALID_ID]
The enumID specified was not valid.

[GSK_CONFLICTING_VALIDATION_SETTING]
The value for GSK_SERVER_AUTH_TYPE or GSK_CLIENT_AUTH_TYPE conflicts with the setting for the validationCallBack.validateRequired field for GSK_CERT_VALIDATION_CALLBACK set by gsk_attribute_set_callback().

[GSK_INVALID_STATE]
One of the following occurred:
[GSK_INVALID_HANDLE]
The handle specified was not valid.

[GSK_ERROR_UNSUPPORTED]
The enumID is currently not supported.

[GSK_ERROR_IO]
An error occurred in SSL processing, check the errno value.

Error Conditions

When the gsk_attribute_set_enum() API fails with return code [GSK_ERROR_IO], errno can be set to:

[EINTR]
Interrupted function call.

[EDEADLK]
Resource deadlock avoided.

[ETERM]
Operation terminated.

If an errno is returned that is not in this list, look in Errno Values for UNIX®-Type Functions for a description of the errno.


Usage Notes

  1. The following GSK_ENUM_ID values may be set in the SSL environment after gsk_environment_open() and before gsk_environment_init(). They are used as defaults for subsequent secure sessions:

    • Start of V7R2 changes GSK_PROTOCOL_TLSV12
    • GSK_PROTOCOL_TLSV11
    • GSK_PROTOCOL_TLSV10
      End of V7R2 changes
    • GSK_PROTOCOL_TLSV1
    • GSK_PROTOCOL_SSLV3
    • GSK_PROTOCOL_SSLV2
    • GSK_SESSION_TYPE
    • GSK_CLIENT_AUTH_TYPE
    • GSK_SERVER_AUTH_TYPE
    • GSK_ENVIRONMENT_CLOSE_OPTIONS
    • Start of V7R2 changesGSK_OCSP_ENABLE
    • GSK_OCSP_NONCE_CHECK_ENABLE
    • GSK_OCSP_NONCE_GENERATION_ENABLE
    • GSK_OCSP_RETRIEVE_VIA_GET
    • GSK_EXTENDED_RENEGOTIATION_CRITICAL_CLIENT
    • GSK_EXTENDED_RENEGOTIATION_CRITICAL_SERVER
    • GSK_ALLOW_UNAUTHENTICATED_RESUME
    • GSK_CERTREQ_DNLIST_ENABLE
      End of V7R2 changes

  2. The following GSK_ENUM_ID values may be set for each individual secure session after gsk_secure_soc_open() and before gsk_secure_soc_init(). These values will override values set in the SSL environment:

    • Start of V7R2 changes GSK_PROTOCOL_TLSV12
    • GSK_PROTOCOL_TLSV11
    • GSK_PROTOCOL_TLSV10
      End of V7R2 changes
    • GSK_PROTOCOL_TLSV1
    • GSK_PROTOCOL_SSLV3
    • GSK_PROTOCOL_SSLV2
    • GSK_SESSION_TYPE
    • GSK_CLIENT_AUTH_TYPE
    • GSK_SERVER_AUTH_TYPE

  3. Start of V7R2 changes When GSK_IBMI_APPLICATION_ID is set, the settings of some of the SSL environment attributes will be determined by the corresponding value in the Application ID definition in Digital Certificate Manager (DCM). These are the enum attributes that can be overwritten by DCM during the call to gsk_environment_init():
    • GSK_PROTOCOL_TLSV12
    • GSK_PROTOCOL_TLSV11
    • GSK_PROTOCOL_TLSV10
    • GSK_PROTOCOL_TLSV1
    • GSK_PROTOCOL_SSLV3
    • GSK_PROTOCOL_SSLV2
    • GSK_OCSP_ENABLE
    • GSK_EXTENDED_RENEGOTIATION_CRITICAL_CLIENT
    • GSK_EXTENDED_RENEGOTIATION_CRITICAL_SERVER

  4. There are two ways to enable OCSP that can be used either separately or together:

    • GSK_OCSP_URL is set with gsk_attribute_set_buffer() to the URL of the OCSP responder. OCSP will be used for revocation status checking regardless of whether the certificate has an AIA extension or not, so it will work with existing certificates.
    • GSK_OCSP_ENABLE is set with gsk_attribute_set_enum() to GSK_TRUE. OCSP will be used if the certificate being validated has an AIA extension with a PKIK_AD_OCSP access method containing a URI of the HTTP location of the OCSP responder.

    When both attributes are set the GSK_OCSP_ENABLE functionality will only be used if GSK_OCSP_URL functionality results in an undetermined revocation status. The definition of undetermined revocation status is located in the Secure Sockets Layer topic.

    Note: Using OCSP results in a performance impact to System SSL.
    End of V7R2 changes


Related Information


API introduced: V5R1