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Support TLS SPKI verify

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This commit is contained in:
Nick Peng
2019-02-22 00:40:30 +08:00
parent 4465ce798a
commit 85b0eed3a2
10 changed files with 159 additions and 29 deletions
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102
src/dns_client.c
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@@ -93,6 +93,9 @@ struct dns_server_info {
/* server type */
dns_server_type_t type;
unsigned char *spki;
int spki_len;
/* client socket */
int fd;
int ttl;
@@ -535,9 +538,25 @@ void _dns_client_group_remove_all(void)
}
/* add dns server information */
int _dns_client_server_add(char *server_ip, struct addrinfo *gai, dns_server_type_t server_type, unsigned int server_flag, unsigned int result_flag, int ttl)
int _dns_client_server_add(char *server_ip, struct addrinfo *gai, dns_server_type_t server_type, unsigned int server_flag, unsigned int result_flag, int ttl, char *spki)
{
struct dns_server_info *server_info = NULL;
unsigned char *spki_data = NULL;
int spki_data_len = 0;
/* read SPKI */
if (spki && (strlen(spki) < DNS_MAX_SPKI_LEN)) {
spki_data = malloc(DNS_MAX_SPKI_LEN);
if (spki_data) {
memset(spki_data, 0, DNS_MAX_SPKI_LEN);
spki_data_len = SSL_base64_decode(spki, spki_data);
if (spki_data_len != SHA256_DIGEST_LENGTH) {
free(spki_data);
spki_data = NULL;
spki_data_len = 0;
}
}
}
if (_dns_client_server_exist(gai, server_type) == 0) {
return 0;
@@ -562,6 +581,8 @@ int _dns_client_server_add(char *server_ip, struct addrinfo *gai, dns_server_typ
server_info->result_flag = result_flag;
server_info->ttl = ttl;
server_info->ttl_range = 0;
server_info->spki = spki_data;
server_info->spki_len = spki_data_len;
if ((server_flag & SERVER_FLAG_EXCLUDE_DEFAULT) == 0) {
if (_dns_client_add_to_group(DNS_SERVER_GROUP_DEFAULT, server_info) != 0) {
@@ -605,6 +626,10 @@ int _dns_client_server_add(char *server_ip, struct addrinfo *gai, dns_server_typ
atomic_inc(&client.dns_server_num);
return 0;
errout:
if (spki_data) {
free(spki_data);
}
if (server_info) {
if (server_info->ssl_ctx) {
SSL_CTX_free(server_info->ssl_ctx);
@@ -673,6 +698,10 @@ void _dns_client_server_remove_all(void)
{
list_del(&server_info->list);
_dns_client_server_close(server_info);
if (server_info->spki) {
free(server_info->spki);
server_info->spki = NULL;
}
free(server_info);
}
pthread_mutex_unlock(&client.server_list_lock);
@@ -707,7 +736,7 @@ int _dns_client_server_remove(char *server_ip, struct addrinfo *gai, dns_server_
return -1;
}
int _dns_client_server_operate(char *server_ip, int port, dns_server_type_t server_type, unsigned int server_flag, unsigned int result_flag, int ttl, int operate)
int _dns_client_server_operate(char *server_ip, int port, dns_server_type_t server_type, unsigned int server_flag, unsigned int result_flag, int ttl, char *spki, int operate)
{
char port_s[8];
int sock_type;
@@ -741,7 +770,7 @@ int _dns_client_server_operate(char *server_ip, int port, dns_server_type_t serv
}
if (operate == 0) {
ret = _dns_client_server_add(server_ip, gai, server_type, server_flag, result_flag, ttl);
ret = _dns_client_server_add(server_ip, gai, server_type, server_flag, result_flag, ttl, spki);
if (ret != 0) {
goto errout;
}
@@ -760,14 +789,14 @@ errout:
return -1;
}
int dns_client_add_server(char *server_ip, int port, dns_server_type_t server_type, unsigned server_flag, unsigned int result_flag, int ttl)
int dns_client_add_server(char *server_ip, int port, dns_server_type_t server_type, unsigned server_flag, unsigned int result_flag, int ttl, char *spki)
{
return _dns_client_server_operate(server_ip, port, server_type, server_flag, result_flag, ttl, 0);
return _dns_client_server_operate(server_ip, port, server_type, server_flag, result_flag, ttl, spki, 0);
}
int dns_client_remove_server(char *server_ip, int port, dns_server_type_t server_type)
{
return _dns_client_server_operate(server_ip, port, server_type, 0, 0, 0, 1);
return _dns_client_server_operate(server_ip, port, server_type, 0, 0, 0, NULL, 1);
}
int dns_server_num(void)
@@ -1653,11 +1682,12 @@ static int _dns_client_tls_verify(struct dns_server_info *server_info)
{
X509 *cert = NULL;
char peer_CN[256];
const EVP_MD *digest;
unsigned char md[EVP_MAX_MD_SIZE];
unsigned int n;
char cert_fingerprint[256];
int i = 0;
int key_len = 0;
unsigned char *key_data = NULL;
unsigned char *key_data_tmp = NULL;
unsigned char *key_sha256 = NULL;
cert = SSL_get_peer_certificate(server_info->ssl);
if (cert == NULL) {
@@ -1666,28 +1696,66 @@ static int _dns_client_tls_verify(struct dns_server_info *server_info)
}
X509_NAME_get_text_by_NID(X509_get_subject_name(cert), NID_commonName, peer_CN, 256);
tlog(TLOG_DEBUG, "peer CN: %s", peer_CN);
digest = EVP_get_digestbyname("sha256");
X509_digest(cert, digest, md, &n);
/* get spki pin */
key_len = i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), NULL);
if (key_len <= 0 ) {
tlog(TLOG_ERROR, "get x509 public key failed.");
goto errout;
}
key_data = OPENSSL_malloc(key_len);
key_data_tmp = key_data;
if (key_data == NULL) {
tlog(TLOG_ERROR, "malloc memory failed.");
goto errout;
}
i2d_X509_PUBKEY(X509_get_X509_PUBKEY(cert), &key_data_tmp);
key_sha256 = SSL_SHA256(key_data, key_len, 0);
if (key_sha256 == NULL) {
tlog(TLOG_ERROR, "get sha256 failed.");
goto errout;
}
char *ptr = cert_fingerprint;
for (i = 0; i < 32; i++) {
*ptr = _dns_client_to_hex(md[i] >> 4 & 0xF);
for (i = 0; i < SHA256_DIGEST_LENGTH; i++) {
*ptr = _dns_client_to_hex(key_sha256[i] >> 4 & 0xF);
ptr++;
*ptr = _dns_client_to_hex(md[i] & 0xF);
*ptr = _dns_client_to_hex(key_sha256[i] & 0xF);
ptr++;
*ptr = ':';
ptr++;
}
ptr--;
*ptr = 0;
tlog(TLOG_DEBUG, "cert fingerprint(%s): %s", "sha256", cert_fingerprint);
tlog(TLOG_DEBUG, "cert SPKI pin(%s): %s", "sha256", cert_fingerprint);
if (server_info->spki) {
if (memcmp(server_info->spki, key_sha256, server_info->spki_len) != 0) {
tlog(TLOG_INFO, "server %s cert spki is invalid", server_info->ip);
goto errout;
} else {
tlog(TLOG_DEBUG, "server %s cert spki verify succeed", server_info->ip);
}
}
OPENSSL_free(key_data);
X509_free(cert);
return 0;
errout:
if (key_data) {
OPENSSL_free(key_data);
}
if (cert) {
X509_free(cert);
}
return -1;
}
static int _dns_client_process_tls(struct dns_server_info *server_info, struct epoll_event *event, unsigned long now)