des.rar_DES C_des

/* Sofware DES functions * written 12 Dec 1986 by Phil Karn, KA9Q; large sections adapted from * the 1977 public-domain program by Jim Gillogly */ #define NULL 0 #ifdef LITTLE_ENDIAN unsigned long byteswap(); #endif /* Tables defined in the Data Encryption Standard documents */ /* initial permutation IP */ static char ip[] = { 58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8, 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7 }; /* final permutation IP^-1 */ static char fp[] = { 40, 8, 48, 16, 56, 24, 64, 32, 39, 7, 47, 15, 55, 23, 63, 31, 38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45, 13, 53, 21, 61, 29, 36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11, 51, 19, 59, 27, 34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41, 9, 49, 17, 57, 25 }; /* expansion operation matrix * This is for reference only; it is unused in the code * as the f() function performs it implicitly for speed */ #ifdef notdef static char ei[] = { 32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9, 8, 9, 10, 11, 12, 13, 12, 13, 14, 15, 16, 17, 16, 17, 18, 19, 20, 21, 20, 21, 22, 23, 24, 25, 24, 25, 26, 27, 28, 29, 28, 29, 30, 31, 32, 1 }; #endif /* permuted choice table (key) */ static char pc1[] = { 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36, 63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4 }; /* number left rotations of pc1 */ static char totrot[] = { 1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28 }; /* permuted choice key (table) */ static char pc2[] = { 14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10, 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2, 41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48, 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32 }; /* The (in)famous S-boxes */ static char si[8][64] = { /* S1 */ 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7, 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8, 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0, 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13, /* S2 */ 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10, 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5, 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15, 13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9, /* S3 */ 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8, 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1, 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7, 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12, /* S4 */ 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15, 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9, 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4, 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14, /* S5 */ 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9, 14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6, 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14, 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3, /* S6 */ 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11, 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8, 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6, 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13, /* S7 */ 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1, 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6, 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2, 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12, /* S8 */ 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7, 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2, 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8, 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 }; /* 32-bit permutation function P used on the output of the S-boxes */ static char p32i[] = { 16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10, 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25 }; /* End of DES-defined tables */ /* Lookup tables initialized once only at startup by desinit() */ static long (*sp_)[64]; /* Combined S and P boxes */ static char (*iperm)[16][8]; /* Initial and final permutations */ static char (*fperm)[16][8]; /* 8 6-bit subkeys for each of 16 rounds, initialized by setkey() */ static unsigned char (*kn)[8]; /* bit 0 is left-most in byte */ static int bytebit[] = { 0200,0100,040,020,010,04,02,01 }; static int nibblebit[] = { 010,04,02,01 }; static int desmode; /* Allocate space and initialize DES lookup arrays * mode == 0: standard Data Encryption Algorithm * mode == 1: DEA without initial and final permutations for speed * mode == 2: DEA without permutations and with 128-byte key (completely * independent subkeys for each round) */ desinit(mode) int mode; { char *malloc(); if(sp_ != NULL){ /* Already initialized */ return 0; } desmode = mode; if((sp_ = (long (*)[64])malloc(sizeof(long) * 8 * 64)) == NULL){ return -1; } spinit(); kn = (unsigned char (*)[8])malloc(sizeof(char) * 8 * 16); if(kn == NULL){ free((char *)sp_); return -1; } if(mode == 1 || mode == 2) /* No permutations */ return 0; iperm = (char (*)[16][8])malloc(sizeof(char) * 16 * 16 * 8); if(iperm == NULL){ free((char *)sp_); free((char *)kn); return -1; } perminit(iperm,ip); fperm = (char (*)[16][8])malloc(sizeof(char) * 16 * 16 * 8); if(fperm == NULL){ free((char *)sp_); free((char *)kn); free((char *)iperm); return -1; } perminit(fperm,fp); return 0; } /* Free up storage used by DES */ desdone() { if(sp_ == NULL) return; /* Already done */ free((char *)sp_); free((char *)kn); if(iperm != NULL) free((char *)iperm); if(fperm != NULL) free((char *)fperm); sp_ = NULL; iperm = NULL; fperm = NULL; kn = NULL; } /* Set key (initialize key schedule array) */ setkey(key) char *key; /* 64 bits (will use only 56) */ { char pc1m[56]; /* place to modify pc1 into */ char pcr[56]; /* place to rotate pc1 into */ register int i,j,l; int m; /* In mode 2, the 128 bytes of subkey are set directly from the * user's key, allowing him to use completely independent * subkeys for each round. Note that the user MUST specify a * full 128 bytes. * * I would like to think that this technique gives the NSA a real * headache, but I'm not THAT naive. */ if(desmode == 2){ for(i=0;i<16;i++) for(j=0;j<8;j++) kn[i][j] = *key++; return; } /* Clear key schedule */ for (i=0; i<16; i++) for (j=0; j<8; j++) kn[i][j]=0; for (j=0; j<56; j++) { /* convert pc1 to bits of key */ l=pc1[j]-1; /* integer bit location */ m = l & 07; /* find bit */ pc1m[j]=(key[l>>3] & /* find which key byte l is in */ bytebit[m]) /* and which bit of that byte */ ? 1 : 0; /* and store 1-bit result */ } for (i=0; i<16; i++) { /* key chunk for each iteration */ for (j=0; j<56; j++) /* rotate pc1 the right amount */ pcr[j] = pc1m[(l=j+totrot[i])<(j<28? 28 : 56) ? l: l-28]; /* rotate left and right halves independently */ for (j=0; j<48; j++){ /* select bits individually */ /* check bit that goes to kn[j] */ if (pcr[pc2[j]-1]){ /* mask it in if it's there */ l= j % 6; kn[i][j/6] |= bytebit[l] >> 2; } } } } /* In-place encryption of 64-bit block */ endes(block) char *block; { register int i; unsigned long work[2]; /* Working data storage */ long tmp; permute(block,iperm,(char *)work); /* Initial Permutation */ #ifdef LITTLE_ENDIAN work[0] = byteswap(work[0]); work[1] = byteswap