int recv_decrypt(struct encryption_ctx *ctx, int sock, unsigned char *buf, size_t *len, int flags) {
char mybuf[4096];
int result = recv(sock, mybuf, *len, flags);
memcpy(buf, mybuf, *len);
decrypt_buf(ctx, buf, len);
return result;
}
static int decrypt_file(void)
{
struct enc_param ep;
ssize_t src_len;
unsigned char *buf = NULL;
int err;
int ret = -1;
src_len = get_file_size(ifname);
if (src_len < 0) {
ERR("unable to get size of '%s'", ifname);
goto out;
}
buf = malloc(src_len);
if (buf == NULL) {
ERR("no memory for the buffer");
goto out;
}
err = read_file_to_buf(ifname, buf, src_len);
if (err) {
ERR("unable to read from file '%s'", ifname);
goto out;
}
memset(&ep, '\0', sizeof(ep));
ep.key = (unsigned char *) crypt_key;
ep.longstate = longstate;
err = decrypt_buf(&ep, buf, src_len);
if (err) {
ERR("unable to decrypt '%s'", ifname);
goto out;
}
printf("Magic\t\t: '%s'\n", ep.magic);
printf("Seed\t\t: 0x%02x\n", ep.seed);
printf("Product\t\t: '%s'\n", ep.product);
printf("Version\t\t: '%s'\n", ep.version);
printf("Data len\t: %u\n", ep.datalen);
printf("Checksum\t: 0x%08x\n", ep.csum);
err = write_buf_to_file(ofname, buf, ep.datalen);
if (err) {
ERR("unable to write to file '%s'", ofname);
goto out;
}
ret = 0;
out:
free(buf);
return ret;
}
static int cipher_buf(u8 *kbuf, u8 *dbuf, int size, CIPHER_KEY *ckey)
{
int i, retv;
u8 tmp1[16], tmp2[16];
memcpy(kbuf + 0x14, ckey->key, 16);
for (i = 0; i < 16; i++) {
kbuf[0x14 + i] ^= amctrl_key3[i];
}
if (ckey->type == 2)
retv = kirk8(kbuf, 16);
else
retv = kirk7(kbuf, 16, 0x39);
if (retv)
return retv;
for (i = 0; i < 16; i++) {
kbuf[i] ^= amctrl_key2[i];
}
memcpy(tmp2, kbuf, 0x10);
if (ckey->seed == 1) {
memset(tmp1, 0, 0x10);
} else {
memcpy(tmp1, tmp2, 0x10);
*(u32*)(tmp1 + 0x0c) = ckey->seed - 1;
}
for (i = 0; i < size; i += 16) {
memcpy(kbuf + 0x14 + i, tmp2, 12);
*(u32*)(kbuf + 0x14 + i + 12) = ckey->seed;
ckey->seed += 1;
}
retv = decrypt_buf(kbuf, size, tmp1, 0x63);
if (retv)
return retv;
for (i = 0; i < size; i++) {
dbuf[i] ^= kbuf[i];
}
return 0;
}
