127 lines
3.9 KiB
C
127 lines
3.9 KiB
C
#include "ecrypt-sync.h"
|
|
|
|
#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))
|
|
|
|
static void salsa20_wordtobyte(u8 output[64],const u32 input[16])
|
|
{
|
|
u32 x[16];
|
|
int i;
|
|
|
|
for (i = 0;i < 16;++i) x[i] = input[i];
|
|
for (i = 20;i > 0;i -= 2) {
|
|
x[ 4] = XOR(x[ 4],ROTATE(PLUS(x[ 0],x[12]), 7));
|
|
x[ 8] = XOR(x[ 8],ROTATE(PLUS(x[ 4],x[ 0]), 9));
|
|
x[12] = XOR(x[12],ROTATE(PLUS(x[ 8],x[ 4]),13));
|
|
x[ 0] = XOR(x[ 0],ROTATE(PLUS(x[12],x[ 8]),18));
|
|
x[ 9] = XOR(x[ 9],ROTATE(PLUS(x[ 5],x[ 1]), 7));
|
|
x[13] = XOR(x[13],ROTATE(PLUS(x[ 9],x[ 5]), 9));
|
|
x[ 1] = XOR(x[ 1],ROTATE(PLUS(x[13],x[ 9]),13));
|
|
x[ 5] = XOR(x[ 5],ROTATE(PLUS(x[ 1],x[13]),18));
|
|
x[14] = XOR(x[14],ROTATE(PLUS(x[10],x[ 6]), 7));
|
|
x[ 2] = XOR(x[ 2],ROTATE(PLUS(x[14],x[10]), 9));
|
|
x[ 6] = XOR(x[ 6],ROTATE(PLUS(x[ 2],x[14]),13));
|
|
x[10] = XOR(x[10],ROTATE(PLUS(x[ 6],x[ 2]),18));
|
|
x[ 3] = XOR(x[ 3],ROTATE(PLUS(x[15],x[11]), 7));
|
|
x[ 7] = XOR(x[ 7],ROTATE(PLUS(x[ 3],x[15]), 9));
|
|
x[11] = XOR(x[11],ROTATE(PLUS(x[ 7],x[ 3]),13));
|
|
x[15] = XOR(x[15],ROTATE(PLUS(x[11],x[ 7]),18));
|
|
x[ 1] = XOR(x[ 1],ROTATE(PLUS(x[ 0],x[ 3]), 7));
|
|
x[ 2] = XOR(x[ 2],ROTATE(PLUS(x[ 1],x[ 0]), 9));
|
|
x[ 3] = XOR(x[ 3],ROTATE(PLUS(x[ 2],x[ 1]),13));
|
|
x[ 0] = XOR(x[ 0],ROTATE(PLUS(x[ 3],x[ 2]),18));
|
|
x[ 6] = XOR(x[ 6],ROTATE(PLUS(x[ 5],x[ 4]), 7));
|
|
x[ 7] = XOR(x[ 7],ROTATE(PLUS(x[ 6],x[ 5]), 9));
|
|
x[ 4] = XOR(x[ 4],ROTATE(PLUS(x[ 7],x[ 6]),13));
|
|
x[ 5] = XOR(x[ 5],ROTATE(PLUS(x[ 4],x[ 7]),18));
|
|
x[11] = XOR(x[11],ROTATE(PLUS(x[10],x[ 9]), 7));
|
|
x[ 8] = XOR(x[ 8],ROTATE(PLUS(x[11],x[10]), 9));
|
|
x[ 9] = XOR(x[ 9],ROTATE(PLUS(x[ 8],x[11]),13));
|
|
x[10] = XOR(x[10],ROTATE(PLUS(x[ 9],x[ 8]),18));
|
|
x[12] = XOR(x[12],ROTATE(PLUS(x[15],x[14]), 7));
|
|
x[13] = XOR(x[13],ROTATE(PLUS(x[12],x[15]), 9));
|
|
x[14] = XOR(x[14],ROTATE(PLUS(x[13],x[12]),13));
|
|
x[15] = XOR(x[15],ROTATE(PLUS(x[14],x[13]),18));
|
|
}
|
|
for (i = 0;i < 16;++i) x[i] = PLUS(x[i],input[i]);
|
|
for (i = 0;i < 16;++i) U32TO8_LITTLE(output + 4 * i,x[i]);
|
|
}
|
|
|
|
void ECRYPT_init(void)
|
|
{
|
|
return;
|
|
}
|
|
|
|
static const char sigma[16] = "expand 32-byte k";
|
|
static const char tau[16] = "expand 16-byte k";
|
|
|
|
void ECRYPT_keysetup(ECRYPT_ctx *x,const u8 *k,u32 kbits,u32 ivbits)
|
|
{
|
|
int i;
|
|
static const char *constants;
|
|
|
|
x->input[1] = U8TO32_LITTLE(k + 0);
|
|
x->input[2] = U8TO32_LITTLE(k + 4);
|
|
x->input[3] = U8TO32_LITTLE(k + 8);
|
|
x->input[4] = U8TO32_LITTLE(k + 12);
|
|
if (kbits == 256) { /* recommended */
|
|
k += 16;
|
|
constants = sigma;
|
|
} else { /* kbits == 128 */
|
|
constants = tau;
|
|
}
|
|
x->input[11] = U8TO32_LITTLE(k + 0);
|
|
x->input[12] = U8TO32_LITTLE(k + 4);
|
|
x->input[13] = U8TO32_LITTLE(k + 8);
|
|
x->input[14] = U8TO32_LITTLE(k + 12);
|
|
x->input[0] = U8TO32_LITTLE(constants + 0);
|
|
x->input[5] = U8TO32_LITTLE(constants + 4);
|
|
x->input[10] = U8TO32_LITTLE(constants + 8);
|
|
x->input[15] = U8TO32_LITTLE(constants + 12);
|
|
}
|
|
|
|
void ECRYPT_ivsetup(ECRYPT_ctx *x,const u8 *iv)
|
|
{
|
|
x->input[6] = U8TO32_LITTLE(iv + 0);
|
|
x->input[7] = U8TO32_LITTLE(iv + 4);
|
|
x->input[8] = 0;
|
|
x->input[9] = 0;
|
|
}
|
|
|
|
void ECRYPT_encrypt_bytes(ECRYPT_ctx *x,const u8 *m,u8 *c,u32 bytes)
|
|
{
|
|
u8 output[64];
|
|
int i;
|
|
|
|
if (!bytes) return;
|
|
for (;;) {
|
|
salsa20_wordtobyte(output,x->input);
|
|
x->input[8] = PLUSONE(x->input[8]);
|
|
if (!x->input[8]) {
|
|
x->input[9] = PLUSONE(x->input[9]);
|
|
/* stopping at 2^70 bytes per nonce is user's responsibility */
|
|
}
|
|
if (bytes <= 64) {
|
|
for (i = 0;i < bytes;++i) c[i] = m[i] ^ output[i];
|
|
return;
|
|
}
|
|
for (i = 0;i < 64;++i) c[i] = m[i] ^ output[i];
|
|
bytes -= 64;
|
|
c += 64;
|
|
m += 64;
|
|
}
|
|
}
|
|
|
|
void ECRYPT_decrypt_bytes(ECRYPT_ctx *x,const u8 *c,u8 *m,u32 bytes)
|
|
{
|
|
ECRYPT_encrypt_bytes(x,c,m,bytes);
|
|
}
|
|
|
|
void ECRYPT_keystream_bytes(ECRYPT_ctx *x,u8 *stream,u32 bytes)
|
|
{
|
|
u32 i;
|
|
for (i = 0;i < bytes;++i) stream[i] = 0;
|
|
ECRYPT_encrypt_bytes(x,stream,stream,bytes);
|
|
}
|