nostr_core_lib/nostr_core/nip005.c

344 lines
11 KiB
C

/*
* NOSTR Core Library - NIP-005: Mapping Nostr keys to DNS-based internet identifiers
*/
#include "nip005.h"
#include "../cjson/cJSON.h"
#include "nostr_common.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h> // For strcasecmp
#include <ctype.h>
#include <curl/curl.h>
// Structure for HTTP response handling
typedef struct {
char* data;
size_t size;
size_t capacity;
} nip05_http_response_t;
/**
* Callback function for curl to write HTTP response data
*/
static size_t nip05_write_callback(void* contents, size_t size, size_t nmemb, void* userp) {
nip05_http_response_t* response = (nip05_http_response_t*)userp;
size_t total_size = size * nmemb;
// Check if we need to expand the buffer
if (response->size + total_size >= response->capacity) {
size_t new_capacity = response->capacity * 2;
if (new_capacity < response->size + total_size + 1) {
new_capacity = response->size + total_size + 1;
}
char* new_data = realloc(response->data, new_capacity);
if (!new_data) {
return 0; // Out of memory
}
response->data = new_data;
response->capacity = new_capacity;
}
// Append the new data
memcpy(response->data + response->size, contents, total_size);
response->size += total_size;
response->data[response->size] = '\0';
return total_size;
}
/**
* Parse and validate a NIP-05 identifier into local part and domain
*/
static int nip05_parse_identifier(const char* identifier, char* local_part, char* domain) {
if (!identifier || !local_part || !domain) {
return NOSTR_ERROR_INVALID_INPUT;
}
// Find the @ symbol
const char* at_pos = strchr(identifier, '@');
if (!at_pos) {
return NOSTR_ERROR_NIP05_INVALID_IDENTIFIER;
}
// Extract local part
size_t local_len = at_pos - identifier;
if (local_len == 0 || local_len >= 64) {
return NOSTR_ERROR_NIP05_INVALID_IDENTIFIER;
}
strncpy(local_part, identifier, local_len);
local_part[local_len] = '\0';
// Extract domain
const char* domain_start = at_pos + 1;
size_t domain_len = strlen(domain_start);
if (domain_len == 0 || domain_len >= 256) {
return NOSTR_ERROR_NIP05_INVALID_IDENTIFIER;
}
strcpy(domain, domain_start);
// Validate characters in local part (a-z0-9-_.)
for (size_t i = 0; i < local_len; i++) {
char c = local_part[i];
if (!((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
(c >= '0' && c <= '9') || c == '-' || c == '_' || c == '.')) {
return NOSTR_ERROR_NIP05_INVALID_IDENTIFIER;
}
}
return NOSTR_SUCCESS;
}
/**
* Make HTTP GET request to a URL
*/
static int nip05_http_get(const char* url, int timeout_seconds, char** response_data) {
if (!url || !response_data) {
return NOSTR_ERROR_INVALID_INPUT;
}
CURL* curl = curl_easy_init();
if (!curl) {
return NOSTR_ERROR_NETWORK_FAILED;
}
nip05_http_response_t response = {0};
response.capacity = 1024;
response.data = malloc(response.capacity);
if (!response.data) {
curl_easy_cleanup(curl);
return NOSTR_ERROR_MEMORY_FAILED;
}
response.data[0] = '\0';
// Set curl options with proper type casting to fix warnings
curl_easy_setopt(curl, CURLOPT_URL, url);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, (curl_write_callback)nip05_write_callback);
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response);
curl_easy_setopt(curl, CURLOPT_TIMEOUT, (long)(timeout_seconds > 0 ? timeout_seconds : NIP05_DEFAULT_TIMEOUT));
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 0L); // NIP-05 forbids redirects
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);
curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 2L);
curl_easy_setopt(curl, CURLOPT_USERAGENT, "nostr-core/1.0");
// Perform the request
CURLcode res = curl_easy_perform(curl);
long response_code = 0;
curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &response_code);
curl_easy_cleanup(curl);
if (res != CURLE_OK) {
free(response.data);
return NOSTR_ERROR_NIP05_HTTP_FAILED;
}
if (response_code != 200) {
free(response.data);
return NOSTR_ERROR_NIP05_HTTP_FAILED;
}
*response_data = response.data;
return NOSTR_SUCCESS;
}
/**
* Validate that a hex string is a valid public key
*/
static int nip05_validate_pubkey_hex(const char* hex_pubkey) {
if (!hex_pubkey) {
return NOSTR_ERROR_INVALID_INPUT;
}
size_t len = strlen(hex_pubkey);
if (len != 64) {
return NOSTR_ERROR_INVALID_INPUT;
}
// Check all characters are valid hex
for (size_t i = 0; i < len; i++) {
char c = hex_pubkey[i];
if (!((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'))) {
return NOSTR_ERROR_INVALID_INPUT;
}
}
return NOSTR_SUCCESS;
}
/**
* Parse a .well-known/nostr.json response and extract pubkey and relays for a specific name
*/
int nostr_nip05_parse_well_known(const char* json_response, const char* local_part,
char* pubkey_hex_out, char*** relays, int* relay_count) {
if (!json_response || !local_part) {
return NOSTR_ERROR_INVALID_INPUT;
}
// Initialize outputs
if (pubkey_hex_out) {
pubkey_hex_out[0] = '\0';
}
if (relays) {
*relays = NULL;
}
if (relay_count) {
*relay_count = 0;
}
// Parse JSON
cJSON* json = cJSON_Parse(json_response);
if (!json) {
return NOSTR_ERROR_NIP05_JSON_PARSE_FAILED;
}
int result = NOSTR_ERROR_NIP05_NAME_NOT_FOUND;
// Get the "names" object
cJSON* names = cJSON_GetObjectItem(json, "names");
if (names && cJSON_IsObject(names)) {
cJSON* pubkey_item = cJSON_GetObjectItem(names, local_part);
if (pubkey_item && cJSON_IsString(pubkey_item)) {
const char* found_pubkey = cJSON_GetStringValue(pubkey_item);
// Validate the public key format
if (nip05_validate_pubkey_hex(found_pubkey) == NOSTR_SUCCESS) {
if (pubkey_hex_out) {
strcpy(pubkey_hex_out, found_pubkey);
}
result = NOSTR_SUCCESS;
// Extract relays if requested
if (relays && relay_count) {
cJSON* relays_obj = cJSON_GetObjectItem(json, "relays");
if (relays_obj && cJSON_IsObject(relays_obj)) {
cJSON* user_relays = cJSON_GetObjectItem(relays_obj, found_pubkey);
if (user_relays && cJSON_IsArray(user_relays)) {
int relay_array_size = cJSON_GetArraySize(user_relays);
if (relay_array_size > 0) {
char** relay_array = malloc(relay_array_size * sizeof(char*));
if (relay_array) {
int valid_relays = 0;
for (int i = 0; i < relay_array_size; i++) {
cJSON* relay_item = cJSON_GetArrayItem(user_relays, i);
if (relay_item && cJSON_IsString(relay_item)) {
const char* relay_url = cJSON_GetStringValue(relay_item);
if (relay_url && strlen(relay_url) > 0) {
relay_array[valid_relays] = malloc(strlen(relay_url) + 1);
if (relay_array[valid_relays]) {
strcpy(relay_array[valid_relays], relay_url);
valid_relays++;
}
}
}
}
if (valid_relays > 0) {
*relays = relay_array;
*relay_count = valid_relays;
} else {
free(relay_array);
}
}
}
}
}
}
}
}
}
cJSON_Delete(json);
return result;
}
/**
* Lookup a public key from a NIP-05 identifier
*/
int nostr_nip05_lookup(const char* nip05_identifier, char* pubkey_hex_out,
char*** relays, int* relay_count, int timeout_seconds) {
if (!nip05_identifier) {
return NOSTR_ERROR_INVALID_INPUT;
}
char local_part[64];
char domain[256];
char url[NOSTR_MAX_URL_SIZE];
// Parse the identifier
int parse_result = nip05_parse_identifier(nip05_identifier, local_part, domain);
if (parse_result != NOSTR_SUCCESS) {
return parse_result;
}
// Construct the .well-known URL
int url_result = snprintf(url, sizeof(url), "https://%s/.well-known/nostr.json?name=%s",
domain, local_part);
if (url_result >= (int)sizeof(url) || url_result < 0) {
return NOSTR_ERROR_INVALID_INPUT;
}
// Make HTTP request
char* response_data = NULL;
int http_result = nip05_http_get(url, timeout_seconds, &response_data);
if (http_result != NOSTR_SUCCESS) {
return http_result;
}
// Parse the response
int parse_response_result = nostr_nip05_parse_well_known(response_data, local_part,
pubkey_hex_out, relays, relay_count);
free(response_data);
return parse_response_result;
}
/**
* Verify a NIP-05 identifier against a public key
*/
int nostr_nip05_verify(const char* nip05_identifier, const char* pubkey_hex,
char*** relays, int* relay_count, int timeout_seconds) {
if (!nip05_identifier || !pubkey_hex) {
return NOSTR_ERROR_INVALID_INPUT;
}
// Validate the input public key format
if (nip05_validate_pubkey_hex(pubkey_hex) != NOSTR_SUCCESS) {
return NOSTR_ERROR_INVALID_INPUT;
}
char found_pubkey[65];
// Lookup the public key for this identifier
int lookup_result = nostr_nip05_lookup(nip05_identifier, found_pubkey,
relays, relay_count, timeout_seconds);
if (lookup_result != NOSTR_SUCCESS) {
return lookup_result;
}
// Compare the public keys (case insensitive)
if (strcasecmp(pubkey_hex, found_pubkey) != 0) {
// Clean up relays if verification failed
if (relays && *relays) {
for (int i = 0; i < (relay_count ? *relay_count : 0); i++) {
free((*relays)[i]);
}
free(*relays);
*relays = NULL;
}
if (relay_count) {
*relay_count = 0;
}
return NOSTR_ERROR_NIP05_PUBKEY_MISMATCH;
}
return NOSTR_SUCCESS;
}