+++ /dev/null
-/*
- * rc5.c RC5-32/16/b
- *
- * Copyright (c) 1999 Pekka Riikonen <priikone@poseidon.pspt.fi>
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the
- * "Software"), to deal in the Software without restriction, including
- * without limitation the rights to use, copy, modify, merge, publish, dis-
- * tribute, sublicense, and/or sell copies of the Software, and to permit
- * persons to whom the Software is furnished to do so, subject to the fol-
- * lowing conditions:
- *
- * The above copyright notice and this permission notice shall be included
- * in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
- * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
- * ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
- * SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABIL-
- * ITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
- * IN THE SOFTWARE.
- *
- * Except as contained in this notice, the name of the authors shall
- * not be used in advertising or otherwise to promote the sale, use or
- * other dealings in this Software without prior written authorization from
- * the authors.
- *
- */
-
-/*
- * Based on RC5 reference code and on description of Bruce Schneier's
- * Applied Cryptography.
- *
- * This implementation has a word size of 32 bits, a rounds of 16 and
- * variable key length from 128 and 192 up to 256 bits.
- *
- */
-
-#include "silc.h"
-#include "rc5_internal.h"
-#include "rc5.h"
-
-/*
- * SILC Crypto API for RC5
- */
-
-/* Sets the key for the cipher. */
-
-SILC_CIPHER_API_SET_KEY(rc5_cbc)
-{
- SilcUInt32 k[8];
-
- SILC_GET_WORD_KEY(key, k, keylen);
- rc5_set_key((RC5Context *)context, k, keylen);
-
- return TRUE;
-}
-
-/* Sets IV for the cipher. */
-
-SILC_CIPHER_API_SET_IV(rc5_cbc)
-{
-
-}
-
-/* Returns the size of the cipher context. */
-
-SILC_CIPHER_API_CONTEXT_LEN(rc5_cbc)
-{
- return sizeof(RC5Context);
-}
-
-/* Encrypts with the cipher in CBC mode. Source and destination buffers
- maybe one and same. */
-
-SILC_CIPHER_API_ENCRYPT(rc5_cbc)
-{
- SilcUInt32 tiv[4];
- int i;
-
- SILC_CBC_GET_IV(tiv, iv);
-
- SILC_CBC_ENC_PRE(tiv, src);
- rc5_encrypt((RC5Context *)context, tiv, tiv);
- SILC_CBC_ENC_POST(tiv, dst, src);
-
- for (i = 16; i < len; i += 16) {
- SILC_CBC_ENC_PRE(tiv, src);
- rc5_encrypt((RC5Context *)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(rc5_cbc)
-{
- SilcUInt32 tmp[4], tmp2[4], tiv[4];
- int i;
-
- SILC_CBC_GET_IV(tiv, iv);
-
- SILC_CBC_DEC_PRE(tmp, src);
- rc5_decrypt((RC5Context *)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);
- rc5_decrypt((RC5Context *)context, tmp, tmp2);
- SILC_CBC_DEC_POST(tmp2, dst, src, tmp, tiv);
- }
-
- SILC_CBC_PUT_IV(tiv, iv);
-
- return TRUE;
-}
-
-/* RC5 encryption */
-#define RC5E(i, A, B) \
- A = A ^ B; \
- A = rotl(A, B) + S[i]; \
- B = B ^ A; \
- B = rotl(B, A) + S[i + 1];
-
-/* RC5 decryption */
-#define RC5D(i, A, B) \
- B = B - S[i + 1]; \
- B = rotr(B, A) ^ A; \
- A = A - S[i]; \
- A = rotr(A, B) ^ B;
-
-/* Sets RC5 key */
-
-int rc5_set_key(RC5Context *ctx, const SilcUInt32 in_key[], int key_len)
-{
- u32 i, j, k, A, B, L[c];
- u32 *out_key = ctx->out_key;
-
- if (key_len < b || key_len > (2 * b))
- return -1;
-
- /* init L */
- for (i = 0; i < key_len / w; i++)
- L[i] = in_key[i];
-
- /* init key array (S) */
- out_key[0] = 0xb7e15163;
- for (i = 1; i < t; i++)
- out_key[i] = out_key[i - 1] + 0x9e3779b9;
-
- /* mix L and key array (S) */
- A = B = 0;
- for (k = i = j = 0; k < (3 * t); k++) {
- A = rotl(out_key[i] + (A + B), 3);
- B += A;
- B = rotl(L[j] + B, B);
- out_key[i] = A;
- L[j] = B;
- i = (i + 1) % t;
- j = (j + 1) % c;
- }
-
- return 0;
-}
-
-/* Encrypts *one* block at a time. */
-
-int rc5_encrypt(RC5Context *ctx, u32 *in, u32 *out)
-{
- u32 A, B;
- u32 *S = ctx->out_key;
-
- A = in[0] + S[0];
- B = in[1] + S[1];
-
- RC5E(2, A, B); RC5E(4, A, B);
- RC5E(6, A, B); RC5E(8, A, B);
- RC5E(10, A, B); RC5E(12, A, B);
- RC5E(14, A, B); RC5E(16, A, B);
- RC5E(18, A, B); RC5E(20, A, B);
- RC5E(22, A, B); RC5E(24, A, B);
- RC5E(26, A, B); RC5E(28, A, B);
- RC5E(30, A, B); RC5E(32, A, B);
-
- out[0] = A;
- out[1] = B;
-
- return 0;
-}
-
-/* Decrypts *one* block at a time. */
-
-int rc5_decrypt(RC5Context *ctx, u32 *in, u32 *out)
-{
- u32 A, B;
- u32 *S = ctx->out_key;
-
- A = in[0];
- B = in[1];
-
- RC5D(32, A, B); RC5D(30, A, B);
- RC5D(28, A, B); RC5D(26, A, B);
- RC5D(24, A, B); RC5D(22, A, B);
- RC5D(20, A, B); RC5D(18, A, B);
- RC5D(16, A, B); RC5D(14, A, B);
- RC5D(12, A, B); RC5D(10, A, B);
- RC5D(8, A, B); RC5D(6, A, B);
- RC5D(4, A, B); RC5D(2, A, B);
-
- out[0] = A - S[0];
- out[1] = B - S[1];
-
- return 0;
-}
projects / silc.git / blobdiff