static int get_sha1_1(const char *name, int len, unsigned char *sha1)
{
int parent, ret;
const char *cp;
/* foo^[0-9] or foo^ (== foo^1); we do not do more than 9 parents. */
if (len > 2 && name[len-2] == '^' &&
name[len-1] >= '0' && name[len-1] <= '9') {
parent = name[len-1] - '0';
len -= 2;
}
else if (len > 1 && name[len-1] == '^') {
parent = 1;
len--;
} else
parent = -1;
if (parent >= 0)
return get_parent(name, len, sha1, parent);
/* "name~3" is "name^^^",
* "name~12" is "name^^^^^^^^^^^^", and
* "name~" and "name~0" are name -- not "name^0"!
*/
parent = 0;
for (cp = name + len - 1; name <= cp; cp--) {
int ch = *cp;
if ('0' <= ch && ch <= '9')
continue;
if (ch != '~')
parent = -1;
break;
}
if (!parent && *cp == '~') {
int len1 = cp - name;
cp++;
while (cp < name + len)
parent = parent * 10 + *cp++ - '0';
return get_nth_ancestor(name, len1, sha1, parent);
}
ret = peel_onion(name, len, sha1);
if (!ret)
return 0;
ret = get_sha1_basic(name, len, sha1);
if (!ret)
return 0;
return get_short_sha1(name, len, sha1, 0);
}
int main(int argc, char *argv[])
{
secp256k1_context *ctx;
struct onion onion;
bool generate = false, decode = false;
assert(EVP_CIPHER_iv_length(EVP_aes_128_ctr()) == sizeof(struct iv));
opt_register_noarg("--help|-h", opt_usage_and_exit,
"--generate <pubkey>... OR\n"
"--decode <privkey>\n"
"Either create an onion message, or decode one step",
"Print this message.");
opt_register_noarg("--generate",
opt_set_bool, &generate,
"Generate onion through the given hex pubkeys");
opt_register_noarg("--decode",
opt_set_bool, &decode,
"Decode onion given the private key");
opt_register_version();
opt_parse(&argc, argv, opt_log_stderr_exit);
ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN);
if (generate) {
secp256k1_pubkey pubkeys[MAX_HOPS];
char *msgs[MAX_HOPS];
size_t i;
if (argc == 1)
opt_usage_exit_fail("Expected at least one pubkey");
if (argc-1 > MAX_HOPS)
opt_usage_exit_fail("Expected at most %u pubkeys",
MAX_HOPS);
for (i = 1; i < argc; i++) {
if (!parse_onion_pubkey(ctx, argv[i], &pubkeys[i-1]))
errx(1, "Bad pubkey '%s'", argv[i]);
msgs[i-1] = make_message(ctx, &pubkeys[i-1]);
}
if (!create_onion(pubkeys, msgs, argc - 1, &onion))
errx(1, "Creating onion packet failed");
if (!write_all(STDOUT_FILENO, &onion, sizeof(onion)))
err(1, "Writing onion packet");
return 0;
} else if (decode) {
struct seckey seckey;
secp256k1_pubkey pubkey;
struct enckey enckey;
struct iv pad_iv;
if (argc != 2)
opt_usage_exit_fail("Expect a privkey with --decode");
if (!hex_decode(argv[1], strlen(argv[1]), &seckey, sizeof(seckey)))
errx(1, "Invalid private key hex '%s'", argv[1]);
if (!secp256k1_ec_pubkey_create(ctx, &pubkey, seckey.u.u8))
errx(1, "Invalid private key '%s'", argv[1]);
if (!read_all(STDIN_FILENO, &onion, sizeof(onion)))
errx(1, "Reading in onion");
if (!decrypt_onion(&seckey, &onion, &enckey, &pad_iv))
errx(1, "Failed decrypting onion for '%s'", argv[1]);
if (strncmp((char *)myhop(&onion)->msg, make_message(ctx, &pubkey),
sizeof(myhop(&onion)->msg)))
errx(1, "Bad message '%s'", (char *)myhop(&onion)->msg);
if (!peel_onion(&onion, &enckey, &pad_iv))
errx(1, "Peeling onion for '%s'", argv[1]);
if (!write_all(STDOUT_FILENO, &onion, sizeof(onion)))
err(1, "Writing onion packet");
return 0;
} else
opt_usage_exit_fail("Need --decode or --generate");
secp256k1_context_destroy(ctx);
return 0;
}
