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Diffstat (limited to 'src/openvpn/ssl_verify_polarssl.c')
-rw-r--r--src/openvpn/ssl_verify_polarssl.c409
1 files changed, 409 insertions, 0 deletions
diff --git a/src/openvpn/ssl_verify_polarssl.c b/src/openvpn/ssl_verify_polarssl.c
new file mode 100644
index 0000000..a32db8d
--- /dev/null
+++ b/src/openvpn/ssl_verify_polarssl.c
@@ -0,0 +1,409 @@
+/*
+ * OpenVPN -- An application to securely tunnel IP networks
+ * over a single TCP/UDP port, with support for SSL/TLS-based
+ * session authentication and key exchange,
+ * packet encryption, packet authentication, and
+ * packet compression.
+ *
+ * Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
+ * Copyright (C) 2010 Fox Crypto B.V. <openvpn@fox-it.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program (see the file COPYING included with this
+ * distribution); if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+/**
+ * @file Control Channel Verification Module PolarSSL backend
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#elif defined(_MSC_VER)
+#include "config-msvc.h"
+#endif
+
+#include "syshead.h"
+
+#if defined(ENABLE_SSL) && defined(ENABLE_CRYPTO_POLARSSL)
+
+#include "ssl_verify.h"
+#include <polarssl/sha1.h>
+
+#define MAX_SUBJECT_LENGTH 256
+
+int
+verify_callback (void *session_obj, x509_cert *cert, int cert_depth,
+ int preverify_ok)
+{
+ struct tls_session *session = (struct tls_session *) session_obj;
+ struct gc_arena gc = gc_new();
+ int ret = 1;
+
+ ASSERT (cert);
+ ASSERT (session);
+
+ session->verified = false;
+
+ /* Remember certificate hash */
+ cert_hash_remember (session, cert_depth, x509_get_sha1_hash(cert, &gc));
+
+ /* did peer present cert which was signed by our root cert? */
+ if (!preverify_ok)
+ {
+ char *subject = x509_get_subject(cert, &gc);
+
+ if (subject)
+ msg (D_TLS_ERRORS, "VERIFY ERROR: depth=%d, %s", cert_depth, subject);
+ else
+ msg (D_TLS_ERRORS, "VERIFY ERROR: depth=%d, could not extract X509 "
+ "subject string from certificate", cert_depth);
+
+ goto cleanup;
+ }
+
+ if (SUCCESS != verify_cert(session, cert, cert_depth))
+ goto cleanup;
+
+ ret = 0;
+
+cleanup:
+ gc_free(&gc);
+
+ /*
+ * PolarSSL expects 1 on failure, 0 on success
+ */
+ return ret;
+}
+
+#ifdef ENABLE_X509ALTUSERNAME
+# warning "X509 alt user name not yet supported for PolarSSL"
+#endif
+
+result_t
+x509_get_username (char *cn, int cn_len,
+ char *x509_username_field, x509_cert *cert)
+{
+ x509_name *name;
+
+ ASSERT( cn != NULL );
+
+ name = &cert->subject;
+
+ /* Find common name */
+ while( name != NULL )
+ {
+ if( memcmp( name->oid.p, OID_CN, OID_SIZE(OID_CN) ) == 0)
+ break;
+
+ name = name->next;
+ }
+
+ /* Not found, return an error if this is the peer's certificate */
+ if( name == NULL )
+ return FAILURE;
+
+ /* Found, extract CN */
+ if (cn_len > name->val.len)
+ memcpy( cn, name->val.p, name->val.len );
+ else
+ {
+ memcpy( cn, name->val.p, cn_len);
+ cn[cn_len-1] = '\0';
+ }
+
+ return SUCCESS;
+}
+
+char *
+x509_get_serial (x509_cert *cert, struct gc_arena *gc)
+{
+ int ret = 0;
+ int i = 0;
+ char *buf = NULL;
+ size_t len = cert->serial.len * 3 + 1;
+
+ buf = gc_malloc(len, true, gc);
+
+ if(x509parse_serial_gets(buf, len-1, &cert->serial) < 0)
+ buf = NULL;
+
+ return buf;
+}
+
+unsigned char *
+x509_get_sha1_hash (x509_cert *cert, struct gc_arena *gc)
+{
+ unsigned char *sha1_hash = gc_malloc(SHA_DIGEST_LENGTH, false, gc);
+ sha1(cert->tbs.p, cert->tbs.len, sha1_hash);
+ return sha1_hash;
+}
+
+char *
+x509_get_subject(x509_cert *cert, struct gc_arena *gc)
+{
+ char tmp_subject[MAX_SUBJECT_LENGTH] = {0};
+ char *subject = NULL;
+
+ int ret = 0;
+
+ ret = x509parse_dn_gets( tmp_subject, MAX_SUBJECT_LENGTH-1, &cert->subject );
+ if (ret > 0)
+ {
+ /* Allocate the required space for the subject */
+ subject = string_alloc(tmp_subject, gc);
+ }
+
+ return subject;
+}
+
+/*
+ * Save X509 fields to environment, using the naming convention:
+ *
+ * X509_{cert_depth}_{name}={value}
+ */
+void
+x509_setenv (struct env_set *es, int cert_depth, openvpn_x509_cert_t *cert)
+{
+ int i;
+ unsigned char c;
+ const x509_name *name;
+ char s[128];
+
+ name = &cert->subject;
+
+ memset( s, 0, sizeof( s ) );
+
+ while( name != NULL )
+ {
+ char name_expand[64+8];
+
+ if( name->oid.len == 2 && memcmp( name->oid.p, OID_X520, 2 ) == 0 )
+ {
+ switch( name->oid.p[2] )
+ {
+ case X520_COMMON_NAME:
+ openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_CN",
+ cert_depth); break;
+
+ case X520_COUNTRY:
+ openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_C",
+ cert_depth); break;
+
+ case X520_LOCALITY:
+ openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_L",
+ cert_depth); break;
+
+ case X520_STATE:
+ openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_ST",
+ cert_depth); break;
+
+ case X520_ORGANIZATION:
+ openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_O",
+ cert_depth); break;
+
+ case X520_ORG_UNIT:
+ openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_OU",
+ cert_depth); break;
+
+ default:
+ openvpn_snprintf (name_expand, sizeof(name_expand),
+ "X509_%d_0x%02X", cert_depth, name->oid.p[2]);
+ break;
+ }
+ }
+ else if( name->oid.len == 8 && memcmp( name->oid.p, OID_PKCS9, 8 ) == 0 )
+ {
+ switch( name->oid.p[8] )
+ {
+ case PKCS9_EMAIL:
+ openvpn_snprintf (name_expand, sizeof(name_expand),
+ "X509_%d_emailAddress", cert_depth); break;
+
+ default:
+ openvpn_snprintf (name_expand, sizeof(name_expand),
+ "X509_%d_0x%02X", cert_depth, name->oid.p[8]);
+ break;
+ }
+ }
+ else
+ {
+ openvpn_snprintf (name_expand, sizeof(name_expand), "X509_%d_\?\?",
+ cert_depth);
+ }
+
+ for( i = 0; i < name->val.len; i++ )
+ {
+ if( i >= (int) sizeof( s ) - 1 )
+ break;
+
+ c = name->val.p[i];
+ if( c < 32 || c == 127 || ( c > 128 && c < 160 ) )
+ s[i] = '?';
+ else s[i] = c;
+ }
+ s[i] = '\0';
+
+ /* Check both strings, set environment variable */
+ string_mod (name_expand, CC_PRINT, CC_CRLF, '_');
+ string_mod ((char*)s, CC_PRINT, CC_CRLF, '_');
+ setenv_str (es, name_expand, (char*)s);
+
+ name = name->next;
+ }
+}
+
+result_t
+x509_verify_ns_cert_type(const x509_cert *cert, const int usage)
+{
+ if (usage == NS_CERT_CHECK_NONE)
+ return SUCCESS;
+ if (usage == NS_CERT_CHECK_CLIENT)
+ return ((cert->ext_types & EXT_NS_CERT_TYPE)
+ && (cert->ns_cert_type & NS_CERT_TYPE_SSL_CLIENT)) ? SUCCESS : FAILURE;
+ if (usage == NS_CERT_CHECK_SERVER)
+ return ((cert->ext_types & EXT_NS_CERT_TYPE)
+ && (cert->ns_cert_type & NS_CERT_TYPE_SSL_SERVER)) ? SUCCESS : FAILURE;
+
+ return FAILURE;
+}
+
+result_t
+x509_verify_cert_ku (x509_cert *cert, const unsigned * const expected_ku,
+ int expected_len)
+{
+ result_t fFound = FAILURE;
+
+ if(!(cert->ext_types & EXT_KEY_USAGE))
+ {
+ msg (D_HANDSHAKE, "Certificate does not have key usage extension");
+ }
+ else
+ {
+ int i;
+ unsigned nku = cert->key_usage;
+
+ msg (D_HANDSHAKE, "Validating certificate key usage");
+ for (i=0; SUCCESS != fFound && i<expected_len; i++)
+ {
+ if (expected_ku[i] != 0)
+ {
+ msg (D_HANDSHAKE, "++ Certificate has key usage %04x, expects "
+ "%04x", nku, expected_ku[i]);
+
+ if (nku == expected_ku[i])
+ {
+ fFound = SUCCESS;
+ }
+ }
+ }
+ }
+ return fFound;
+}
+
+result_t
+x509_verify_cert_eku (x509_cert *cert, const char * const expected_oid)
+{
+ result_t fFound = FAILURE;
+
+ if (!(cert->ext_types & EXT_EXTENDED_KEY_USAGE))
+ {
+ msg (D_HANDSHAKE, "Certificate does not have extended key usage extension");
+ }
+ else
+ {
+ x509_sequence *oid_seq = &(cert->ext_key_usage);
+
+ msg (D_HANDSHAKE, "Validating certificate extended key usage");
+ while (oid_seq != NULL)
+ {
+ x509_buf *oid = &oid_seq->buf;
+ char oid_num_str[1024];
+ const char *oid_str;
+
+ oid_str = x509_oid_get_description(oid);
+ if (oid_str != NULL)
+ {
+ msg (D_HANDSHAKE, "++ Certificate has EKU (str) %s, expects %s",
+ oid_str, expected_oid);
+ if (!strcmp (expected_oid, oid_str))
+ {
+ fFound = SUCCESS;
+ break;
+ }
+ }
+
+ if (0 == x509_oid_get_numeric_string( oid_num_str,
+ sizeof (oid_num_str), oid))
+ {
+ msg (D_HANDSHAKE, "++ Certificate has EKU (oid) %s, expects %s",
+ oid_num_str, expected_oid);
+ if (!strcmp (expected_oid, oid_num_str))
+ {
+ fFound = SUCCESS;
+ break;
+ }
+ }
+ oid_seq = oid_seq->next;
+ }
+ }
+
+ return fFound;
+}
+
+result_t
+x509_write_pem(FILE *peercert_file, x509_cert *peercert)
+{
+ msg (M_WARN, "PolarSSL does not support writing peer certificate in PEM format");
+ return FAILURE;
+}
+
+/*
+ * check peer cert against CRL
+ */
+result_t
+x509_verify_crl(const char *crl_file, x509_cert *cert, const char *subject)
+{
+ result_t retval = FAILURE;
+ x509_crl crl = {0};
+
+ if (x509parse_crlfile(&crl, crl_file) != 0)
+ {
+ msg (M_ERR, "CRL: cannot read CRL from file %s", crl_file);
+ goto end;
+ }
+
+ if(cert->issuer_raw.len != crl.issuer_raw.len ||
+ memcmp(crl.issuer_raw.p, cert->issuer_raw.p, crl.issuer_raw.len) != 0)
+ {
+ msg (M_WARN, "CRL: CRL %s is from a different issuer than the issuer of "
+ "certificate %s", crl_file, subject);
+ retval = SUCCESS;
+ goto end;
+ }
+
+ if (0 != x509parse_revoked(cert, &crl))
+ {
+ msg (D_HANDSHAKE, "CRL CHECK FAILED: %s is REVOKED", subject);
+ goto end;
+ }
+
+ retval = SUCCESS;
+ msg (D_HANDSHAKE, "CRL CHECK OK: %s",subject);
+
+end:
+ x509_crl_free(&crl);
+ return retval;
+}
+
+#endif /* #if defined(ENABLE_SSL) && defined(ENABLE_CRYPTO_POLARSSL) */
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-13 04:16:06 +0000