Crypt-OICQ-1[1].0.zip_crypt_crypt::oicq

/* $Id: tiny_crypt.c,v 1.2 2003/10/01 12:27:33 tans Exp $ */ #include <string.h> #define TEA_ROUNDS 0x10 #define TEA_DELTA 0x9E3779B9 #define TEA_SUM 0xE3779B90 /*********************************** * TEA block encryption function ***********************************/ void tiny_encrypt(unsigned long *const v, unsigned long *const w, const unsigned long *const k) { register unsigned long y = v[0], z = v[1], a = k[0], b = k[1], c = k[2], d = k[3], n = TEA_ROUNDS, sum = 0, delta = TEA_DELTA; while (n-- > 0) { sum += delta; y += (z << 4) + a ^ z + sum ^ (z >> 5) + b; z += (y << 4) + c ^ y + sum ^ (y >> 5) + d; } w[0] = y; w[1] = z; } /*********************************** * TEA block decryption function ***********************************/ void tiny_decrypt(unsigned long *const v, unsigned long *const w, const unsigned long *const k) { register unsigned long y = v[0], z = v[1], a = k[0], b = k[1], c = k[2], d = k[3], n = TEA_ROUNDS, sum = TEA_SUM, delta = TEA_DELTA; while (n-- > 0) { z -= (y << 4) + c ^ y + sum ^ (y >> 5) + d; y -= (z << 4) + a ^ z + sum ^ (z >> 5) + b; sum -= delta; } w[0] = y; w[1] = z; } /*************************************** input : 64 bits in network order output: 64 bits in network order dir: 0 for encryption, 1 for decryption key: 128 bits of key ****************************************/ void tiny_crypt (const unsigned char *input, const unsigned char *key, int dir, unsigned long *output) { unsigned long v[2], k[4]; int i; memcpy(v, input, 8); memcpy(k, key, 16); v[0] = ntohl(v[0]); v[1] = ntohl(v[1]); for (i = 0; i < 4; i++) { k[i] = ntohl(k[i]); } if (dir == 0) { tiny_encrypt(v, output, k); } else { tiny_decrypt(v, output, k); } output[0] = htonl(output[0]); output[1] = htonl(output[1]); }