int serval_open_keyring(const char *keyring_path,
const size_t keyring_len,
keyring_file **_keyring) {
char keyring_path_str[PATH_MAX] = {0};
if (keyring_path == NULL || keyring_len == 0) { // if no keyring specified, use default keyring
strcpy(keyring_path_str,serval_path);
if (serval_path[strlen(serval_path) - 1] != '/')
strcat(keyring_path_str,"/");
strcat(keyring_path_str,"serval.keyring");
// Fetching SAS keys requires setting the SERVALINSTANCE_PATH environment variable
CHECK_ERR(setenv("SERVALINSTANCE_PATH",serval_path,1) == 0,"Failed to set SERVALINSTANCE_PATH env variable");
}
else { // otherwise, use specified keyring (NOTE: if keyring does not exist, it will be created)
CHECK(keyring_len < PATH_MAX,"Keyring length too long");
strncpy(keyring_path_str,keyring_path,keyring_len);
keyring_path_str[keyring_len] = '\0';
}
CHECK_ERR((*_keyring = keyring_open(keyring_path_str)),"Failed to open specified keyring file");
if (keyring_enter_pin(*_keyring, KEYRING_PIN) <= 0) {
/* put initial identity in if we don't have any visible */
CHECK_ERR(keyring_seed(*_keyring) == 0,"Failed to seed keyring");
}
return 1;
error:
return 0;
}
int
serval_open_keyring(svl_crypto_ctx *ctx)
{
CHECK_ERR(ctx,"Invalid ctx");
if (ctx->keyring_len == 0) {
// if no keyring specified, use default keyring
CHECK(serval_path,"Default Serval path not initialized");
char keyring_path_str[PATH_MAX] = {0};
strcpy(keyring_path_str, serval_path);
if (serval_path[strlen(serval_path) - 1] != '/')
strcat(keyring_path_str, "/");
strcat(keyring_path_str, "serval.keyring");
// Fetching SAS keys requires setting the SERVALINSTANCE_PATH environment variable
CHECK_ERR(setenv("SERVALINSTANCE_PATH", serval_path, 1) == 0,
"Failed to set SERVALINSTANCE_PATH env variable");
ctx->keyring_len = strlen(keyring_path_str);
ctx->keyring_path = h_malloc(ctx->keyring_len + 1);
strcpy(ctx->keyring_path,keyring_path_str);
hattach(ctx->keyring_path,ctx);
} else {
// otherwise, use specified keyring (NOTE: if keyring does not exist, it will be created)
CHECK(ctx->keyring_len < PATH_MAX, "Keyring length too long");
}
ctx->keyring_file = keyring_open(ctx->keyring_path);
CHECK_ERR(ctx->keyring_file, "Failed to open specified keyring file");
if (keyring_enter_pin(ctx->keyring_file, KEYRING_PIN) <= 0) {
// put initial identity in if we don't have any visible
CHECK_ERR(keyring_seed(ctx->keyring_file) == 0, "Failed to seed keyring");
}
return 1;
error:
return 0;
}
int serval_sign(const char *sid,
const size_t sid_len,
const unsigned char *msg,
const size_t msg_len,
char *sig_buffer,
const size_t sig_size,
const char *keyringName,
const size_t keyring_len) {
keyring_identity *new_ident;
char keyringFile[1024];
assert(msg_len);
if (sid) assert(sid_len == 2*SID_SIZE);
if (keyringName == NULL || keyring_len == 0) {
FORM_SERVAL_INSTANCE_PATH(keyringFile, "serval.keyring"); // if no keyring specified, use default keyring
}
else { // otherwise, use specified keyring (NOTE: if keyring does not exist, it will be created)
strncpy(keyringFile,keyringName,keyring_len);
keyringFile[keyring_len] = '\0';
}
keyring = keyring_open(keyringFile);
keyring_enter_pin(keyring, KEYRING_PIN); // unlocks Serval keyring for using identities (also initializes global default identity my_subscriber)
if (!sid) {
//create new sid
int c;
for(c=0;c<keyring->context_count;c++) { // cycle through the keyring contexts until we find one with room for another identity
new_ident = keyring_create_identity(keyring,keyring->contexts[c], KEYRING_PIN); // create new Serval identity
if (new_ident)
break;
}
if (!new_ident) {
fprintf(stderr, "failed to create new SID\n");
return 1;
}
if (keyring_commit(keyring)) { // need to commit keyring or else new identity won't be saved (needs root permissions)
fprintf(stderr, "Failed to save new SID into keyring...make sure you are running as root!\n");
return 1;
}
sid = alloca_tohex_sid(new_ident->subscriber->sid); // convert SID from binary to hex
} else {
if (!str_is_subscriber_id(sid)) {
fprintf(stderr,"Invalid SID\n");
return 1;
}
}
unsigned char packedSid[SID_SIZE];
stowSid(packedSid,0,sid);
unsigned char *key=keyring_find_sas_private(keyring, packedSid, NULL); // get SAS key associated with our SID
if (!key)
return 1;
unsigned char hash[crypto_hash_sha512_BYTES];
unsigned long long sig_length = SIGNATURE_BYTES;
crypto_hash_sha512(hash, msg, msg_len); // create sha512 hash of message, which will then be signed
unsigned char signed_msg[msg_len + sig_length];
memcpy(signed_msg,msg,msg_len);
int ret = crypto_create_signature(key, hash, crypto_hash_sha512_BYTES, &signed_msg[msg_len], &sig_length); // create signature of message hash, append it to end of message
if (!ret) { //success
printf("%s\n", alloca_tohex(signed_msg + msg_len, sig_length));
printf("%s\n",sid);
if (sig_size > 0) {
if (sig_size >= 2*sig_length + 1) {
strncpy(sig_buffer,alloca_tohex(signed_msg + msg_len,sig_length),2*sig_length);
sig_buffer[2*sig_length] = '\0';
} else
fprintf(stderr,"Insufficient signature buffer size\n");
}
}
keyring_free(keyring);
return ret;
}