Skip to content
CHANGES 574 KiB
Newer Older
11001 11002 11003 11004 11005 11006 11007 11008 11009 11010 11011 11012 11013 11014 11015 11016 11017 11018 11019 11020 11021 11022 11023 11024 11025 11026 11027 11028 11029 11030 11031 11032 11033 11034 11035 11036 11037 11038 11039 11040 11041 11042 11043 11044 11045 11046 11047 11048 11049 11050 11051 11052 11053 11054 11055 11056 11057 11058 11059 11060 11061 11062 11063 11064 11065 11066 11067 11068 11069 11070 11071 11072 11073 11074 11075 11076 11077 11078 11079 11080 11081 11082 11083 11084 11085 11086 11087 11088 11089 11090 11091 11092 11093 11094 11095 11096 11097 11098 11099 11100 11101 11102 11103 11104 11105 11106 11107 11108 11109 11110 11111 11112 11113 11114 11115 11116 11117 11118 11119 11120 11121 11122 11123 11124 11125 11126 11127 11128 11129 11130 11131 11132 11133 11134 11135 11136 11137 11138 11139 11140 11141 11142 11143 11144 11145 11146 11147 11148 11149 11150 11151 11152 11153 11154 11155 11156 11157 11158 11159 11160 11161 11162 11163 11164 11165 11166 11167 11168 11169 11170 11171 11172 11173 11174 11175 11176 11177 11178 11179 11180 11181 11182 11183 11184 11185 11186 11187 11188 11189 11190 11191 11192 11193 11194 11195 11196 11197 11198 11199 11200 11201 11202 11203 11204 11205 11206 11207 11208 11209 11210 11211 11212 11213 11214 11215 11216 11217 11218 11219 11220 11221 11222 11223 11224 11225 11226 11227 11228 11229 11230 11231 11232 11233 11234 11235 11236 11237 11238 11239 11240 11241 11242 11243 11244 11245 11246 11247 11248 11249 11250 11251 11252 11253 11254 11255 11256 11257 11258 11259 11260 11261 11262 11263 11264 11265 11266 11267 11268 11269 11270 11271 11272 11273 11274 11275 11276 11277 11278 11279 11280 11281 11282 11283 11284 11285 11286 11287 11288 11289 11290 11291 11292 11293 11294 11295 11296 11297 11298 11299 11300 11301 11302 11303 11304 11305 11306 11307 11308 11309 11310 11311 11312 11313 11314 11315 11316 11317 11318 11319 11320 11321 11322 11323 11324 11325 11326 11327 11328 11329 11330 11331 11332 11333 11334 11335 11336 11337 11338 11339 11340 11341 11342 11343 11344 11345 11346 11347 11348 11349 11350 11351 11352 11353 11354 11355 11356 11357 11358 11359 11360 11361 11362 11363 11364 11365 11366 11367 11368 11369 11370 11371 11372 11373 11374 11375 11376 11377 11378 11379 11380 11381 11382 11383 11384 11385 11386 11387 11388 11389 11390 11391 11392 11393 11394 11395 11396 11397 11398 11399 11400 11401 11402 11403 11404 11405 11406 11407 11408 11409 11410 11411 11412 11413 11414 11415 11416 11417 11418 11419 11420 11421 11422 11423 11424 11425 11426 11427 11428 11429 11430 11431 11432 11433 11434 11435 11436 11437 11438 11439 11440 11441 11442 11443 11444 11445 11446 11447 11448 11449 11450 11451 11452 11453 11454 11455 11456 11457 11458 11459 11460 11461 11462 11463 11464 11465 11466 11467 11468 11469 11470 11471 11472 11473 11474 11475 11476 11477 11478 11479 11480 11481 11482 11483 11484 11485 11486 11487 11488 11489 11490 11491 11492 11493 11494 11495 11496 11497 11498 11499 11500 11501 11502 11503 11504 11505 11506 11507 11508 11509 11510 11511 11512 11513 11514 11515 11516 11517 11518 11519 11520 11521 11522 11523 11524 11525 11526 11527 11528 11529 11530 11531 11532 11533 11534 11535 11536 11537 11538 11539 11540 11541 11542 11543 11544 11545 11546 11547 11548 11549 11550 11551 11552 11553 11554 11555 11556 11557 11558 11559 11560 11561 11562 11563 11564 11565 11566 11567 11568 11569 11570 11571 11572 11573 11574 11575 11576 11577 11578 11579 11580 11581 11582 11583 11584 11585 11586 11587 11588 11589 11590 11591 11592 11593 11594 11595 11596 11597 11598 11599 11600 11601 11602 11603 11604 11605 11606 11607 11608 11609 11610 11611 11612 11613 11614 11615 11616 11617 11618 11619 11620 11621 11622 11623 11624 11625 11626 11627 11628 11629 11630 11631 11632 11633 11634 11635 11636 11637 11638 11639 11640 11641 11642 11643 11644 11645 11646 11647 11648 11649 11650 11651 11652 11653 11654 11655 11656 11657 11658 11659 11660 11661 11662 11663 11664 11665 11666 11667 11668 11669 11670 11671 11672 11673 11674 11675 11676 11677 11678 11679 11680 11681 11682 11683 11684 11685 11686 11687 11688 11689 11690 11691 11692 11693 11694 11695 11696 11697 11698 11699 11700 11701 11702 11703 11704 11705 11706 11707 11708 11709 11710 11711 11712 11713 11714 11715 11716 11717 11718 11719 11720 11721 11722 11723 11724 11725 11726 11727 11728 11729 11730 11731 11732 11733 11734 11735 11736 11737 11738 11739 11740 11741 11742 11743 11744 11745 11746 11747 11748 11749 11750 11751 11752 11753 11754 11755 11756 11757 11758 11759 11760 11761 11762 11763 11764 11765 11766 11767 11768 11769 11770 11771 11772 11773 11774 11775 11776 11777 11778 11779 11780 11781 11782 11783 11784 11785 11786 11787 11788 11789 11790 11791 11792 11793 11794 11795 11796 11797 11798 11799 11800 11801 11802 11803 11804 11805 11806 11807 11808 11809 11810 11811 11812 11813 11814 11815 11816 11817 11818 11819 11820 11821 11822 11823 11824 11825 11826 11827 11828 11829 11830 11831 11832 11833 11834 11835 11836 11837 11838 11839 11840 11841 11842 11843 11844 11845 11846 11847 11848 11849 11850 11851 11852 11853 11854 11855 11856 11857 11858 11859 11860 11861 11862 11863 11864 11865 11866 11867 11868 11869 11870 11871 11872 11873 11874 11875 11876 11877 11878 11879 11880 11881 11882 11883 11884 11885 11886 11887 11888 11889 11890 11891 11892 11893 11894 11895 11896 11897 11898 11899 11900 11901 11902 11903 11904 11905 11906 11907 11908 11909 11910 11911 11912 11913 11914 11915 11916 11917 11918 11919 11920 11921 11922 11923 11924 11925 11926 11927 11928 11929 11930 11931 11932 11933 11934 11935 11936 11937 11938 11939 11940 11941 11942 11943 11944 11945 11946 11947 11948 11949 11950 11951 11952 11953 11954 11955 11956 11957 11958 11959 11960 11961 11962 11963 11964 11965 11966 11967 11968 11969 11970 11971 11972 11973 11974 11975 11976 11977 11978 11979 11980 11981 11982 11983 11984 11985 11986 11987 11988 11989 11990 11991 11992 11993 11994 11995 11996 11997 11998 11999 12000
     (Check if this is true? OpenPGP calls them "strong".)
     [Ulf Möller]

  *) Merge the functionality of "dh" and "gendh" programs into a new program
     "dhparam". The old programs are retained for now but will handle DH keys
     (instead of parameters) in future.
     [Steve Henson]

  *) Make the ciphers, s_server and s_client programs check the return values
     when a new cipher list is set.
     [Steve Henson]

  *) Enhance the SSL/TLS cipher mechanism to correctly handle the TLS 56bit
     ciphers. Before when the 56bit ciphers were enabled the sorting was
     wrong.

     The syntax for the cipher sorting has been extended to support sorting by
     cipher-strength (using the strength_bits hard coded in the tables).
     The new command is "@STRENGTH" (see also doc/apps/ciphers.pod).

     Fix a bug in the cipher-command parser: when supplying a cipher command
     string with an "undefined" symbol (neither command nor alphanumeric
     [A-Za-z0-9], ssl_set_cipher_list used to hang in an endless loop. Now
     an error is flagged.

     Due to the strength-sorting extension, the code of the
     ssl_create_cipher_list() function was completely rearranged. I hope that
     the readability was also increased :-)
     [Lutz Jaenicke <Lutz.Jaenicke@aet.TU-Cottbus.DE>]

  *) Minor change to 'x509' utility. The -CAcreateserial option now uses 1
     for the first serial number and places 2 in the serial number file. This
     avoids problems when the root CA is created with serial number zero and
     the first user certificate has the same issuer name and serial number
     as the root CA.
     [Steve Henson]

  *) Fixes to X509_ATTRIBUTE utilities, change the 'req' program so it uses
     the new code. Add documentation for this stuff.
     [Steve Henson]

  *) Changes to X509_ATTRIBUTE utilities. These have been renamed from
     X509_*() to X509at_*() on the grounds that they don't handle X509
     structures and behave in an analogous way to the X509v3 functions:
     they shouldn't be called directly but wrapper functions should be used
     instead.

     So we also now have some wrapper functions that call the X509at functions
     when passed certificate requests. (TO DO: similar things can be done with
     PKCS#7 signed and unsigned attributes, PKCS#12 attributes and a few other
     things. Some of these need some d2i or i2d and print functionality
     because they handle more complex structures.)
     [Steve Henson]

  *) Add missing #ifndefs that caused missing symbols when building libssl
     as a shared library without RSA.  Use #ifndef NO_SSL2 instead of
     NO_RSA in ssl/s2*.c.
     [Kris Kennaway <kris@hub.freebsd.org>, modified by Ulf Möller]

  *) Precautions against using the PRNG uninitialized: RAND_bytes() now
     has a return value which indicates the quality of the random data
     (1 = ok, 0 = not seeded).  Also an error is recorded on the thread's
     error queue. New function RAND_pseudo_bytes() generates output that is
     guaranteed to be unique but not unpredictable. RAND_add is like
     RAND_seed, but takes an extra argument for an entropy estimate
     (RAND_seed always assumes full entropy).
     [Ulf Möller]

  *) Do more iterations of Rabin-Miller probable prime test (specifically,
     3 for 1024-bit primes, 6 for 512-bit primes, 12 for 256-bit primes
     instead of only 2 for all lengths; see BN_prime_checks_for_size definition
     in crypto/bn/bn_prime.c for the complete table).  This guarantees a
     false-positive rate of at most 2^-80 for random input.
     [Bodo Moeller]

  *) Rewrite ssl3_read_n (ssl/s3_pkt.c) avoiding a couple of bugs.
     [Bodo Moeller]

  *) New function X509_CTX_rget_chain() (renamed to X509_CTX_get1_chain
     in the 0.9.5 release), this returns the chain
     from an X509_CTX structure with a dup of the stack and all
     the X509 reference counts upped: so the stack will exist
     after X509_CTX_cleanup() has been called. Modify pkcs12.c
     to use this.

     Also make SSL_SESSION_print() print out the verify return
     code.
     [Steve Henson]

  *) Add manpage for the pkcs12 command. Also change the default
     behaviour so MAC iteration counts are used unless the new
     -nomaciter option is used. This improves file security and
     only older versions of MSIE (4.0 for example) need it.
     [Steve Henson]

  *) Honor the no-xxx Configure options when creating .DEF files.
     [Ulf Möller]

  *) Add PKCS#10 attributes to field table: challengePassword,
     unstructuredName and unstructuredAddress. These are taken from
     draft PKCS#9 v2.0 but are compatible with v1.2 provided no
     international characters are used.

     More changes to X509_ATTRIBUTE code: allow the setting of types
     based on strings. Remove the 'loc' parameter when adding
     attributes because these will be a SET OF encoding which is sorted
     in ASN1 order.
     [Steve Henson]

  *) Initial changes to the 'req' utility to allow request generation
     automation. This will allow an application to just generate a template
     file containing all the field values and have req construct the
     request.

     Initial support for X509_ATTRIBUTE handling. Stacks of these are
     used all over the place including certificate requests and PKCS#7
     structures. They are currently handled manually where necessary with
     some primitive wrappers for PKCS#7. The new functions behave in a
     manner analogous to the X509 extension functions: they allow
     attributes to be looked up by NID and added.

     Later something similar to the X509V3 code would be desirable to
     automatically handle the encoding, decoding and printing of the
     more complex types. The string types like challengePassword can
     be handled by the string table functions.

     Also modified the multi byte string table handling. Now there is
     a 'global mask' which masks out certain types. The table itself
     can use the flag STABLE_NO_MASK to ignore the mask setting: this
     is useful when for example there is only one permissible type
     (as in countryName) and using the mask might result in no valid
     types at all.
     [Steve Henson]

  *) Clean up 'Finished' handling, and add functions SSL_get_finished and
     SSL_get_peer_finished to allow applications to obtain the latest
     Finished messages sent to the peer or expected from the peer,
     respectively.  (SSL_get_peer_finished is usually the Finished message
     actually received from the peer, otherwise the protocol will be aborted.)

     As the Finished message are message digests of the complete handshake
     (with a total of 192 bits for TLS 1.0 and more for SSL 3.0), they can
     be used for external authentication procedures when the authentication
     provided by SSL/TLS is not desired or is not enough.
     [Bodo Moeller]

  *) Enhanced support for Alpha Linux is added. Now ./config checks if
     the host supports BWX extension and if Compaq C is present on the
     $PATH. Just exploiting of the BWX extension results in 20-30%
     performance kick for some algorithms, e.g. DES and RC4 to mention
     a couple. Compaq C in turn generates ~20% faster code for MD5 and
     SHA1.
     [Andy Polyakov]

  *) Add support for MS "fast SGC". This is arguably a violation of the
     SSL3/TLS protocol. Netscape SGC does two handshakes: the first with
     weak crypto and after checking the certificate is SGC a second one
     with strong crypto. MS SGC stops the first handshake after receiving
     the server certificate message and sends a second client hello. Since
     a server will typically do all the time consuming operations before
     expecting any further messages from the client (server key exchange
     is the most expensive) there is little difference between the two.

     To get OpenSSL to support MS SGC we have to permit a second client
     hello message after we have sent server done. In addition we have to
     reset the MAC if we do get this second client hello.
     [Steve Henson]

  *) Add a function 'd2i_AutoPrivateKey()' this will automatically decide
     if a DER encoded private key is RSA or DSA traditional format. Changed
     d2i_PrivateKey_bio() to use it. This is only needed for the "traditional"
     format DER encoded private key. Newer code should use PKCS#8 format which
     has the key type encoded in the ASN1 structure. Added DER private key
     support to pkcs8 application.
     [Steve Henson]

  *) SSL 3/TLS 1 servers now don't request certificates when an anonymous
     ciphersuites has been selected (as required by the SSL 3/TLS 1
     specifications).  Exception: When SSL_VERIFY_FAIL_IF_NO_PEER_CERT
     is set, we interpret this as a request to violate the specification
     (the worst that can happen is a handshake failure, and 'correct'
     behaviour would result in a handshake failure anyway).
     [Bodo Moeller]

  *) In SSL_CTX_add_session, take into account that there might be multiple
     SSL_SESSION structures with the same session ID (e.g. when two threads
     concurrently obtain them from an external cache).
     The internal cache can handle only one SSL_SESSION with a given ID,
     so if there's a conflict, we now throw out the old one to achieve
     consistency.
     [Bodo Moeller]

  *) Add OIDs for idea and blowfish in CBC mode. This will allow both
     to be used in PKCS#5 v2.0 and S/MIME.  Also add checking to
     some routines that use cipher OIDs: some ciphers do not have OIDs
     defined and so they cannot be used for S/MIME and PKCS#5 v2.0 for
     example.
     [Steve Henson]

  *) Simplify the trust setting structure and code. Now we just have
     two sequences of OIDs for trusted and rejected settings. These will
     typically have values the same as the extended key usage extension
     and any application specific purposes.

     The trust checking code now has a default behaviour: it will just
     check for an object with the same NID as the passed id. Functions can
     be provided to override either the default behaviour or the behaviour
     for a given id. SSL client, server and email already have functions
     in place for compatibility: they check the NID and also return "trusted"
     if the certificate is self signed.
     [Steve Henson]

  *) Add d2i,i2d bio/fp functions for PrivateKey: these convert the
     traditional format into an EVP_PKEY structure.
     [Steve Henson]

  *) Add a password callback function PEM_cb() which either prompts for
     a password if usr_data is NULL or otherwise assumes it is a null
     terminated password. Allow passwords to be passed on command line
     environment or config files in a few more utilities.
     [Steve Henson]

  *) Add a bunch of DER and PEM functions to handle PKCS#8 format private
     keys. Add some short names for PKCS#8 PBE algorithms and allow them
     to be specified on the command line for the pkcs8 and pkcs12 utilities.
     Update documentation.
     [Steve Henson]

  *) Support for ASN1 "NULL" type. This could be handled before by using
     ASN1_TYPE but there wasn't any function that would try to read a NULL
     and produce an error if it couldn't. For compatibility we also have
     ASN1_NULL_new() and ASN1_NULL_free() functions but these are faked and
     don't allocate anything because they don't need to.
     [Steve Henson]

  *) Initial support for MacOS is now provided. Examine INSTALL.MacOS
     for details.
     [Andy Polyakov, Roy Woods <roy@centicsystems.ca>]

  *) Rebuild of the memory allocation routines used by OpenSSL code and
     possibly others as well.  The purpose is to make an interface that
     provide hooks so anyone can build a separate set of allocation and
     deallocation routines to be used by OpenSSL, for example memory
     pool implementations, or something else, which was previously hard
     since Malloc(), Realloc() and Free() were defined as macros having
     the values malloc, realloc and free, respectively (except for Win32
     compilations).  The same is provided for memory debugging code.
     OpenSSL already comes with functionality to find memory leaks, but
     this gives people a chance to debug other memory problems.

     With these changes, a new set of functions and macros have appeared:

       CRYPTO_set_mem_debug_functions()         [F]
       CRYPTO_get_mem_debug_functions()         [F]
       CRYPTO_dbg_set_options()                 [F]
       CRYPTO_dbg_get_options()                 [F]
       CRYPTO_malloc_debug_init()               [M]

     The memory debug functions are NULL by default, unless the library
     is compiled with CRYPTO_MDEBUG or friends is defined.  If someone
     wants to debug memory anyway, CRYPTO_malloc_debug_init() (which
     gives the standard debugging functions that come with OpenSSL) or
     CRYPTO_set_mem_debug_functions() (tells OpenSSL to use functions
     provided by the library user) must be used.  When the standard
     debugging functions are used, CRYPTO_dbg_set_options can be used to
     request additional information:
     CRYPTO_dbg_set_options(V_CYRPTO_MDEBUG_xxx) corresponds to setting
     the CRYPTO_MDEBUG_xxx macro when compiling the library.

     Also, things like CRYPTO_set_mem_functions will always give the
     expected result (the new set of functions is used for allocation
     and deallocation) at all times, regardless of platform and compiler
     options.

     To finish it up, some functions that were never use in any other
     way than through macros have a new API and new semantic:

       CRYPTO_dbg_malloc()
       CRYPTO_dbg_realloc()
       CRYPTO_dbg_free()

     All macros of value have retained their old syntax.
     [Richard Levitte and Bodo Moeller]

  *) Some S/MIME fixes. The OID for SMIMECapabilities was wrong, the
     ordering of SMIMECapabilities wasn't in "strength order" and there
     was a missing NULL in the AlgorithmIdentifier for the SHA1 signature
     algorithm.
     [Steve Henson]

  *) Some ASN1 types with illegal zero length encoding (INTEGER,
     ENUMERATED and OBJECT IDENTIFIER) choked the ASN1 routines.
     [Frans Heymans <fheymans@isaserver.be>, modified by Steve Henson]

  *) Merge in my S/MIME library for OpenSSL. This provides a simple
     S/MIME API on top of the PKCS#7 code, a MIME parser (with enough
     functionality to handle multipart/signed properly) and a utility
     called 'smime' to call all this stuff. This is based on code I
     originally wrote for Celo who have kindly allowed it to be
     included in OpenSSL.
     [Steve Henson]

  *) Add variants des_set_key_checked and des_set_key_unchecked of
     des_set_key (aka des_key_sched).  Global variable des_check_key
     decides which of these is called by des_set_key; this way
     des_check_key behaves as it always did, but applications and
     the library itself, which was buggy for des_check_key == 1,
     have a cleaner way to pick the version they need.
     [Bodo Moeller]

  *) New function PKCS12_newpass() which changes the password of a
     PKCS12 structure.
     [Steve Henson]

  *) Modify X509_TRUST and X509_PURPOSE so it also uses a static and
     dynamic mix. In both cases the ids can be used as an index into the
     table. Also modified the X509_TRUST_add() and X509_PURPOSE_add()
     functions so they accept a list of the field values and the
     application doesn't need to directly manipulate the X509_TRUST
     structure.
     [Steve Henson]

  *) Modify the ASN1_STRING_TABLE stuff so it also uses bsearch and doesn't
     need initialising.
     [Steve Henson]

  *) Modify the way the V3 extension code looks up extensions. This now
     works in a similar way to the object code: we have some "standard"
     extensions in a static table which is searched with OBJ_bsearch()
     and the application can add dynamic ones if needed. The file
     crypto/x509v3/ext_dat.h now has the info: this file needs to be
     updated whenever a new extension is added to the core code and kept
     in ext_nid order. There is a simple program 'tabtest.c' which checks
     this. New extensions are not added too often so this file can readily
     be maintained manually.

     There are two big advantages in doing things this way. The extensions
     can be looked up immediately and no longer need to be "added" using
     X509V3_add_standard_extensions(): this function now does nothing.
     [Side note: I get *lots* of email saying the extension code doesn't
      work because people forget to call this function]
     Also no dynamic allocation is done unless new extensions are added:
     so if we don't add custom extensions there is no need to call
     X509V3_EXT_cleanup().
     [Steve Henson]

  *) Modify enc utility's salting as follows: make salting the default. Add a
     magic header, so unsalted files fail gracefully instead of just decrypting
     to garbage. This is because not salting is a big security hole, so people
     should be discouraged from doing it.
     [Ben Laurie]

  *) Fixes and enhancements to the 'x509' utility. It allowed a message
     digest to be passed on the command line but it only used this
     parameter when signing a certificate. Modified so all relevant
     operations are affected by the digest parameter including the
     -fingerprint and -x509toreq options. Also -x509toreq choked if a
     DSA key was used because it didn't fix the digest.
     [Steve Henson]

  *) Initial certificate chain verify code. Currently tests the untrusted
     certificates for consistency with the verify purpose (which is set
     when the X509_STORE_CTX structure is set up) and checks the pathlength.

     There is a NO_CHAIN_VERIFY compilation option to keep the old behaviour:
     this is because it will reject chains with invalid extensions whereas
     every previous version of OpenSSL and SSLeay made no checks at all.

     Trust code: checks the root CA for the relevant trust settings. Trust
     settings have an initial value consistent with the verify purpose: e.g.
     if the verify purpose is for SSL client use it expects the CA to be
     trusted for SSL client use. However the default value can be changed to
     permit custom trust settings: one example of this would be to only trust
     certificates from a specific "secure" set of CAs.

     Also added X509_STORE_CTX_new() and X509_STORE_CTX_free() functions
     which should be used for version portability: especially since the
     verify structure is likely to change more often now.

     SSL integration. Add purpose and trust to SSL_CTX and SSL and functions
     to set them. If not set then assume SSL clients will verify SSL servers
     and vice versa.

     Two new options to the verify program: -untrusted allows a set of
     untrusted certificates to be passed in and -purpose which sets the
     intended purpose of the certificate. If a purpose is set then the
     new chain verify code is used to check extension consistency.
     [Steve Henson]

  *) Support for the authority information access extension.
     [Steve Henson]

  *) Modify RSA and DSA PEM read routines to transparently handle
     PKCS#8 format private keys. New *_PUBKEY_* functions that handle
     public keys in a format compatible with certificate
     SubjectPublicKeyInfo structures. Unfortunately there were already
     functions called *_PublicKey_* which used various odd formats so
     these are retained for compatibility: however the DSA variants were
     never in a public release so they have been deleted. Changed dsa/rsa
     utilities to handle the new format: note no releases ever handled public
     keys so we should be OK.

     The primary motivation for this change is to avoid the same fiasco
     that dogs private keys: there are several incompatible private key
     formats some of which are standard and some OpenSSL specific and
     require various evil hacks to allow partial transparent handling and
     even then it doesn't work with DER formats. Given the option anything
     other than PKCS#8 should be dumped: but the other formats have to
     stay in the name of compatibility.

     With public keys and the benefit of hindsight one standard format
     is used which works with EVP_PKEY, RSA or DSA structures: though
     it clearly returns an error if you try to read the wrong kind of key.

     Added a -pubkey option to the 'x509' utility to output the public key.
     Also rename the EVP_PKEY_get_*() to EVP_PKEY_rget_*()
     (renamed to EVP_PKEY_get1_*() in the OpenSSL 0.9.5 release) and add
     EVP_PKEY_rset_*() functions (renamed to EVP_PKEY_set1_*())
     that do the same as the EVP_PKEY_assign_*() except they up the
     reference count of the added key (they don't "swallow" the
     supplied key).
     [Steve Henson]

  *) Fixes to crypto/x509/by_file.c the code to read in certificates and
     CRLs would fail if the file contained no certificates or no CRLs:
     added a new function to read in both types and return the number
     read: this means that if none are read it will be an error. The
     DER versions of the certificate and CRL reader would always fail
     because it isn't possible to mix certificates and CRLs in DER format
     without choking one or the other routine. Changed this to just read
     a certificate: this is the best we can do. Also modified the code
     in apps/verify.c to take notice of return codes: it was previously
     attempting to read in certificates from NULL pointers and ignoring
     any errors: this is one reason why the cert and CRL reader seemed
     to work. It doesn't check return codes from the default certificate
     routines: these may well fail if the certificates aren't installed.
     [Steve Henson]

  *) Code to support otherName option in GeneralName.
     [Steve Henson]

  *) First update to verify code. Change the verify utility
     so it warns if it is passed a self signed certificate:
     for consistency with the normal behaviour. X509_verify
     has been modified to it will now verify a self signed
     certificate if *exactly* the same certificate appears
     in the store: it was previously impossible to trust a
     single self signed certificate. This means that:
     openssl verify ss.pem
     now gives a warning about a self signed certificate but
     openssl verify -CAfile ss.pem ss.pem
     is OK.
     [Steve Henson]

  *) For servers, store verify_result in SSL_SESSION data structure
     (and add it to external session representation).
     This is needed when client certificate verifications fails,
     but an application-provided verification callback (set by
     SSL_CTX_set_cert_verify_callback) allows accepting the session
     anyway (i.e. leaves x509_store_ctx->error != X509_V_OK
     but returns 1): When the session is reused, we have to set
     ssl->verify_result to the appropriate error code to avoid
     security holes.
     [Bodo Moeller, problem pointed out by Lutz Jaenicke]

  *) Fix a bug in the new PKCS#7 code: it didn't consider the
     case in PKCS7_dataInit() where the signed PKCS7 structure
     didn't contain any existing data because it was being created.
     [Po-Cheng Chen <pocheng@nst.com.tw>, slightly modified by Steve Henson]

  *) Add a salt to the key derivation routines in enc.c. This
     forms the first 8 bytes of the encrypted file. Also add a
     -S option to allow a salt to be input on the command line.
     [Steve Henson]

  *) New function X509_cmp(). Oddly enough there wasn't a function
     to compare two certificates. We do this by working out the SHA1
     hash and comparing that. X509_cmp() will be needed by the trust
     code.
     [Steve Henson]

  *) SSL_get1_session() is like SSL_get_session(), but increments
     the reference count in the SSL_SESSION returned.
     [Geoff Thorpe <geoff@eu.c2.net>]

  *) Fix for 'req': it was adding a null to request attributes.
     Also change the X509_LOOKUP and X509_INFO code to handle
     certificate auxiliary information.
     [Steve Henson]

  *) Add support for 40 and 64 bit RC2 and RC4 algorithms: document
     the 'enc' command.
     [Steve Henson]

  *) Add the possibility to add extra information to the memory leak
     detecting output, to form tracebacks, showing from where each
     allocation was originated: CRYPTO_push_info("constant string") adds
     the string plus current file name and line number to a per-thread
     stack, CRYPTO_pop_info() does the obvious, CRYPTO_remove_all_info()
     is like calling CYRPTO_pop_info() until the stack is empty.
     Also updated memory leak detection code to be multi-thread-safe.
     [Richard Levitte]

  *) Add options -text and -noout to pkcs7 utility and delete the
     encryption options which never did anything. Update docs.
     [Steve Henson]

  *) Add options to some of the utilities to allow the pass phrase
     to be included on either the command line (not recommended on
     OSes like Unix) or read from the environment. Update the
     manpages and fix a few bugs.
     [Steve Henson]

  *) Add a few manpages for some of the openssl commands.
     [Steve Henson]

  *) Fix the -revoke option in ca. It was freeing up memory twice,
     leaking and not finding already revoked certificates.
     [Steve Henson]

  *) Extensive changes to support certificate auxiliary information.
     This involves the use of X509_CERT_AUX structure and X509_AUX
     functions. An X509_AUX function such as PEM_read_X509_AUX()
     can still read in a certificate file in the usual way but it
     will also read in any additional "auxiliary information". By
     doing things this way a fair degree of compatibility can be
     retained: existing certificates can have this information added
     using the new 'x509' options.

     Current auxiliary information includes an "alias" and some trust
     settings. The trust settings will ultimately be used in enhanced
     certificate chain verification routines: currently a certificate
     can only be trusted if it is self signed and then it is trusted
     for all purposes.
     [Steve Henson]

  *) Fix assembler for Alpha (tested only on DEC OSF not Linux or *BSD).
     The problem was that one of the replacement routines had not been working
     since SSLeay releases.  For now the offending routine has been replaced
     with non-optimised assembler.  Even so, this now gives around 95%
     performance improvement for 1024 bit RSA signs.
     [Mark Cox]

  *) Hack to fix PKCS#7 decryption when used with some unorthodox RC2
     handling. Most clients have the effective key size in bits equal to
     the key length in bits: so a 40 bit RC2 key uses a 40 bit (5 byte) key.
     A few however don't do this and instead use the size of the decrypted key
     to determine the RC2 key length and the AlgorithmIdentifier to determine
     the effective key length. In this case the effective key length can still
     be 40 bits but the key length can be 168 bits for example. This is fixed
     by manually forcing an RC2 key into the EVP_PKEY structure because the
     EVP code can't currently handle unusual RC2 key sizes: it always assumes
     the key length and effective key length are equal.
     [Steve Henson]

  *) Add a bunch of functions that should simplify the creation of
     X509_NAME structures. Now you should be able to do:
     X509_NAME_add_entry_by_txt(nm, "CN", MBSTRING_ASC, "Steve", -1, -1, 0);
     and have it automatically work out the correct field type and fill in
     the structures. The more adventurous can try:
     X509_NAME_add_entry_by_txt(nm, field, MBSTRING_UTF8, str, -1, -1, 0);
     and it will (hopefully) work out the correct multibyte encoding.
     [Steve Henson]

  *) Change the 'req' utility to use the new field handling and multibyte
     copy routines. Before the DN field creation was handled in an ad hoc
     way in req, ca, and x509 which was rather broken and didn't support
     BMPStrings or UTF8Strings. Since some software doesn't implement
     BMPStrings or UTF8Strings yet, they can be enabled using the config file
     using the dirstring_type option. See the new comment in the default
     openssl.cnf for more info.
     [Steve Henson]

  *) Make crypto/rand/md_rand.c more robust:
     - Assure unique random numbers after fork().
     - Make sure that concurrent threads access the global counter and
       md serializably so that we never lose entropy in them
       or use exactly the same state in multiple threads.
       Access to the large state is not always serializable because
       the additional locking could be a performance killer, and
       md should be large enough anyway.
     [Bodo Moeller]

  *) New file apps/app_rand.c with commonly needed functionality
     for handling the random seed file.

     Use the random seed file in some applications that previously did not:
          ca,
          dsaparam -genkey (which also ignored its '-rand' option),
          s_client,
          s_server,
          x509 (when signing).
     Except on systems with /dev/urandom, it is crucial to have a random
     seed file at least for key creation, DSA signing, and for DH exchanges;
     for RSA signatures we could do without one.

     gendh and gendsa (unlike genrsa) used to read only the first byte
     of each file listed in the '-rand' option.  The function as previously
     found in genrsa is now in app_rand.c and is used by all programs
     that support '-rand'.
     [Bodo Moeller]

  *) In RAND_write_file, use mode 0600 for creating files;
     don't just chmod when it may be too late.
     [Bodo Moeller]

  *) Report an error from X509_STORE_load_locations
     when X509_LOOKUP_load_file or X509_LOOKUP_add_dir failed.
     [Bill Perry]

  *) New function ASN1_mbstring_copy() this copies a string in either
     ASCII, Unicode, Universal (4 bytes per character) or UTF8 format
     into an ASN1_STRING type. A mask of permissible types is passed
     and it chooses the "minimal" type to use or an error if not type
     is suitable.
     [Steve Henson]

  *) Add function equivalents to the various macros in asn1.h. The old
     macros are retained with an M_ prefix. Code inside the library can
     use the M_ macros. External code (including the openssl utility)
     should *NOT* in order to be "shared library friendly".
     [Steve Henson]

  *) Add various functions that can check a certificate's extensions
     to see if it usable for various purposes such as SSL client,
     server or S/MIME and CAs of these types. This is currently
     VERY EXPERIMENTAL but will ultimately be used for certificate chain
     verification. Also added a -purpose flag to x509 utility to
     print out all the purposes.
     [Steve Henson]

  *) Add a CRYPTO_EX_DATA to X509 certificate structure and associated
     functions.
     [Steve Henson]

  *) New X509V3_{X509,CRL,REVOKED}_get_d2i() functions. These will search
     for, obtain and decode and extension and obtain its critical flag.
     This allows all the necessary extension code to be handled in a
     single function call.
     [Steve Henson]

  *) RC4 tune-up featuring 30-40% performance improvement on most RISC
     platforms. See crypto/rc4/rc4_enc.c for further details.
     [Andy Polyakov]

  *) New -noout option to asn1parse. This causes no output to be produced
     its main use is when combined with -strparse and -out to extract data
     from a file (which may not be in ASN.1 format).
     [Steve Henson]

  *) Fix for pkcs12 program. It was hashing an invalid certificate pointer
     when producing the local key id.
     [Richard Levitte <levitte@stacken.kth.se>]

  *) New option -dhparam in s_server. This allows a DH parameter file to be
     stated explicitly. If it is not stated then it tries the first server
     certificate file. The previous behaviour hard coded the filename
     "server.pem".
     [Steve Henson]

  *) Add -pubin and -pubout options to the rsa and dsa commands. These allow
     a public key to be input or output. For example:
     openssl rsa -in key.pem -pubout -out pubkey.pem
     Also added necessary DSA public key functions to handle this.
     [Steve Henson]

  *) Fix so PKCS7_dataVerify() doesn't crash if no certificates are contained
     in the message. This was handled by allowing
     X509_find_by_issuer_and_serial() to tolerate a NULL passed to it.
     [Steve Henson, reported by Sampo Kellomaki <sampo@mail.neuronio.pt>]

  *) Fix for bug in d2i_ASN1_bytes(): other ASN1 functions add an extra null
     to the end of the strings whereas this didn't. This would cause problems
     if strings read with d2i_ASN1_bytes() were later modified.
     [Steve Henson, reported by Arne Ansper <arne@ats.cyber.ee>]

  *) Fix for base64 decode bug. When a base64 bio reads only one line of
     data and it contains EOF it will end up returning an error. This is
     caused by input 46 bytes long. The cause is due to the way base64
     BIOs find the start of base64 encoded data. They do this by trying a
     trial decode on each line until they find one that works. When they
     do a flag is set and it starts again knowing it can pass all the
     data directly through the decoder. Unfortunately it doesn't reset
     the context it uses. This means that if EOF is reached an attempt
     is made to pass two EOFs through the context and this causes the
     resulting error. This can also cause other problems as well. As is
     usual with these problems it takes *ages* to find and the fix is
     trivial: move one line.
     [Steve Henson, reported by ian@uns.ns.ac.yu (Ivan Nejgebauer) ]

  *) Ugly workaround to get s_client and s_server working under Windows. The
     old code wouldn't work because it needed to select() on sockets and the
     tty (for keypresses and to see if data could be written). Win32 only
     supports select() on sockets so we select() with a 1s timeout on the
     sockets and then see if any characters are waiting to be read, if none
     are present then we retry, we also assume we can always write data to
     the tty. This isn't nice because the code then blocks until we've
     received a complete line of data and it is effectively polling the
     keyboard at 1s intervals: however it's quite a bit better than not
     working at all :-) A dedicated Windows application might handle this
     with an event loop for example.
     [Steve Henson]

  *) Enhance RSA_METHOD structure. Now there are two extra methods, rsa_sign
     and rsa_verify. When the RSA_FLAGS_SIGN_VER option is set these functions
     will be called when RSA_sign() and RSA_verify() are used. This is useful
     if rsa_pub_dec() and rsa_priv_enc() equivalents are not available.
     For this to work properly RSA_public_decrypt() and RSA_private_encrypt()
     should *not* be used: RSA_sign() and RSA_verify() must be used instead.
     This necessitated the support of an extra signature type NID_md5_sha1
     for SSL signatures and modifications to the SSL library to use it instead
     of calling RSA_public_decrypt() and RSA_private_encrypt().
     [Steve Henson]

  *) Add new -verify -CAfile and -CApath options to the crl program, these
     will lookup a CRL issuers certificate and verify the signature in a
     similar way to the verify program. Tidy up the crl program so it
     no longer accesses structures directly. Make the ASN1 CRL parsing a bit
     less strict. It will now permit CRL extensions even if it is not
     a V2 CRL: this will allow it to tolerate some broken CRLs.
     [Steve Henson]

  *) Initialize all non-automatic variables each time one of the openssl
     sub-programs is started (this is necessary as they may be started
     multiple times from the "OpenSSL>" prompt).
     [Lennart Bang, Bodo Moeller]

  *) Preliminary compilation option RSA_NULL which disables RSA crypto without
     removing all other RSA functionality (this is what NO_RSA does). This
     is so (for example) those in the US can disable those operations covered
     by the RSA patent while allowing storage and parsing of RSA keys and RSA
     key generation.
     [Steve Henson]

  *) Non-copying interface to BIO pairs.
     (still largely untested)
     [Bodo Moeller]

  *) New function ANS1_tag2str() to convert an ASN1 tag to a descriptive
     ASCII string. This was handled independently in various places before.
     [Steve Henson]

  *) New functions UTF8_getc() and UTF8_putc() that parse and generate
     UTF8 strings a character at a time.
     [Steve Henson]

  *) Use client_version from client hello to select the protocol
     (s23_srvr.c) and for RSA client key exchange verification
     (s3_srvr.c), as required by the SSL 3.0/TLS 1.0 specifications.
     [Bodo Moeller]

  *) Add various utility functions to handle SPKACs, these were previously
     handled by poking round in the structure internals. Added new function
     NETSCAPE_SPKI_print() to print out SPKAC and a new utility 'spkac' to
     print, verify and generate SPKACs. Based on an original idea from
     Massimiliano Pala <madwolf@comune.modena.it> but extensively modified.
     [Steve Henson]

  *) RIPEMD160 is operational on all platforms and is back in 'make test'.
     [Andy Polyakov]

  *) Allow the config file extension section to be overwritten on the
     command line. Based on an original idea from Massimiliano Pala
     <madwolf@comune.modena.it>. The new option is called -extensions
     and can be applied to ca, req and x509. Also -reqexts to override
     the request extensions in req and -crlexts to override the crl extensions
     in ca.
     [Steve Henson]

  *) Add new feature to the SPKAC handling in ca.  Now you can include
     the same field multiple times by preceding it by "XXXX." for example:
     1.OU="Unit name 1"
     2.OU="Unit name 2"
     this is the same syntax as used in the req config file.
     [Steve Henson]

  *) Allow certificate extensions to be added to certificate requests. These
     are specified in a 'req_extensions' option of the req section of the
     config file. They can be printed out with the -text option to req but
     are otherwise ignored at present.
     [Steve Henson]

  *) Fix a horrible bug in enc_read() in crypto/evp/bio_enc.c: if the first
     data read consists of only the final block it would not decrypted because
     EVP_CipherUpdate() would correctly report zero bytes had been decrypted.
     A misplaced 'break' also meant the decrypted final block might not be
     copied until the next read.
     [Steve Henson]

  *) Initial support for DH_METHOD. Again based on RSA_METHOD. Also added
     a few extra parameters to the DH structure: these will be useful if
     for example we want the value of 'q' or implement X9.42 DH.
     [Steve Henson]

  *) Initial support for DSA_METHOD. This is based on the RSA_METHOD and
     provides hooks that allow the default DSA functions or functions on a
     "per key" basis to be replaced. This allows hardware acceleration and
     hardware key storage to be handled without major modification to the
     library. Also added low level modexp hooks and CRYPTO_EX structure and
     associated functions.
     [Steve Henson]

  *) Add a new flag to memory BIOs, BIO_FLAG_MEM_RDONLY. This marks the BIO
     as "read only": it can't be written to and the buffer it points to will
     not be freed. Reading from a read only BIO is much more efficient than
     a normal memory BIO. This was added because there are several times when
     an area of memory needs to be read from a BIO. The previous method was
     to create a memory BIO and write the data to it, this results in two
     copies of the data and an O(n^2) reading algorithm. There is a new
     function BIO_new_mem_buf() which creates a read only memory BIO from
     an area of memory. Also modified the PKCS#7 routines to use read only
     memory BIOs.
     [Steve Henson]

  *) Bugfix: ssl23_get_client_hello did not work properly when called in
     state SSL23_ST_SR_CLNT_HELLO_B, i.e. when the first 7 bytes of
     a SSLv2-compatible client hello for SSLv3 or TLSv1 could be read,
     but a retry condition occurred while trying to read the rest.
     [Bodo Moeller]

  *) The PKCS7_ENC_CONTENT_new() function was setting the content type as
     NID_pkcs7_encrypted by default: this was wrong since this should almost
     always be NID_pkcs7_data. Also modified the PKCS7_set_type() to handle
     the encrypted data type: this is a more sensible place to put it and it
     allows the PKCS#12 code to be tidied up that duplicated this
     functionality.
     [Steve Henson]

  *) Changed obj_dat.pl script so it takes its input and output files on
     the command line. This should avoid shell escape redirection problems
     under Win32.
     [Steve Henson]

  *) Initial support for certificate extension requests, these are included
     in things like Xenroll certificate requests. Included functions to allow
     extensions to be obtained and added.
     [Steve Henson]

  *) -crlf option to s_client and s_server for sending newlines as
     CRLF (as required by many protocols).
     [Bodo Moeller]

 Changes between 0.9.3a and 0.9.4  [09 Aug 1999]

  *) Install libRSAglue.a when OpenSSL is built with RSAref.
     [Ralf S. Engelschall]

  *) A few more ``#ifndef NO_FP_API / #endif'' pairs for consistency.
     [Andrija Antonijevic <TheAntony2@bigfoot.com>]

  *) Fix -startdate and -enddate (which was missing) arguments to 'ca'
     program.
     [Steve Henson]

  *) New function DSA_dup_DH, which duplicates DSA parameters/keys as
     DH parameters/keys (q is lost during that conversion, but the resulting
     DH parameters contain its length).

     For 1024-bit p, DSA_generate_parameters followed by DSA_dup_DH is
     much faster than DH_generate_parameters (which creates parameters
     where p = 2*q + 1), and also the smaller q makes DH computations
     much more efficient (160-bit exponentiation instead of 1024-bit
     exponentiation); so this provides a convenient way to support DHE
     ciphersuites in SSL/TLS servers (see ssl/ssltest.c).  It is of
     utter importance to use
         SSL_CTX_set_options(s_ctx, SSL_OP_SINGLE_DH_USE);
     or
         SSL_set_options(s_ctx, SSL_OP_SINGLE_DH_USE);
     when such DH parameters are used, because otherwise small subgroup
     attacks may become possible!
     [Bodo Moeller]

  *) Avoid memory leak in i2d_DHparams.
     [Bodo Moeller]

  *) Allow the -k option to be used more than once in the enc program:
     this allows the same encrypted message to be read by multiple recipients.
     [Steve Henson]

  *) New function OBJ_obj2txt(buf, buf_len, a, no_name), this converts
     an ASN1_OBJECT to a text string. If the "no_name" parameter is set then
     it will always use the numerical form of the OID, even if it has a short
     or long name.
     [Steve Henson]

  *) Added an extra RSA flag: RSA_FLAG_EXT_PKEY. Previously the rsa_mod_exp
     method only got called if p,q,dmp1,dmq1,iqmp components were present,
     otherwise bn_mod_exp was called. In the case of hardware keys for example
     no private key components need be present and it might store extra data
     in the RSA structure, which cannot be accessed from bn_mod_exp.
     By setting RSA_FLAG_EXT_PKEY rsa_mod_exp will always be called for
     private key operations.
     [Steve Henson]

  *) Added support for SPARC Linux.
     [Andy Polyakov]

  *) pem_password_cb function type incompatibly changed from
          typedef int pem_password_cb(char *buf, int size, int rwflag);
     to
          ....(char *buf, int size, int rwflag, void *userdata);
     so that applications can pass data to their callbacks:
     The PEM[_ASN1]_{read,write}... functions and macros now take an
     additional void * argument, which is just handed through whenever
     the password callback is called.
     [Damien Miller <dmiller@ilogic.com.au>; tiny changes by Bodo Moeller]

     New function SSL_CTX_set_default_passwd_cb_userdata.

     Compatibility note: As many C implementations push function arguments
     onto the stack in reverse order, the new library version is likely to
     interoperate with programs that have been compiled with the old
     pem_password_cb definition (PEM_whatever takes some data that
     happens to be on the stack as its last argument, and the callback
     just ignores this garbage); but there is no guarantee whatsoever that
     this will work.

  *) The -DPLATFORM="\"$(PLATFORM)\"" definition and the similar -DCFLAGS=...
     (both in crypto/Makefile.ssl for use by crypto/cversion.c) caused
     problems not only on Windows, but also on some Unix platforms.
     To avoid problematic command lines, these definitions are now in an
     auto-generated file crypto/buildinf.h (created by crypto/Makefile.ssl
     for standard "make" builds, by util/mk1mf.pl for "mk1mf" builds).
     [Bodo Moeller]

  *) MIPS III/IV assembler module is reimplemented.
     [Andy Polyakov]

  *) More DES library cleanups: remove references to srand/rand and
     delete an unused file.
     [Ulf Möller]

  *) Add support for the free Netwide assembler (NASM) under Win32,
     since not many people have MASM (ml) and it can be hard to obtain.
     This is currently experimental but it seems to work OK and pass all
     the tests. Check out INSTALL.W32 for info.
     [Steve Henson]

  *) Fix memory leaks in s3_clnt.c: All non-anonymous SSL3/TLS1 connections
     without temporary keys kept an extra copy of the server key,
     and connections with temporary keys did not free everything in case
     of an error.
     [Bodo Moeller]

  *) New function RSA_check_key and new openssl rsa option -check
     for verifying the consistency of RSA keys.
     [Ulf Moeller, Bodo Moeller]

  *) Various changes to make Win32 compile work:
     1. Casts to avoid "loss of data" warnings in p5_crpt2.c
     2. Change unsigned int to int in b_dump.c to avoid "signed/unsigned
        comparison" warnings.
     3. Add sk_<TYPE>_sort to DEF file generator and do make update.
     [Steve Henson]

  *) Add a debugging option to PKCS#5 v2 key generation function: when
     you #define DEBUG_PKCS5V2 passwords, salts, iteration counts and
     derived keys are printed to stderr.
     [Steve Henson]

  *) Copy the flags in ASN1_STRING_dup().
     [Roman E. Pavlov <pre@mo.msk.ru>]

  *) The x509 application mishandled signing requests containing DSA
     keys when the signing key was also DSA and the parameters didn't match.

     It was supposed to omit the parameters when they matched the signing key:
     the verifying software was then supposed to automatically use the CA's
     parameters if they were absent from the end user certificate.

     Omitting parameters is no longer recommended. The test was also
     the wrong way round! This was probably due to unusual behaviour in
     EVP_cmp_parameters() which returns 1 if the parameters match.
     This meant that parameters were omitted when they *didn't* match and
     the certificate was useless. Certificates signed with 'ca' didn't have
     this bug.
     [Steve Henson, reported by Doug Erickson <Doug.Erickson@Part.NET>]

  *) Memory leak checking (-DCRYPTO_MDEBUG) had some problems.
     The interface is as follows:
     Applications can use
         CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ON) aka MemCheck_start(),
         CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_OFF) aka MemCheck_stop();
     "off" is now the default.
     The library internally uses
         CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_DISABLE) aka MemCheck_off(),
         CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ENABLE) aka MemCheck_on()
     to disable memory-checking temporarily.

     Some inconsistent states that previously were possible (and were
     even the default) are now avoided.

     -DCRYPTO_MDEBUG_TIME is new and additionally stores the current time
     with each memory chunk allocated; this is occasionally more helpful
     than just having a counter.

     -DCRYPTO_MDEBUG_THREAD is also new and adds the thread ID.

     -DCRYPTO_MDEBUG_ALL enables all of the above, plus any future
     extensions.