Skip to content
Permalink
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
220 lines (179 sloc) 4.58 KB
/* radare - LGPL - Copyright 2016 - pancake */
//Implemented AES version of RC6. keylen = 16, 23, or 32 bytes; w = 32; and r = 20.
#include <r_lib.h>
#include <r_crypto.h>
#define Pw 0xb7e15163
#define Qw 0x9e3779b9
#define BLOCK_SIZE 16
#define r 20
#define w 32
#define ROTL(x,y) (((x)<<((y)&(w-1))) | ((x)>>(w-((y)&(w-1)))))
#define ROTR(x,y) (((x)>>((y)&(w-1))) | ((x)<<(w-((y)&(w-1)))))
struct rc6_state{
ut32 S[2*r+4];
int key_size;
};
static bool flag;
static bool rc6_init(struct rc6_state *const state, const ut8 *key, int keylen, int direction) {
if (keylen != 128/8 && keylen != 192/8 && keylen != 256/8) {
return false;
}
flag = (direction != 0);
int u = w / 8;
int c = keylen / u;
int t = 2 * r + 4;
#ifdef _MSC_VER
ut32 *L = (ut32*) malloc (sizeof (ut32) * c);
#else
ut32 L[c];
#endif
ut32 A = 0, B = 0, k = 0, j = 0;
ut32 v = 3 * t; //originally v = 2 * ((c > t) ? c : t);
int i, off;
for (i = 0, off = 0; i < c; i++) {
L[i] = ((key[off++] & 0xff));
L[i] |= ((key[off++] & 0xff) << 8);
L[i] |= ((key[off++] & 0xff) << 16);
L[i] |= ((key[off++] & 0xff) << 24);
}
(state->S)[0] = Pw;
for (i = 1; i < t; i++) {
(state->S)[i] = (state->S)[i-1] + Qw;
}
for (i = 0; i < v; i++) {
A = (state->S)[k] = ROTL(((state->S)[k] + A + B), 3);
B = L[j] = ROTL((L[j] + A + B), (A + B));
k = (k + 1) % t;
j = (j + 1) % c;
}
state->key_size = keylen/8;
#ifdef _MSC_VER
free (L);
#endif
return true;
}
static void rc6_encrypt(struct rc6_state *const state, const ut8 *inbuf, ut8 *outbuf) {
ut32 t, u;
ut32 aux;
ut32 data[BLOCK_SIZE / 4];
int i;
int off = 0;
for (i = 0; i < BLOCK_SIZE / 4; i++) {
data[i] = ((inbuf[off++] & 0xff));
data[i] |= ((inbuf[off++] & 0xff) << 8);
data[i] |= ((inbuf[off++] & 0xff) << 16);
data[i] |= ((inbuf[off++] & 0xff) << 24);
}
ut32 A = data[0], B = data[1], C = data[2], D = data[3];
// S is key
B = B + (state->S)[0];
D = D + (state->S)[1];
for (i = 1; i <= r; i++) {
t = ROTL(B * (2 * B + 1), 5); //lgw == 5
u = ROTL(D * (2 * D + 1), 5);
A = ROTL(A ^ t, u) + (state->S)[2 * i];
C = ROTL(C ^ u, t) + (state->S)[2 * i + 1];
aux = A;
A = B;
B = C;
C = D;
D = aux;
}
A = A + (state->S)[2*(r+1)];
C = C + (state->S)[2*(r+1)+1];
data[0] = A;
data[1] = B;
data[2] = C;
data[3] = D;
for (i = 0; i < BLOCK_SIZE; i++) {
outbuf[i] = (ut8)((data[i / 4] >> (i % 4) * 8) & 0xff);
}
}
static void rc6_decrypt(struct rc6_state *const state, const ut8 *inbuf, ut8 *outbuf) {
ut32 t, u;
ut32 aux;
ut32 data[BLOCK_SIZE / 4];
int i;
int off = 0;
for (i = 0; i < BLOCK_SIZE / 4; i++) {
data[i] = (inbuf[off++] & 0xff);
data[i] |= ((inbuf[off++] & 0xff) << 8);
data[i] |= ((inbuf[off++] & 0xff) << 16);
data[i] |= ((inbuf[off++] & 0xff) << 24);
}
ut32 A = data[0], B = data[1], C = data[2], D = data[3];
C = C - (state->S)[2 * (r + 1) + 1];
A = A - (state->S)[2 * (r + 1)];
for (i = r; i >= 1; i--) {
aux = D;
D = C;
C = B;
B = A;
A = aux;
u = ROTL(D * (2 * D + 1), 5);
t = ROTL(B * (2 * B + 1), 5);
C = ROTR(C - (state->S)[2 * i + 1], t) ^ u;
A = ROTR(A - (state->S)[2 * i], u) ^ t;
}
D = D - (state->S)[1];
B = B - (state->S)[0];
data[0] = A;
data[1] = B;
data[2] = C;
data[3] = D;
for (i = 0; i < BLOCK_SIZE; i++) {
outbuf[i] = (ut8)((data[i / 4] >> (i % 4) * 8) & 0xff);
}
}
static struct rc6_state st;
static bool rc6_set_key(RCrypto *cry, const ut8 *key, int keylen, int mode, int direction) {
return rc6_init (&st, key, keylen, direction);
}
static int rc6_get_key_size(RCrypto *cry) {
return st.key_size;
}
static bool rc6_use(const char *algo) {
return !strcmp (algo, "rc6");
}
static bool update(RCrypto *cry, const ut8 *buf, int len) {
if (len % BLOCK_SIZE != 0) { //let user handle with with pad.
eprintf ("Input should be multiple of 128bit.\n");
return false;
}
const int blocks = len / BLOCK_SIZE;
ut8 *obuf = calloc (1, len);
if (!obuf) {
return false;
}
int i;
if (flag) {
for (i = 0; i < blocks; i++) {
rc6_decrypt (&st, buf + BLOCK_SIZE * i, obuf + BLOCK_SIZE * i);
}
} else {
for (i = 0; i < blocks; i++) {
rc6_encrypt (&st, buf + BLOCK_SIZE * i, obuf + BLOCK_SIZE * i);
}
}
r_crypto_append (cry, obuf, len);
free (obuf);
return true;
}
static bool final(RCrypto *cry, const ut8 *buf, int len) {
return update (cry, buf, len);
}
RCryptoPlugin r_crypto_plugin_rc6 = {
.name = "rc6",
.set_key = rc6_set_key,
.get_key_size = rc6_get_key_size,
.use = rc6_use,
.update = update,
.final = final
};
#ifndef R2_PLUGIN_INCORE
R_API RLibStruct radare_plugin = {
.type = R_LIB_TYPE_CRYPTO,
.data = &r_crypto_plugin_rc6,
.version = R2_VERSION
};
#endif
You can’t perform that action at this time.