+++ /dev/null
-/* Modified for SILC. -Pekka */
-
-/* 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 "silcincludes.h"
-#include "rc6_internal.h"
-#include "rc6.h"
-
-/*
- * SILC Crypto API for RC6
- */
-
-/* Sets the key for the cipher. */
-
-SILC_CIPHER_API_SET_KEY(rc6)
-{
- SilcUInt32 k[8];
-
- SILC_GET_WORD_KEY(key, k, keylen);
- rc6_set_key((RC6Context *)context, k, keylen);
-
- return TRUE;
-}
-
-/* Sets the string as a new key for the cipher. The string is first
- hashed and then used as a new key. */
-
-SILC_CIPHER_API_SET_KEY_WITH_STRING(rc6)
-{
- return FALSE;
-}
-
-/* Encrypts with the cipher in CBC mode. Source and destination buffers
- maybe one and same. */
-
-SILC_CIPHER_API_ENCRYPT_CBC(rc6)
-{
- SilcUInt32 tiv[4];
- int i;
-
- SILC_CBC_GET_IV(tiv, iv);
-
- SILC_CBC_ENC_PRE(tiv, src);
- rc6_encrypt((RC6Context *)context, tiv, tiv);
- SILC_CBC_ENC_POST(tiv, dst, src);
-
- for (i = 16; i < len; i += 16) {
- SILC_CBC_ENC_PRE(tiv, src);
- rc6_encrypt((RC6Context *)context, tiv, tiv);
- SILC_CBC_ENC_POST(tiv, dst, src);
- }
-
- SILC_CBC_PUT_IV(tiv, iv);
-
- return TRUE;
-}
-
-/* Decrypts with the cipher in CBC mode. Source and destination buffers
- maybe one and same. */
-
-SILC_CIPHER_API_DECRYPT_CBC(rc6)
-{
- SilcUInt32 tmp[4], tmp2[4], tiv[4];
- int i;
-
- SILC_CBC_GET_IV(tiv, iv);
-
- SILC_CBC_DEC_PRE(tmp, src);
- rc6_decrypt((RC6Context *)context, tmp, tmp2);
- SILC_CBC_DEC_POST(tmp2, dst, src, tmp, tiv);
-
- for (i = 16; i < len; i += 16) {
- SILC_CBC_DEC_PRE(tmp, src);
- rc6_decrypt((RC6Context *)context, tmp, tmp2);
- SILC_CBC_DEC_POST(tmp2, dst, src, tmp, tiv);
- }
-
- SILC_CBC_PUT_IV(tiv, iv);
-
- return TRUE;
-}
-
-/* Returns the size of the cipher context. */
-
-SILC_CIPHER_API_CONTEXT_LEN(rc6)
-{
- return sizeof(RC6Context);
-}
-
-
-#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
-
-/* initialise the key schedule from the user supplied key */
-
-u4byte *rc6_set_key(RC6Context *ctx,
- const u4byte in_key[], const u4byte key_len)
-{
- u4byte i, j, k, a, b, l[8], t;
- u4byte *l_key = ctx->l_key;
-
- 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 rc6_encrypt(RC6Context *ctx,
- const u4byte in_blk[4], u4byte out_blk[4])
-{
- u4byte a,b,c,d,t,u;
- u4byte *l_key = ctx->l_key;
-
- 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 rc6_decrypt(RC6Context *ctx,
- const u4byte in_blk[4], u4byte out_blk[4])
-{
- u4byte a,b,c,d,t,u;
- u4byte *l_key = ctx->l_key;
-
- 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;
-};
projects / silc.git / commitdiff