gsk_attribute_set_numeric_value()--Set numeric information for a secure session or an SSL environment

 #include <gskssl.h>

 int gsk_attribute_set_numeric_value(gsk_handle my_gsk_handle,
                                     GSK_NUM_ID numID,
                                     int numValue);

The gsk_attribute_set_numeric_value() function is used to set specific numeric information for a secure session or an SSL environment.

Parameters

my_gsk_handle  (Input) 

One of the following handles:

• The handle for the secure session. (my_session_handle)
• The handle for the SSL environment. (my_env_handle)

numID  (Input) 

One of the following operations:

• GSK_FD (300) - numValue is a socket descriptor to be used for this secure session.
  
  
• GSK_V2_SESSION_TIMEOUT (301) - numValue is the SSL Version 2 session time-out for the SSL environment. numValue must be in the range 0-100 seconds.
  
  
• GSK_V3_SESSION_TIMEOUT (302) - numValue is the SSL Version 3 and TLS Version 1.x session time-out for the SSL environment. numValue must be in the range 0-86400 seconds (24 hours).
  
  
• GSK_OS400_READ_TIMEOUT (6993) - numValue is the receive time-out for the secure session or the SSL environment. numValue must be in milliseconds. A numValue of 0 is the default which means to wait forever.
  
  
• GSK_HANDSHAKE_TIMEOUT (6998) - numValue is the SSL handshake time-out for the secure session or the SSL environment. numValue must be in seconds. A numValue of 0 is the default which means to wait forever.
  
  
• GSK_OCSP_MAX_RESPONSE_SIZE (315) - numValue is the maximum response size in bytes that will be accepted from the Online Certificate Status Protocol OCSP responder. When the response size is greater, the response is rejected. Default is 20480.
  
  
• GSK_OCSP_TIMEOUT (318) - numValue is the receive timeout in seconds to wait for a response from the OCSP responder. This value should be less than or equal to the value for GSK_HANDSHAKE_TIMEOUT as that setting applies to the entire handshake wait time. Default is 10. (Note: GSK_HANDSHAKE_TIMEOUT default is to wait forever)
  
  
• GSK_OCSP_NONCE_SIZE (324) - numValue is the size in bytes that will be generated as an OCSP nonce if nonce is to be generated. The default is 0 which is a special value meaning use the System SSL default size of 8. Setting this value greater than 512 will result in the value being set to 512.
  
  
• GSK_OCSP_CLIENT_CACHE_SIZE (326) - numValue indicates if OCSP response caching is enabled for the SSL environment. The default value is 1, indicating this SSL environment will both create cache entries and use cache entries in the System SSL system level OCSP response cache. A value of 0 disables both cache creates and cache lookups for the SSL environment. The System SSL system level cache size is unlimited.
  
  
• GSK_OCSP_PROXY_SERVER_PORT (312) - numValue is the port of the proxy server to which OCSP requests will be sent if GSK_OCSP_PROXY_SERVER_NAME is set. A value of 0 indicates the default proxy server port (80) will be used.
  
  
• GSK_SSL_EXTN_MAXFRAGMENT_SIZE (321) - numValue is the client secure session's preferred SSL fragment size. The fragment size is negotiated with the server using an optional TLS extension. System SSL will send the maximum fragmentation length extension in the extended client hello when not set to the default value of 16384. If the server agrees to the smaller fragment size both sides of the secure session will immediately start fragmenting the data to that size. The typical System SSL application should not change this setting. Note: This attribute is not applicable to System SSL server sessions as they always support all valid sizes for this extension. Valid values are 512, 1024, 2048, and 4096.
  
  
• GSK_TLS_CBCPROTECTION_METHOD (329) - Sets an optional SSL Version 3 or TLS Version 1.0 CBC IV Protection method. The default value is GSK_TLS_CBCPROTECTION_METHOD_NONE (0). numValue must specify one of the following:
  
  • GSK_TLS_CBCPROTECTION_METHOD_NONE (0) - No method is employed.
  • GSK_TLS_CBCPROTECTION_METHOD_ZEROBYTEFRAGMENT(1) - A zero byte fragment is prepended to each data record sent.
  • GSK_TLS_CBCPROTECTION_METHOD_ONEBYTEFRAGMENT(2) - The data record is sent in multiple records with the first record containing one byte.
  • GSK_TLS_CBCPROTECTION_METHOD_DELAYEDONEBYTEFRAGMENT(3) - The first write operation is unaffected. After the first write operation, the data record is sent in multiple records with the first record containing one byte.
  
  

numValue  (Input) 

An integer value to be updated for the specified numID.

Authorities

No authorization is required.

Return Value

gsk_attribute_set_numeric_value() returns an integer. Possible values are:

[GSK_OK]

gsk_attribute_set_numeric_value() was successful.

[GSK_INVALID_STATE]

One of the following occurred:

• numID cannot be set in the SSL environment after a gsk_environment_init() has been issued.
• numID cannot be set for a secure session after a gsk_secure_soc_init() has been issued.

[GSK_ATTRIBUTE_INVALID_ID]

The numID specified was not valid.

[GSK_ATTRIBUTE_INVALID_NUMERIC_VALUE]

The numValue specified was not valid.

[GSK_INVALID_HANDLE]

A handle was specified that was not valid.

[GSK_ERROR_UNSUPPORTED]

The numID is currently not supported.

[GSK_ERROR_IO]

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

Error Conditions

When the gsk_attribute_set_numeric_value() 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_NUM_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:
   
   
   • GSK_V2_SESSION_TIMEOUT
   • GSK_V3_SESSION_TIMEOUT
   • GSK_HANDSHAKE_TIMEOUT
   • GSK_OS400_READ_TIMEOUT
   • GSK_OCSP_PROXY_SERVER_PORT
   • GSK_OCSP_MAX_RESPONSE_SIZE
   • GSK_OCSP_TIMEOUT
   • GSK_OCSP_NONCE_SIZE
   • GSK_OCSP_CLIENT_CACHE_SIZE
   • GSK_SSL_EXTN_MAXFRAGMENT_SIZE
   • GSK_TLS_CBCPROTECTION_METHOD
     
   
   
2. The following GSK_NUM_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:
   
   
   • GSK_FD
   • GSK_HANDSHAKE_TIMEOUT
   • GSK_OS400_READ_TIMEOUT
   
   
3. The following GSK_NUM_ID values are currently not supported in the IBM^® i implementation:
   • GSK_V2_SIDCACHE_SIZE
   • GSK_V3_SIDCACHE_SIZE
   • GSK_LDAP_SERVER_PORT
   
   
4. The GSK_FD value is a socket descriptor that must have an address family of AF_INET or AF_INET6 and a socket type of SOCK_STREAM.
   
   
5. The following information should be considered when using GSK_TLS_CBCPROTECTION_METHOD:
   
   
   • These methods only apply to SSL Version 3 and TLS Version 1.0 when using CBC cipher suites.
   • Setting GSK_TLS_CBCPROTECTION_METHOD_ONEBYTEFRAGMENT may generally interfere with application protocols that expect complete records.
   • It is recommended that TLS Version 1.1 or higher is used instead of the above mitigation methods.
   • Stream ciphers are not subject to attack and may be used as a mitigation method.
   
   
   

Related Information

• gsk_attribute_get_numeric_value()--Get numeric information about a secure session or an SSL environment
  
  
• gsk_attribute_set_buffer()--Set character string information for a secure session or an SSL environment.
  
  
• gsk_attribute_set_enum()--Set enumerated information for a secure session or an SSL environment.
  
  
• gsk_environment_init()--Initialize an SSL environment
  
  
• gsk_environment_open()--Get a handle for an SSL environment
  
  
• gsk_secure_soc_init()--Negotiate a secure session
  
  
• gsk_secure_soc_misc()--Perform miscellaneous functions for a secure session
  
  
• gsk_secure_soc_open()--Get a handle for a secure session
  
  
• gsk_strerror()--Retrieve GSK runtime error message