char *
check_alt_names(char *host, char *fqdn, X509 *x509)
{
char *found, *buf;
const GENERAL_NAMES *ans;
const GENERAL_NAME *p;
int n;
ans = X509_get_ext_d2i(x509, NID_subject_alt_name, NULL, NULL);
if (ans == NULL)
return (NULL);
n = sk_GENERAL_NAME_num(ans);
found = NULL;
while (n-- > 0 && found == NULL) {
p = sk_GENERAL_NAME_value(ans, n);
if (p == NULL || p->type != GEN_DNS)
continue;
if (ASN1_STRING_to_UTF8((u_char **)&buf, p->d.dNSName) <= 0)
continue;
if (fnmatch(buf, host, FNM_NOESCAPE|FNM_CASEFOLD) == 0 ||
(fqdn != NULL &&
fnmatch(buf, fqdn, FNM_NOESCAPE|FNM_CASEFOLD) == 0))
found = buf;
OPENSSL_free(buf);
}
sk_GENERAL_NAME_free(ans);
return (found);
}
static
bool extract_x509_extension(X509 *cert, char *fieldname, char *out, int size)
{
bool retval = false;
X509_EXTENSION *pExt;
char *buf = 0;
int length = 0;
GENERAL_NAMES *extensions;
int nid = OBJ_txt2nid(fieldname);
extensions = (GENERAL_NAMES *)X509_get_ext_d2i(cert, nid, NULL, NULL);
if ( extensions )
{
int numalts;
int i;
/* get amount of alternatives,
* RFC2459 claims there MUST be at least
* one, but we don't depend on it...
*/
numalts = sk_GENERAL_NAME_num(extensions);
/* loop through all alternatives */
for (i=0; i<numalts; i++)
{
/* get a handle to alternative name number i */
const GENERAL_NAME *name = sk_GENERAL_NAME_value (extensions, i );
switch (name->type)
{
case GEN_EMAIL:
ASN1_STRING_to_UTF8((unsigned char**)&buf, name->d.ia5);
if ( strlen (buf) != name->d.ia5->length )
{
msg (D_TLS_ERRORS, "ASN1 ERROR: string contained terminating zero");
OPENSSL_free (buf);
} else {
strncpynt(out, buf, size);
OPENSSL_free(buf);
retval = true;
}
break;
default:
msg (D_TLS_ERRORS, "ASN1 ERROR: can not handle field type %i",
name->type);
break;
}
}
sk_GENERAL_NAME_free (extensions);
}
return retval;
}
/*
Function:
GetX509NameInfo
Used by System.Security.Cryptography.X509Certificates' OpenSslX509CertificateReader as the entire
implementation of X509Certificate2.GetNameInfo.
Return values:
NULL if the certificate is invalid or no name information could be found, otherwise a pointer to a
memory-backed BIO structure which contains the answer to the GetNameInfo query
*/
BIO*
GetX509NameInfo(
X509* x509,
int nameType,
int forIssuer)
{
static const char szOidUpn[] = "1.3.6.1.4.1.311.20.2.3";
if (!x509 || !x509->cert_info || nameType < NAME_TYPE_SIMPLE || nameType > NAME_TYPE_URL)
{
return NULL;
}
// Algorithm behaviors (pseudocode). When forIssuer is true, replace "Subject" with "Issuer" and
// SAN (Subject Alternative Names) with IAN (Issuer Alternative Names).
//
// SimpleName: Subject[CN] ?? Subject[OU] ?? Subject[O] ?? Subject[E] ?? Subject.Rdns.FirstOrDefault() ?? SAN.Entries.FirstOrDefault(type == GEN_EMAIL);
// EmailName: SAN.Entries.FirstOrDefault(type == GEN_EMAIL) ?? Subject[E];
// UpnName: SAN.Entries.FirsOrDefaultt(type == GEN_OTHER && entry.AsOther().OID == szOidUpn).AsOther().Value;
// DnsName: SAN.Entries.FirstOrDefault(type == GEN_DNS) ?? Subject[CN];
// DnsFromAlternativeName: SAN.Entries.FirstOrDefault(type == GEN_DNS);
// UrlName: SAN.Entries.FirstOrDefault(type == GEN_URI);
if (nameType == NAME_TYPE_SIMPLE)
{
X509_NAME* name = forIssuer ? x509->cert_info->issuer : x509->cert_info->subject;
if (name)
{
ASN1_STRING* cn = NULL;
ASN1_STRING* ou = NULL;
ASN1_STRING* o = NULL;
ASN1_STRING* e = NULL;
ASN1_STRING* firstRdn = NULL;
// Walk the list backwards because it is stored in stack order
for (int i = X509_NAME_entry_count(name) - 1; i >= 0; --i)
{
X509_NAME_ENTRY* entry = X509_NAME_get_entry(name, i);
if (!entry)
{
continue;
}
ASN1_OBJECT* oid = X509_NAME_ENTRY_get_object(entry);
ASN1_STRING* str = X509_NAME_ENTRY_get_data(entry);
if (!oid || !str)
{
continue;
}
int nid = OBJ_obj2nid(oid);
if (nid == NID_commonName)
{
// CN wins, so no need to keep looking.
cn = str;
break;
}
else if (nid == NID_organizationalUnitName)
{
ou = str;
}
else if (nid == NID_organizationName)
{
o = str;
}
else if (nid == NID_pkcs9_emailAddress)
{
e = str;
}
else if (!firstRdn)
{
firstRdn = str;
}
}
ASN1_STRING* answer = cn;
// If there was no CN, but there was something, then perform fallbacks.
if (!answer && firstRdn)
{
answer = ou;
if (!answer)
{
answer = o;
}
if (!answer)
{
answer = e;
}
if (!answer)
{
answer = firstRdn;
}
}
if (answer)
{
BIO* b = BIO_new(BIO_s_mem());
ASN1_STRING_print_ex(b, answer, 0);
return b;
}
}
}
if (nameType == NAME_TYPE_SIMPLE ||
nameType == NAME_TYPE_DNS ||
nameType == NAME_TYPE_DNSALT ||
nameType == NAME_TYPE_EMAIL ||
nameType == NAME_TYPE_UPN ||
nameType == NAME_TYPE_URL)
{
int expectedType = -1;
switch (nameType)
{
case NAME_TYPE_DNS:
case NAME_TYPE_DNSALT:
expectedType = GEN_DNS;
break;
case NAME_TYPE_SIMPLE:
case NAME_TYPE_EMAIL:
expectedType = GEN_EMAIL;
break;
case NAME_TYPE_UPN:
expectedType = GEN_OTHERNAME;
break;
case NAME_TYPE_URL:
expectedType = GEN_URI;
break;
}
STACK_OF(GENERAL_NAME)* altNames =
X509_get_ext_d2i(x509, forIssuer ? NID_issuer_alt_name : NID_subject_alt_name, NULL, NULL);
if (altNames)
{
int i;
for (i = 0; i < sk_GENERAL_NAME_num(altNames); ++i)
{
GENERAL_NAME* altName = sk_GENERAL_NAME_value(altNames, i);
if (altName && altName->type == expectedType)
{
ASN1_STRING* str = NULL;
switch (nameType)
{
case NAME_TYPE_DNS:
case NAME_TYPE_DNSALT:
str = altName->d.dNSName;
break;
case NAME_TYPE_SIMPLE:
case NAME_TYPE_EMAIL:
str = altName->d.rfc822Name;
break;
case NAME_TYPE_URL:
str = altName->d.uniformResourceIdentifier;
break;
case NAME_TYPE_UPN:
{
OTHERNAME* value = altName->d.otherName;
if (value)
{
// Enough more padding than szOidUpn that a \0 won't accidentally align
char localOid[sizeof(szOidUpn) + 3];
int cchLocalOid = 1 + OBJ_obj2txt(localOid, sizeof(localOid), value->type_id, 1);
if (sizeof(szOidUpn) == cchLocalOid &&
0 == strncmp(localOid, szOidUpn, sizeof(szOidUpn)))
{
//OTHERNAME->ASN1_TYPE->union.field
str = value->value->value.asn1_string;
}
}
break;
}
}
if (str)
{
BIO* b = BIO_new(BIO_s_mem());
ASN1_STRING_print_ex(b, str, 0);
sk_GENERAL_NAME_free(altNames);
return b;
}
}
}
sk_GENERAL_NAME_free(altNames);
}
}
if (nameType == NAME_TYPE_EMAIL ||
nameType == NAME_TYPE_DNS)
{
X509_NAME* name = forIssuer ? x509->cert_info->issuer : x509->cert_info->subject;
int expectedNid = NID_undef;
switch (nameType)
{
case NAME_TYPE_EMAIL:
expectedNid = NID_pkcs9_emailAddress;
break;
case NAME_TYPE_DNS:
expectedNid = NID_commonName;
break;
}
if (name)
{
// Walk the list backwards because it is stored in stack order
for (int i = X509_NAME_entry_count(name) - 1; i >= 0; --i)
{
X509_NAME_ENTRY* entry = X509_NAME_get_entry(name, i);
if (!entry)
{
continue;
}
ASN1_OBJECT* oid = X509_NAME_ENTRY_get_object(entry);
ASN1_STRING* str = X509_NAME_ENTRY_get_data(entry);
if (!oid || !str)
{
continue;
}
int nid = OBJ_obj2nid(oid);
if (nid == expectedNid)
{
BIO* b = BIO_new(BIO_s_mem());
ASN1_STRING_print_ex(b, str, 0);
return b;
}
}
}
}
return NULL;
}
static Str
ssl_check_cert_ident(X509 * x, char *hostname)
{
int i;
Str ret = NULL;
int match_ident = FALSE;
/*
* All we need to do here is check that the CN matches.
*
* From RFC2818 3.1 Server Identity:
* If a subjectAltName extension of type dNSName is present, that MUST
* be used as the identity. Otherwise, the (most specific) Common Name
* field in the Subject field of the certificate MUST be used. Although
* the use of the Common Name is existing practice, it is deprecated and
* Certification Authorities are encouraged to use the dNSName instead.
*/
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;
GENERAL_NAME *gn;
X509V3_EXT_METHOD *method;
Str seen_dnsname = NULL;
n = sk_GENERAL_NAME_num(alt);
for (i = 0; i < n; i++) {
gn = sk_GENERAL_NAME_value(alt, i);
if (gn->type == GEN_DNS) {
char *sn = ASN1_STRING_data(gn->d.ia5);
int sl = ASN1_STRING_length(gn->d.ia5);
if (!seen_dnsname)
seen_dnsname = Strnew();
/* replace \0 to make full string visible to user */
if (sl != strlen(sn)) {
int i;
for (i = 0; i < sl; ++i) {
if (!sn[i])
sn[i] = '!';
}
}
Strcat_m_charp(seen_dnsname, sn, " ", NULL);
if (sl == strlen(sn) /* catch \0 in SAN */
&& ssl_match_cert_ident(sn, sl, hostname))
break;
}
}
method = X509V3_EXT_get(ex);
sk_GENERAL_NAME_free(alt);
if (i < n) /* Found a match */
match_ident = TRUE;
else if (seen_dnsname)
/* FIXME: gettextize? */
ret = Sprintf("Bad cert ident from %s: dNSName=%s", hostname,
seen_dnsname->ptr);
}
}
if (match_ident == FALSE && ret == NULL) {
X509_NAME *xn;
char buf[2048];
int slen;
xn = X509_get_subject_name(x);
slen = X509_NAME_get_text_by_NID(xn, NID_commonName, buf, sizeof(buf));
if ( slen == -1)
/* FIXME: gettextize? */
ret = Strnew_charp("Unable to get common name from peer cert");
else if (slen != strlen(buf)
|| !ssl_match_cert_ident(buf, strlen(buf), hostname)) {
/* replace \0 to make full string visible to user */
if (slen != strlen(buf)) {
int i;
for (i = 0; i < slen; ++i) {
if (!buf[i])
buf[i] = '!';
}
}
/* FIXME: gettextize? */
ret = Sprintf("Bad cert ident %s from %s", buf, hostname);
}
else
match_ident = TRUE;
}
return ret;
}
/*
* This function is based on verifyhost in libcurl - I hope that it is correct.
*/
static int verify_ssl_host_name(X509 *server_cert, unsigned char *host)
{
unsigned char ipv4_address[4];
#ifdef SUPPORT_IPV6
unsigned char ipv6_address[16];
#endif
unsigned char *address = NULL;
int address_len = 0;
int type = GEN_DNS;
STACK_OF(GENERAL_NAME) *altnames;
if (!numeric_ip_address(host, ipv4_address)) {
address = ipv4_address;
address_len = 4;
type = GEN_IPADD;
}
#ifdef SUPPORT_IPV6
if (!numeric_ipv6_address(host, ipv6_address, NULL)) {
address = ipv6_address;
address_len = 16;
type = GEN_IPADD;
}
#endif
#if 1
altnames = X509_get_ext_d2i(server_cert, NID_subject_alt_name, NULL, NULL);
if (altnames) {
int retval = 1;
int i;
int n_altnames = sk_GENERAL_NAME_num(altnames);
for (i = 0; i < n_altnames; i++) {
const GENERAL_NAME *altname = sk_GENERAL_NAME_value(altnames, i);
const unsigned char *altname_ptr;
int altname_len;
if (altname->type != type) {
if (altname->type == GEN_IPADD || altname->type == GEN_DNS || altname->type == GEN_URI)
retval = S_INVALID_CERTIFICATE;
continue;
}
altname_ptr = ASN1_STRING_data(altname->d.ia5);
altname_len = ASN1_STRING_length(altname->d.ia5);
if (type == GEN_IPADD) {
if (altname_len == address_len && !memcmp(altname_ptr, address, address_len)) {
retval = 0;
break;
}
} else {
if (altname_len == (int)strlen(cast_const_char altname_ptr) && !check_host_name(altname_ptr, host)) {
retval = 0;
break;
}
}
retval = S_INVALID_CERTIFICATE;
}
sk_GENERAL_NAME_free(altnames);
if (retval != 1)
return retval;
}
#endif
{
unsigned char *nulstr = cast_uchar "";
unsigned char *peer_CN = nulstr;
X509_NAME *name;
int j, i = -1;
retval = 1;
name = X509_get_subject_name(server_cert);
if (name)
while ((j = X509_NAME_get_index_by_NID(name, NID_commonName, i)) >= 0)
i = j;
if (i >= 0) {
ASN1_STRING *tmp = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(name, i));
if (tmp) {
if (ASN1_STRING_type(tmp) == V_ASN1_UTF8STRING) {
j = ASN1_STRING_length(tmp);
if (j >= 0) {
peer_CN = OPENSSL_malloc(j + 1);
if (peer_CN) {
memcpy(peer_CN, ASN1_STRING_data(tmp), j);
peer_CN[j] = '\0';
}
}
} else {
j = ASN1_STRING_to_UTF8(&peer_CN, tmp);
}
if (peer_CN && (int)strlen(cast_const_char peer_CN) != j) {
retval = S_INVALID_CERTIFICATE;
}
}
}
if (peer_CN && peer_CN != nulstr) {
if (retval == 1 && !check_host_name(peer_CN, host))
retval = 0;
OPENSSL_free(peer_CN);
}
if (retval != 1)
return retval;
}
return S_INVALID_CERTIFICATE;
}
gboolean
tls_verify_certificate_name(X509 *cert, const gchar *host_name)
{
gchar pattern_buf[256];
gint ext_ndx;
gboolean found = FALSE, result = FALSE;
ext_ndx = X509_get_ext_by_NID(cert, NID_subject_alt_name, -1);
if (ext_ndx >= 0)
{
/* ok, there's a subjectAltName extension, check that */
X509_EXTENSION *ext;
STACK_OF(GENERAL_NAME) *alt_names;
GENERAL_NAME *gen_name;
ext = X509_get_ext(cert, ext_ndx);
alt_names = X509V3_EXT_d2i(ext);
if (alt_names)
{
gint num, i;
num = sk_GENERAL_NAME_num(alt_names);
for (i = 0; !result && i < num; i++)
{
gen_name = sk_GENERAL_NAME_value(alt_names, i);
if (gen_name->type == GEN_DNS)
{
guchar *dnsname = ASN1_STRING_data(gen_name->d.dNSName);
guint dnsname_len = ASN1_STRING_length(gen_name->d.dNSName);
if (dnsname_len > sizeof(pattern_buf) - 1)
{
found = TRUE;
result = FALSE;
break;
}
memcpy(pattern_buf, dnsname, dnsname_len);
pattern_buf[dnsname_len] = 0;
/* we have found a DNS name as alternative subject name */
found = TRUE;
result = tls_wildcard_match(host_name, pattern_buf);
}
else if (gen_name->type == GEN_IPADD)
{
char *dotted_ip = inet_ntoa(*(struct in_addr *) gen_name->d.iPAddress->data);
g_strlcpy(pattern_buf, dotted_ip, sizeof(pattern_buf));
found = TRUE;
result = strcasecmp(host_name, pattern_buf) == 0;
}
}
sk_GENERAL_NAME_free(alt_names);
}
}
if (!found)
{
/* hmm. there was no subjectAltName (this is deprecated, but still
* widely used), look up the Subject, most specific CN */
X509_NAME *name;
name = X509_get_subject_name(cert);
if (X509_NAME_get_text_by_NID(name, NID_commonName, pattern_buf, sizeof(pattern_buf)) != -1)
{
result = tls_wildcard_match(host_name, pattern_buf);
}
}
if (!result)
{
msg_error("Certificate subject does not match configured hostname",
evt_tag_str("hostname", host_name),
evt_tag_str("certificate", pattern_buf),
NULL);
}
else
{
msg_verbose("Certificate subject matches configured hostname",
evt_tag_str("hostname", host_name),
evt_tag_str("certificate", pattern_buf),
NULL);
}
return result;
}
static int
_SSL_check_subject_altname (X509 *cert, const char *host)
{
STACK_OF(GENERAL_NAME) *altname_stack = NULL;
GInetAddress *addr;
GSocketFamily family;
int type = GEN_DNS;
int count, i;
int rv = -1;
altname_stack = X509_get_ext_d2i (cert, NID_subject_alt_name, NULL, NULL);
if (altname_stack == NULL)
return -1;
addr = g_inet_address_new_from_string (host);
if (addr != NULL)
{
family = g_inet_address_get_family (addr);
if (family == G_SOCKET_FAMILY_IPV4 || family == G_SOCKET_FAMILY_IPV6)
type = GEN_IPADD;
}
count = sk_GENERAL_NAME_num(altname_stack);
for (i = 0; i < count; i++)
{
GENERAL_NAME *altname;
altname = sk_GENERAL_NAME_value (altname_stack, i);
if (altname->type != type)
continue;
if (type == GEN_DNS)
{
unsigned char *data;
int format;
format = ASN1_STRING_type (altname->d.dNSName);
if (format == V_ASN1_IA5STRING)
{
data = ASN1_STRING_data (altname->d.dNSName);
if (ASN1_STRING_length (altname->d.dNSName) != (int)strlen(data))
{
g_warning("NUL byte in subjectAltName, probably a malicious certificate.\n");
rv = -2;
break;
}
if (_SSL_match_hostname (data, host) == 0)
{
rv = 0;
break;
}
}
else
g_warning ("unhandled subjectAltName dNSName encoding (%d)\n", format);
}
else if (type == GEN_IPADD)
{
unsigned char *data;
const guint8 *addr_bytes;
int datalen, addr_len;
datalen = ASN1_STRING_length (altname->d.iPAddress);
data = ASN1_STRING_data (altname->d.iPAddress);
addr_bytes = g_inet_address_to_bytes (addr);
addr_len = (int)g_inet_address_get_native_size (addr);
if (datalen == addr_len && memcmp (data, addr_bytes, addr_len) == 0)
{
rv = 0;
break;
}
}
}
if (addr != NULL)
g_object_unref (addr);
sk_GENERAL_NAME_free (altname_stack);
return rv;
}
/* Confirm the peer identity, by checking if the certificate subject
* matches the peer's DNS name or IP address. Matching is performed in
* accordance with RFC 2818:
*
* If the certificate has a subjectAltName extension, all names of type
* IPAddress or dnsName present there, will be compared to data->host,
* depending on it's contents.
* In case there's no subjectAltName extension, commonName (CN) parts
* of the certificate subject field will be used instead of IPAddress
* and dnsName entries. For IP addresses, common names must contain IPs
* in presentation format (1.2.3.4 or 2001:DB8:15:dead::)
* Finally, if no subjectAltName or common names are present, the
* certificate is considered to not match the peer.
*
* The structure of X509 certificates and all fields referenced above
* are described in RFC 5280.
*
* The certificate must be pointed by cert and the peer's host must be
* placed in data->host. The format is a regular DNS name or an IP in
* presentation format (see above).
*
* Return value: 1 if the certificate matches the peer, 0 otherwise.
*/
static int ssl_verifycn(X509 *cert, ssl_appdata *data)
{
char *cn;
int crit = 0, match = 0;
ASN1_OCTET_STRING *ip;
GENERAL_NAMES *altname; /* SubjectAltName ::= GeneralNames */
ip = a2i_IPADDRESS(data->host); /* check if it's an IP or a hostname */
if ((altname = X509_get_ext_d2i(cert, NID_subject_alt_name, &crit, NULL))) {
GENERAL_NAME *gn;
/* Loop through the general names in altname and pick these
of type ip address or dns name */
while (!match && (gn = sk_GENERAL_NAME_pop(altname))) {
/* if the peer's host is an IP, we're only interested in
matching against iPAddress general names, otherwise
we'll only look for dnsName's */
if (ip) {
if (gn->type == GEN_IPADD)
match = !ASN1_STRING_cmp(gn->d.ip, ip);
} else if (gn->type == GEN_DNS) {
/* IA5string holds ASCII data */
cn = (char *) ASN1_STRING_data(gn->d.ia5);
match = ssl_hostmatch(cn, data->host);
}
}
sk_GENERAL_NAME_free(altname);
} else { /* no subjectAltName, try to match against the subject CNs */
X509_NAME *subj; /* certificate subject */
/* the following is just for information */
switch (crit) {
case 0:
debug0("TLS: X509 subjectAltName cannot be decoded");
break;
case -1:
debug0("TLS: X509 has no subjectAltName extension");
break;
case -2:
debug0("TLS: X509 has multiple subjectAltName extensions");
}
/* no subject name either? A completely broken certificate :) */
if (!(subj = X509_get_subject_name(cert))) {
putlog(data->loglevel, "*", "TLS: peer certificate has no subject: %s",
data->host);
match = 0;
} else { /* we have a subject name, look at it */
int pos = -1;
ASN1_STRING *name;
/* Look for commonName attributes in the subject name */
pos = X509_NAME_get_index_by_NID(subj, NID_commonName, pos);
if (pos == -1) /* sorry */
putlog(data->loglevel, "*", "TLS: Peer has no common names and "
"no subjectAltName extension. Verification failed.");
/* Loop through all common names which may be present in the subject
name until we find a match. */
while (!match && pos != -1) {
name = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(subj, pos));
cn = (char *) ASN1_STRING_data(name);
if (ip)
match = a2i_IPADDRESS(cn) ? (ASN1_STRING_cmp(ip, a2i_IPADDRESS(cn)) ? 0 : 1) : 0;
else
match = ssl_hostmatch(cn, data->host);
pos = X509_NAME_get_index_by_NID(subj, NID_commonName, pos);
}
}
}
if (ip)
ASN1_OCTET_STRING_free(ip);
return match;
}
gboolean
z_proxy_ssl_host_iface_check_name_method(ZProxyHostIface *s,
const gchar *host_name,
gchar *reason_buf, gsize reason_len)
{
ZProxySslHostIface *self = Z_CAST(s, ZProxySslHostIface);
gint ext_ndx;
gboolean found = FALSE, result = FALSE;
gchar pattern_buf[256];
if (self->hostname_checked)
return self->hostname_check_result;
pattern_buf[0] = 0;
ext_ndx = X509_get_ext_by_NID(self->server_cert, NID_subject_alt_name, -1);
if (ext_ndx >= 0)
{
/* ok, there's a subjectAltName extension, check that */
X509_EXTENSION *ext;
STACK_OF(GENERAL_NAME) *alt_names;
GENERAL_NAME *gen_name;
ext = X509_get_ext(self->server_cert, ext_ndx);
alt_names = X509V3_EXT_d2i(ext);
if (alt_names)
{
gint num, i;
num = sk_GENERAL_NAME_num(alt_names);
for (i = 0; i < num; i++)
{
gen_name = sk_GENERAL_NAME_value(alt_names, i);
if (gen_name->type == GEN_DNS)
{
guchar *dnsname = ASN1_STRING_data(gen_name->d.dNSName);
guint dnsname_len = ASN1_STRING_length(gen_name->d.dNSName);
if (dnsname_len > sizeof(pattern_buf) - 1)
{
found = TRUE;
result = FALSE;
break;
}
memcpy(pattern_buf, dnsname, dnsname_len);
pattern_buf[dnsname_len] = 0;
/* we have found a DNS name as alternative subject name */
found = TRUE;
result = z_proxy_ssl_host_iface_check_wildcard(s->owner, host_name, pattern_buf);
break;
}
else if (gen_name->type == GEN_IPADD)
{
z_inet_ntoa(pattern_buf, sizeof(pattern_buf), *(struct in_addr *) gen_name->d.iPAddress->data);
found = TRUE;
result = strcmp(host_name, pattern_buf) == 0;
break;
}
}
sk_GENERAL_NAME_free(alt_names);
}
}
if (!found)
{
/* hmm. there was no subjectAltName (this is deprecated, but still
* widely used), look up the Subject, most specific CN */
X509_NAME *name;
name = X509_get_subject_name(self->server_cert);
if (X509_NAME_get_text_by_NID(name, NID_commonName, pattern_buf, sizeof(pattern_buf)) != -1)
{
result = z_proxy_ssl_host_iface_check_wildcard(s->owner, host_name, pattern_buf);
}
}
if (!result && reason_buf)
{
g_snprintf(reason_buf, reason_len, "Certificate does not belong to target host (certificate: %s, host %s)",
pattern_buf, host_name);
}
self->hostname_checked = TRUE;
self->hostname_check_result = result;
return result;
}
int
ssl_check_subject_altname(X509 *cert, char *host)
{
STACK_OF(GENERAL_NAME) *altname_stack = NULL;
union { struct in_addr ip4; struct in6_addr ip6; } addrbuf;
int addrlen, type;
int count, i;
int rv = -1;
altname_stack =
X509_get_ext_d2i(cert, NID_subject_alt_name, NULL, NULL);
if (altname_stack == NULL)
return -1;
if (inet_pton(AF_INET, host, &addrbuf) == 1) {
type = GEN_IPADD;
addrlen = 4;
} else if (inet_pton(AF_INET6, host, &addrbuf) == 1) {
type = GEN_IPADD;
addrlen = 16;
} else
type = GEN_DNS;
count = sk_GENERAL_NAME_num(altname_stack);
for (i = 0; i < count; i++) {
GENERAL_NAME *altname;
altname = sk_GENERAL_NAME_value(altname_stack, i);
if (altname->type != type)
continue;
if (type == GEN_DNS) {
unsigned char *data;
int format;
format = ASN1_STRING_type(altname->d.dNSName);
if (format == V_ASN1_IA5STRING) {
data = ASN1_STRING_data(altname->d.dNSName);
if (ASN1_STRING_length(altname->d.dNSName) !=
(int)strlen(data)) {
fprintf(ttyout, "%s: NUL byte in "
"subjectAltName, probably a "
"malicious certificate.\n",
getprogname());
rv = -2;
break;
}
if (ssl_match_hostname(data, host) == 0) {
rv = 0;
break;
}
} else
fprintf(ttyout, "%s: unhandled subjectAltName "
"dNSName encoding (%d)\n", getprogname(),
format);
} else if (type == GEN_IPADD) {
unsigned char *data;
int datalen;
datalen = ASN1_STRING_length(altname->d.iPAddress);
data = ASN1_STRING_data(altname->d.iPAddress);
if (datalen == addrlen &&
memcmp(data, &addrbuf, addrlen) == 0) {
rv = 0;
break;
}
}
}
sk_GENERAL_NAME_free(altname_stack);
return rv;
}
bool
ssl_check_certificate (int fd, const char *host)
{
X509 *cert;
GENERAL_NAMES *subjectAltNames;
char common_name[256];
long vresult;
bool success = true;
bool alt_name_checked = false;
/* If the user has specified --no-check-cert, we still want to warn
him about problems with the server's certificate. */
const char *severity = opt.check_cert ? _("ERROR") : _("WARNING");
struct openssl_transport_context *ctx = fd_transport_context (fd);
SSL *conn = ctx->conn;
assert (conn != NULL);
cert = SSL_get_peer_certificate (conn);
if (!cert)
{
logprintf (LOG_NOTQUIET, _("%s: No certificate presented by %s.\n"),
severity, quotearg_style (escape_quoting_style, host));
success = false;
goto no_cert; /* must bail out since CERT is NULL */
}
IF_DEBUG
{
char *subject = X509_NAME_oneline (X509_get_subject_name (cert), 0, 0);
char *issuer = X509_NAME_oneline (X509_get_issuer_name (cert), 0, 0);
DEBUGP (("certificate:\n subject: %s\n issuer: %s\n",
quotearg_n_style (0, escape_quoting_style, subject),
quotearg_n_style (1, escape_quoting_style, issuer)));
OPENSSL_free (subject);
OPENSSL_free (issuer);
}
vresult = SSL_get_verify_result (conn);
if (vresult != X509_V_OK)
{
char *issuer = X509_NAME_oneline (X509_get_issuer_name (cert), 0, 0);
logprintf (LOG_NOTQUIET,
_("%s: cannot verify %s's certificate, issued by %s:\n"),
severity, quotearg_n_style (0, escape_quoting_style, host),
quote_n (1, issuer));
/* Try to print more user-friendly (and translated) messages for
the frequent verification errors. */
switch (vresult)
{
case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
logprintf (LOG_NOTQUIET,
_(" Unable to locally verify the issuer's authority.\n"));
break;
case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
logprintf (LOG_NOTQUIET,
_(" Self-signed certificate encountered.\n"));
break;
case X509_V_ERR_CERT_NOT_YET_VALID:
logprintf (LOG_NOTQUIET, _(" Issued certificate not yet valid.\n"));
break;
case X509_V_ERR_CERT_HAS_EXPIRED:
logprintf (LOG_NOTQUIET, _(" Issued certificate has expired.\n"));
break;
default:
/* For the less frequent error strings, simply provide the
OpenSSL error message. */
logprintf (LOG_NOTQUIET, " %s\n",
X509_verify_cert_error_string (vresult));
}
success = false;
/* Fall through, so that the user is warned about *all* issues
with the cert (important with --no-check-certificate.) */
}
/* Check that HOST matches the common name in the certificate.
#### The following remains to be done:
- When matching against common names, it should loop over all
common names and choose the most specific one, i.e. the last
one, not the first one, which the current code picks.
- Ensure that ASN1 strings from the certificate are encoded as
UTF-8 which can be meaningfully compared to HOST. */
subjectAltNames = X509_get_ext_d2i (cert, NID_subject_alt_name, NULL, NULL);
if (subjectAltNames)
{
/* Test subject alternative names */
/* Do we want to check for dNSNAmes or ipAddresses (see RFC 2818)?
* Signal it by host_in_octet_string. */
ASN1_OCTET_STRING *host_in_octet_string = a2i_IPADDRESS (host);
int numaltnames = sk_GENERAL_NAME_num (subjectAltNames);
int i;
for (i=0; i < numaltnames; i++)
{
const GENERAL_NAME *name =
sk_GENERAL_NAME_value (subjectAltNames, i);
if (name)
{
if (host_in_octet_string)
{
if (name->type == GEN_IPADD)
{
/* Check for ipAddress */
/* TODO: Should we convert between IPv4-mapped IPv6
* addresses and IPv4 addresses? */
alt_name_checked = true;
if (!ASN1_STRING_cmp (host_in_octet_string,
name->d.iPAddress))
break;
}
}
else if (name->type == GEN_DNS)
{
/* dNSName should be IA5String (i.e. ASCII), however who
* does trust CA? Convert it into UTF-8 for sure. */
unsigned char *name_in_utf8 = NULL;
/* Check for dNSName */
alt_name_checked = true;
if (0 <= ASN1_STRING_to_UTF8 (&name_in_utf8, name->d.dNSName))
{
/* Compare and check for NULL attack in ASN1_STRING */
if (pattern_match ((char *)name_in_utf8, host) &&
(strlen ((char *)name_in_utf8) ==
(size_t) ASN1_STRING_length (name->d.dNSName)))
{
OPENSSL_free (name_in_utf8);
break;
}
OPENSSL_free (name_in_utf8);
}
}
}
}
sk_GENERAL_NAME_free (subjectAltNames);
if (host_in_octet_string)
ASN1_OCTET_STRING_free(host_in_octet_string);
if (alt_name_checked == true && i >= numaltnames)
{
logprintf (LOG_NOTQUIET,
_("%s: no certificate subject alternative name matches\n"
"\trequested host name %s.\n"),
severity, quote_n (1, host));
success = false;
}
}
if (alt_name_checked == false)
{
/* Test commomName */
X509_NAME *xname = X509_get_subject_name(cert);
common_name[0] = '\0';
X509_NAME_get_text_by_NID (xname, NID_commonName, common_name,
sizeof (common_name));
if (!pattern_match (common_name, host))
{
logprintf (LOG_NOTQUIET, _("\
%s: certificate common name %s doesn't match requested host name %s.\n"),
severity, quote_n (0, common_name), quote_n (1, host));
success = false;
}
