/**
* Constructs a path leading to the chosen server settings directory. Used
* internally by file_path_player() and file_path_server().
* @return
*
*/
static StringBuffer *file_path_server_internal(void)
{
StringBuffer *sb;
sb = stringbuffer_new();
stringbuffer_append_string(sb, "settings/");
SOFT_ASSERT_RC(selected_server != NULL, sb, "Selected server is NULL.");
SOFT_ASSERT_RC(!string_isempty(selected_server->hostname), sb,
"Selected server has empty hostname.");
stringbuffer_append_printf(sb, "servers/%s-%d/", selected_server->hostname,
selected_server->port);
return sb;
}
/**
* Get absolute path to the specified relative path. This path will typically
* point to the to client data directory (which is usually located in the user's
* home/appdata directory), but depending on the specified mode, extra actions
* may be performed. These ensure that if you're trying to access a file that
* does not yet exist in the client data directory, it will be read from the
* client installation directory instead (unless it's being appended to, in
* which case it will be copied to the client data directory first).
*
* Generally, you should almost always use this when you need to construct a
* path, or use one of the many @ref file_wrapper_functions.
* @param fname
* The file path.
* @param mode
* File mode.
* @return
* The absolute path. Must be freed.
*/
char *file_path(const char *path, const char *mode)
{
bool is_write, is_append;
StringBuffer *sb;
char version[MAX_BUF], client_path[HUGE_BUF], *new_path;
HARD_ASSERT(path != NULL);
HARD_ASSERT(mode != NULL);
SOFT_ASSERT_RC(path[0] != '/', estrdup(path),
"Path is already absolute: %s", path);
sb = stringbuffer_new();
stringbuffer_append_printf(sb, "%s/.atrinik/%s/%s", get_config_dir(),
package_get_version_partial(VS(version)), path);
new_path = stringbuffer_sub(sb, 0, 0);
is_write = is_append = false;
if (strchr(mode, 'w') != NULL) {
is_write = true;
} else if (strchr(mode, '+') != NULL || strchr(mode, 'a') != NULL) {
is_append = true;
}
if (is_write || is_append) {
if (access(new_path, W_OK) != 0) {
char *dirname;
/* Ensure directories exist if we're going to use this path for
* writing/appending. */
dirname = path_dirname(new_path);
mkdir_recurse(dirname);
efree(dirname);
if (is_append) {
get_data_dir_file(VS(client_path), path);
copy_file(client_path, new_path);
}
}
} else {
if (access(new_path, R_OK) != 0) {
get_data_dir_file(VS(client_path), path);
stringbuffer_seek(sb, 0);
stringbuffer_append_string(sb, client_path);
}
}
efree(new_path);
return stringbuffer_finish(sb);
}
/**
* Verify resolved address of a server against the server's metaserver
* certificate.
*
* @param server
* Server to verify.
* @param host
* Host address.
* @return
* True if the resolved address is equal to the one in the certificate,
* false otherwise.
*/
bool
metaserver_cert_verify_host (server_struct *server, const char *host)
{
HARD_ASSERT(server != NULL);
HARD_ASSERT(host != NULL);
/* No certificate, nothing to verify. */
if (server->cert_info == NULL) {
return true;
}
struct sockaddr_storage addr;
SOFT_ASSERT_RC(socket_host2addr(host, &addr), false,
"Failed to convert host to IP address");
switch (addr.ss_family) {
case AF_INET:
if (strcmp(host, server->cert_info->ipv4_address) != 0) {
LOG(ERROR, "!!! Certificate IPv4 address error: %s != %s !!!",
host, server->cert_info->ipv4_address);
return false;
}
break;
case AF_INET6:
if (strcmp(host, server->cert_info->ipv6_address) != 0) {
LOG(ERROR, "!!! Certificate IPv6 address error: %s != %s !!!",
host, server->cert_info->ipv6_address);
return false;
}
break;
default:
LOG(ERROR, "!!! Unknown address family %u !!!", addr.ss_family);
return false;
}
return true;
}
/**
* Parse the metaserver certificate information.
*
* @param server
* Metaserver entry.
* @return
* True on success, false on failure.
*/
static bool
parse_metaserver_cert (server_struct *server)
{
HARD_ASSERT(server != NULL);
if (server->cert == NULL || server->cert_sig == NULL) {
/* No certificate. */
return true;
}
/* Generate a SHA512 hash of the certificate's contents. */
unsigned char cert_digest[SHA512_DIGEST_LENGTH];
if (SHA512((unsigned char *) server->cert,
strlen(server->cert),
cert_digest) == NULL) {
LOG(ERROR, "SHA512() failed: %s",
ERR_error_string(ERR_get_error(), NULL));
return false;
}
char cert_hash[SHA512_DIGEST_LENGTH * 2 + 1];
SOFT_ASSERT_RC(string_tohex(VS(cert_digest),
VS(cert_hash),
false) == sizeof(cert_hash) - 1,
false,
"string_tohex failed");
string_tolower(cert_hash);
/* Verify the signature. */
if (!curl_verify(CURL_PKEY_TRUST_ULTIMATE,
cert_hash,
strlen(cert_hash),
server->cert_sig,
server->cert_sig_len)) {
LOG(ERROR, "Failed to verify signature");
return false;
}
server_cert_info_t *info = ecalloc(1, sizeof(*info));
char buf[MAX_BUF];
size_t pos = 0;
bool in_info = false;
while (string_get_word(server->cert, &pos, '\n', VS(buf), 0)) {
char *cp = buf;
string_skip_whitespace(cp);
string_strip_newline(cp);
if (*cp == '\0') {
continue;
}
if (strcmp(cp, cert_begin_str) == 0) {
in_info = true;
continue;
} else if (!in_info) {
continue;
} else if (strcmp(cp, cert_end_str) == 0) {
break;
}
char *cps[2];
if (string_split(cp, cps, arraysize(cps), ':') != arraysize(cps)) {
LOG(ERROR, "Parsing error");
continue;
}
string_tolower(cps[0]);
string_skip_whitespace(cps[1]);
const char *key = cps[0];
const char *value = cps[1];
char **content = NULL;
if (strcmp(key, "name") == 0) {
content = &info->name;
} else if (strcmp(key, "hostname") == 0) {
content = &info->hostname;
} else if (strcmp(key, "ipv4 address") == 0) {
content = &info->ipv4_address;
} else if (strcmp(key, "ipv6 address") == 0) {
content = &info->ipv6_address;
} else if (strcmp(key, "public key") == 0) {
content = &info->pubkey;
} else if (strcmp(key, "port") == 0) {
info->port = atoi(value);
} else if (strcmp(key, "crypto port") == 0) {
info->port_crypto = atoi(value);
} else {
LOG(DEVEL, "Unrecognized key: %s", key);
continue;
}
if (content != NULL) {
StringBuffer *sb = stringbuffer_new();
if (*content != NULL) {
stringbuffer_append_string(sb, *content);
stringbuffer_append_char(sb, '\n');
efree(*content);
}
stringbuffer_append_string(sb, value);
*content = stringbuffer_finish(sb);
}
}
/* Ensure we got the data we need. */
if (info->name == NULL ||
info->hostname == NULL ||
info->pubkey == NULL ||
info->port_crypto <= 0 ||
(info->ipv4_address == NULL) != (info->ipv6_address == NULL)) {
LOG(ERROR,
"Certificate is missing required data.");
goto error;
}
/* Ensure certificate attributes match the advertised ones. */
if (strcmp(info->hostname, server->hostname) != 0) {
LOG(ERROR,
"Certificate hostname does not match advertised hostname.");
goto error;
}
if (strcmp(info->name, server->name) != 0) {
LOG(ERROR,
"Certificate name does not match advertised name.");
goto error;
}
if (info->port != server->port) {
LOG(ERROR,
"Certificate port does not match advertised port.");
goto error;
}
if (info->port_crypto != server->port_crypto) {
LOG(ERROR,
"Certificate crypto port does not match advertised crypto port.");
goto error;
}
server->cert_info = info;
return true;
error:
metaserver_cert_free(info);
return false;
}