add chacha20 code

test/chacha20/cc20.c

@@ -0,0 +1,108 @@
+// https://github.com/shiffthq/chacha20/blob/master/src/chacha20.c
+
+#include "cc20.h"
+
+static inline void u32t8le(uint32_t v, uint8_t p[4]) {
+ p[0] = v & 0xff;
+ p[1] = (v >> 8) & 0xff;
+ p[2] = (v >> 16) & 0xff;
+ p[3] = (v >> 24) & 0xff;
+}
+
+static inline uint32_t u8t32le(uint8_t p[4]) {
+ uint32_t value = p[3];
+
+ value = (value << 8) | p[2];
+ value = (value << 8) | p[1];
+ value = (value << 8) | p[0];
+
+ return value;
+}
+
+static inline uint32_t rotl32(uint32_t x, int n) {
+ // https://blog.regehr.org/archives/1063
+ return x << n | (x >> (-n & 31));
+}
+
+// https://tools.ietf.org/html/rfc7539#section-2.1
+static void chacha20_quarterround(uint32_t *x, int a, int b, int c, int d) {
+ x[a] += x[b]; x[d] = rotl32(x[d] ^ x[a], 16);
+ x[c] += x[d]; x[b] = rotl32(x[b] ^ x[c], 12);
+ x[a] += x[b]; x[d] = rotl32(x[d] ^ x[a], 8);
+ x[c] += x[d]; x[b] = rotl32(x[b] ^ x[c], 7);
+}
+
+static void chacha20_serialize(uint32_t in[16], uint8_t output[64]) {
+ int i;
+ for (i = 0; i < 16; i++) {
+ u32t8le(in[i], output + (i << 2));
+ }
+}
+
+static void chacha20_block(uint32_t in[16], uint8_t out[64], int num_rounds) {
+ int i;
+ uint32_t x[16];
+
+ // memcpy(x, in, sizeof(uint32_t) * 16);
+ memcpy(x, in, 4 * 16); // patch for IRRE chcc
+
+ for (i = num_rounds; i > 0; i -= 2) {
+ chacha20_quarterround(x, 0, 4, 8, 12);
+ chacha20_quarterround(x, 1, 5, 9, 13);
+ chacha20_quarterround(x, 2, 6, 10, 14);
+ chacha20_quarterround(x, 3, 7, 11, 15);
+ chacha20_quarterround(x, 0, 5, 10, 15);
+ chacha20_quarterround(x, 1, 6, 11, 12);
+ chacha20_quarterround(x, 2, 7, 8, 13);
+ chacha20_quarterround(x, 3, 4, 9, 14);
+ }
+
+ for (i = 0; i < 16; i++) {
+ x[i] += in[i];
+ }
+
+ chacha20_serialize(x, out);
+}
+
+// https://tools.ietf.org/html/rfc7539#section-2.3
+static void chacha20_init_state(uint32_t s[16], uint8_t key[32], uint32_t counter, uint8_t nonce[12]) {
+ int i;
+
+ // refer: https://dxr.mozilla.org/mozilla-beta/source/security/nss/lib/freebl/chacha20.c
+ // convert magic number to string: "expand 32-byte k"
+ s[0] = 0x61707865;
+ s[1] = 0x3320646e;
+ s[2] = 0x79622d32;
+ s[3] = 0x6b206574;
+
+ for (i = 0; i < 8; i++) {
+ s[4 + i] = u8t32le(key + i * 4);
+ }
+
+ s[12] = counter;
+
+ for (i = 0; i < 3; i++) {
+ s[13 + i] = u8t32le(nonce + i * 4);
+ }
+}
+
+void ChaCha20XOR(uint8_t key[32], uint32_t counter, uint8_t nonce[12], uint8_t *in, uint8_t *out, int inlen) {
+ int i, j;
+
+ uint32_t s[16];
+ uint8_t block[64];
+
+ chacha20_init_state(s, key, counter, nonce);
+
+ for (i = 0; i < inlen; i += 64) {
+ chacha20_block(s, block, 20);
+ s[12]++;
+
+ for (j = i; j < i + 64; j++) {
+ if (j >= inlen) {
+ break;
+ }
+ out[j] = in[j] ^ block[j - i];
+ }
+ }
+}

test/chacha20/cc20.h

@@ -0,0 +1,7 @@
+// https://github.com/shiffthq/chacha20/blob/master/src/chacha20.h
+#ifndef __CHACHA20_H
+#define __CHACHA20_H
+
+void ChaCha20XOR(uint8_t key[32], uint32_t counter, uint8_t nonce[12], uint8_t *input, uint8_t *output, int inputlen);
+
+#endif

test/chacha20/test1.c

@@ -0,0 +1,104 @@
+#ifdef DESKTOP
+#include <stdio.h>
+#include <stdint.h>
+#endif
+
+#include "../lib/corlib.h"
+#include "cc20.h"
+
+#define PLAINTEXT_LEN 114
+
+bool compare_bytes(uint8_t *a, uint8_t *b, int len) {
+ for (int i = 0; i < len; i++) {
+ if (a[i] != b[i]) {
+ return false;
+ }
+ }
+ return true;
+}
+
+int main(int argc, char **argv) {
+ int i;
+
+ uint8_t key[] = {
+ 0x00, 0x01, 0x02, 0x03,
+ 0x04, 0x05, 0x06, 0x07,
+ 0x08, 0x09, 0x0a, 0x0b,
+ 0x0c, 0x0d, 0x0e, 0x0f,
+ 0x10, 0x11, 0x12, 0x13,
+ 0x14, 0x15, 0x16, 0x17,
+ 0x18, 0x19, 0x1a, 0x1b,
+ 0x1c, 0x1d, 0x1e, 0x1f
+ };
+
+ uint8_t nonce[] = {
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x4a, 0x00, 0x00, 0x00, 0x00
+ };
+
+ uint8_t input[PLAINTEXT_LEN] = {
+ 0x4c, 0x61, 0x64, 0x69, 0x65, 0x73, 0x20, 0x61, 0x6e, 0x64, 0x20, 0x47, 0x65, 0x6e, 0x74, 0x6c,
+ 0x65, 0x6d, 0x65, 0x6e, 0x20, 0x6f, 0x66, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x61, 0x73,
+ 0x73, 0x20, 0x6f, 0x66, 0x20, 0x27, 0x39, 0x39, 0x3a, 0x20, 0x49, 0x66, 0x20, 0x49, 0x20, 0x63,
+ 0x6f, 0x75, 0x6c, 0x64, 0x20, 0x6f, 0x66, 0x66, 0x65, 0x72, 0x20, 0x79, 0x6f, 0x75, 0x20, 0x6f,
+ 0x6e, 0x6c, 0x79, 0x20, 0x6f, 0x6e, 0x65, 0x20, 0x74, 0x69, 0x70, 0x20, 0x66, 0x6f, 0x72, 0x20,
+ 0x74, 0x68, 0x65, 0x20, 0x66, 0x75, 0x74, 0x75, 0x72, 0x65, 0x2c, 0x20, 0x73, 0x75, 0x6e, 0x73,
+ 0x63, 0x72, 0x65, 0x65, 0x6e, 0x20, 0x77, 0x6f, 0x75, 0x6c, 0x64, 0x20, 0x62, 0x65, 0x20, 0x69,
+ 0x74, 0x2e
+ };
+
+ uint8_t encrypt[PLAINTEXT_LEN];
+ uint8_t decrypt[PLAINTEXT_LEN];
+
+ ChaCha20XOR(key, 1, nonce, input, encrypt, PLAINTEXT_LEN);
+ ChaCha20XOR(key, 1, nonce, encrypt, decrypt, PLAINTEXT_LEN);
+
+#ifdef DESKTOP
+ printf("\nkey:");
+ for (i = 0; i < 32; i++) {
+ if (!(i % 16)) {
+ printf("\n");
+ }
+ printf("%02x ", key[i]);
+ }
+
+ printf("\n\nnonce:\n");
+ for (i = 0; i < 12; i++) {
+ printf("%02x ", nonce[i]);
+ }
+
+ printf("\n\nplaintext:");
+ for (i = 0; i < PLAINTEXT_LEN; i++) {
+ if (!(i % 16)) {
+ printf("\n");
+ }
+ printf("%02x ", input[i]);
+ }
+
+ printf("\n\nencrypted:");
+ for (i = 0; i < PLAINTEXT_LEN; i++) {
+ if (!(i % 16)) {
+ printf("\n");
+ }
+ printf("%02x ", encrypt[i]);
+ }
+
+ printf("\n\ndecrypted:");
+ for (i = 0; i < PLAINTEXT_LEN; i++) {
+ if (!(i % 16)) {
+ printf("\n");
+ }
+ printf("%02x ", decrypt[i]);
+ }
+
+ printf("\n");
+#endif
+
+ // check that the encryption and decryption worked
+ if (!compare_bytes(input, decrypt, PLAINTEXT_LEN)) {
+ return 1;
+ }
+
+ return 0;
+}
+
+#include "cc20.c"

test/lib/corlib.h

@@ -9,6 +9,10 @@
 #define UINT (unsigned int)
 #define VOID (void)
 
+#define int8_t char
+#define uint8_t unsigned char
+#define int16_t short
+#define uint16_t unsigned short
 #define int32_t int
 #define uint32_t unsigned int
 #define int64_t long