CHANGES

 OpenSSL CHANGES
 _______________

 Changes between 0.9.8i and 0.9.9  [xx XXX xxxx]

  *) To cater for systems that provide a pointer-based thread ID rather
     than numeric, deprecate the current numeric thread ID mechanism and
     replace it with a structure and associated callback type. This
     mechanism allows a numeric "hash" to be extracted from a thread ID in
     either case, and on platforms where pointers are larger than 'long',
     mixing is done to help ensure the numeric 'hash' is usable even if it
     can't be guaranteed unique. The default mechanism is to use "&errno"
     as a pointer-based thread ID to distinguish between threads.

     Applications that want to provide their own thread IDs should now use
     CRYPTO_THREADID_set_callback() to register a callback that will call
     either CRYPTO_THREADID_set_numeric() or CRYPTO_THREADID_set_pointer().

     (This new approach replaces the functions CRYPTO_set_idptr_callback(),
     CRYPTO_get_idptr_callback(), and CRYPTO_thread_idptr() that existed in
     OpenSSL 0.9.9-dev between June 2006 and August 2008. Also, if an
     application was previously providing a numeric thread callback that
     was inappropriate for distinguishing threads, then uniqueness might
     have been obtained with &errno that happened immediately in the
     intermediate development versions of OpenSSL; this is no longer the
     case, the numeric thread callback will now override the automatic use
     of &errno.)
     [Geoff Thorpe, with help from Bodo Moeller]

  *) Initial support for different CRL issuing certificates. This covers a
     simple case where the self issued certificates in the chain exist and
     the real CRL issuer is higher in the existing chain.
     [Steve Henson]

  *) 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]

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

  *) 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.