Clarify ordering of certificates when using certificate chains

[thirdparty/openssl.git] / CHANGES

 OpenSSL CHANGES
 _______________

 Changes between 0.9.7a and 0.9.8  [xx XXX xxxx]

  *) Add support for STORE in ENGINE.
     [Richard Levitte]

  *) Add the STORE type.  The intention is to provide a common interface
     to certificate and key stores, be they simple file-based stores, or
     HSM-type store, or LDAP stores, or...
     NOTE: The code is currently UNTESTED and isn't really used anywhere.
     [Richard Levitte]

  *) Add a generic structure called OPENSSL_ITEM.  This can be used to
     pass a list of arguments to any function as well as provide a way
     for a function to pass data back to the caller.
     [Richard Levitte]

  *) Add the functions BUF_strndup() and BUF_memdup().  BUF_strndup()
     works like BUF_strdup() but can be used to duplicate a portion of
     a string.  The copy gets NUL-terminated.  BUF_memdup() duplicates
     a memory area.
     [Richard Levitte]

  *) Add the function sk_find_ex() which works like sk_find(), but will
     return an index to an element even if an exact match couldn't be
     found.  The index is guaranteed to point at the element where the
     searched-for key would be inserted to preserve sorting order.
     [Richard Levitte]

  *) Add the function OBJ_bsearch_ex() which works like OBJ_bsearch() but
     takes an extra flags argument for optional functionality.  Currently,
     the following flags are defined:

	OBJ_BSEARCH_VALUE_ON_NOMATCH
	This one gets OBJ_bsearch_ex() to return a pointer to the first
	element where the comparing function returns a negative or zero
	number.

	OBJ_BSEARCH_FIRST_VALUE_ON_MATCH
	This one gets OBJ_bsearch_ex() to return a pointer to the first
	element where the comparing function returns zero.  This is useful
	if there are more than one element where the comparing function
	returns zero.
     [Richard Levitte]

  *) Make it possible to create self-signed certificates with 'openssl ca'
     in such a way that the self-signed certificate becomes part of the
     CA database and uses the same mechanisms for serial number generation
     as all other certificate signing.  The new flag '-selfsign' enables
     this functionality.  Adapt CA.sh and CA.pl.in.
     [Richard Levitte]

  *) Add functionality to check the public key of a certificate request
     against a given private.  This is useful to check that a certificate
     request can be signed by that key (self-signing).
     [Richard Levitte]

  *) Make it possible to have multiple active certificates with the same
     subject in the CA index file.  This is done only if the keyword
     'unique_subject' is set to 'no' in the main CA section (default
     if 'CA_default') of the configuration file.  The value is saved
     with the database itself in a separate index attribute file,
     named like the index file with '.attr' appended to the name.
     [Richard Levitte]

  *) Generate muti valued AVAs using '+' notation in config files for
     req and dirName.
     [Steve Henson]

  *) Support for nameConstraints certificate extension.
     [Steve Henson]

  *) Support for policyConstraints certificate extension.
     [Steve Henson]

  *) Support for policyMappings certificate extension.
     [Steve Henson]

  *) Fixed a typo bug that would cause ENGINE_set_default() to set an
     ENGINE as defaults for all supported algorithms irrespective of
     the 'flags' parameter. 'flags' is now honoured, so applications
     should make sure they are passing it correctly.
     [Geoff Thorpe]

  *) Make sure the default DSA_METHOD implementation only uses its
     dsa_mod_exp() and/or bn_mod_exp() handlers if they are non-NULL,
     and change its own handlers to be NULL so as to remove unnecessary
     indirection. This lets alternative implementations fallback to the
     default implementation more easily.
     [Geoff Thorpe]

  *) Support for directoryName in GeneralName related extensions
     in config files.
     [Steve Henson]

  *) Make it possible to link applications using Makefile.shared.
     Make that possible even when linking against static libraries!
     [Richard Levitte]

  *) Various fixes to base64 BIO and non blocking I/O. On write 
     flushes were not handled properly if the BIO retried. On read
     data was not being buffered properly and had various logic bugs.
     [Steve Henson]

  *) Support for single pass processing for S/MIME signing. This now
     means that S/MIME signing can be done from a pipe, in addition
     cleartext signing (multipart/signed type) is effectively streaming
     and the signed data does not need to be all held in memory.

     This is done with a new flag PKCS7_STREAM. When this flag is set
     PKCS7_sign() only initializes the PKCS7 structure and the actual signing
     is done after the data is output (and digests calculated) in
     SMIME_write_PKCS7().
     [Steve Henson]

  *) Add full support for -rpath/-R, both in shared libraries and
     applications, at least on the platforms where it's known how
     to do it.
     [Richard Levitte]

  *) In crypto/ec/ec_mult.c, implement fast point multiplication with
     precomputation, based on wNAF splitting: EC_GROUP_precompute_mult()
     will now compute a table of multiples of the generator that
     makes subsequent invocations of EC_POINTs_mul() or EC_POINT_mul()
     faster (notably in the case of a single point multiplication,
     scalar * generator).
     [Nils Larsch, Bodo Moeller]

  *) IPv6 support for certificate extensions. The various extensions
     which use the IP:a.b.c.d can now take IPv6 addresses using the
     formats of RFC1884 2.2 . IPv6 addresses are now also displayed
     correctly.
     [Steve Henson]

  *) Added an ENGINE that implements RSA by performing private key
     exponentiations with the GMP library. The conversions to and from
     GMP's mpz_t format aren't optimised nor are any montgomery forms
     cached, and on x86 it appears OpenSSL's own performance has caught up.
     However there are likely to be other architectures where GMP could
     provide a boost. This ENGINE is not built in by default, but it can be
     specified at Configure time and should be accompanied by the necessary
     linker additions, eg;
         ./config -DOPENSSL_USE_GMP -lgmp
     [Geoff Thorpe]

  *) "openssl engine" will not display ENGINE/DSO load failure errors when
     testing availability of engines with "-t" - the old behaviour is
     produced by increasing the feature's verbosity with "-tt".
     [Geoff Thorpe]

  *) ECDSA routines: under certain error conditions uninitialized BN objects
     could be freed. Solution: make sure initialization is performed early
     enough. (Reported and fix supplied by Nils Larsch <nla@trustcenter.de>
     via PR#459)
     [Lutz Jaenicke]

  *) Key-generation can now be implemented in RSA_METHOD, DSA_METHOD
     and DH_METHOD (eg. by ENGINE implementations) to override the normal
     software implementations. For DSA and DH, parameter generation can
     also be overriden by providing the appropriate method callbacks.
     [Geoff Thorpe]

  *) Change the "progress" mechanism used in key-generation and
     primality testing to functions that take a new BN_GENCB pointer in
     place of callback/argument pairs. The new API functions have "_ex"
     postfixes and the older functions are reimplemented as wrappers for
     the new ones. The OPENSSL_NO_DEPRECATED symbol can be used to hide
     declarations of the old functions to help (graceful) attempts to
     migrate to the new functions. Also, the new key-generation API
     functions operate on a caller-supplied key-structure and return
     success/failure rather than returning a key or NULL - this is to
     help make "keygen" another member function of RSA_METHOD etc.

     Example for using the new callback interface:

          int (*my_callback)(int a, int b, BN_GENCB *cb) = ...;
          void *my_arg = ...;
          BN_GENCB my_cb;

          BN_GENCB_set(&my_cb, my_callback, my_arg);

          return BN_is_prime_ex(some_bignum, BN_prime_checks, NULL, &cb);
          /* For the meaning of a, b in calls to my_callback(), see the
           * documentation of the function that calls the callback.
           * cb will point to my_cb; my_arg can be retrieved as cb->arg.
           * my_callback should return 1 if it wants BN_is_prime_ex()
           * to continue, or 0 to stop.
           */

     [Geoff Thorpe]

  *) Change the ZLIB compression method to be stateful, and make it
     available to TLS with the number defined in 
     draft-ietf-tls-compression-04.txt.
     [Richard Levitte]

  *) Add the ASN.1 structures and functions for CertificatePair, which
     is defined as follows (according to X.509_4thEditionDraftV6.pdf):

     CertificatePair ::= SEQUENCE {
        forward		[0]	Certificate OPTIONAL,
        reverse		[1]	Certificate OPTIONAL,
        -- at least one of the pair shall be present -- }

     Also implement the PEM functions to read and write certificate
     pairs, and defined the PEM tag as "CERTIFICATE PAIR".

     This needed to be defined, mostly for the sake of the LDAP
     attribute crossCertificatePair, but may prove useful elsewhere as
     well.
     [Richard Levitte]

  *) Make it possible to inhibit symlinking of shared libraries in
     Makefile.shared, for Cygwin's sake.
     [Richard Levitte]

  *) Extend the BIGNUM API by creating new macros that behave like
     functions

          void BN_set_sign(BIGNUM *a, int neg);
          int BN_get_sign(const BIGNUM *a);

     and avoid the need to access 'a->neg' directly in applications.
     [Nils Larsch  <nla@trustcenter.de>]

  *) Implement fast modular reduction for pseudo-Mersenne primes
     used in NIST curves (crypto/bn/bn_nist.c, crypto/ec/ecp_nist.c).
     EC_GROUP_new_curve_GFp() will now automatically use this
     if applicable.
     [Nils Larsch <nla@trustcenter.de>]

  *) Add new lock type (CRYPTO_LOCK_BN).
     [Bodo Moeller]

  *) Change the ENGINE framework to automatically load engines
     dynamically from specific directories unless they could be
     found to already be built in or loaded.  Move all the
     current engines except for the cryptodev one to a new
     directory engines/.
     The engines in engines/ are built as shared libraries if
     the "shared" options was given to ./Configure or ./config.
     Otherwise, they are inserted in libcrypto.a.
     /usr/local/ssl/engines is the default directory for dynamic
     engines, but that can be overriden at configure time through
     the usual use of --prefix and/or --openssldir, and at run
     time with the environment variable OPENSSL_ENGINES.
     [Geoff Thorpe and Richard Levitte]

  *) Add Makefile.shared, a helper makefile to build shared
     libraries.  Addapt Makefile.org.
     [Richard Levitte]

  *) Add version info to Win32 DLLs.
     [Peter 'Luna' Runestig" <peter@runestig.com>]

  *) Add new 'medium level' PKCS#12 API. Certificates and keys
     can be added using this API to created arbitrary PKCS#12
     files while avoiding the low level API.

     New options to PKCS12_create(), key or cert can be NULL and
     will then be omitted from the output file. The encryption
     algorithm NIDs can be set to -1 for no encryption, the mac
     iteration count can be set to 0 to omit the mac.

     Enhance pkcs12 utility by making the -nokeys and -nocerts
     options work when creating a PKCS#12 file. New option -nomac
     to omit the mac, NONE can be set for an encryption algorithm.
     New code is modified to use the enhanced PKCS12_create()
     instead of the low level API.
     [Steve Henson]

  *) Extend ASN1 encoder to support indefinite length constructed
     encoding. This can output sequences tags and octet strings in
     this form. Modify pk7_asn1.c to support indefinite length
     encoding. This is experimental and needs additional code to
     be useful, such as an ASN1 bio and some enhanced streaming
     PKCS#7 code.

     Extend template encode functionality so that tagging is passed
     down to the template encoder.
     [Steve Henson]

  *) Let 'openssl req' fail if an argument to '-newkey' is not
     recognized instead of using RSA as a default.
     [Bodo Moeller]

  *) Add support for ECC-based ciphersuites from draft-ietf-tls-ecc-01.txt.
     As these are not official, they are not included in "ALL";
     the "ECCdraft" ciphersuite group alias can be used to select them.
     [Vipul Gupta and Sumit Gupta (Sun Microsystems Laboratories)]

  *) Add ECDH engine support.
     [Nils Gura and Douglas Stebila (Sun Microsystems Laboratories)]

  *) Add ECDH in new directory crypto/ecdh/.
     [Douglas Stebila (Sun Microsystems Laboratories)]

  *) Let BN_rand_range() abort with an error after 100 iterations
     without success (which indicates a broken PRNG).
     [Bodo Moeller]

  *) Change BN_mod_sqrt() so that it verifies that the input value
     is really the square of the return value.  (Previously,
     BN_mod_sqrt would show GIGO behaviour.)
     [Bodo Moeller]

  *) Add named elliptic curves over binary fields from X9.62, SECG,
     and WAP/WTLS; add OIDs that were still missing.

     [Sheueling Chang Shantz and Douglas Stebila
     (Sun Microsystems Laboratories)]

  *) Extend the EC library for elliptic curves over binary fields
     (new files ec2_smpl.c, ec2_smpt.c, ec2_mult.c in crypto/ec/).
     New EC_METHOD:

          EC_GF2m_simple_method

     New API functions:

          EC_GROUP_new_curve_GF2m
          EC_GROUP_set_curve_GF2m
          EC_GROUP_get_curve_GF2m
          EC_POINT_set_affine_coordinates_GF2m
          EC_POINT_get_affine_coordinates_GF2m
          EC_POINT_set_compressed_coordinates_GF2m

     Point compression for binary fields is disabled by default for
     patent reasons (compile with OPENSSL_EC_BIN_PT_COMP defined to
     enable it).

     As binary polynomials are represented as BIGNUMs, various members
     of the EC_GROUP and EC_POINT data structures can be shared
     between the implementations for prime fields and binary fields;
     the above ..._GF2m functions (except for EX_GROUP_new_curve_GF2m)
     are essentially identical to their ..._GFp counterparts.
     (For simplicity, the '..._GFp' prefix has been dropped from
     various internal method names.)

     An internal 'field_div' method (similar to 'field_mul' and
     'field_sqr') has been added; this is used only for binary fields.

     [Sheueling Chang Shantz and Douglas Stebila
     (Sun Microsystems Laboratories)]

  *) Optionally dispatch EC_POINT_mul(), EC_POINT_precompute_mult()
     through methods ('mul', 'precompute_mult').

     The generic implementations (now internally called 'ec_wNAF_mul'
     and 'ec_wNAF_precomputed_mult') remain the default if these
     methods are undefined.

     [Sheueling Chang Shantz and Douglas Stebila
     (Sun Microsystems Laboratories)]

  *) New function EC_GROUP_get_degree, which is defined through
     EC_METHOD.  For curves over prime fields, this returns the bit
     length of the modulus.

     [Sheueling Chang Shantz and Douglas Stebila
     (Sun Microsystems Laboratories)]

  *) New functions EC_GROUP_dup, EC_POINT_dup.
     (These simply call ..._new  and ..._copy).

     [Sheueling Chang Shantz and Douglas Stebila
     (Sun Microsystems Laboratories)]

  *) Add binary polynomial arithmetic software in crypto/bn/bn_gf2m.c.
     Polynomials are represented as BIGNUMs (where the sign bit is not
     used) in the following functions [macros]:  

          BN_GF2m_add
          BN_GF2m_sub             [= BN_GF2m_add]
          BN_GF2m_mod             [wrapper for BN_GF2m_mod_arr]
          BN_GF2m_mod_mul         [wrapper for BN_GF2m_mod_mul_arr]
          BN_GF2m_mod_sqr         [wrapper for BN_GF2m_mod_sqr_arr]
          BN_GF2m_mod_inv
          BN_GF2m_mod_exp         [wrapper for BN_GF2m_mod_exp_arr]
          BN_GF2m_mod_sqrt        [wrapper for BN_GF2m_mod_sqrt_arr]
          BN_GF2m_mod_solve_quad  [wrapper for BN_GF2m_mod_solve_quad_arr]
          BN_GF2m_cmp             [= BN_ucmp]

     (Note that only the 'mod' functions are actually for fields GF(2^m).
     BN_GF2m_add() is misnomer, but this is for the sake of consistency.)

     For some functions, an the irreducible polynomial defining a
     field can be given as an 'unsigned int[]' with strictly
     decreasing elements giving the indices of those bits that are set;
     i.e., p[] represents the polynomial
          f(t) = t^p[0] + t^p[1] + ... + t^p[k]
     where
          p[0] > p[1] > ... > p[k] = 0.
     This applies to the following functions:

          BN_GF2m_mod_arr
          BN_GF2m_mod_mul_arr
          BN_GF2m_mod_sqr_arr
          BN_GF2m_mod_inv_arr        [wrapper for BN_GF2m_mod_inv]
          BN_GF2m_mod_div_arr        [wrapper for BN_GF2m_mod_div]
          BN_GF2m_mod_exp_arr
          BN_GF2m_mod_sqrt_arr
          BN_GF2m_mod_solve_quad_arr
          BN_GF2m_poly2arr
          BN_GF2m_arr2poly

     Conversion can be performed by the following functions:

          BN_GF2m_poly2arr
          BN_GF2m_arr2poly

     bntest.c has additional tests for binary polynomial arithmetic.

     Two implementations for BN_GF2m_mod_div() are available.
     The default algorithm simply uses BN_GF2m_mod_inv() and
     BN_GF2m_mod_mul().  The alternative algorithm is compiled in only
     if OPENSSL_SUN_GF2M_DIV is defined (patent pending; read the
     copyright notice in crypto/bn/bn_gf2m.c before enabling it).

     [Sheueling Chang Shantz and Douglas Stebila
     (Sun Microsystems Laboratories)]

  *) Add new error code 'ERR_R_DISABLED' that can be used when some
     functionality is disabled at compile-time.
     [Douglas Stebila <douglas.stebila@sun.com>]

  *) Change default behaviour of 'openssl asn1parse' so that more
     information is visible when viewing, e.g., a certificate:

     Modify asn1_parse2 (crypto/asn1/asn1_par.c) so that in non-'dump'
     mode the content of non-printable OCTET STRINGs is output in a
     style similar to INTEGERs, but with '[HEX DUMP]' prepended to
     avoid the appearance of a printable string.
     [Nils Larsch <nla@trustcenter.de>]

  *) Add 'asn1_flag' and 'asn1_form' member to EC_GROUP with access
     functions
          EC_GROUP_set_asn1_flag()
          EC_GROUP_get_asn1_flag()
          EC_GROUP_set_point_conversion_form()
          EC_GROUP_get_point_conversion_form()
     These control ASN1 encoding details:
     - Curves (i.e., groups) are encoded explicitly unless asn1_flag
       has been set to OPENSSL_EC_NAMED_CURVE.
     - Points are encoded in uncompressed form by default; options for
       asn1_for are as for point2oct, namely
          POINT_CONVERSION_COMPRESSED
          POINT_CONVERSION_UNCOMPRESSED
          POINT_CONVERSION_HYBRID

     Also add 'seed' and 'seed_len' members to EC_GROUP with access
     functions
          EC_GROUP_set_seed()
          EC_GROUP_get0_seed()
          EC_GROUP_get_seed_len()
     This is used only for ASN1 purposes (so far).
     [Nils Larsch <nla@trustcenter.de>]

  *) Add 'field_type' member to EC_METHOD, which holds the NID
     of the appropriate field type OID.  The new function
     EC_METHOD_get_field_type() returns this value.
     [Nils Larsch <nla@trustcenter.de>]

  *) Add functions 
          EC_POINT_point2bn()
          EC_POINT_bn2point()
          EC_POINT_point2hex()
          EC_POINT_hex2point()
     providing useful interfaces to EC_POINT_point2oct() and
     EC_POINT_oct2point().
     [Nils Larsch <nla@trustcenter.de>]

  *) Change internals of the EC library so that the functions
          EC_GROUP_set_generator()
          EC_GROUP_get_generator()
          EC_GROUP_get_order()
          EC_GROUP_get_cofactor()
     are implemented directly in crypto/ec/ec_lib.c and not dispatched
     to methods, which would lead to unnecessary code duplication when
     adding different types of curves.
     [Nils Larsch <nla@trustcenter.de> with input by Bodo Moeller]

  *) Implement compute_wNAF (crypto/ec/ec_mult.c) without BIGNUM
     arithmetic, and such that modified wNAFs are generated
     (which avoid length expansion in many cases).
     [Bodo Moeller]

  *) Add a function EC_GROUP_check_discriminant() (defined via
     EC_METHOD) that verifies that the curve discriminant is non-zero.

     Add a function EC_GROUP_check() that makes some sanity tests
     on a EC_GROUP, its generator and order.  This includes
     EC_GROUP_check_discriminant().
     [Nils Larsch <nla@trustcenter.de>]

  *) Add ECDSA in new directory crypto/ecdsa/.

     Add applications 'openssl ecparam' and 'openssl ecdsa'
     (these are based on 'openssl dsaparam' and 'openssl dsa').

     ECDSA support is also included in various other files across the
     library.  Most notably,
     - 'openssl req' now has a '-newkey ecdsa:file' option;
     - EVP_PKCS82PKEY (crypto/evp/evp_pkey.c) now can handle ECDSA;
     - X509_PUBKEY_get (crypto/asn1/x_pubkey.c) and
       d2i_PublicKey (crypto/asn1/d2i_pu.c) have been modified to make
       them suitable for ECDSA where domain parameters must be
       extracted before the specific public key;
     - ECDSA engine support has been added.
     [Nils Larsch <nla@trustcenter.de>]

  *) Include some named elliptic curves, and add OIDs from X9.62,
     SECG, and WAP/WTLS.  Each curve can be obtained from the new
     function
          EC_GROUP_new_by_nid(),
     and the list of available named curves can be obtained with
          EC_get_builtin_curves().
     Also add a 'curve_name' member to EC_GROUP objects, which can be
     accessed via
         EC_GROUP_set_nid()
         EC_GROUP_get_nid()
     [Nils Larsch <nla@trustcenter.de, Bodo Moeller]
 
  *) Remove a few calls to bn_wexpand() in BN_sqr() (the one in there
     was actually never needed) and in BN_mul().  The removal in BN_mul()
     required a small change in bn_mul_part_recursive() and the addition
     of the functions bn_cmp_part_words(), bn_sub_part_words() and
     bn_add_part_words(), which do the same thing as bn_cmp_words(),
     bn_sub_words() and bn_add_words() except they take arrays with
     differing sizes.
     [Richard Levitte]

 Changes between 0.9.7a and 0.9.7b  [xx XXX 2003]

  *) Countermeasure against the Klima-Pokorny-Rosa extension of
     Bleichbacher's attack on PKCS #1 v1.5 padding: treat
     a protocol version number mismatch like a decryption error
     in ssl3_get_client_key_exchange (ssl/s3_srvr.c).
     [Bodo Moeller]

  *) Turn on RSA blinding by default in the default implementation
     to avoid a timing attack. Applications that don't want it can call
     RSA_blinding_off() or use the new flag RSA_FLAG_NO_BLINDING.
     They would be ill-advised to do so in most cases.
     [Ben Laurie, Steve Henson, Geoff Thorpe, Bodo Moeller]

  *) Change RSA blinding code so that it works when the PRNG is not
     seeded (in this case, the secret RSA exponent is abused as
     an unpredictable seed -- if it is not unpredictable, there
     is no point in blinding anyway).  Make RSA blinding thread-safe
     by remembering the creator's thread ID in rsa->blinding and
     having all other threads use local one-time blinding factors
     (this requires more computation than sharing rsa->blinding, but
     avoids excessive locking; and if an RSA object is not shared
     between threads, blinding will still be very fast).
     [Bodo Moeller]

yet to be integrated into this CVS branch:
- Geoff's ENGINE_set_default() fix

  *) Target "mingw" now allows native Windows code to be generated in
     the Cygwin environment as well as with the MinGW compiler.
     [Ulf Moeller] 

 Changes between 0.9.7 and 0.9.7a  [19 Feb 2003]

  *) In ssl3_get_record (ssl/s3_pkt.c), minimize information leaked
     via timing by performing a MAC computation even if incorrrect
     block cipher padding has been found.  This is a countermeasure
     against active attacks where the attacker has to distinguish
     between bad padding and a MAC verification error. (CAN-2003-0078)

     [Bodo Moeller; problem pointed out by Brice Canvel (EPFL),
     Alain Hiltgen (UBS), Serge Vaudenay (EPFL), and
     Martin Vuagnoux (EPFL, Ilion)]

  *) Make the no-err option work as intended.  The intention with no-err
     is not to have the whole error stack handling routines removed from
     libcrypto, it's only intended to remove all the function name and
     reason texts, thereby removing some of the footprint that may not
     be interesting if those errors aren't displayed anyway.

     NOTE: it's still possible for any application or module to have it's
     own set of error texts inserted.  The routines are there, just not
     used by default when no-err is given.
     [Richard Levitte]

  *) Add support for FreeBSD on IA64.
     [dirk.meyer@dinoex.sub.org via Richard Levitte, resolves #454]

  *) Adjust DES_cbc_cksum() so it returns the same value as the MIT
     Kerberos function mit_des_cbc_cksum().  Before this change,
     the value returned by DES_cbc_cksum() was like the one from
     mit_des_cbc_cksum(), except the bytes were swapped.
     [Kevin Greaney <Kevin.Greaney@hp.com> and Richard Levitte]

  *) Allow an application to disable the automatic SSL chain building.
     Before this a rather primitive chain build was always performed in
     ssl3_output_cert_chain(): an application had no way to send the 
     correct chain if the automatic operation produced an incorrect result.

     Now the chain builder is disabled if either:

     1. Extra certificates are added via SSL_CTX_add_extra_chain_cert().

     2. The mode flag SSL_MODE_NO_AUTO_CHAIN is set.

     The reasoning behind this is that an application would not want the
     auto chain building to take place if extra chain certificates are
     present and it might also want a means of sending no additional
     certificates (for example the chain has two certificates and the
     root is omitted).
     [Steve Henson]

  *) Add the possibility to build without the ENGINE framework.
     [Steven Reddie <smr@essemer.com.au> via Richard Levitte]

  *) Under Win32 gmtime() can return NULL: check return value in
     OPENSSL_gmtime(). Add error code for case where gmtime() fails.
     [Steve Henson]

  *) DSA routines: under certain error conditions uninitialized BN objects
     could be freed. Solution: make sure initialization is performed early
     enough. (Reported and fix supplied by Ivan D Nestlerode <nestler@MIT.EDU>,
     Nils Larsch <nla@trustcenter.de> via PR#459)
     [Lutz Jaenicke]

  *) Another fix for SSLv2 session ID handling: the session ID was incorrectly
     checked on reconnect on the client side, therefore session resumption
     could still fail with a "ssl session id is different" error. This
     behaviour is masked when SSL_OP_ALL is used due to
     SSL_OP_MICROSOFT_SESS_ID_BUG being set.
     Behaviour observed by Crispin Flowerday <crispin@flowerday.cx> as
     followup to PR #377.
     [Lutz Jaenicke]

  *) IA-32 assembler support enhancements: unified ELF targets, support
     for SCO/Caldera platforms, fix for Cygwin shared build.
     [Andy Polyakov]

  *) Add support for FreeBSD on sparc64.  As a consequence, support for
     FreeBSD on non-x86 processors is separate from x86 processors on
     the config script, much like the NetBSD support.
     [Richard Levitte & Kris Kennaway <kris@obsecurity.org>]

 Changes between 0.9.6h and 0.9.7  [31 Dec 2002]

  *) Fix session ID handling in SSLv2 client code: the SERVER FINISHED
     code (06) was taken as the first octet of the session ID and the last
     octet was ignored consequently. As a result SSLv2 client side session
     caching could not have worked due to the session ID mismatch between
     client and server.
     Behaviour observed by Crispin Flowerday <crispin@flowerday.cx> as
     PR #377.
     [Lutz Jaenicke]

  *) Change the declaration of needed Kerberos libraries to use EX_LIBS
     instead of the special (and badly supported) LIBKRB5.  LIBKRB5 is
     removed entirely.
     [Richard Levitte]

  *) The hw_ncipher.c engine requires dynamic locks.  Unfortunately, it
     seems that in spite of existing for more than a year, many application
     author have done nothing to provide the necessary callbacks, which
     means that this particular engine will not work properly anywhere.
     This is a very unfortunate situation which forces us, in the name
     of usability, to give the hw_ncipher.c a static lock, which is part
     of libcrypto.
     NOTE: This is for the 0.9.7 series ONLY.  This hack will never
     appear in 0.9.8 or later.  We EXPECT application authors to have
     dealt properly with this when 0.9.8 is released (unless we actually
     make such changes in the libcrypto locking code that changes will
     have to be made anyway).
     [Richard Levitte]

  *) In asn1_d2i_read_bio() repeatedly call BIO_read() until all content
     octets have been read, EOF or an error occurs. Without this change
     some truncated ASN1 structures will not produce an error.
     [Steve Henson]

  *) Disable Heimdal support, since it hasn't been fully implemented.
     Still give the possibility to force the use of Heimdal, but with
     warnings and a request that patches get sent to openssl-dev.
     [Richard Levitte]

  *) Add the VC-CE target, introduce the WINCE sysname, and add
     INSTALL.WCE and appropriate conditionals to make it build.
     [Steven Reddie <smr@essemer.com.au> via Richard Levitte]

  *) Change the DLL names for Cygwin to cygcrypto-x.y.z.dll and
     cygssl-x.y.z.dll, where x, y and z are the major, minor and
     edit numbers of the version.
     [Corinna Vinschen <vinschen@redhat.com> and Richard Levitte]

  *) Introduce safe string copy and catenation functions
     (BUF_strlcpy() and BUF_strlcat()).
     [Ben Laurie (CHATS) and Richard Levitte]

  *) Avoid using fixed-size buffers for one-line DNs.
     [Ben Laurie (CHATS)]

  *) Add BUF_MEM_grow_clean() to avoid information leakage when
     resizing buffers containing secrets, and use where appropriate.
     [Ben Laurie (CHATS)]

  *) Avoid using fixed size buffers for configuration file location.
     [Ben Laurie (CHATS)]

  *) Avoid filename truncation for various CA files.
     [Ben Laurie (CHATS)]

  *) Use sizeof in preference to magic numbers.
     [Ben Laurie (CHATS)]

  *) Avoid filename truncation in cert requests.
     [Ben Laurie (CHATS)]

  *) Add assertions to check for (supposedly impossible) buffer
     overflows.
     [Ben Laurie (CHATS)]

  *) Don't cache truncated DNS entries in the local cache (this could
     potentially lead to a spoofing attack).
     [Ben Laurie (CHATS)]

  *) Fix various buffers to be large enough for hex/decimal
     representations in a platform independent manner.
     [Ben Laurie (CHATS)]

  *) Add CRYPTO_realloc_clean() to avoid information leakage when
     resizing buffers containing secrets, and use where appropriate.
     [Ben Laurie (CHATS)]

  *) Add BIO_indent() to avoid much slightly worrying code to do
     indents.
     [Ben Laurie (CHATS)]

  *) Convert sprintf()/BIO_puts() to BIO_printf().
     [Ben Laurie (CHATS)]

  *) buffer_gets() could terminate with the buffer only half
     full. Fixed.
     [Ben Laurie (CHATS)]

  *) Add assertions to prevent user-supplied crypto functions from
     overflowing internal buffers by having large block sizes, etc.
     [Ben Laurie (CHATS)]

  *) New OPENSSL_assert() macro (similar to assert(), but enabled
     unconditionally).
     [Ben Laurie (CHATS)]

  *) Eliminate unused copy of key in RC4.
     [Ben Laurie (CHATS)]

  *) Eliminate unused and incorrectly sized buffers for IV in pem.h.
     [Ben Laurie (CHATS)]

  *) Fix off-by-one error in EGD path.
     [Ben Laurie (CHATS)]

  *) If RANDFILE path is too long, ignore instead of truncating.
     [Ben Laurie (CHATS)]

  *) Eliminate unused and incorrectly sized X.509 structure
     CBCParameter.
     [Ben Laurie (CHATS)]

  *) Eliminate unused and dangerous function knumber().
     [Ben Laurie (CHATS)]

  *) Eliminate unused and dangerous structure, KSSL_ERR.
     [Ben Laurie (CHATS)]

  *) Protect against overlong session ID context length in an encoded
     session object. Since these are local, this does not appear to be
     exploitable.
     [Ben Laurie (CHATS)]

  *) Change from security patch (see 0.9.6e below) that did not affect
     the 0.9.6 release series:

     Remote buffer overflow in SSL3 protocol - an attacker could
     supply an oversized master key in Kerberos-enabled versions.
     (CAN-2002-0657)
     [Ben Laurie (CHATS)]

  *) Change the SSL kerb5 codes to match RFC 2712.
     [Richard Levitte]

  *) Make -nameopt work fully for req and add -reqopt switch.
     [Michael Bell <michael.bell@rz.hu-berlin.de>, Steve Henson]

  *) The "block size" for block ciphers in CFB and OFB mode should be 1.
     [Steve Henson, reported by Yngve Nysaeter Pettersen <yngve@opera.com>]

  *) Make sure tests can be performed even if the corresponding algorithms
     have been removed entirely.  This was also the last step to make
     OpenSSL compilable with DJGPP under all reasonable conditions.
     [Richard Levitte, Doug Kaufman <dkaufman@rahul.net>]

  *) Add cipher selection rules COMPLEMENTOFALL and COMPLEMENTOFDEFAULT
     to allow version independent disabling of normally unselected ciphers,
     which may be activated as a side-effect of selecting a single cipher.

     (E.g., cipher list string "RSA" enables ciphersuites that are left
     out of "ALL" because they do not provide symmetric encryption.
     "RSA:!COMPLEMEMENTOFALL" avoids these unsafe ciphersuites.)
     [Lutz Jaenicke, Bodo Moeller]

  *) Add appropriate support for separate platform-dependent build
     directories.  The recommended way to make a platform-dependent
     build directory is the following (tested on Linux), maybe with
     some local tweaks:

	# Place yourself outside of the OpenSSL source tree.  In
	# this example, the environment variable OPENSSL_SOURCE
	# is assumed to contain the absolute OpenSSL source directory.
	mkdir -p objtree/"`uname -s`-`uname -r`-`uname -m`"
	cd objtree/"`uname -s`-`uname -r`-`uname -m`"
	(cd $OPENSSL_SOURCE; find . -type f) | while read F; do
		mkdir -p `dirname $F`
		ln -s $OPENSSL_SOURCE/$F $F
	done

     To be absolutely sure not to disturb the source tree, a "make clean"
     is a good thing.  If it isn't successfull, don't worry about it,
     it probably means the source directory is very clean.
     [Richard Levitte]

  *) Make sure any ENGINE control commands make local copies of string
     pointers passed to them whenever necessary. Otherwise it is possible
     the caller may have overwritten (or deallocated) the original string
     data when a later ENGINE operation tries to use the stored values.