From f2978fefa13eb92b73922e49d2f6c12b4f92ea85 Mon Sep 17 00:00:00 2001
From: Christian Heimes <christian@python.org>
Date: Fri, 10 Jan 2020 18:35:02 +0100
Subject: [PATCH] Use OpenSSL API to verify host
Replace custom hostname and IP address verification with OpenSSL 1.0.2
APIs.
---
libraries/libldap/tls_o.c | 184 ++++++--------------------------------
1 file changed, 28 insertions(+), 156 deletions(-)
diff --git a/libraries/libldap/tls_o.c b/libraries/libldap/tls_o.c
index e52c5507c..5adf7b74f 100644
--- a/libraries/libldap/tls_o.c
+++ b/libraries/libldap/tls_o.c
@@ -660,25 +660,15 @@ tlso_session_peer_dn( tls_session *sess, struct berval *der_dn )
return 0;
}
-/* what kind of hostname were we given? */
-#define IS_DNS 0
-#define IS_IP4 1
-#define IS_IP6 2
-
static int
tlso_session_chkhost( LDAP *ld, tls_session *sess, const char *name_in )
{
tlso_session *s = (tlso_session *)sess;
- int i, ret = LDAP_LOCAL_ERROR;
+ int ret = LDAP_LOCAL_ERROR;
X509 *x;
const char *name;
- char *ptr;
- int ntype = IS_DNS, nlen;
-#ifdef LDAP_PF_INET6
- struct in6_addr addr;
-#else
- struct in_addr addr;
-#endif
+ int flags = X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS;
+ ASN1_OCTET_STRING *ip;
if( ldap_int_hostname &&
( !name_in || !strcasecmp( name_in, "localhost" ) ) )
@@ -687,7 +677,6 @@ tlso_session_chkhost( LDAP *ld, tls_session *sess, const char *name_in )
} else {
name = name_in;
}
- nlen = strlen(name);
x = tlso_get_cert(s);
if (!x) {
@@ -619,150 +619,32 @@ tlso_session_chkhost( LDAP *ld, tls_session *sess, const char *name_in )
return LDAP_SUCCESS;
}
-#ifdef LDAP_PF_INET6
- if (inet_pton(AF_INET6, name, &addr)) {
- ntype = IS_IP6;
- } else
-#endif
- if ((ptr = strrchr(name, '.')) && isdigit((unsigned char)ptr[1])) {
- if (inet_aton(name, (struct in_addr *)&addr)) ntype = IS_IP4;
- }
-
- i = X509_get_ext_by_NID(x, NID_subject_alt_name, -1);
- if (i >= 0) {
- X509_EXTENSION *ex;
- STACK_OF(GENERAL_NAME) *alt;
-
- ex = X509_get_ext(x, i);
- alt = X509V3_EXT_d2i(ex);
- if (alt) {
- int n, len2 = 0;
- char *domain = NULL;
- GENERAL_NAME *gn;
-
- if (ntype == IS_DNS) {
- domain = strchr(name, '.');
- if (domain) {
- len2 = nlen - (domain-name);
- }
- }
- n = sk_GENERAL_NAME_num(alt);
- for (i=0; i<n; i++) {
- char *sn;
- int sl;
- gn = sk_GENERAL_NAME_value(alt, i);
- if (gn->type == GEN_DNS) {
- if (ntype != IS_DNS) continue;
-
- sn = (char *) ASN1_STRING_data(gn->d.ia5);
- sl = ASN1_STRING_length(gn->d.ia5);
-
- /* ignore empty */
- if (sl == 0) continue;
-
- /* Is this an exact match? */
- if ((nlen == sl) && !strncasecmp(name, sn, nlen)) {
- break;
- }
-
- /* Is this a wildcard match? */
- if (domain && (sn[0] == '*') && (sn[1] == '.') &&
- (len2 == sl-1) && !strncasecmp(domain, &sn[1], len2))
- {
- break;
- }
-
- } else if (gn->type == GEN_IPADD) {
- if (ntype == IS_DNS) continue;
-
- sn = (char *) ASN1_STRING_data(gn->d.ia5);
- sl = ASN1_STRING_length(gn->d.ia5);
-
-#ifdef LDAP_PF_INET6
- if (ntype == IS_IP6 && sl != sizeof(struct in6_addr)) {
- continue;
- } else
-#endif
- if (ntype == IS_IP4 && sl != sizeof(struct in_addr)) {
- continue;
- }
- if (!memcmp(sn, &addr, sl)) {
- break;
- }
- }
- }
-
- GENERAL_NAMES_free(alt);
- if (i < n) { /* Found a match */
- ret = LDAP_SUCCESS;
- }
- }
- }
-
- if (ret != LDAP_SUCCESS) {
- X509_NAME *xn;
- X509_NAME_ENTRY *ne;
- ASN1_OBJECT *obj;
- ASN1_STRING *cn = NULL;
- int navas;
-
- /* find the last CN */
- obj = OBJ_nid2obj( NID_commonName );
- if ( !obj ) goto no_cn; /* should never happen */
-
- xn = X509_get_subject_name(x);
- navas = X509_NAME_entry_count( xn );
- for ( i=navas-1; i>=0; i-- ) {
- ne = X509_NAME_get_entry( xn, i );
- if ( !OBJ_cmp( X509_NAME_ENTRY_get_object(ne), obj )) {
- cn = X509_NAME_ENTRY_get_data( ne );
- break;
- }
+ /* attempt to encode name as IP address */
+ ip = a2i_IPADDRESS(name);
+ if (ip == NULL) {
+ ERR_clear_error();
+ /* it's a hostname */
+ if (X509_check_host(x, name, strlen(name), flags, NULL) == 1) {
+ ret = LDAP_SUCCESS;
}
-
- if( !cn )
- {
-no_cn:
- Debug( LDAP_DEBUG_ANY,
- "TLS: unable to get common name from peer certificate.\n",
- 0, 0, 0 );
- ret = LDAP_CONNECT_ERROR;
- if ( ld->ld_error ) {
- LDAP_FREE( ld->ld_error );
- }
- ld->ld_error = LDAP_STRDUP(
- _("TLS: unable to get CN from peer certificate"));
-
- } else if ( cn->length == nlen &&
- strncasecmp( name, (char *) cn->data, nlen ) == 0 ) {
+ } else {
+ /* It's an IPv4 or IPv6 address */
+ if (X509_check_ip(x, ASN1_STRING_data(ip),
+ ASN1_STRING_length(ip), 0) == 1) {
ret = LDAP_SUCCESS;
-
- } else if (( cn->data[0] == '*' ) && ( cn->data[1] == '.' )) {
- char *domain = strchr(name, '.');
- if( domain ) {
- int dlen;
-
- dlen = nlen - (domain-name);
-
- /* Is this a wildcard match? */
- if ((dlen == cn->length-1) &&
- !strncasecmp(domain, (char *) &cn->data[1], dlen)) {
- ret = LDAP_SUCCESS;
- }
- }
}
+ ASN1_OCTET_STRING_free(ip);
+ }
- if( ret == LDAP_LOCAL_ERROR ) {
- Debug( LDAP_DEBUG_ANY, "TLS: hostname (%s) does not match "
- "common name in certificate (%.*s).\n",
- name, cn->length, cn->data );
- ret = LDAP_CONNECT_ERROR;
- if ( ld->ld_error ) {
- LDAP_FREE( ld->ld_error );
- }
- ld->ld_error = LDAP_STRDUP(
- _("TLS: hostname does not match CN in peer certificate"));
+ if( ret == LDAP_LOCAL_ERROR ) {
+ Debug( LDAP_DEBUG_ANY, "TLS: hostname (%s) does not match "
+ "peer certificate.\n", name, 0, 0);
+ ret = LDAP_CONNECT_ERROR;
+ if ( ld->ld_error ) {
+ LDAP_FREE( ld->ld_error );
}
+ ld->ld_error = LDAP_STRDUP(
+ _("TLS: hostname does not match peer certificate"));
}
X509_free(x);
return ret;