lokinet/crypto/xchacha20/hchacha.c
2018-10-23 07:29:37 -04:00

103 lines
2.2 KiB
C

#include <stdint.h>
#include <stdlib.h>
#include <sodium/crypto_core_hchacha20.h>
#include <sodium/private/common.h>
#define QUARTERROUND(A, B, C, D) \
do \
{ \
A += B; \
D = ROTL32(D ^ A, 16); \
C += D; \
B = ROTL32(B ^ C, 12); \
A += B; \
D = ROTL32(D ^ A, 8); \
C += D; \
B = ROTL32(B ^ C, 7); \
} while(0)
int
crypto_core_hchacha20(unsigned char *out, const unsigned char *in,
const unsigned char *k, const unsigned char *c)
{
int i;
uint32_t x0, x1, x2, x3, x4, x5, x6, x7;
uint32_t x8, x9, x10, x11, x12, x13, x14, x15;
if(c == NULL)
{
x0 = 0x61707865;
x1 = 0x3320646e;
x2 = 0x79622d32;
x3 = 0x6b206574;
}
else
{
x0 = LOAD32_LE(c + 0);
x1 = LOAD32_LE(c + 4);
x2 = LOAD32_LE(c + 8);
x3 = LOAD32_LE(c + 12);
}
x4 = LOAD32_LE(k + 0);
x5 = LOAD32_LE(k + 4);
x6 = LOAD32_LE(k + 8);
x7 = LOAD32_LE(k + 12);
x8 = LOAD32_LE(k + 16);
x9 = LOAD32_LE(k + 20);
x10 = LOAD32_LE(k + 24);
x11 = LOAD32_LE(k + 28);
x12 = LOAD32_LE(in + 0);
x13 = LOAD32_LE(in + 4);
x14 = LOAD32_LE(in + 8);
x15 = LOAD32_LE(in + 12);
for(i = 0; i < 10; i++)
{
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);
}
STORE32_LE(out + 0, x0);
STORE32_LE(out + 4, x1);
STORE32_LE(out + 8, x2);
STORE32_LE(out + 12, x3);
STORE32_LE(out + 16, x12);
STORE32_LE(out + 20, x13);
STORE32_LE(out + 24, x14);
STORE32_LE(out + 28, x15);
return 0;
}
size_t
crypto_core_hchacha20_outputbytes(void)
{
return crypto_core_hchacha20_OUTPUTBYTES;
}
size_t
crypto_core_hchacha20_inputbytes(void)
{
return crypto_core_hchacha20_INPUTBYTES;
}
size_t
crypto_core_hchacha20_keybytes(void)
{
return crypto_core_hchacha20_KEYBYTES;
}
size_t
crypto_core_hchacha20_constbytes(void)
{
return crypto_core_hchacha20_CONSTBYTES;
}