UPGRADING

$Id$

PHP 5.6 UPGRADE NOTES

1. Backward Incompatible Changes
2. New Features
3. Changes in SAPI modules
4. Deprecated Functionality
5. Changed Functions
6. New Functions
7. New Classes and Interfaces
8. Removed Extensions
9. Other Changes to Extensions
10. New Global Constants
11. Changes to INI File Handling
12. Other Changes


========================================
1. Backward Incompatible Changes
========================================

- Core:
  By fixing bug #66015 it is no longer possible to overwrite keys in static scalar
  arrays. Quick example to illustrate:
  class Test {
       const FIRST = 1;
       public $array = array(
           self::FIRST => 'first',
           'second',
           'third'
       );
  }
  Test::$array will have as expected three array keys (1, 2, 3) and no longer
  two (0, 1). self::FIRST will no longer overwrite 'third' having key 1 then,
  but will mark the beginning of indexing. 

- JSON:
  json_decode() no longer accepts non-lowercase variants of lone JSON true,
  false or null values. For example, True or FALSE will now cause json_decode to
  return NULL and set an error value you can fetch with json_last_error().
  This affects JSON texts consisting solely of true, false or null. Text
  containing non-lowercase values inside JSON arrays or objects has never been
  accepted.

- OpenSSL:
  To prevent man-in-the-middle attacks against encrypted transfers client
  streams now verify peer certificates by default. Previous versions
  required users to manually enable peer verification. As a result of this
  change, existing code using ssl:// or tls:// stream wrappers (e.g.
  file_get_contents(), fsockopen(), stream_socket_client()) may no longer
  connect successfully without manually disabling peer verification via the
  stream context's "verify_peer" setting. Encrypted transfers delegate to
  operating system certificate stores by default if not overridden via the
  new openssl.cafile and openssl.cafile ini directives or via call-time SSL
  context options, so most users should be unaffected by this transparent
  security enhancement. (https://wiki.php.net/rfc/tls-peer-verification)

- Mcrypt:
  The mcrypt_encrypt(), mcrypt_decrypt() and mcrypt_{MODE}() functions no
  longer accept keys or IVs with incorrect sizes. Furthermore an IV is now
  required if the used block cipher mode requires it.

========================================
2. New Features
========================================

- Added constant scalar expressions syntax.
  (https://wiki.php.net/rfc/const_scalar_exprs)

- Added dedicated syntax for variadic functions.
  (https://wiki.php.net/rfc/variadics)

- Added support for argument unpacking to complement the variadic syntax.
  (https://wiki.php.net/rfc/argument_unpacking)

- Added an exponentiation operator (**).
  (https://wiki.php.net/rfc/pow-operator)

- Added unified default encoding. default_charset=UTF-8 and functions/extensions
  use encoding settings honor default_charset.

- The php://input stream is now re-usable and can be used concurrently with
  enable_post_data_reading=0.

- Added use function and use const.
  (https://wiki.php.net/rfc/use_function)

- Added a function for timing attack safe string comparison
  (https://wiki.php.net/rfc/timing_attack)

- Added gost-crypto (CryptoPro S-box) hash algorithm.

- Stream wrappers verify peer certificates and host names by default in
  encrypted client streams.

- Added openssl certificate fingerprint support (inclusive stream context
  option).

- Added support for SAN x509 extension matching when verifing host names in
  encrypted streams.

- Added a range of new SSL context options for improved encrypted stream
  server security (https://wiki.php.net/rfc/improved-tls-defaults):

    . "honor_cipher_order" allows servers to prioritize cipher suites of their
      choosing when negotiating SSL/TLS handshakes.
    . "single_ecdh_use" and "single_dh_use" allow for improved forward
      secrecy in encrypted stream servers.
    . "dh_param" allows specification of pre-generated key generation
       parameters when negotiating ephemeral DHE ciphers in stream servers.
    . "ecdh_curve" allows stream servers to specify which curve to use when
       negotiating ephemeral ECDHE ciphers (defaults to NIST P-256).
    . "rsa_key_size" SSL context option gives stream servers control
      over the key size (in bits) used when negotiating RSA ciphers.
    . "capture_session_meta" if specified stores an array of data describing
      the TLS session's protocol/cipher in the "session_meta" SSL context key.

- Added automatic mitigation against client-initated TLS renegotiation DoS
  attacks in encrypted server streams. Renegotiation limiting may be
  customized via three new SSL context options:

    . "reneg_limit" (number of allowed renegotiations per time window)
    . "reneg_window" (renegotiation time window in seconds)
    . "reneg_limit_callback" (optional notification callback on limiting)

- Encrypted TLS servers now support the server name indication (SNI) TLS
  extension via the new "SNI_server_certs" SSL context option.

- Added "crypto_method" SSL context option for use in encrypted streams.

- Added "peer_name" SSL context option to better reflect peer certificate
  name matching using SAN extension (replaces deprecated "CN_match").

- Added stream wrapper support when specifying "cafile" SSL context paths.

- Independent peer cert and peer name validation is now available via a new
  boolean "verify_peer_name" SSL context option. This option is enabled by
  default in encrypted client streams.

- Added protocol-specific tlsv1.0://, tlsv1.1:// and tlsv1.2:// encryption
  stream wrappers. tls:// wrapper now supports TLSv1.1 and TLSv1.2 (previously
  only supported TLSv1).

- Stream crypto method specification now accepts flags instead of values
  allowing support for multiple discrete protocols in a given stream.

- PostgreSQL database connections may now be established asynchronously using
  new constants and polling functions in ext/pgsql.

- Non-blocking read/write query behavior now optionally available in database
  operations using the ext/pgsql extension.

========================================
3. Changes in SAPI modules
========================================

- Added phpdbg SAPI.
  (https://wiki.php.net/rfc/phpdbg)

- Support for FPM workers changing the apparmor profile through the pool configuration.
  (https://wiki.php.net/rfc/fpm_change_hat)

- Support for several XML MIME types in the built-in CLI server. For static
  files with extensions .xml, .xsl, .xsd the Content-Type header
  application/xml is now sent automatically.

========================================
4. Deprecated Functionality
========================================

- Incompatible context calls:
  Instance calls from an incompatible context are now deprecated and issue
  E_DEPRECATED instead of E_STRICT. See https://wiki.php.net/rfc/incompat_ctx

- The "CN_match" and "SNI_server_name" SSL context options are deprecated in
  favor of the new "peer_name" option. Name verification now checks certificate
  SAN names as well as the CN field and the specific name fields are deprecated
  to avoid confusion. Their use triggers E_DEPRECATED but continues to work as
  before. If specified, the specific values take precedence over the general
  "peer_name" value.

- Deprecated PDO::PGSQL_ATTR_DISABLE_NATIVE_PREPARED_STATEMENT, an
  undocument constant effectively equivalent to PDO::ATTR_EMULATE_PREPARES.

- Deprecated INIs: Following INIs are deprecated in favour of new
  internal_encoding/input_encoding/output_encoding. Refer to "Changes to
  encodings in PHP 5.6" in "11. Other Changes" section for more details.

    iconv.input_encoding
    iconv.output_encoding
    iconv.internal_encoding
    mbstring.http_input
    mbstring.http_output
    mbstring.internal_encoding

========================================
5. Changed Functions
========================================

- cURL:
  CURLOPT_SAFE_UPLOAD is now turned on by default and uploads with @file 
  do not work unless it is explicitly set to false.

  curl_setopt() now supports the following nullable settings (>= 5.5.11): 
    . CURLOPT_CUSTOMREQUEST
    . CURLOPT_FTPPORT
    . CURLOPT_RANGE
    . CURLOPT_FTP_ACCOUNT
    . CURLOPT_RTSP_SESSION_ID
    . CURLOPT_KRBLEVEL
    . CURLOPT_KRB4LEVEL

- Strings:
  substr_compare() now allows $length to be zero.

- Crypt:
  crypt() will now raise an E_NOTICE error if the salt parameter is omitted.
  See: https://wiki.php.net/rfc/crypt_function_salt

- Mcrypt:
  The $source parameter of mcrypt_create_iv() now defaults to
  MCRYPT_DEV_URANDOM instead of MCRYPT_DEV_RANDOM.

- OpenSSL:
  The $crypto_type parameter is now optional in stream_socket_enable_crypto()
  if the stream's SSL context specifies the new "crypto_type" option. The
  crypto method from the context is used as a fallback if no crypto method is
  specified at call-time.

- XMLReader:
  XMLReader::getAttributeNs and XMLReader::getAttributeNo now return NULL if
  the attribute could not be found, just like XMLReader::getAttribute.

- Pgsql:
  pg_insert()/pg_select()/pg_update()/pg_delete() are no longer EXPERIMENTAL.
  The following functions no longer block until query write completion if the
  socket stream underlying a database connection is set to non-blocking mode:
    . pg_send_execute()
    . pg_send_prepare()
    . pg_send_query()
    . pg_send_query_params()

- unserialize:
  Manipulated serialization strings for objects implementing Serializable by
  replacing "C:" with "O:" at the start will now produce an error.

========================================
6. New Functions
========================================

- GMP:
  Added gmp_root($a, $nth) and gmp_rootrem($a, $nth) for calculating nth roots.

- Hash
  Added hash_equals($known_string, $user_string)

- OpenSSL:
  Added string openssl_x509_fingerprint($x509, $type, $binary).
  Added string openssl_spki_new($private_key, $challenge, $algorithm)
  Added bool openssl_spki_verify($spkac)
  Added string openssl_spki_export($spkac)
  Added string openssl_spki_export_challenge($spkac)
  Added array openssl_get_cert_locations()

- LDAP:
  Added ldap_escape($value, $ignore = "", $flags = 0).
  Added ldap_modify_batch($link_identifier, $dn, $modifications) described in 
  https://wiki.php.net/rfc/ldap_modify_batch.

- Pgsql:
  Added pg_socket($connection) to allow async connections and non-blocking IO
  Added pg_connect_poll($connection) for establishing async connections
  Added pg_consume_input($connection) for non-blocking query result consumption
  Added pg_flush($connection) for non-blocking query write completion

- PDO_pgsql
  Added PDO::pgsqlGetNotify($result_type = PDO::FETCH_USE_DEFAULT, $ms_timeout = 0)
  Added PDO::pgsqlGetPid()

- Zip:
  Added ZipArchive::setPassword($password)

- SPL
  Added SplFileObject::fread($length) to complement fwrite() method (>= 5.5.11)

========================================
7. New Classes and Interfaces
========================================


========================================
8. Removed Extensions
========================================


========================================
9. Other Changes to Extensions
========================================

- cURL:
  - The following constants have been removed as they are now marked "obsolete"
    in the underlying library and never had any effect to begin with:
      . CURLOPT_CLOSEPOLICY
      . CURLCLOSEPOLICY_CALLBACK
      . CURLCLOSEPOLICY_LEAST_RECENTLY_USED
      . CURLCLOSEPOLICY_LEAST_TRAFFIC
      . CURLCLOSEPOLICY_OLDEST
      . CURLCLOSEPOLICY_SLOWEST

- GMP:
  The GMP extension now uses objects as the underlying data structure, rather
  than resources. GMP instances now support dumping, serialization, cloning,
  casts to primitive types and have overloaded operators.
  (RFC: https://wiki.php.net/rfc/operator_overloading_gmp)

- OCI8:
  - Added Implicit Result Set support for Oracle Database 12c with a
    new oci_get_implicit_resultset() function.
  - Using 'oci_execute($s, OCI_NO_AUTO_COMMIT)' for a SELECT no longer
    unnecessarily initiates an internal ROLLBACK during connection
    close.
  - Multi-row OCI_RETURN_LOB queries require fewer "round trips" to the database.
  - Added DTrace probes enabled with PHP's generic --enable-dtrace
  - The oci_internal_debug() function is now a no-op.
  - The phpinfo() output format for OCI8 has changed.

- OpenSSL:
  - The "SNI_enabled" SSL stream context option is now set to TRUE by default
    if supported by the underlying openssl library.

- PCRE:
  - The information collected by the (*MARK) backtracking control verb is now
    collected into the "MARK" index of the $matches array for preg_match(),
    preg_match_all() and preg_replace_callback().

- Pgsql:
  - pg_insert()/pg_select()/pg_update()/pg_delete()/pg_meta_data()/pg_convert()
    are no longer EXPERIMENTAL
  - Added PGSQL_DML_ESCAPE option for pg_insert()/pg_select()/pg_update()/pg_delete()
    that simply escapes all supplied parameters. These functions can be as fast as
    native query. Unvalidated data(Unknown data types) is passed as string.
    JSON/Array/etc are supported both PGSQL_DML_ESCAPE and pg_convert() as string.
  - pg_select() returns PostgreSQL query resource when query is executed.
  - Added extended flag parameter for pg_meta_data(). pg_meta_data() always
    returns "is enum" attribute.
  - The new pg_socket() function returns a socket stream with no behavior other
    than to allow IO-readiness polling on a DB connection socket. Calling
    stream_set_blocking() on its result enables non-blocking behavior.
  - Passing the new PGSQL_CONNECT_ASYNC flag to pg_connect() allows applications
    to poll for IO readiness via pg_connect_poll() and establish connections
    asynchronously.

- PDO_pgsql:
  - Added PDO::PGSQL_ATTR_DISABLE_PREPARES constant to execute the queries
    without preparing them, while still passing parameters separately from
    the command text using PQexecParams.
  - Added LISTEN/NOTIFY support via PDO::pgsqlGetNotify / PDO::pgsqlGetPid()
    as described in https://bugs.php.net/bug.php?id=42614.

========================================
10. New Global Constants
========================================

- LDAP:
  LDAP_ESCAPE_FILTER int(1)
  LDAP_ESCAPE_DN     int(2)

- Pgsql:
  PGSQL_DML_ESCAPE   int(4096)
  PGSQL_CONNECT_ASYNC
  PGSQL_CONNECTION_STARTED
  PGSQL_CONNECTION_MADE
  PGSQL_CONNECTION_AWAITING_RESPONSE
  PGSQL_CONNECTION_AUTH_OK
  PGSQL_CONNECTION_SSL_STARTUP
  PGSQL_CONNECTION_SETENV
  PGSQL_POLLING_FAILED
  PGSQL_POLLING_READING
  PGSQL_POLLING_WRITING
  PGSQL_POLLING_OK
  PGSQL_POLLING_ACTIVE

- OpenSSL:
  STREAM_CRYPTO_METHOD_TLSv1_0_CLIENT   int(9)
  STREAM_CRYPTO_METHOD_TLSv1_1_CLIENT   int(17)
  STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT   int(33)
  STREAM_CRYPTO_METHOD_ANY_CLIENT       int(63)
  STREAM_CRYPTO_METHOD_TLSv1_0_SERVER   int(8)
  STREAM_CRYPTO_METHOD_TLSv1_1_SERVER   int(16)
  STREAM_CRYPTO_METHOD_TLSv1_2_SERVER   int(32)
  STREAM_CRYPTO_METHOD_ANY_SERVER       int(62)
  OPENSSL_DEFAULT_STREAM_CIPHERS        string

========================================
11. Changes to INI File Handling
========================================

- Core:
  Changed always_populate_raw_post_data to throw a deprecation warning when
  enabled and to recognize the value -1 for never populating the global 
  $HTTP_RAW_POST_DATA variable, which will be default in future PHP versions.

  default_charset is set to UTF-8. It was empty previously. default_charset
  is used where it is applicable. Iconv/Mbstring/htmlentities/htmlspecialchars/
  html_entity_decode use default_charset as default encoding.

  internal_encoding/input_encoding/output_encoding is added for encoding
  handling modules. Refer to "Changes to encodings in PHP 5.6" in "11. Other Changes"
  section for more details.

- cURL:
  If the new openssl.cafile ini directive is specified ext/curl will give the
  openssl path precedence over its own curl.cainfo directive.

- OpenSSL:
  openssl.cafile and openssl.capath ini directives have been added to allow
  global CA default specification as necessary.

========================================
12. Other Changes
========================================

- File upload:
  Uploads equal or greater than 2GB in size are now accepted.

- HTTP stream wrapper:
  HTTP 1.1 requests now include a Connection: close header unless explicitly
  overridden by setting a Connection header via the header context option.

- PDO_pgsql
  A libpq version providing PQexecParams, PQprepare, PQescapeStringConn,
  PQescapeByteaConn is now required. According to the release notes that means
  8.0.8+ or 8.1.4+. 

- Zip:
  New --with-libzip option allow to use system libzip. Version > 0.11 required,
  Version >= 0.11.2 recommended for all features.

- Changes to encodings in PHP 5.6
  The default value of default_charset is now UTF-8 when it is not
  explicitly set in php.ini

  The following php.ini parameters were added:
    internal_encoding
    input_encoding
    output_encoding

  The values of the following php.ini parameters have become empty in
  PHP 5.6 (previously they were all ISO-8859-1)

    iconv.input_encoding
    iconv.output_encoding
    iconv.internal_encoding

  Changes were made to character set handling in:
   - the iconv and mbstring extensions,
   - and htmlentities(), htmlspecialchars(), html_entity_decode() functions

  The precedence for these is now:

   default_charset < internal/input/output_encoding < (mbstring.* || iconv.*) < function parameter

  For example, the easiest way to use the UTF-8 encoding is to set
  default_charset=UTF-8 and leave the following php.ini parameters

  empty:

    iconv.input_encoding
    iconv.output_encoding
    iconv.internal_encoding
    mbstring.http_input
    mbstring.http_output
    mbstring.internal_encoding
    internal_encoding
    input_encoding
    output_encoding

  The mb_regex_encoding() default setting is changed from EUC-JP to UTF-8.