gsk_attribute_set_buffer()--Set character information for a secure session or environment


  Syntax

 #include <gskssl.h>

 int gsk_attribute_set_buffer(gsk_handle my_gsk_handle,
                              GSK_BUF_ID bufID,
                              const char *buffer,
                              int bufSize);

  Service Program Name: QSYS/QSOSSLSR

  Default Public Authority: *USE

  Threadsafe: Yes

The gsk_attribute_set_buffer() function is used to set a specified buffer attribute to a value inside the specified secure session or 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 secure environment. (my_env_handle)

bufID  (Input) 
Indicates one of the following operations:

  • GSK_KEYRING_FILE (201) - buffer points to the name of the certificate store file to be used for the secure session or environment. Authority to the certificate store file will be checked on the gsk_environment_init() API or the gsk_secure_soc_init() API.

  • GSK_KEYRING_PW (202) - buffer points to the password for the certificate store file to be used for the secure session or environment.

  • GSK_KEYRING_LABEL (203) - buffer points to the certificate label associated with the certificate in the certificate store to be used for the secure session or environment.

  • GSK_KEYRING_LABEL_EX (254) - buffer points to a list of up to four comma delimited string values of the certificate labels associated with the certificates in the certificate store to be used for the secure session or environment.

  • GSK_IBMI_APPLICATION_ID (6999) - buffer points to the application identifier to be used for the secure environment.

  • Start of V7R3 changes GSK_TLSV13_CIPHER_SPECS_EX (2008) - buffer points to a list of comma delimited string values of the TLS Version 1.3 ciphers to be used for the secure session or environment. End of V7R3 changes

  • GSK_TLSV12_CIPHER_SPECS_EX (243) - buffer points to a list of comma delimited string values of the TLS Version 1.2 ciphers to be used for the secure session or environment.

    GSK_TLSV12_CIPHER_SPECS (238) (Deprecated) - buffer points to a list of two-character string codes of the TLS Version 1.2 ciphers to be used for the secure session or environment. Setting this to NULL will result in the System TLS default list of ciphers being used as indicated in the usage notes.
    Replaced by GSK_TLSV12_CIPHER_SPECS_EX as some new ciphers can be not represented by two characters. The ciphers that can not be represented will be used for this session/environment where appropriate based on other settings however those ciphers will not appear for this attribute.

    See the usage notes for the format of the ciphers for either of the attributes.

  • GSK_TLSV11_CIPHER_SPECS_EX (242) - buffer points to a list of comma delimited string values of the TLS Version 1.1 ciphers to be used for the secure session or environment.

    GSK_TLSV11_CIPHER_SPECS (237) (Deprecated) - buffer points to a list of two-character string codes of the TLS Version 1.1 ciphers to be used for the secure session or environment. Setting this to NULL will result in the System TLS default list of ciphers being used as indicated in the usage notes.
    Replaced by GSK_TLSV11_CIPHER_SPECS_EX as some new ciphers can be not represented by two characters. The ciphers that can not be represented will be used for this session/environment where appropriate based on other settings however those ciphers will not appear for this attribute.

    See the usage notes for the format of the ciphers for either of the attributes.

  • GSK_TLSV10_CIPHER_SPECS_EX (241) - buffer points to a list of comma delimited string values of the TLS Version 1.0 ciphers to be used for the secure session or environment.

    GSK_TLSV10_CIPHER_SPECS (236) (Deprecated) - buffer points to a list of two-character string codes of the TLS Version 1.0 ciphers to be used for the secure session or environment. Setting this to NULL will result in the System TLS default list of ciphers being used as indicated in the usage notes.
    Replaced by GSK_TLSV10_CIPHER_SPECS_EX as some new ciphers can be not represented by two characters. The ciphers that can not be represented will be used for this session/environment where appropriate based on other settings however those ciphers will not appear for this attribute.

    See the usage notes for the format of the ciphers for either of the attributes.

  • GSK_V3_CIPHER_SPECS_EX (240) - buffer points to a list of comma delimited string values of the SSL Version 3 ciphers to be used for the secure session or environment.

    GSK_V3_CIPHER_SPECS (206) (Deprecated) - buffer points to a list of two-character string codes of the SSL Version 3 ciphers to be used for the secure session or environment. For compatibility with previous releases, if this value is set, its value will be duplicated into the GSK_TLSV10_CIPHER_SPECS and GSK_TLSV10_CIPHER_SPECS_EX values if the default value has not been changed by an explicit set call for either of those attributes.
    Replaced by GSK_V3_CIPHER_SPECS_EX as some new ciphers can be not represented by two characters.

    See the usage notes for the format of the ciphers for either of the attributes.

  • GSK_V2_CIPHER_SPECS (205) - buffer points to the list of SSL Version 2 ciphers to be used for the secure session or environment.

  • GSK_SSL_EXTN_SIGALG (245) - buffer points to the list of comma delimited string values of signature algorithms to be supported by the secure environment when using TLS version 1.2. See the usage notes for the format of the signature algorithms.

  • GSK_OCSP_URL (221) - buffer points to the URL of the Online Certificate Status Protocol (OCSP) responder to query during certificate validation. HTTP is the only supported protocol; therefore, the URL must begin with "http://". This attribute has precedence over GSK_OSCP_ENABLE. See the usage notes for additional information on the interaction of OCSP attributes.

  • GSK_OCSP_PROXY_SERVER_NAME (223) - buffer points to the name of the proxy server to which OCSP requests should be sent. For example, myocspproxy.com. If set, all OCSP requests will be sent to the proxy HTTP server for processing.

  • GSK_SSL_EXTN_SERVERNAME_REQUEST (230) - buffer points to a string that represents the Fully Qualified Domain Name (FQDN) of the server the client intends to communicate with. The value is used in the TLS Server Name Indication (SNI) extension request as defined by RFC 6066.

  • GSK_SSL_EXTN_SERVERNAME_CRITICAL_REQUEST (231) - buffer points to a string that represents the FQDN of the server the client intends to communicate with. The value is used in the TLS SNI extension request as defined by RFC 6066.

    This attribute should be used instead of GSK_SSL_EXTN_SERVERNAME_REQUEST if the server must respond affirmatively to the FQDN in the SNI request. The secure connection will fail when the server does not provide that affirmation.

    NOTE - The use of this attribute will result in interoperability issues with servers that do not support the SNI extension.

  • GSK_SSL_EXTN_SERVERNAME_LIST (232) - buffer points to both a null-terminated FQDN and certificate label to be set for the server. The FQDN and certificate label strings are separated by a NULL character (i.e., "www.gskit.org\0my_label\0"). The label must be from the certificate store file specified for the secure environment. This would be *SYSTEM if GSK_IBMI_APPLICATION_ID is set. The server will use the certificate and private key for any secure connections with a matching client SNI FQDN request. If the client SNI request is not matched, the server session will use the configured default certificate with no SNI acknowledgment. This attribute can be set multiple times to create an array of FQDN and certificate label pairs.

  • GSK_SSL_EXTN_SERVERNAME_CRITICAL_LIST (233) - buffer points to both a null-terminated FQDN and certificate label to be set for the server. Use this attribute instead of GSK_SSL_EXTN_SERVERNAME_LIST if the client SNI request must match an entry in this list and result in an error if it is not matched. This critical condition only applies when a client sends the SNI extension and does not apply when the client does not send the extension. This attribute can be set multiple times to create an array of FQDN and certificate label pairs.

  • Start of V7R3 changes GSK_SSL_EXTN_ALPN (276) - buffer points to a list of comma delimited string values of the Application-Layer Protocol Negotiation (ALPN) protocols IDs to be used for the secure session or environment. End of V7R3 changes

  • Start of V7R3 changes GSK_TLS_EXTN_SIG_SCHEME (2001) - buffer points to the list of comma delimited string values of signature scheme algorithms to be supported by the secure environment when using TLS version 1.3. See the usage notes for the format of the signature algorithms.

  • GSK_TLS_EXTN_SIG_SCHEME_CERT (2003) - buffer points to the list of comma delimited string values of signature scheme certificate algorithms to be supported by the secure environment when using TLS version 1.3. See the usage notes for the format of the signature algorithms.

  • GSK_TLS_EXTN_SUPPORTED_GROUPS (2005) - buffer points to the list of comma delimited string values of groups to be supported by the secure environment when using TLS version 1.2 and newer versions. See the usage notes for the format of the supported groups. End of V7R3 changes


buffer  (Input) 
A pointer to the information to be used for the secure session or the TLS environment.

The data in the buffer is assumed to be represented in the CCSID (coded character set identifier) currently in effect for the job. If the CCSID of the job is 65535, this buffer is assumed to be represented in the default CCSID of the job.

bufSize  (Input) 
The length of the buffer information. If bufSize is specified as 0, the length of bufSize will be calculated.

Authorities

No authorization is required.


Return Value

gsk_attribute_set_buffer() returns an integer. Possible values are:

[GSK_OK]
gsk_attribute_set_buffer() was successful.

[GSK_ATTRIBUTE_INVALID_ID]
The bufID value is not a valid identifier.

[GSK_ATTRIBUTE_INVALID_LENGTH]
The bufSize specified or the length of buffer is not valid.

[GSK_INVALID_HANDLE]
my_gsk_handle is not a valid handle that was received from issuing gsk_environment_open() or gsk_secure_soc_open().

[GSK_IBMI_ERROR_INVALID_POINTER]
The buffer pointer is not valid.

[GSK_INVALID_STATE]
One of the following occurred:
[GSK_INVALID_PARAMETER]
The buffer value contains an invalid value for the bufID being set. For example an invalid cipher suite was specified.

[GSK_ERROR_BAD_V3_CIPHER]
An SSLV3 cipher suite was specified that is not valid.

[GSK_ERROR_BAD_V2_CIPHER]
An SSLV2 cipher suite was specified that is not valid.

[GSK_ERROR_UNSUPPORTED]
The bufID value is currently not supported.

[GSK_INSUFFICIENT_STORAGE]
Not able to allocate storage for the requested operation.

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

Error Conditions

When the gsk_attribute_set_buffer() 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_BUF_ID values may be set in the secure environment after gsk_environment_open() and before gsk_environment_init(). They are used as defaults for subsequent secure sessions:

    • GSK_KEYRING_FILE
    • GSK_KEYRING_PW
    • GSK_KEYRING_LABEL
    • GSK_KEYRING_LABEL_EX
    • GSK_IBMI_APPLICATION_ID
    • Start of V7R3 changesGSK_TLSV13_CIPHER_SPECS_EX End of V7R3 changes
    • GSK_TLSV12_CIPHER_SPECS_EX
    • GSK_TLSV12_CIPHER_SPECS
    • GSK_TLSV11_CIPHER_SPECS_EX
    • GSK_TLSV11_CIPHER_SPECS
    • GSK_TLSV10_CIPHER_SPECS_EX
    • GSK_TLSV10_CIPHER_SPECS
    • GSK_V3_CIPHER_SPECS_EX
    • GSK_V3_CIPHER_SPECS
    • GSK_V2_CIPHER_SPECS
    • GSK_SSL_EXTN_SIGALG
    • GSK_OCSP_URL
    • GSK_OCSP_PROXY_SERVER_NAME
    • GSK_SSL_EXTN_SERVERNAME_REQUEST
    • GSK_SSL_EXTN_SERVERNAME_CRITICAL_REQUEST
    • GSK_SSL_EXTN_SERVERNAME_LIST
    • GSK_SSL_EXTN_SERVERNAME_CRITICAL_LIST
    • Start of V7R3 changesGSK_SSL_EXTN_ALPNEnd of V7R3 changes
    • Start of V7R3 changesGSK_TLS_EXTN_SIG_SCHEME
    • GSK_TLS_EXTN_SIG_SCHEME_CERT
    • GSK_TLS_EXTN_SUPPORTED_GROUPSEnd of V7R3 changes

  2. The following GSK_BUF_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 secure environment:

    • GSK_KEYRING_LABEL
    • GSK_KEYRING_LABEL_EX
    • Start of V7R3 changesGSK_TLSV13_CIPHER_SPECS_EX End of V7R3 changes
    • GSK_TLSV12_CIPHER_SPECS_EX
    • GSK_TLSV12_CIPHER_SPECS
    • GSK_TLSV11_CIPHER_SPECS_EX
    • GSK_TLSV11_CIPHER_SPECS
    • GSK_TLSV10_CIPHER_SPECS_EX
    • GSK_TLSV10_CIPHER_SPECS
    • GSK_V3_CIPHER_SPECS_EX
    • GSK_V3_CIPHER_SPECS
    • GSK_V2_CIPHER_SPECS
    • Start of V7R3 changesGSK_SSL_EXTN_ALPN
      End of V7R3 changes

  3. Start of V7R3 changesThis table shows the mapping between the three different representations of a cipher specification on the system. For each protocol version the cipher specifications that are supported are indicated by the "X" in the appropriate column.


    End of V7R3 changes

  4. Start of V7R3 changes The following GSK_TLSV13_CIPHER_SPECS_EX string is the default TLS Version 1.3 cipher list used when the operating system is installed:
       "TLS_AES_128_GCM_SHA256,TLS_AES_256_GCM_SHA384,TLS_CHACHA20_POLY1305_SHA256"
    
  5. The following GSK_TLSV12_CIPHER_SPECS_EX string is the default TLS Version 1.2 cipher list used when the operating system is installed:
       'TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
        TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
        TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
        TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_GCM_SHA384,
        TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384,
        TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,
        TLS_RSA_WITH_AES_128_CBC_SHA256,TLS_RSA_WITH_AES_128_CBC_SHA,
        TLS_RSA_WITH_AES_256_CBC_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA'
    
    The GSK_TLSV12_CIPHER_SPECS equivalent list is '9C9D3C2F3D35'.

    Note: The GSK_TLSV12_CIPHER_SPECS list may not reflect all of the ciphers in use by the environment or session if ciphers that do not have a GSK_TLSV12_CIPHER_SPECS equivalent representation are enabled.
    End of V7R3 changes

  6. Start of V7R3 changes The following GSK_TLSV11_CIPHER_SPECS_EX string is the default TLS Version 1.1 cipher list used when the operating system is installed:
      'TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA'
    
    The GSK_TLSV11_CIPHER_SPECS equivalent list is '2F35'.
    End of V7R3 changes

  7. Start of V7R3 changes The following GSK_TLSV10_CIPHER_SPECS_EX string is the default TLS Version 1.0 cipher list used when the operating system is installed:
      'TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_CBC_SHA'
    
    The GSK_TLSV10_CIPHER_SPECS equivalent list is '2F35'.
    End of V7R3 changes

  8. Start of V7R3 changes SSL Version 3 support is disabled when the operating system is installed. If SSL Version 3 is enabled (not recommended), the following GSK_V3_CIPHER_SPECS_EX string is the default SSL Version 3 cipher list used when the operating system is installed:
      ''
    
    The GSK_V3_CIPHER_SPECS equivalent list is ''.
    End of V7R3 changes

  9. SSL Version 2 support is disabled when the operating system is installed resulting in no SSL Version 2 ciphers being supported. If SSL Version 2 is enabled (not recommended), the following GSK_V2_CIPHER_SPECS values are the SSL Version 2 ciphers that would be supported if the shipped supported cipher list has not been altered.
    
        1 = *RSA_RC4_128_MD5
        2 = *RSA_EXPORT_RC4_40_MD5
        4 = *RSA_EXPORT_RC2_CBC_40_MD5
        NULL = Default cipher specs are used, however no SSLv2 ciphers are eligible
            to be default cipher specs.   Thus, the default list contains no ciphers.
    
    The following GSK_V2_CIPHER_SPECS values are the SSL Version 2 ciphers potentially supported if an administrator later enables SSL Version 2:
        1 = *RSA_RC4_128_MD5
        2 = *RSA_EXPORT_RC4_40_MD5
        3 = *RSA_RC2_CBC_128_MD5
        4 = *RSA_EXPORT_RC2_CBC_40_MD5
        6 = *RSA_DES_CBC_MD5
        7 = *RSA_3DES_EDE_CBC_MD5
        NULL = Default cipher specs are used, however no SSLv2 ciphers are eligible
            to be default cipher specs.   Thus, the default list contains no ciphers.
    
  10. Start of V7R3 changes The current default cipher suite list can be different from the install time list due to changes made to the QSSLCSL (TLS cipher specification list) system value via the Change System Value (CHGSYSVAL) command. A cipher suite removed from the TLS cipher specification list will also be removed from the default cipher suite lists shown here. A cipher suite removed from the eligible default cipher specification list using System Service Tools (SST) Advanced Analysis Command SSLCONFIG will also be removed from the default cipher suite list shown here. For additional information see the help text for SSLCONFIG. The order of the cipher suites in QSSLCSL will be used to order the cipher suites in the default list. gsk_attribute_get_buffer() for GSK_TLSV13_CIPHER_SPECS_EX, GSK_TLSV12_CIPHER_SPECS_EX, GSK_TLSV11_CIPHER_SPECS_EX, GSK_TLSV10_CIPHER_SPECS_EX, and GSK_V3_CIPHER_SPECS_EX can be used to determine the current default cipher suite list configuration for the appropriate protocol version. The default list might be empty based on system configuration resulting in the null character (\0) being returned by gsk_attribute_get_buffer(). End of V7R3 changes

  11. Start of V7R3 changes The following GSK_SSL_EXTN_SIGALG strings represent the signature algorithms supported:
    • GSK_TLS_SIGALG_RSA_WITH_MD5 (not supported as shipped)
    • GSK_TLS_SIGALG_RSA_WITH_SHA1
    • GSK_TLS_SIGALG_RSA_WITH_SHA224
    • GSK_TLS_SIGALG_RSA_WITH_SHA256
    • GSK_TLS_SIGALG_RSA_WITH_SHA384
    • GSK_TLS_SIGALG_RSA_WITH_SHA512
    • GSK_TLS_SIGALG_ECDSA_WITH_SHA1
    • GSK_TLS_SIGALG_ECDSA_WITH_SHA224
    • GSK_TLS_SIGALG_ECDSA_WITH_SHA256
    • GSK_TLS_SIGALG_ECDSA_WITH_SHA384
    • GSK_TLS_SIGALG_ECDSA_WITH_SHA512

    The supported signature algorithms that can be used by System TLS can be changed using System Service Tools (SST) Advanced Analysis Command SSLCONFIG.

    The following GSK_SSL_EXTN_SIGALG string is the default ordered list supported when the operating system is installed:
       "GSK_TLS_SIGALG_ECDSA_WITH_SHA512,GSK_TLS_SIGALG_ECDSA_WITH_SHA384,GSK_TLS_SIGALG_ECDSA_WITH_SHA256,
        GSK_TLS_SIGALG_ECDSA_WITH_SHA224,GSK_TLS_SIGALG_ECDSA_WITH_SHA1,GSK_TLS_SIGALG_RSA_WITH_SHA512,
        GSK_TLS_SIGALG_RSA_WITH_SHA384,GSK_TLS_SIGALG_RSA_WITH_SHA256,GSK_TLS_SIGALG_RSA_WITH_SHA225,
        GSK_TLS_SIGALG_RSA_WITH_SHA1"
    
    The default string used by System TLS can be changed using System Service Tools (SST) Advanced Analysis Command SSLCONFIG.
    End of V7R3 changes

  12. The list of supported cipher suites and the ordered list of default cipher suites are configurable from the Change System Value (CHGSYSVAL) command. The Display System Value (DSPSYSVAL) command or the Retrieve System Values (QWCRSVAL) API can be used to determine the current settings of the supported ciphers (QSSLCSL) and protocols (QSSLPCL) for system TLS.

  13. The following are the possible scenarios for the use of GSK_KEYRING_LABEL and GSK_KEYRING_LABEL_EX:

    • GSK_KEYRING_LABEL or GSK_KEYRING_LABEL_EX can be set after gsk_environment_open() and before gsk_environment_init() to indicate which certificate(s) in the GSK_KEYRING_FILE to use for the secure environment.
    • GSK_KEYRING_LABEL or GSK_KEYRING_LABEL_EX can be set after gsk_secure_soc_open() and before gsk_secure_soc_init() to indicate which certificate(s) in the GSK_KEYRING_FILE to use for the secure session.
    • If both GSK_KEYRING_LABEL and GSK_KEYRING_LABEL_EX are set, the GSK_KEYRING_LABEL_EX value will indicate which certificate(s) in the GSK_KEYRING_FILE to use for the secure session or environment.
    • If GSK_KEYRING_LABEL and GSK_KEYRING_LABEL_EX are not set, the default certificate label in the GSK_KEYRING_FILE is used for the secure environment.

  14. If GSK_IBMI_APPLICATION_ID is set, the GSK_KEYRING_FILE, the GSK_KEYRING_LABEL, the GSK_KEYRING_LABEL_EX, and the GSK_KEYRING_PASSWORD values are ignored.

  15. When GSK_IBMI_APPLICATION_ID is set, the settings of some of the secure environment attributes will be determined by the corresponding value in the Application ID definition in Digital Certificate Manager (DCM). These are the buffer attributes that can be overwritten by DCM during the call to gsk_environment_init():
    • Start of V7R3 changesGSK_TLSV13_CIPHER_SPECS_EX End of V7R3 changes
    • GSK_TLSV12_CIPHER_SPECS_EX
    • GSK_TLSV11_CIPHER_SPECS_EX
    • GSK_TLSV10_CIPHER_SPECS_EX
    • GSK_TLSV12_CIPHER_SPECS
    • GSK_TLSV11_CIPHER_SPECS
    • GSK_TLSV10_CIPHER_SPECS
    • GSK_SSL_EXTN_SIGALG
    • GSK_OCSP_URL
    • Start of V7R3 changesGSK_TLS_EXTN_SIG_SCHEME
    • GSK_TLS_EXTN_SIG_SCHEME_CERTEnd of V7R3 changes

  16. When GSK_IBMI_APPLICATION_ID is set, the settings of some of the secure environment attributes will be affected by the corresponding value in the Application ID definition in Digital Certificate Manager (DCM). These are the buffer attributes that can be appended by DCM to the end of the existing secure environment buffer attributes during the call to gsk_environment_init():
    • GSK_SSL_EXTN_SERVERNAME_LIST
    • GSK_SSL_EXTN_SERVERNAME_CRITICAL_LIST

  17. 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 Authority Information Access (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 TLS.

  18. Per RFC 6066 Transport Layer Security (TLS) Extensions: Extension Definitions , the main purpose of Server Name Indication (SNI) support is to allow TLS clients to provide to the TLS server the name of the server they are contacting. This functionality is desirable in order to facilitate secure connections to servers that host multiple 'virtual' servers at a single underlying network address.

    TLS servers that do not host multiple 'virtual' servers may find that configuring GSK_SSL_EXTN_SERVERNAME_LIST allows for improved interoperability with TLS clients that are using the equivalent of GSK_SSL_EXTN_SERVERNAME_CRITICAL_REQUEST on their platform.

  19. The following is a possible scenario for the use of GSK_TLSV12_CIPHER_SPECS_EX:
        gsk_attribute_set_buffer(GSK_TLSV12_CIPHER_SPECS_EX)
        gsk_attribute_get_buffer(GSK_TLSV12_CIPHER_SPECS_EX)
        gsk_attribute_set_buffer(GSK_TLSV12_CIPHER_SPECS)
    
    In the example above, the two calls to gsk_attribute_set_buffer() using GSK_TLSV12_CIPHER_SPECS_EX and GSK_TLSV12_CIPHER_SPECS will modify the same cipher list. The buffer returned to gsk_attribute_get_buffer() will no longer be accurate after the second set call. The cipher spec list was modified by the second set, so another get call would be necessary to retrieve the current cipher list. This also applies to GSK_TLSV11_CIPHER_SPECS_EX, GSK_TLSV10_CIPHER_SPECS_EX, and GSK_V3_CIPHER_SPECS_EX.

  20. Start of V7R3 changes The following GSK_TLS_EXTN_SIG_SCHEME strings represent the signature scheme algorithms supported:
    • GSK_TLS_SIG_SCHEME_ECDSA_SECP256R1_SHA256
    • GSK_TLS_SIG_SCHEME_ECDSA_SECP384R1_SHA384
    • GSK_TLS_SIG_SCHEME_ECDSA_SECP521R1_SHA512
    • GSK_TLS_SIG_SCHEME_RSA_PSS_RSAE_SHA256
    • GSK_TLS_SIG_SCHEME_RSA_PSS_RSAE_SHA384
    • GSK_TLS_SIG_SCHEME_RSA_PSS_RSAE_SHA512

    The supported signature scheme algorithms that can be used by System TLS can be changed using SSLCONFIG.

    The following GSK_TLS_EXTN_SIG_SCHEME string is the default ordered list supported when the operating system is installed:
       "GSK_TLS_SIG_SCHEME_ECDSA_SECP521R1_SHA512,GSK_TLS_SIG_SCHEME_ECDSA_SECP384R1_SHA384,
        GSK_TLS_SIG_SCHEME_ECDSA_SECP256R1_SHA256,GSK_TLS_SIG_SCHEME_RSA_PSS_RSAE_SHA512,
        GSK_TLS_SIG_SCHEME_RSA_PSS_RSAE_SHA384,GSK_TLS_SIG_SCHEME_RSA_PSS_RSAE_SHA256"
    
    The default string used by System TLS can be changed using SSLCONFIG.

  21. The following GSK_TLS_EXTN_SIG_SCHEME_CERT strings represent the signature scheme certificate algorithms supported:
    • GSK_TLS_SIG_SCHEME_RSA_PKCS1_SHA1
    • GSK_TLS_SIG_SCHEME_RSA_PKCS1_SHA256
    • GSK_TLS_SIG_SCHEME_RSA_PKCS1_SHA384
    • GSK_TLS_SIG_SCHEME_RSA_PKCS1_SHA512
    • GSK_TLS_SIG_SCHEME_ECDSA_SHA1
    • GSK_TLS_SIG_SCHEME_ECDSA_SECP256R1_SHA256
    • GSK_TLS_SIG_SCHEME_ECDSA_SECP384R1_SHA384
    • GSK_TLS_SIG_SCHEME_ECDSA_SECP521R1_SHA512
    • GSK_TLS_SIG_SCHEME_RSA_PSS_RSAE_SHA256
    • GSK_TLS_SIG_SCHEME_RSA_PSS_RSAE_SHA384
    • GSK_TLS_SIG_SCHEME_RSA_PSS_RSAE_SHA512

    The supported signature scheme certificate algorithms that can be used by System TLS can be changed using SSLCONFIG.

    The following GSK_TLS_EXTN_SIG_SCHEME_CERT string is the default ordered list supported when the operating system is installed:
       "GSK_TLS_SIG_SCHEME_ECDSA_SECP521R1_SHA512,GSK_TLS_SIG_SCHEME_ECDSA_SECP384R1_SHA384,
        GSK_TLS_SIG_SCHEME_ECDSA_SECP256R1_SHA256,GSK_TLS_SIG_SCHEME_ECDSA_SHA1,
        GSK_TLS_SIG_SCHEME_RSA_PSS_RSAE_SHA512,GSK_TLS_SIG_SCHEME_RSA_PSS_RSAE_SHA384,
        GSK_TLS_SIG_SCHEME_RSA_PSS_RSAE_SHA256,GSK_TLS_SIG_SCHEME_RSA_PKCS1_SHA512,
        GSK_TLS_SIG_SCHEME_RSA_PKCS1_SHA384,GSK_TLS_SIG_SCHEME_RSA_PKCS1_SHA256,
        GSK_TLS_SIG_SCHEME_RSA_PKCS1_SHA1"
    
    The default string used by System TLS can be changed using SSLCONFIG.

  22. The following GSK_TLS_EXTN_SUPPORTED_GROUPS strings represent the groups supported:
    • GSK_TLS_SUPPORTED_GROUP_ECDHE_X25519
    • GSK_TLS_SUPPORTED_GROUP_ECDHE_X448
    • GSK_TLS_SUPPORTED_GROUP_ECDHE_SECP256R1
    • GSK_TLS_SUPPORTED_GROUP_ECDHE_SECP384R1
    • GSK_TLS_SUPPORTED_GROUP_ECDHE_SECP521R1
    • GSK_TLS_SUPPORTED_GROUP_ECDHE_SECP224R1
    • GSK_TLS_SUPPORTED_GROUP_ECDHE_SECP192R1

    The supported groups that can be used by System TLS can be changed using SSLCONFIG.

    The following GSK_TLS_EXTN_SUPPORTED_GROUPS string is the default ordered list supported when the operating system is installed:
       "GSK_TLS_SUPPORTED_GROUP_ECDHE_SECP256R1,GSK_TLS_SUPPORTED_GROUP_ECDHE_SECP384R1,
        GSK_TLS_SUPPORTED_GROUP_ECDHE_X25519,GSK_TLS_SUPPORTED_GROUP_ECDHE_SECP521R1,
        GSK_TLS_SUPPORTED_GROUP_ECDHE_X448"
    
    The default string used by System TLS can be changed using SSLCONFIG. End of V7R3 changes


Related Information



API introduced: V5R1