aes算法的C语言实现

#include <string.h> #include "aes.h" #include "commonage.h" #define byte unsigned char #define BPOLY 0x1b //!< Lower 8 bits of (x^8+x^4+x^3+x+1), ie. (x^4+x^3+x+1). #define BLOCKSIZE 16 //!< Block size in number of bytes. #define KEYBITS 128 //!< Use AES128. #define ROUNDS 10 //!< Number of rounds. #define KEYLENGTH 16 //!< Key length in number of bytes. byte xdata block1[ 256 ]; //!< Workspace 1. byte xdata block2[ 256 ]; //!< Worksapce 2. byte xdata * powTbl; //!< Final location of exponentiation lookup table. byte xdata * logTbl; //!< Final location of logarithm lookup table. byte xdata * sBox; //!< Final location of s-box. byte xdata * sBoxInv; //!< Final location of inverse s-box. byte xdata * expandedKey; //!< Final location of expanded key. void CalcPowLog( byte * powTbl, byte * logTbl ) { byte xdata i = 0; byte xdata t = 1; do { // Use 0x03 as root for exponentiation and logarithms. powTbl[i] = t; logTbl[t] = i; i++; // Muliply t by 3 in GF(2^8). t ^= (t << 1) ^ (t & 0x80 ? BPOLY : 0); } while( t != 1 ); // Cyclic properties ensure that i < 255. powTbl[255] = powTbl[0]; // 255 = '-0', 254 = -1, etc. } void CalcSBox( byte * sBox ) { byte xdata i, rot; byte xdata temp; byte xdata result; // Fill all entries of sBox[]. i = 0; do { // Inverse in GF(2^8). if( i > 0 ) { temp = powTbl[ 255 - logTbl[i] ]; } else { temp = 0; } // Affine transformation in GF(2). result = temp ^ 0x63; // Start with adding a vector in GF(2). for( rot = 0; rot < 4; rot++ ) { // Rotate left. temp = (temp<<1) | (temp>>7); // Add rotated byte in GF(2). result ^= temp; } // Put result in table. sBox[i] = result; } while( ++i != 0 ); } void CalcSBoxInv( byte * sBox, byte * sBoxInv ) { byte xdata i = 0; byte xdata j = 0; // Iterate through all elements in sBoxInv using i. do { // Search through sBox using j. cleardog(); do { // Check if current j is the inverse of current i. if( sBox[ j ] == i ) { // If so, set sBoxInc and indicate search finished. sBoxInv[ i ] = j; j = 255; } } while( ++j != 0 ); } while( ++i != 0 ); } void CycleLeft( byte * row ) { // Cycle 4 bytes in an array left once. byte xdata temp = row[0]; row[0] = row[1]; row[1] = row[2]; row[2] = row[3]; row[3] = temp; } void InvMixColumn( byte * column ) { byte xdata r0, r1, r2, r3; r0 = column[1] ^ column[2] ^ column[3]; r1 = column[0] ^ column[2] ^ column[3]; r2 = column[0] ^ column[1] ^ column[3]; r3 = column[0] ^ column[1] ^ column[2]; column[0] = (column[0] << 1) ^ (column[0] & 0x80 ? BPOLY : 0); column[1] = (column[1] << 1) ^ (column[1] & 0x80 ? BPOLY : 0); column[2] = (column[2] << 1) ^ (column[2] & 0x80 ? BPOLY : 0); column[3] = (column[3] << 1) ^ (column[3] & 0x80 ? BPOLY : 0); r0 ^= column[0] ^ column[1]; r1 ^= column[1] ^ column[2]; r2 ^= column[2] ^ column[3]; r3 ^= column[0] ^ column[3]; column[0] = (column[0] << 1) ^ (column[0] & 0x80 ? BPOLY : 0); column[1] = (column[1] << 1) ^ (column[1] & 0x80 ? BPOLY : 0); column[2] = (column[2] << 1) ^ (column[2] & 0x80 ? BPOLY : 0); column[3] = (column[3] << 1) ^ (column[3] & 0x80 ? BPOLY : 0); r0 ^= column[0] ^ column[2]; r1 ^= column[1] ^ column[3]; r2 ^= column[0] ^ column[2]; r3 ^= column[1] ^ column[3]; column[0] = (column[0] << 1) ^ (column[0] & 0x80 ? BPOLY : 0); column[1] = (column[1] << 1) ^ (column[1] & 0x80 ? BPOLY : 0); column[2] = (column[2] << 1) ^ (column[2] & 0x80 ? BPOLY : 0); column[3] = (column[3] << 1) ^ (column[3] & 0x80 ? BPOLY : 0); column[0] ^= column[1] ^ column[2] ^ column[3]; r0 ^= column[0]; r1 ^= column[0]; r2 ^= column[0]; r3 ^= column[0]; column[0] = r0; column[1] = r1; column[2] = r2; column[3] = r3; } byte Multiply( unsigned char num, unsigned char factor ) { byte mask = 1; byte result = 0; while( mask != 0 ) { // Check bit of factor given by mask. if( mask & factor ) { // Add current multiple of num in GF(2). result ^= num; } // Shift mask to indicate next bit. mask <<= 1; // Double num. num = (num << 1) ^ (num & 0x80 ? BPOLY : 0); } return result; } byte DotProduct( unsigned char * vector1, unsigned char * vector2 ) { byte result = 0; result ^= Multiply( *vector1++, *vector2++ ); result ^= Multiply( *vector1++, *vector2++ ); result ^= Multiply( *vector1++, *vector2++ ); result ^= Multiply( *vector1 , *vector2 ); return result; } void MixColumn( byte * column ) { byte xdata row[8] = { 0x02, 0x03, 0x01, 0x01, 0x02, 0x03, 0x01, 0x01 }; // Prepare first row of matrix twice, to eliminate need for cycling. byte xdata result[4]; // Take dot products of each matrix row and the column vector. result[0] = DotProduct( row+0, column ); result[1] = DotProduct( row+3, column ); result[2] = DotProduct( row+2, column ); result[3] = DotProduct( row+1, column ); // Copy temporary result to original column. column[0] = result[0]; column[1] = result[1]; column[2] = result[2]; column[3] = result[3]; } void SubBytes( byte * bytes, byte count ) { do { *bytes = sBox[ *bytes ]; // Substitute every byte in state. bytes++; } while( --count ); } void InvSubBytesAndXOR( byte * bytes, byte * key, byte count ) { do { // *bytes = sBoxInv[ *bytes ] ^ *key; // Inverse substitute every byte in state and add key. *bytes = block2[ *bytes ] ^ *key; // Use block2 directly. Increases speed. bytes++; key++; } while( --count ); } void InvShiftRows( byte * state ) { byte temp; // Note: State is arranged column by column. // Cycle second row right one time. temp = state[ 1 + 3*4 ]; state[ 1 + 3*4 ] = state[ 1 + 2*4 ]; state[ 1 + 2*4 ] = state[ 1 + 1*4 ]; state[ 1 + 1*4 ] = state[ 1 + 0*4 ]; state[ 1 + 0*4 ] = temp; // Cycle third row right two times. temp = state[ 2 + 0*4 ]; state[ 2 + 0*4 ] = state[ 2 + 2*4 ]; state[ 2 + 2*4 ] = temp; temp = state[ 2 + 1*4 ]; state[ 2 + 1*4 ] = state[ 2 + 3*4 ]; state[ 2 + 3*4 ] = temp; // Cycle fourth row right three times, ie. left once. temp = state[ 3 + 0*4 ]; state[ 3 + 0*4 ] = state[ 3 + 1*4 ]; state[ 3 + 1*4 ] = state[ 3 + 2*4 ]; state[ 3 + 2*4 ] = state[ 3 + 3*4 ]; state[ 3 + 3*4 ] = temp; } void ShiftRows( byte * state ) { byte temp; // Note: State is arranged column by column. // Cycle second row left one time. temp = state[ 1 + 0*4 ]; state[ 1 + 0*4 ] = state[ 1 + 1*4 ]; state[ 1 + 1*4 ] = state[ 1 + 2*4 ]; state[ 1 + 2*4 ] = state[ 1 + 3*4 ]; state[ 1 + 3*4 ] = temp; // Cycle third row left two times. temp = state[ 2 + 0*4 ]; state[ 2 + 0*4 ] = state[ 2 + 2*4 ]; state[ 2 + 2*4 ] = temp; temp = state[ 2 + 1*4 ]; state[ 2 + 1*4 ] = state[ 2 + 3*4 ]; state[ 2 + 3*4 ] = temp; // Cycle fourth row left three times, ie. right once. temp = state[ 3 + 3*4 ]; state[ 3 + 3*4 ] = state[ 3 + 2*4 ]; state[ 3 + 2*4 ] = state[ 3 + 1*4 ]; state[ 3 + 1*4 ] = state[ 3 + 0*4 ]; state[ 3 + 0*4 ] = temp; } void InvMixColumns( byte * state ) { InvMixColumn( state + 0*4 ); InvMixColumn( state + 1*4 ); InvMixColumn( state + 2*4 ); InvMixColumn( state + 3*4 ); } void MixColumns( byte * state ) { MixColumn( state + 0*4 ); MixColumn( state + 1*4 ); MixColumn( state + 2*4 ); MixColumn( state + 3*4 ); } void XORBytes( byte * bytes1, byte * bytes2, byte count ) { do { *bytes1 ^= *bytes2; // Add in GF(2), ie. XOR. bytes1++; bytes2++;