Example of AES256 encryption algorithm implemented by PHP

This article mainly introduces PHP's AES256 encryption algorithm, including the corresponding class files and demo instances, with another PHPmcrypt encryption instance for your reference.

This article mainly introduces PHP's AES256 encryption algorithm, including the corresponding class files and demo instances, with another PHP mcrypt encryption instance for your reference.

This example describes how PHP implements the AES256 encryption algorithm. It is a common encryption algorithm. Share it with you for your reference. The details are as follows:

The aes. class. php file is as follows:

<? Php /*------------------------------------- --* // * AES implementation in PHP (c) chris Veness 2005-2011. right of free use is granted for all * // * either cial or non-commercial cial use under CC-BY licence. no warranty of any form is offered. *//*------------------------------------ --*/class Aes {/*** AES Cipher function: encrypt 'input' with Rijndael algorithm ** @ param input message as byte-array (16 bytes) * @ param w key schedule as 2D byte-array (Nr + 1 x Nb bytes)-* generated from the cipher key by keyExpansion () * @ return ciphertext as byte-array (16 bytes) */public static function cipher ($ input, $ w) {// main cipher function [§ 5. 1] $ Nb = 4; // block size (in words): no of columns in State (fixed at 4 for AES) $ Nr = count ($ w)/$ Nb-1; // no of rounds: 10/12/14 for 128/192/256-bit keys $ state = array (); // initialise 4xNb byte-array 'state' with input [§ 3. 4] for ($ I = 0; $ I <4 * $ Nb; $ I ++) $ state [$ I % 4] [floor ($ I/4)] = $ input [$ I]; $ state = self: addRoundKey ($ state, $ w, 0, $ Nb); for ($ round = 1; $ round <$ Nr; $ round ++) {// apply Nr rounds $ state = self: subBytes ($ state, $ Nb); $ state = self: shif TRows ($ state, $ Nb); $ state = self: mixColumns ($ state, $ Nb); $ state = self: addRoundKey ($ state, $ w, $ round, $ Nb) ;}$ state = self: subBytes ($ state, $ Nb); $ state = self: shiftRows ($ state, $ Nb ); $ state = self: addRoundKey ($ state, $ w, $ Nr, $ Nb); $ output = array (4 * $ Nb ); // convert state to 1-d array before returning [§ 3. 4] for ($ I = 0; $ I <4 * $ Nb; $ I ++) $ output [$ I] = $ state [$ I % 4] [floor ($ I/4)]; return $ output;} priv Ate static function addRoundKey ($ state, $ w, $ rnd, $ Nb) {// xor Round Key into state S [§ 5. 1.4] for ($ r = 0; $ r <4; $ r ++) {for ($ c = 0; $ c <$ Nb; $ c ++) $ state [$ r] [$ c] ^ = $ w [$ rnd * 4 + $ c] [$ r];} return $ state ;} private static function subBytes ($ s, $ Nb) {// apply SBox to state S [§ 5. 1.1] for ($ r = 0; $ r <4; $ r ++) {for ($ c = 0; $ c <$ Nb; $ c ++) $ s [$ r] [$ c] = self: $ sBox [$ s [$ r] [$ c];} return $ s;} private static function shi FtRows ($ s, $ Nb) {// shift row r of state S left by r bytes [§ 5. 1.2] $ t = array (4); for ($ r = 1; $ r <4; $ r ++) {for ($ c = 0; $ c <4; $ c ++) $ t [$ c] = $ s [$ r] [($ c + $ r) % $ Nb]; // shift into temp copyfor ($ c = 0; $ c <4; $ c ++) $ s [$ r] [$ c] = $ t [$ c]; // and copy back} // note that this will work for Nb = 4,5, 6, but not 7,8 (always 4 for AES): return $ s; // see references Df} private static function mixColumns ($ s, $ Nb) {// combine bytes of each col of state S [§ 5. 1.3] for ($ c = 0; $ c <4; $ c ++) {$ a = array (4 ); // 'A' is a copy of the current column from 's' $ B = array (4 ); // 'B' is a • {02} in GF (2 ^ 8) for ($ I = 0; $ I <4; $ I ++) {$ a [$ I] = $ s [$ I] [$ c]; $ B [$ I] = $ s [$ I] [$ c] & 0x80? $ S [$ I] [$ c] <1 ^ 0x011b: $ s [$ I] [$ c] <1 ;} // a [n] ^ B [n] is a • {03} in GF (2 ^ 8) $ s [0] [$ c] = $ B [0] ^ $ a [1] ^ $ B [1] ^ $ a [2] ^ $ a [3]; // 2 * a0 + 3 * a1 + a2 + a3 $ s [1] [$ c] = $ a [0] ^ $ B [1] ^ $ a [2] ^ $ B [2] ^ $ a [3]; // a0 * 2 * a1 + 3 * a2 + a3 $ s [2] [$ c] = $ a [0] ^ $ a [1] ^ $ B [2] ^ $ a [3] ^ $ B [3]; // a0 + a1 + 2 * a2 + 3 * a3 $ s [3] [$ c] = $ a [0] ^ $ B [0] ^ $ a [1] ^ $ a [2] ^ $ B [3]; // 3 * a0 + a1 + a2 + 2 * a3} return $ s;}/*** Key exp Ansion for Rijndael cipher (): performs key expansion on cipher key * to generate a key schedule ** @ param key cipher key byte-array (16 bytes) * @ return key schedule as 2D byte-array (Nr + 1 x Nb bytes) */public static function keyExpansion ($ key) {// generate Key Schedule from Cipher Key [§ 5. 2] $ Nb = 4; // block size (in words): no of columns in state (fixed at 4 for AES) $ Nk = count ($ key)/4; // key leng Th (in words): 4/6/8 for 128/192/256-bit keys $ Nr = $ Nk + 6; // no of rounds: 10/12/14 for 128/192/256-bit keys $ w = array (); $ temp = array (); for ($ I = 0; $ I <$ Nk; $ I ++) {$ r = array ($ key [4 * $ I], $ key [4 * $ I + 1], $ key [4 * $ I + 2], $ key [4 * $ I + 3]); $ w [$ I] = $ r ;} for ($ I = $ Nk; $ I <($ Nb * ($ Nr + 1); $ I ++) {$ w [$ I] = array (); for ($ t = 0; $ t <4; $ t ++) $ temp [$ t] = $ w [$ I-1] [$ t]; if ($ I % $ Nk = 0) {$ temp = self: subWord (self: rotWor D ($ temp); for ($ t = 0; $ t <4; $ t ++) $ temp [$ t] ^ = self :: $ rCon [$ I/$ Nk] [$ t];} else if ($ Nk> 6 & $ I % $ Nk = 4) {$ temp = self :: subWord ($ temp) ;}for ($ t = 0; $ t <4; $ t ++) $ w [$ I] [$ t] = $ w [$ I-$ Nk] [$ t] ^ $ temp [$ t];} return $ w ;} private static function subWord ($ w) {// apply SBox to 4-byte word wfor ($ I = 0; $ I <4; $ I ++) $ w [$ I] = self: $ sBox [$ w [$ I]; return $ w;} private static function rotWord ($ w) {// rotate 4-byte w Ord w left by one byte $ tmp = $ w [0]; for ($ I = 0; $ I <3; $ I ++) $ w [$ I] = $ w [$ I + 1]; $ w [3] = $ tmp; return $ w ;} // sBox is pre-computed multiplicative inverse in GF (2 ^ 8) used in subBytes and keyExpansion [§ 5. 1.1] private static $ sBox = array (0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30,0x01,0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59,0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, 0xb7, 0xfd, 0x93,0x26,0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31,0x15,0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96,0x05, 0x9a, 0x07,0x12,0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,0x09,0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33,0x85,0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21,0x10, 0xff, 0xf3, 0xd2, 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97,0x44,0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19,0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90,0x88,0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, 0xe0, 0x32, 0x3a, 0x0a, 0x49,0x06,0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62,0x91,0x95, 0xe4, 0x79, 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, 0x70, 0x3e, 0xb5, 0x66,0x48,0x03, 0xf6, 0x0e, 0x61,0x35,0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, 0xe1, 0xf8, 0x98,0x11,0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55,0x28, 0xdf, 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42,0x68,0x41,0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 ); // rCon is Round Constant used for the Key Expansion [1st col is 2 ^ (r-1) in GF (2 ^ 8)] [§ 5. 2] private static $ rCon = array (0x00, 0x00, 0x00, 0x00), array (0x01, 0x00, 0x00, 0x00), array (0x02, 0x00, 0x00, 0x00), array (0x04, 0x00, 0x00, 0x00), array (0x08, 0x00, 0x00, 0x00), array (0x10, 0x00, 0x00, 0x00), array (0x20, 0x00, 0x00, 0x00), array (0x40, 0x00, 0x00, 0x00), array (0x80, 0x00, 0x00, 0x00), array (0x1b, 0x00, 0x00, 0x00), array (0x36, 0x00, 0x00, 0x00);}?>

The file aesctr. class. php is as follows: