Update from stable branch.

[thirdparty/openssl.git] / CHANGES

 OpenSSL CHANGES
 _______________

 Changes between 0.9.8g and 0.9.9  [xx XXX xxxx]

  *) Removed effectively defunct crypto/store from the build.
     [Ben Laurie]

  *) Revamp of STACK to provide stronger type-checking. Still to come:
     TXT_DB, bsearch(?), OBJ_bsearch, qsort, CRYPTO_EX_DATA, ASN1_VALUE,
     ASN1_STRING, CONF_VALUE.
     [Ben Laurie]

  *) Add a new SSL_MODE_RELEASE_BUFFERS mode flag to release unused buffer
     RAM on SSL connections.  This option can save about 34k per idle SSL.
     [Nick Mathewson]

  *) Expand ENGINE to support engine supplied SSL client certificate functions.
     [Steve Henson]

  *) Revamp of LHASH to provide stronger type-checking. Still to come:
     STACK, TXT_DB, bsearch, qsort.
     [Ben Laurie]

  *) Not all of this is true any longer.
     Will have to be updated to reflect all subsequent changes to cryptlib.c.
                                                                       --bodo


     To support arbitrarily-typed thread IDs, deprecate the existing
     type-specific APIs for a general purpose CRYPTO_THREADID
     interface. Applications can choose the thread ID
     callback type it wishes to register, as before;

        void CRYPTO_set_id_callback(unsigned long (*func)(void));
        void CRYPTO_set_idptr_callback(void *(*func)(void));

     but retrieval, copies, and comparisons of thread IDs are via
     type-independent interfaces;

        void CRYPTO_THREADID_set(CRYPTO_THREADID *id);
        void CRYPTO_THREADID_cmp(const CRYPTO_THREADID *id1,
                                 const CRYPTO_THREADID *id2);
        void CRYPTO_THREADID_cpy(CRYPTO_THREADID *dst,
                                 const CRYPTO_THREADID *src);

     Also, for code that needs a thread ID "value" for use in
     hash-tables or logging, a "hash" is available by;

        unsigned long CRYPTO_THREADID_hash(const CRYPTO_THREADID *id);

     This hash value is likely to be the thread ID anyway, but
     otherwise it will be unique if possible or as collision-free as
     possible if uniqueness can't be guaranteed on the target
     architecture.

     The following functions are deprecated;
        unsigned long (*CRYPTO_get_id_callback(void))(void);
        unsigned long CRYPTO_thread_id(void);

     As a consequence of the above, there are similar deprecations of
     BN_BLINDING functions in favour of CRYPTO_THREADID-based
     alternatives;

        #ifndef OPENSSL_NO_DEPRECATED
        unsigned long BN_BLINDING_get_thread_id(const BN_BLINDING *);
        void BN_BLINDING_set_thread_id(BN_BLINDING *, unsigned long);
        #endif
        void BN_BLINDING_set_thread(BN_BLINDING *);
        int BN_BLINDING_cmp_thread(const BN_BLINDING *, const
                                   CRYPTO_THREADID *);

     Also, the ERR_remove_state(int pid) API has been deprecated;

        #ifndef OPENSSL_NO_DEPRECATED
        void ERR_remove_state(unsigned long pid)
        #endif
        void ERR_remove_thread_state(CRYPTO_THREADID *tid);

     [Geoff Thorpe]

  *) Initial support for Cryptographic Message Syntax (aka CMS) based
     on RFC3850, RFC3851 and RFC3852. New cms directory and cms utility,
     support for data, signedData, compressedData, digestedData and
     encryptedData, envelopedData types included. Scripts to check against
     RFC4134 examples draft and interop and consistency checks of many
     content types and variants.
     [Steve Henson]

  *) Add options to enc utility to support use of zlib compression BIO.
     [Steve Henson]

  *) Extend mk1mf to support importing of options and assembly language
     files from Configure script, currently only included in VC-WIN32.
     The assembly language rules can now optionally generate the source
     files from the associated perl scripts.
     [Steve Henson]

  *) Implement remaining functionality needed to support GOST ciphersuites.
     Interop testing has been performed using CryptoPro implementations.
     [Victor B. Wagner <vitus@cryptocom.ru>]

  *) s390x assembler pack.
     [Andy Polyakov]

  *) ARMv4 assembler pack. ARMv4 refers to v4 and later ISA, not CPU
     "family."
     [Andy Polyakov]

  *) Implement Opaque PRF Input TLS extension as specified in
     draft-rescorla-tls-opaque-prf-input-00.txt.  Since this is not an
     official specification yet and no extension type assignment by
     IANA exists, this extension (for now) will have to be explicitly
     enabled when building OpenSSL by providing the extension number
     to use.  For example, specify an option

         -DTLSEXT_TYPE_opaque_prf_input=0x9527

     to the "config" or "Configure" script to enable the extension,
     assuming extension number 0x9527 (which is a completely arbitrary
     and unofficial assignment based on the MD5 hash of the Internet
     Draft).  Note that by doing so, you potentially lose
     interoperability with other TLS implementations since these might
     be using the same extension number for other purposes.

     SSL_set_tlsext_opaque_prf_input(ssl, src, len) is used to set the
     opaque PRF input value to use in the handshake.  This will create
     an interal copy of the length-'len' string at 'src', and will
     return non-zero for success.

     To get more control and flexibility, provide a callback function
     by using

          SSL_CTX_set_tlsext_opaque_prf_input_callback(ctx, cb)
          SSL_CTX_set_tlsext_opaque_prf_input_callback_arg(ctx, arg)

     where

          int (*cb)(SSL *, void *peerinput, size_t len, void *arg);
          void *arg;

     Callback function 'cb' will be called in handshakes, and is
     expected to use SSL_set_tlsext_opaque_prf_input() as appropriate.
     Argument 'arg' is for application purposes (the value as given to
     SSL_CTX_set_tlsext_opaque_prf_input_callback_arg() will directly
     be provided to the callback function).  The callback function
     has to return non-zero to report success: usually 1 to use opaque
     PRF input just if possible, or 2 to enforce use of the opaque PRF
     input.  In the latter case, the library will abort the handshake
     if opaque PRF input is not successfully negotiated.

     Arguments 'peerinput' and 'len' given to the callback function
     will always be NULL and 0 in the case of a client.  A server will
     see the client's opaque PRF input through these variables if
     available (NULL and 0 otherwise).  Note that if the server
     provides an opaque PRF input, the length must be the same as the
     length of the client's opaque PRF input.

     Note that the callback function will only be called when creating
     a new session (session resumption can resume whatever was
     previously negotiated), and will not be called in SSL 2.0
     handshakes; thus, SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv2) or
     SSL_set_options(ssl, SSL_OP_NO_SSLv2) is especially recommended
     for applications that need to enforce opaque PRF input.

     [Bodo Moeller]

  *) Update ssl code to support digests other than SHA1+MD5 for handshake
     MAC. 

     [Victor B. Wagner <vitus@cryptocom.ru>]

  *) Add RFC4507 support to OpenSSL. This includes the corrections in
     RFC4507bis. The encrypted ticket format is an encrypted encoded
     SSL_SESSION structure, that way new session features are automatically
     supported.

     If a client application caches session in an SSL_SESSION structure
     support is transparent because tickets are now stored in the encoded
     SSL_SESSION.
     
     The SSL_CTX structure automatically generates keys for ticket
     protection in servers so again support should be possible
     with no application modification.

     If a client or server wishes to disable RFC4507 support then the option
     SSL_OP_NO_TICKET can be set.

     Add a TLS extension debugging callback to allow the contents of any client
     or server extensions to be examined.

     This work was sponsored by Google.
     [Steve Henson]

  *) Final changes to avoid use of pointer pointer casts in OpenSSL.
     OpenSSL should now compile cleanly on gcc 4.2
     [Peter Hartley <pdh@utter.chaos.org.uk>, Steve Henson]

  *) Update SSL library to use new EVP_PKEY MAC API. Include generic MAC
     support including streaming MAC support: this is required for GOST
     ciphersuite support.
     [Victor B. Wagner <vitus@cryptocom.ru>, Steve Henson]

  *) Add option -stream to use PKCS#7 streaming in smime utility. New
     function i2d_PKCS7_bio_stream() and PEM_write_PKCS7_bio_stream()
     to output in BER and PEM format.
     [Steve Henson]

  *) Experimental support for use of HMAC via EVP_PKEY interface. This
     allows HMAC to be handled via the EVP_DigestSign*() interface. The
     EVP_PKEY "key" in this case is the HMAC key, potentially allowing
     ENGINE support for HMAC keys which are unextractable. New -mac and
     -macopt options to dgst utility.
     [Steve Henson]

  *) New option -sigopt to dgst utility. Update dgst to use
     EVP_Digest{Sign,Verify}*. These two changes make it possible to use
     alternative signing paramaters such as X9.31 or PSS in the dgst 
     utility.
     [Steve Henson]

  *) Change ssl_cipher_apply_rule(), the internal function that does
     the work each time a ciphersuite string requests enabling
     ("foo+bar"), moving ("+foo+bar"), disabling ("-foo+bar", or
     removing ("!foo+bar") a class of ciphersuites: Now it maintains
     the order of disabled ciphersuites such that those ciphersuites
     that most recently went from enabled to disabled not only stay
     in order with respect to each other, but also have higher priority
     than other disabled ciphersuites the next time ciphersuites are
     enabled again.

     This means that you can now say, e.g., "PSK:-PSK:HIGH" to enable
     the same ciphersuites as with "HIGH" alone, but in a specific
     order where the PSK ciphersuites come first (since they are the
     most recently disabled ciphersuites when "HIGH" is parsed).

     Also, change ssl_create_cipher_list() (using this new
     funcionality) such that between otherwise identical
     cihpersuites, ephemeral ECDH is preferred over ephemeral DH in
     the default order.
     [Bodo Moeller]

  *) Change ssl_create_cipher_list() so that it automatically
     arranges the ciphersuites in reasonable order before starting
     to process the rule string.  Thus, the definition for "DEFAULT"
     (SSL_DEFAULT_CIPHER_LIST) now is just "ALL:!aNULL:!eNULL", but
     remains equivalent to "AES:ALL:!aNULL:!eNULL:+aECDH:+kRSA:+RC4:@STRENGTH".
     This makes it much easier to arrive at a reasonable default order
     in applications for which anonymous ciphers are OK (meaning
     that you can't actually use DEFAULT).
     [Bodo Moeller; suggested by Victor Duchovni]

  *) Split the SSL/TLS algorithm mask (as used for ciphersuite string
     processing) into multiple integers instead of setting
     "SSL_MKEY_MASK" bits, "SSL_AUTH_MASK" bits, "SSL_ENC_MASK",
     "SSL_MAC_MASK", and "SSL_SSL_MASK" bits all in a single integer.
     (These masks as well as the individual bit definitions are hidden
     away into the non-exported interface ssl/ssl_locl.h, so this
     change to the definition of the SSL_CIPHER structure shouldn't
     affect applications.)  This give us more bits for each of these
     categories, so there is no longer a need to coagulate AES128 and
     AES256 into a single algorithm bit, and to coagulate Camellia128
     and Camellia256 into a single algorithm bit, which has led to all
     kinds of kludges.

     Thus, among other things, the kludge introduced in 0.9.7m and
     0.9.8e for masking out AES256 independently of AES128 or masking
     out Camellia256 independently of AES256 is not needed here in 0.9.9.

     With the change, we also introduce new ciphersuite aliases that
     so far were missing: "AES128", "AES256", "CAMELLIA128", and
     "CAMELLIA256".
     [Bodo Moeller]

  *) Add support for dsa-with-SHA224 and dsa-with-SHA256.
     Use the leftmost N bytes of the signature input if the input is
     larger than the prime q (with N being the size in bytes of q).
     [Nils Larsch]

  *) Very *very* experimental PKCS#7 streaming encoder support. Nothing uses
     it yet and it is largely untested.
     [Steve Henson]

  *) Add support for the ecdsa-with-SHA224/256/384/512 signature types.
     [Nils Larsch]

  *) Initial incomplete changes to avoid need for function casts in OpenSSL
     some compilers (gcc 4.2 and later) reject their use. Safestack is
     reimplemented.  Update ASN1 to avoid use of legacy functions. 
     [Steve Henson]

  *) Win32/64 targets are linked with Winsock2.
     [Andy Polyakov]

  *) Add an X509_CRL_METHOD structure to allow CRL processing to be redirected
     to external functions. This can be used to increase CRL handling 
     efficiency especially when CRLs are very large by (for example) storing
     the CRL revoked certificates in a database.
     [Steve Henson]

  *) Overhaul of by_dir code. Add support for dynamic loading of CRLs so
     new CRLs added to a directory can be used. New command line option
     -verify_return_error to s_client and s_server. This causes real errors
     to be returned by the verify callback instead of carrying on no matter
     what. This reflects the way a "real world" verify callback would behave.
     [Steve Henson]

  *) GOST engine, supporting several GOST algorithms and public key formats.
     Kindly donated by Cryptocom.
     [Cryptocom]

  *) Partial support for Issuing Distribution Point CRL extension. CRLs
     partitioned by DP are handled but no indirect CRL or reason partitioning
     (yet). Complete overhaul of CRL handling: now the most suitable CRL is
     selected via a scoring technique which handles IDP and AKID in CRLs.
     [Steve Henson]

  *) New X509_STORE_CTX callbacks lookup_crls() and lookup_certs() which
     will ultimately be used for all verify operations: this will remove the
     X509_STORE dependency on certificate verification and allow alternative
     lookup methods.  X509_STORE based implementations of these two callbacks.
     [Steve Henson]

  *) Allow multiple CRLs to exist in an X509_STORE with matching issuer names.
     Modify get_crl() to find a valid (unexpired) CRL if possible.
     [Steve Henson]

  *) New function X509_CRL_match() to check if two CRLs are identical. Normally
     this would be called X509_CRL_cmp() but that name is already used by
     a function that just compares CRL issuer names. Cache several CRL 
     extensions in X509_CRL structure and cache CRLDP in X509.
     [Steve Henson]

  *) Store a "canonical" representation of X509_NAME structure (ASN1 Name)
     this maps equivalent X509_NAME structures into a consistent structure.
     Name comparison can then be performed rapidly using memcmp().
     [Steve Henson]

  *) Non-blocking OCSP request processing. Add -timeout option to ocsp 
     utility.
     [Steve Henson]

  *) Allow digests to supply their own micalg string for S/MIME type using
     the ctrl EVP_MD_CTRL_MICALG.
     [Steve Henson]

  *) During PKCS7 signing pass the PKCS7 SignerInfo structure to the
     EVP_PKEY_METHOD before and after signing via the EVP_PKEY_CTRL_PKCS7_SIGN
     ctrl. It can then customise the structure before and/or after signing
     if necessary.
     [Steve Henson]

  *) New function OBJ_add_sigid() to allow application defined signature OIDs
     to be added to OpenSSLs internal tables. New function OBJ_sigid_free()
     to free up any added signature OIDs.
     [Steve Henson]

  *) New functions EVP_CIPHER_do_all(), EVP_CIPHER_do_all_sorted(),
     EVP_MD_do_all() and EVP_MD_do_all_sorted() to enumerate internal
     digest and cipher tables. New options added to openssl utility:
     list-message-digest-algorithms and list-cipher-algorithms.
     [Steve Henson]

  *) In addition to the numerical (unsigned long) thread ID, provide
     for a pointer (void *) thread ID.  This helps accomodate systems
     that do not provide an unsigned long thread ID.  OpenSSL assumes
     it is in the same thread iff both the numerical and the pointer
     thread ID agree; so applications are just required to define one
     of them appropriately (e.g., by using a pointer to a per-thread
     memory object malloc()ed by the application for the pointer-type
     thread ID).  Exactly analoguous to the existing functions

        void CRYPTO_set_id_callback(unsigned long (*func)(void));
        unsigned long (*CRYPTO_get_id_callback(void))(void);
        unsigned long CRYPTO_thread_id(void);

     we now have additional functions

        void CRYPTO_set_idptr_callback(void *(*func)(void));
        void *(*CRYPTO_get_idptr_callback(void))(void);
        void *CRYPTO_thread_idptr(void);

     also in <openssl/crypto.h>.  The default value for
     CRYPTO_thread_idptr() if the application has not provided its own
     callback is &errno.
     [Bodo Moeller]

     -- NOTE -- this change has been reverted and replaced with a
     type-independent wrapper (ie. applications do not have to check
     two type-specific thread ID representations as implied in this
     change note). However, the "idptr" callback form described here
     can still be registered. Please see the more recent CHANGES note
     regarding CRYPTO_THREADID. [Geoff Thorpe]
     -- NOTE --

  *) Change the array representation of binary polynomials: the list
     of degrees of non-zero coefficients is now terminated with -1.
     Previously it was terminated with 0, which was also part of the
     value; thus, the array representation was not applicable to
     polynomials where t^0 has coefficient zero.  This change makes
     the array representation useful in a more general context.
     [Douglas Stebila]

  *) Various modifications and fixes to SSL/TLS cipher string
     handling.  For ECC, the code now distinguishes between fixed ECDH
     with RSA certificates on the one hand and with ECDSA certificates
     on the other hand, since these are separate ciphersuites.  The
     unused code for Fortezza ciphersuites has been removed.

     For consistency with EDH, ephemeral ECDH is now called "EECDH"
     (not "ECDHE").  For consistency with the code for DH
     certificates, use of ECDH certificates is now considered ECDH
     authentication, not RSA or ECDSA authentication (the latter is
     merely the CA's signing algorithm and not actively used in the
     protocol).

     The temporary ciphersuite alias "ECCdraft" is no longer
     available, and ECC ciphersuites are no longer excluded from "ALL"
     and "DEFAULT".  The following aliases now exist for RFC 4492
     ciphersuites, most of these by analogy with the DH case:

         kECDHr   - ECDH cert, signed with RSA
         kECDHe   - ECDH cert, signed with ECDSA
         kECDH    - ECDH cert (signed with either RSA or ECDSA)
         kEECDH   - ephemeral ECDH
         ECDH     - ECDH cert or ephemeral ECDH

         aECDH    - ECDH cert
         aECDSA   - ECDSA cert
         ECDSA    - ECDSA cert

         AECDH    - anonymous ECDH
         EECDH    - non-anonymous ephemeral ECDH (equivalent to "kEECDH:-AECDH")

     [Bodo Moeller]

  *) Add additional S/MIME capabilities for AES and GOST ciphers if supported.
     Use correct micalg parameters depending on digest(s) in signed message.
     [Steve Henson]

  *) Add engine support for EVP_PKEY_ASN1_METHOD. Add functions to process
     an ENGINE asn1 method. Support ENGINE lookups in the ASN1 code.
     [Steve Henson]

  *) Initial engine support for EVP_PKEY_METHOD. New functions to permit
     an engine to register a method. Add ENGINE lookups for methods and
     functional reference processing.
     [Steve Henson]

  *) New functions EVP_Digest{Sign,Verify)*. These are enchance versions of
     EVP_{Sign,Verify}* which allow an application to customise the signature
     process.
     [Steve Henson]

  *) New -resign option to smime utility. This adds one or more signers
     to an existing PKCS#7 signedData structure. Also -md option to use an
     alternative message digest algorithm for signing.
     [Steve Henson]

  *) Tidy up PKCS#7 routines and add new functions to make it easier to
     create PKCS7 structures containing multiple signers. Update smime
     application to support multiple signers.
     [Steve Henson]

  *) New -macalg option to pkcs12 utility to allow setting of an alternative
     digest MAC.
     [Steve Henson]

  *) Initial support for PKCS#5 v2.0 PRFs other than default SHA1 HMAC.
     Reorganize PBE internals to lookup from a static table using NIDs,
     add support for HMAC PBE OID translation. Add a EVP_CIPHER ctrl:
     EVP_CTRL_PBE_PRF_NID this allows a cipher to specify an alternative
     PRF which will be automatically used with PBES2.
     [Steve Henson]

  *) Replace the algorithm specific calls to generate keys in "req" with the
     new API.
     [Steve Henson]

  *) Update PKCS#7 enveloped data routines to use new API. This is now
     supported by any public key method supporting the encrypt operation. A
     ctrl is added to allow the public key algorithm to examine or modify
     the PKCS#7 RecipientInfo structure if it needs to: for RSA this is
     a no op.
     [Steve Henson]

  *) Add a ctrl to asn1 method to allow a public key algorithm to express
     a default digest type to use. In most cases this will be SHA1 but some
     algorithms (such as GOST) need to specify an alternative digest. The
     return value indicates how strong the prefernce is 1 means optional and
     2 is mandatory (that is it is the only supported type). Modify
     ASN1_item_sign() to accept a NULL digest argument to indicate it should
     use the default md. Update openssl utilities to use the default digest
     type for signing if it is not explicitly indicated.
     [Steve Henson]

  *) Use OID cross reference table in ASN1_sign() and ASN1_verify(). New 
     EVP_MD flag EVP_MD_FLAG_PKEY_METHOD_SIGNATURE. This uses the relevant
     signing method from the key type. This effectively removes the link
     between digests and public key types.
     [Steve Henson]

  *) Add an OID cross reference table and utility functions. Its purpose is to
     translate between signature OIDs such as SHA1WithrsaEncryption and SHA1,
     rsaEncryption. This will allow some of the algorithm specific hackery
     needed to use the correct OID to be removed. 
     [Steve Henson]

  *) Remove algorithm specific dependencies when setting PKCS7_SIGNER_INFO
     structures for PKCS7_sign(). They are now set up by the relevant public
     key ASN1 method.
     [Steve Henson]

  *) Add provisional EC pkey method with support for ECDSA and ECDH.
     [Steve Henson]

  *) Add support for key derivation (agreement) in the API, DH method and
     pkeyutl.
     [Steve Henson]

  *) Add DSA pkey method and DH pkey methods, extend DH ASN1 method to support
     public and private key formats. As a side effect these add additional 
     command line functionality not previously available: DSA signatures can be
     generated and verified using pkeyutl and DH key support and generation in
     pkey, genpkey.
     [Steve Henson]

  *) BeOS support.
     [Oliver Tappe <zooey@hirschkaefer.de>]

  *) New make target "install_html_docs" installs HTML renditions of the
     manual pages.
     [Oliver Tappe <zooey@hirschkaefer.de>]

  *) New utility "genpkey" this is analagous to "genrsa" etc except it can
     generate keys for any algorithm. Extend and update EVP_PKEY_METHOD to
     support key and parameter generation and add initial key generation
     functionality for RSA.
     [Steve Henson]

  *) Add functions for main EVP_PKEY_method operations. The undocumented
     functions EVP_PKEY_{encrypt,decrypt} have been renamed to
     EVP_PKEY_{encrypt,decrypt}_old. 
     [Steve Henson]

  *) Initial definitions for EVP_PKEY_METHOD. This will be a high level public
     key API, doesn't do much yet.
     [Steve Henson]

  *) New function EVP_PKEY_asn1_get0_info() to retrieve information about
     public key algorithms. New option to openssl utility:
     "list-public-key-algorithms" to print out info.
     [Steve Henson]

  *) Implement the Supported Elliptic Curves Extension for
     ECC ciphersuites from draft-ietf-tls-ecc-12.txt.
     [Douglas Stebila]

  *) Don't free up OIDs in OBJ_cleanup() if they are in use by EVP_MD or
     EVP_CIPHER structures to avoid later problems in EVP_cleanup().
     [Steve Henson]

  *) New utilities pkey and pkeyparam. These are similar to algorithm specific
     utilities such as rsa, dsa, dsaparam etc except they process any key
     type.
     [Steve Henson]

  *) Transfer public key printing routines to EVP_PKEY_ASN1_METHOD. New 
     functions EVP_PKEY_print_public(), EVP_PKEY_print_private(),
     EVP_PKEY_print_param() to print public key data from an EVP_PKEY
     structure.
     [Steve Henson]

  *) Initial support for pluggable public key ASN1.
     De-spaghettify the public key ASN1 handling. Move public and private
     key ASN1 handling to a new EVP_PKEY_ASN1_METHOD structure. Relocate
     algorithm specific handling to a single module within the relevant
     algorithm directory. Add functions to allow (near) opaque processing
     of public and private key structures.
     [Steve Henson]

  *) Implement the Supported Point Formats Extension for
     ECC ciphersuites from draft-ietf-tls-ecc-12.txt.
     [Douglas Stebila]

  *) Add initial support for RFC 4279 PSK TLS ciphersuites. Add members
     for the psk identity [hint] and the psk callback functions to the
     SSL_SESSION, SSL and SSL_CTX structure.
     
     New ciphersuites:
         PSK-RC4-SHA, PSK-3DES-EDE-CBC-SHA, PSK-AES128-CBC-SHA,
         PSK-AES256-CBC-SHA
 
     New functions:
         SSL_CTX_use_psk_identity_hint
         SSL_get_psk_identity_hint
         SSL_get_psk_identity
         SSL_use_psk_identity_hint

     [Mika Kousa and Pasi Eronen of Nokia Corporation]

  *) Add RFC 3161 compliant time stamp request creation, response generation
     and response verification functionality.