简介

This is an interface to the mcrypt library, which supports a wide variety of block algorithms such as DES, TripleDES, Blowfish (default), 3-WAY, SAFER-SK64, SAFER-SK128, TWOFISH, TEA, RC2 and GOST in CBC, OFB, CFB and ECB cipher modes. Additionally, it supports RC6 and IDEA which are considered "non-free".

需求

These functions work using » mcrypt. To use it, download libmcrypt-x.x.tar.gz from » http://mcrypt.sourceforge.net/ and follow the included installation instructions. Windows users will find all the needed compiled mcrypt binaries at » http://ftp.emini.dk/pub/php/win32/mcrypt/.

As of PHP 5.0.0 you will need libmcrypt Version 2.5.6 or greater.

If you linked against libmcrypt 2.4.x or higher, the following additional block algorithms are supported: CAST, LOKI97, RIJNDAEL, SAFERPLUS, SERPENT and the following stream ciphers: ENIGMA (crypt), PANAMA, RC4 and WAKE. With libmcrypt 2.4.x or higher another cipher mode is also available; nOFB.

安装

You need to compile PHP with the --with-mcrypt[=DIR] parameter to enable this extension. DIR is the mcrypt install directory. Make sure you compile libmcrypt with the option --disable-posix-threads.

运行时配置

这些函数的行为受 php.ini 的影响。

有关 PHP_INI_* 常量进一步的细节与定义参见附录H, php.ini 配置选项。

资源类型

mcrypt_module_open() returns an encryption descriptor.

预定义常量

以下常量由本扩展模块定义，因此只有在本扩展模块被编译到 PHP 中，或者在运行时被动态加载后才有效。

Mcrypt can operate in four block cipher modes (CBC, OFB, CFB, and ECB). If linked against libmcrypt-2.4.x or higher the functions can also operate in the block cipher mode nOFB and in STREAM mode. Below you find a list with all supported encryption modes together with the constants that are defines for the encryption mode. For a more complete reference and discussion see Applied Cryptography by Schneier (ISBN 0-471-11709-9).

Some other mode and random device constants:

Mcrypt ciphers

Here is a list of ciphers which are currently supported by the mcrypt extension. For a complete list of supported ciphers, see the defines at the end of mcrypt.h. The general rule with the mcrypt-2.2.x API is that you can access the cipher from PHP with MCRYPT_ciphername. With the libmcrypt-2.4.x and libmcrypt-2.5.x API these constants also work, but it is possible to specify the name of the cipher as a string with a call to mcrypt_module_open().

You must (in CFB and OFB mode) or can (in CBC mode) supply an initialization vector (IV) to the respective cipher function. The IV must be unique and must be the same when decrypting/encrypting. With data which is stored encrypted, you can take the output of a function of the index under which the data is stored (e.g. the MD5 key of the filename). Alternatively, you can transmit the IV together with the encrypted data (see chapter 9.3 of Applied Cryptography by Schneier (ISBN 0-471-11709-9) for a discussion of this topic).

范例

Mcrypt can be used to encrypt and decrypt using the above mentioned ciphers. If you linked against libmcrypt-2.2.x, the four important mcrypt commands (mcrypt_cfb(), mcrypt_cbc(), mcrypt_ecb(), and mcrypt_ofb()) can operate in both modes which are named MCRYPT_ENCRYPT and MCRYPT_DECRYPT, respectively.

This example will give you the encrypted data as a string in $encrypted_data.

If you linked against libmcrypt 2.4.x or 2.5.x, these functions are still available, but it is recommended that you use the advanced functions.

This example will give you the encrypted data as a string in $encrypted_data. For a full example see mcrypt_module_open().

目录

mcrypt_cbc Encrypt/decrypt data in CBC mode

mcrypt_cfb Encrypt/decrypt data in CFB mode

mcrypt_create_iv Create an initialization vector (IV) from a random source

mcrypt_decrypt Decrypts crypttext with given parameters

mcrypt_ecb Deprecated: Encrypt/decrypt data in ECB mode

mcrypt_enc_get_algorithms_name Returns the name of the opened algorithm

mcrypt_enc_get_block_size Returns the blocksize of the opened algorithm

mcrypt_enc_get_iv_size Returns the size of the IV of the opened algorithm

mcrypt_enc_get_key_size Returns the maximum supported keysize of the opened mode

mcrypt_enc_get_modes_name Returns the name of the opened mode

mcrypt_enc_get_supported_key_sizes Returns an array with the supported keysizes of the opened algorithm

mcrypt_enc_is_block_algorithm_mode Checks whether the encryption of the opened mode works on blocks

mcrypt_enc_is_block_algorithm Checks whether the algorithm of the opened mode is a block algorithm

mcrypt_enc_is_block_mode Checks whether the opened mode outputs blocks

mcrypt_enc_self_test This function runs a self test on the opened module

mcrypt_encrypt Encrypts plaintext with given parameters

mcrypt_generic_deinit This function deinitializes an encryption module

mcrypt_generic_end This function terminates encryption

mcrypt_generic_init This function initializes all buffers needed for encryption

mcrypt_generic This function encrypts data

mcrypt_get_block_size Get the block size of the specified cipher

mcrypt_get_cipher_name Get the name of the specified cipher

mcrypt_get_iv_size Returns the size of the IV belonging to a specific cipher/mode combination

mcrypt_get_key_size Get the key size of the specified cipher

mcrypt_list_algorithms Get an array of all supported ciphers

mcrypt_list_modes Get an array of all supported modes

mcrypt_module_close Close the mcrypt module

mcrypt_module_get_algo_block_size Returns the blocksize of the specified algorithm

mcrypt_module_get_algo_key_size Returns the maximum supported keysize of the opened mode

mcrypt_module_get_supported_key_sizes Returns an array with the supported keysizes of the opened algorithm

mcrypt_module_is_block_algorithm_mode Returns if the specified module is a block algorithm or not

mcrypt_module_is_block_algorithm This function checks whether the specified algorithm is a block algorithm

mcrypt_module_is_block_mode Returns if the specified mode outputs blocks or not

mcrypt_module_open Opens the module of the algorithm and the mode to be used

mcrypt_module_self_test This function runs a self test on the specified module

mcrypt_ofb Encrypt/decrypt data in OFB mode

mdecrypt_generic Decrypt data