337 lines
8.3 KiB
C
337 lines
8.3 KiB
C
/****************************************************************************
|
|
* crypto/chacha_private.h
|
|
* $OpenBSD: chacha_private.h,v 1.4 2020/07/22 13:54:30 tobhe Exp $
|
|
*
|
|
* chacha-merged.c version 20080118
|
|
* D. J. Bernstein
|
|
* Public domain.
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <string.h>
|
|
#include <sys/types.h>
|
|
|
|
typedef struct
|
|
{
|
|
uint32_t input[16]; /* could be compressed */
|
|
}
|
|
chacha_ctx;
|
|
|
|
#define U8C(v) (v##U)
|
|
#define U32C(v) (v##U)
|
|
|
|
#define U8V(v) ((uint8_t)(v) & U8C(0xFF))
|
|
#define U32V(v) ((uint32_t)(v) & U32C(0xFFFFFFFF))
|
|
|
|
#define ROTL32(v, n) \
|
|
(U32V((v) << (n)) | ((v) >> (32 - (n))))
|
|
|
|
#define U8TO32_LITTLE(p) \
|
|
(((uint32_t)((p)[0])) | \
|
|
((uint32_t)((p)[1]) << 8) | \
|
|
((uint32_t)((p)[2]) << 16) | \
|
|
((uint32_t)((p)[3]) << 24)) \
|
|
|
|
#define U32TO8_LITTLE(p, v) \
|
|
do { \
|
|
(p)[0] = U8V((v)); \
|
|
(p)[1] = U8V((v) >> 8); \
|
|
(p)[2] = U8V((v) >> 16); \
|
|
(p)[3] = U8V((v) >> 24); \
|
|
} while (0)
|
|
|
|
#define ROTATE(v, c) (ROTL32(v, c))
|
|
#define XOR(v, w) ((v) ^ (w))
|
|
#define PLUS(v, w) (U32V((v) + (w)))
|
|
#define PLUSONE(v) (PLUS((v), 1))
|
|
|
|
#define QUARTERROUND(a, b, c, d) \
|
|
do \
|
|
{ \
|
|
a = PLUS(a, b); d = ROTATE(XOR(d, a), 16); \
|
|
c = PLUS(c, d); b = ROTATE(XOR(b, c), 12); \
|
|
a = PLUS(a, b); d = ROTATE(XOR(d, a), 8); \
|
|
c = PLUS(c, d); b = ROTATE(XOR(b, c), 7); \
|
|
} \
|
|
while (0)
|
|
|
|
static const char sigma[16] = "expand 32-byte k";
|
|
static const char tau[16] = "expand 16-byte k";
|
|
|
|
static inline void hchacha20(FAR uint32_t *derived_key,
|
|
FAR const uint8_t *nonce,
|
|
FAR const uint8_t *key)
|
|
{
|
|
int i;
|
|
uint32_t x[] =
|
|
{
|
|
U8TO32_LITTLE(sigma + 0),
|
|
U8TO32_LITTLE(sigma + 4),
|
|
U8TO32_LITTLE(sigma + 8),
|
|
U8TO32_LITTLE(sigma + 12),
|
|
U8TO32_LITTLE(key + 0),
|
|
U8TO32_LITTLE(key + 4),
|
|
U8TO32_LITTLE(key + 8),
|
|
U8TO32_LITTLE(key + 12),
|
|
U8TO32_LITTLE(key + 16),
|
|
U8TO32_LITTLE(key + 20),
|
|
U8TO32_LITTLE(key + 24),
|
|
U8TO32_LITTLE(key + 28),
|
|
U8TO32_LITTLE(nonce + 0),
|
|
U8TO32_LITTLE(nonce + 4),
|
|
U8TO32_LITTLE(nonce + 8),
|
|
U8TO32_LITTLE(nonce + 12)
|
|
};
|
|
|
|
for (i = 20; i > 0; i -= 2)
|
|
{
|
|
QUARTERROUND(x[0], x[4], x[8], x[12]);
|
|
QUARTERROUND(x[1], x[5], x[9], x[13]);
|
|
QUARTERROUND(x[2], x[6], x[10], x[14]);
|
|
QUARTERROUND(x[3], x[7], x[11], x[15]);
|
|
QUARTERROUND(x[0], x[5], x[10], x[15]);
|
|
QUARTERROUND(x[1], x[6], x[11], x[12]);
|
|
QUARTERROUND(x[2], x[7], x[8], x[13]);
|
|
QUARTERROUND(x[3], x[4], x[9], x[14]);
|
|
}
|
|
|
|
memcpy(derived_key + 0, x + 0, sizeof(uint32_t) * 4);
|
|
memcpy(derived_key + 4, x + 12, sizeof(uint32_t) * 4);
|
|
}
|
|
|
|
static void chacha_keysetup(FAR chacha_ctx *x,
|
|
FAR const uint8_t *k,
|
|
FAR uint32_t kbits)
|
|
{
|
|
FAR const char *constants;
|
|
|
|
x->input[4] = U8TO32_LITTLE(k + 0);
|
|
x->input[5] = U8TO32_LITTLE(k + 4);
|
|
x->input[6] = U8TO32_LITTLE(k + 8);
|
|
x->input[7] = U8TO32_LITTLE(k + 12);
|
|
if (kbits == 256)
|
|
{
|
|
/* recommended */
|
|
|
|
k += 16;
|
|
constants = sigma;
|
|
}
|
|
else
|
|
{
|
|
/* kbits == 128 */
|
|
|
|
constants = tau;
|
|
}
|
|
|
|
x->input[8] = U8TO32_LITTLE(k + 0);
|
|
x->input[9] = U8TO32_LITTLE(k + 4);
|
|
x->input[10] = U8TO32_LITTLE(k + 8);
|
|
x->input[11] = U8TO32_LITTLE(k + 12);
|
|
x->input[0] = U8TO32_LITTLE(constants + 0);
|
|
x->input[1] = U8TO32_LITTLE(constants + 4);
|
|
x->input[2] = U8TO32_LITTLE(constants + 8);
|
|
x->input[3] = U8TO32_LITTLE(constants + 12);
|
|
}
|
|
|
|
static void chacha_ivsetup(FAR chacha_ctx *x,
|
|
FAR const uint8_t *iv,
|
|
FAR const uint8_t *counter)
|
|
{
|
|
x->input[12] = counter == NULL ? 0 : U8TO32_LITTLE(counter + 0);
|
|
x->input[13] = counter == NULL ? 0 : U8TO32_LITTLE(counter + 4);
|
|
x->input[14] = U8TO32_LITTLE(iv + 0);
|
|
x->input[15] = U8TO32_LITTLE(iv + 4);
|
|
}
|
|
|
|
static void chacha_encrypt_bytes(FAR chacha_ctx *x,
|
|
FAR const uint8_t *m,
|
|
FAR uint8_t *c,
|
|
uint32_t bytes)
|
|
{
|
|
uint32_t x0;
|
|
uint32_t x1;
|
|
uint32_t x2;
|
|
uint32_t x3;
|
|
uint32_t x4;
|
|
uint32_t x5;
|
|
uint32_t x6;
|
|
uint32_t x7;
|
|
uint32_t x8;
|
|
uint32_t x9;
|
|
uint32_t x10;
|
|
uint32_t x11;
|
|
uint32_t x12;
|
|
uint32_t x13;
|
|
uint32_t x14;
|
|
uint32_t x15;
|
|
uint32_t j0;
|
|
uint32_t j1;
|
|
uint32_t j2;
|
|
uint32_t j3;
|
|
uint32_t j4;
|
|
uint32_t j5;
|
|
uint32_t j6;
|
|
uint32_t j7;
|
|
uint32_t j8;
|
|
uint32_t j9;
|
|
uint32_t j10;
|
|
uint32_t j11;
|
|
uint32_t j12;
|
|
uint32_t j13;
|
|
uint32_t j14;
|
|
uint32_t j15;
|
|
FAR uint8_t *ctarget = NULL;
|
|
uint8_t tmp[64];
|
|
u_int i;
|
|
|
|
if (!bytes)
|
|
{
|
|
return;
|
|
}
|
|
|
|
j0 = x->input[0];
|
|
j1 = x->input[1];
|
|
j2 = x->input[2];
|
|
j3 = x->input[3];
|
|
j4 = x->input[4];
|
|
j5 = x->input[5];
|
|
j6 = x->input[6];
|
|
j7 = x->input[7];
|
|
j8 = x->input[8];
|
|
j9 = x->input[9];
|
|
j10 = x->input[10];
|
|
j11 = x->input[11];
|
|
j12 = x->input[12];
|
|
j13 = x->input[13];
|
|
j14 = x->input[14];
|
|
j15 = x->input[15];
|
|
|
|
for (; ; )
|
|
{
|
|
if (bytes < 64)
|
|
{
|
|
for (i = 0; i < bytes; ++i)
|
|
{
|
|
tmp[i] = m[i];
|
|
}
|
|
|
|
m = tmp;
|
|
ctarget = c;
|
|
c = tmp;
|
|
}
|
|
|
|
x0 = j0;
|
|
x1 = j1;
|
|
x2 = j2;
|
|
x3 = j3;
|
|
x4 = j4;
|
|
x5 = j5;
|
|
x6 = j6;
|
|
x7 = j7;
|
|
x8 = j8;
|
|
x9 = j9;
|
|
x10 = j10;
|
|
x11 = j11;
|
|
x12 = j12;
|
|
x13 = j13;
|
|
x14 = j14;
|
|
x15 = j15;
|
|
for (i = 20; i > 0; i -= 2)
|
|
{
|
|
QUARTERROUND(x0, x4, x8, x12);
|
|
QUARTERROUND(x1, x5, x9, x13);
|
|
QUARTERROUND(x2, x6, x10, x14);
|
|
QUARTERROUND(x3, x7, x11, x15);
|
|
QUARTERROUND(x0, x5, x10, x15);
|
|
QUARTERROUND(x1, x6, x11, x12);
|
|
QUARTERROUND(x2, x7, x8, x13);
|
|
QUARTERROUND(x3, x4, x9, x14);
|
|
}
|
|
|
|
x0 = PLUS(x0, j0);
|
|
x1 = PLUS(x1, j1);
|
|
x2 = PLUS(x2, j2);
|
|
x3 = PLUS(x3, j3);
|
|
x4 = PLUS(x4, j4);
|
|
x5 = PLUS(x5, j5);
|
|
x6 = PLUS(x6, j6);
|
|
x7 = PLUS(x7, j7);
|
|
x8 = PLUS(x8, j8);
|
|
x9 = PLUS(x9, j9);
|
|
x10 = PLUS(x10, j10);
|
|
x11 = PLUS(x11, j11);
|
|
x12 = PLUS(x12, j12);
|
|
x13 = PLUS(x13, j13);
|
|
x14 = PLUS(x14, j14);
|
|
x15 = PLUS(x15, j15);
|
|
|
|
#ifndef KEYSTREAM_ONLY
|
|
x0 = XOR(x0, U8TO32_LITTLE(m + 0));
|
|
x1 = XOR(x1, U8TO32_LITTLE(m + 4));
|
|
x2 = XOR(x2, U8TO32_LITTLE(m + 8));
|
|
x3 = XOR(x3, U8TO32_LITTLE(m + 12));
|
|
x4 = XOR(x4, U8TO32_LITTLE(m + 16));
|
|
x5 = XOR(x5, U8TO32_LITTLE(m + 20));
|
|
x6 = XOR(x6, U8TO32_LITTLE(m + 24));
|
|
x7 = XOR(x7, U8TO32_LITTLE(m + 28));
|
|
x8 = XOR(x8, U8TO32_LITTLE(m + 32));
|
|
x9 = XOR(x9, U8TO32_LITTLE(m + 36));
|
|
x10 = XOR(x10, U8TO32_LITTLE(m + 40));
|
|
x11 = XOR(x11, U8TO32_LITTLE(m + 44));
|
|
x12 = XOR(x12, U8TO32_LITTLE(m + 48));
|
|
x13 = XOR(x13, U8TO32_LITTLE(m + 52));
|
|
x14 = XOR(x14, U8TO32_LITTLE(m + 56));
|
|
x15 = XOR(x15, U8TO32_LITTLE(m + 60));
|
|
#endif
|
|
|
|
j12 = PLUSONE(j12);
|
|
if (!j12)
|
|
{
|
|
j13 = PLUSONE(j13);
|
|
|
|
/* stopping at 2^70 bytes per nonce is user's responsibility */
|
|
}
|
|
|
|
U32TO8_LITTLE(c + 0, x0);
|
|
U32TO8_LITTLE(c + 4, x1);
|
|
U32TO8_LITTLE(c + 8, x2);
|
|
U32TO8_LITTLE(c + 12, x3);
|
|
U32TO8_LITTLE(c + 16, x4);
|
|
U32TO8_LITTLE(c + 20, x5);
|
|
U32TO8_LITTLE(c + 24, x6);
|
|
U32TO8_LITTLE(c + 28, x7);
|
|
U32TO8_LITTLE(c + 32, x8);
|
|
U32TO8_LITTLE(c + 36, x9);
|
|
U32TO8_LITTLE(c + 40, x10);
|
|
U32TO8_LITTLE(c + 44, x11);
|
|
U32TO8_LITTLE(c + 48, x12);
|
|
U32TO8_LITTLE(c + 52, x13);
|
|
U32TO8_LITTLE(c + 56, x14);
|
|
U32TO8_LITTLE(c + 60, x15);
|
|
|
|
if (bytes <= 64)
|
|
{
|
|
if (bytes < 64)
|
|
{
|
|
for (i = 0; i < bytes; ++i)
|
|
{
|
|
ctarget[i] = c[i];
|
|
}
|
|
}
|
|
|
|
x->input[12] = j12;
|
|
x->input[13] = j13;
|
|
return;
|
|
}
|
|
|
|
bytes -= 64;
|
|
c += 64;
|
|
#ifndef KEYSTREAM_ONLY
|
|
m += 64;
|
|
#endif
|
|
}
|
|
}
|