RC6算法C优化.zip_Rc6_语音编解码

/* This is an independent implementation of the encryption algorithm: */ /* */ /* RC6 by Ron Rivest and RSA Labs */ /* */ /* which is a candidate algorithm in the Advanced Encryption Standard */ /* programme of the US National Institute of Standards and Technology. */ /* */ /* Copyright in this implementation is held by Dr B R Gladman but I */ /* hereby give permission for its free direct or derivative use subject */ /* to acknowledgment of its origin and compliance with any conditions */ /* that the originators of the algorithm place on its exploitation. */ /* */ /* Dr Brian Gladman (gladman@seven77.demon.co.uk) 14th January 1999 */ /* Timing data for RC6 (rc6.c) 128 bit key: Key Setup: 1632 cycles Encrypt: 270 cycles = 94.8 mbits/sec Decrypt: 226 cycles = 113.3 mbits/sec Mean: 248 cycles = 103.2 mbits/sec 192 bit key: Key Setup: 1885 cycles Encrypt: 267 cycles = 95.9 mbits/sec Decrypt: 235 cycles = 108.9 mbits/sec Mean: 251 cycles = 102.0 mbits/sec 256 bit key: Key Setup: 1877 cycles Encrypt: 270 cycles = 94.8 mbits/sec Decrypt: 227 cycles = 112.8 mbits/sec Mean: 249 cycles = 103.0 mbits/sec */ #include "../std_defs.h" static char *alg_name[] = { "rc6", "rc6.c", "rc6" }; char **cipher_name() { return alg_name; } #define f_rnd(i,a,b,c,d) \ u = rotl(d * (d + d + 1), 5); \ t = rotl(b * (b + b + 1), 5); \ a = rotl(a ^ t, u) + l_key[i]; \ c = rotl(c ^ u, t) + l_key[i + 1] #define i_rnd(i,a,b,c,d) \ u = rotl(d * (d + d + 1), 5); \ t = rotl(b * (b + b + 1), 5); \ c = rotr(c - l_key[i + 1], t) ^ u; \ a = rotr(a - l_key[i], u) ^ t u4byte l_key[44]; /* storage for the key schedule */ /* initialise the key schedule from the user supplied key */ u4byte *set_key(const u4byte in_key[], const u4byte key_len) { u4byte i, j, k, a, b, l[8], t; l_key[0] = 0xb7e15163; for(k = 1; k < 44; ++k) l_key[k] = l_key[k - 1] + 0x9e3779b9; for(k = 0; k < key_len / 32; ++k) l[k] = in_key[k]; t = (key_len / 32) - 1; // t = (key_len / 32); a = b = i = j = 0; for(k = 0; k < 132; ++k) { a = rotl(l_key[i] + a + b, 3); b += a; b = rotl(l[j] + b, b); l_key[i] = a; l[j] = b; i = (i == 43 ? 0 : i + 1); // i = (i + 1) % 44; j = (j == t ? 0 : j + 1); // j = (j + 1) % t; } return l_key; }; /* encrypt a block of text */ void encrypt(const u4byte in_blk[4], u4byte out_blk[4]) { u4byte a,b,c,d,t,u; a = in_blk[0]; b = in_blk[1] + l_key[0]; c = in_blk[2]; d = in_blk[3] + l_key[1]; f_rnd( 2,a,b,c,d); f_rnd( 4,b,c,d,a); f_rnd( 6,c,d,a,b); f_rnd( 8,d,a,b,c); f_rnd(10,a,b,c,d); f_rnd(12,b,c,d,a); f_rnd(14,c,d,a,b); f_rnd(16,d,a,b,c); f_rnd(18,a,b,c,d); f_rnd(20,b,c,d,a); f_rnd(22,c,d,a,b); f_rnd(24,d,a,b,c); f_rnd(26,a,b,c,d); f_rnd(28,b,c,d,a); f_rnd(30,c,d,a,b); f_rnd(32,d,a,b,c); f_rnd(34,a,b,c,d); f_rnd(36,b,c,d,a); f_rnd(38,c,d,a,b); f_rnd(40,d,a,b,c); out_blk[0] = a + l_key[42]; out_blk[1] = b; out_blk[2] = c + l_key[43]; out_blk[3] = d; }; /* decrypt a block of text */ void decrypt(const u4byte in_blk[4], u4byte out_blk[4]) { u4byte a,b,c,d,t,u; d = in_blk[3]; c = in_blk[2] - l_key[43]; b = in_blk[1]; a = in_blk[0] - l_key[42]; i_rnd(40,d,a,b,c); i_rnd(38,c,d,a,b); i_rnd(36,b,c,d,a); i_rnd(34,a,b,c,d); i_rnd(32,d,a,b,c); i_rnd(30,c,d,a,b); i_rnd(28,b,c,d,a); i_rnd(26,a,b,c,d); i_rnd(24,d,a,b,c); i_rnd(22,c,d,a,b); i_rnd(20,b,c,d,a); i_rnd(18,a,b,c,d); i_rnd(16,d,a,b,c); i_rnd(14,c,d,a,b); i_rnd(12,b,c,d,a); i_rnd(10,a,b,c,d); i_rnd( 8,d,a,b,c); i_rnd( 6,c,d,a,b); i_rnd( 4,b,c,d,a); i_rnd( 2,a,b,c,d); out_blk[3] = d - l_key[1]; out_blk[2] = c; out_blk[1] = b - l_key[0]; out_blk[0] = a; };