[svn-upgrade] Integrating new upstream version, strongswan (4.1.1)

1 files changed, 2241 insertions, 0 deletions

diff --git a/src/pluto/x509.c b/src/pluto/x509.c
new file mode 100644
index 000000000..2521244f7
--- /dev/null
+++ b/src/pluto/x509.c
@@ -0,0 +1,2241 @@
+/* Support of X.509 certificates
+ * Copyright (C) 2000 Andreas Hess, Patric Lichtsteiner, Roger Wegmann
+ * Copyright (C) 2001 Marco Bertossa, Andreas Schleiss
+ * Copyright (C) 2002 Mario Strasser
+ * Copyright (C) 2000-2004 Andreas Steffen, Zuercher Hochschule Winterthur
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ *
+ * RCSID $Id: x509.c,v 1.36 2006/04/10 16:08:33 as Exp $
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <dirent.h>
+#include <time.h>
+#include <sys/types.h>
+
+#include <freeswan.h>
+#include <ipsec_policy.h>
+
+#include "constants.h"
+#include "defs.h"
+#include "mp_defs.h"
+#include "log.h"
+#include "id.h"
+#include "asn1.h"
+#include "oid.h"
+#include "pkcs1.h"
+#include "x509.h"
+#include "crl.h"
+#include "ca.h"
+#include "certs.h"
+#include "keys.h"
+#include "whack.h"
+#include "fetch.h"
+#include "ocsp.h"
+#include "sha1.h"
+
+/* chained lists of X.509 end certificates */
+
+static x509cert_t *x509certs     = NULL;
+
+/* ASN.1 definition of a basicConstraints extension */
+
+static const asn1Object_t basicConstraintsObjects[] = {
+  { 0, "basicConstraints",		ASN1_SEQUENCE,     ASN1_NONE }, /*  0 */
+  { 1,   "CA",				ASN1_BOOLEAN,      ASN1_DEF |
+							   ASN1_BODY }, /*  1 */
+  { 1,   "pathLenConstraint",		ASN1_INTEGER,      ASN1_OPT |
+							   ASN1_BODY }, /*  2 */
+  { 1,   "end opt",			ASN1_EOC,          ASN1_END  }  /*  3 */
+};
+
+#define BASIC_CONSTRAINTS_CA	1
+#define BASIC_CONSTRAINTS_ROOF	4
+
+/* ASN.1 definition of time */
+
+static const asn1Object_t timeObjects[] = {
+  { 0,   "utcTime",			ASN1_UTCTIME,         ASN1_OPT |
+							      ASN1_BODY }, /*  0 */
+  { 0,   "end opt",			ASN1_EOC,             ASN1_END  }, /*  1 */
+  { 0,   "generalizeTime",		ASN1_GENERALIZEDTIME, ASN1_OPT |
+							      ASN1_BODY }, /*  2 */
+  { 0,   "end opt",			ASN1_EOC,             ASN1_END  }  /*  3 */
+};
+
+#define TIME_UTC		0
+#define TIME_GENERALIZED	2
+#define TIME_ROOF		4
+
+/* ASN.1 definition of a keyIdentifier */
+
+static const asn1Object_t keyIdentifierObjects[] = {
+  { 0,   "keyIdentifier",		ASN1_OCTET_STRING, ASN1_BODY }  /*  0 */
+};
+
+/* ASN.1 definition of a authorityKeyIdentifier extension */
+
+static const asn1Object_t authorityKeyIdentifierObjects[] = {
+  { 0,   "authorityKeyIdentifier",	ASN1_SEQUENCE,     ASN1_NONE }, /*  0 */
+  { 1,     "keyIdentifier",		ASN1_CONTEXT_S_0,  ASN1_OPT |
+							   ASN1_OBJ  }, /*  1 */
+  { 1,     "end opt",			ASN1_EOC,          ASN1_END  }, /*  2 */
+  { 1,     "authorityCertIssuer",	ASN1_CONTEXT_C_1,  ASN1_OPT |
+							   ASN1_OBJ  }, /*  3 */
+  { 1,     "end opt",			ASN1_EOC,          ASN1_END  }, /*  4 */
+  { 1,     "authorityCertSerialNumber",	ASN1_CONTEXT_S_2,  ASN1_OPT |
+							   ASN1_BODY }, /*  5 */
+  { 1,     "end opt",			ASN1_EOC,          ASN1_END  }  /*  6 */
+};
+
+#define AUTH_KEY_ID_KEY_ID		1
+#define AUTH_KEY_ID_CERT_ISSUER		3
+#define AUTH_KEY_ID_CERT_SERIAL		5
+#define AUTH_KEY_ID_ROOF		7
+
+/* ASN.1 definition of a authorityInfoAccess extension */
+
+static const asn1Object_t authorityInfoAccessObjects[] = {
+  { 0,   "authorityInfoAccess",         ASN1_SEQUENCE,     ASN1_LOOP }, /*  0 */
+  { 1,     "accessDescription",         ASN1_SEQUENCE,     ASN1_NONE }, /*  1 */
+  { 2,       "accessMethod",            ASN1_OID,          ASN1_BODY }, /*  2 */
+  { 2,       "accessLocation",          ASN1_EOC,          ASN1_RAW  }, /*  3 */
+  { 0,   "end loop",                    ASN1_EOC,          ASN1_END  }  /*  4 */
+};
+
+#define AUTH_INFO_ACCESS_METHOD		2
+#define AUTH_INFO_ACCESS_LOCATION	3
+#define AUTH_INFO_ACCESS_ROOF		5
+
+/* ASN.1 definition of a extendedKeyUsage extension */
+
+static const asn1Object_t extendedKeyUsageObjects[] = {
+  { 0, "extendedKeyUsage",		ASN1_SEQUENCE,     ASN1_LOOP }, /*  0 */
+  { 1,   "keyPurposeID",		ASN1_OID,     	   ASN1_BODY }, /*  1 */
+  { 0, "end loop",			ASN1_EOC,	   ASN1_END  }, /*  2 */
+};
+
+#define EXT_KEY_USAGE_PURPOSE_ID	1
+#define EXT_KEY_USAGE_ROOF		3
+
+/* ASN.1 definition of generalNames */
+
+static const asn1Object_t generalNamesObjects[] = {
+  { 0, "generalNames",			ASN1_SEQUENCE,     ASN1_LOOP }, /*  0 */
+  { 1,   "generalName",			ASN1_EOC,          ASN1_RAW  }, /*  1 */
+  { 0, "end loop",			ASN1_EOC,          ASN1_END  }  /*  2 */
+};
+
+#define GENERAL_NAMES_GN	1
+#define GENERAL_NAMES_ROOF	3
+
+/* ASN.1 definition of generalName */
+
+static const asn1Object_t generalNameObjects[] = {
+  { 0,   "otherName",			ASN1_CONTEXT_C_0,  ASN1_OPT |
+							   ASN1_BODY }, /*  0 */
+  { 0,   "end choice",			ASN1_EOC,          ASN1_END  }, /*  1 */
+  { 0,   "rfc822Name",			ASN1_CONTEXT_S_1,  ASN1_OPT |
+							   ASN1_BODY }, /*  2 */
+  { 0,   "end choice",			ASN1_EOC,          ASN1_END  }, /*  3 */
+  { 0,   "dnsName",			ASN1_CONTEXT_S_2,  ASN1_OPT |
+							   ASN1_BODY }, /*  4 */
+  { 0,   "end choice",			ASN1_EOC,          ASN1_END  }, /*  5 */
+  { 0,   "x400Address",			ASN1_CONTEXT_S_3,  ASN1_OPT |
+							   ASN1_BODY }, /*  6 */
+  { 0,   "end choice",			ASN1_EOC,          ASN1_END  }, /*  7 */
+  { 0,   "directoryName",		ASN1_CONTEXT_C_4,  ASN1_OPT |
+							   ASN1_BODY }, /*  8 */
+  { 0,   "end choice",			ASN1_EOC,          ASN1_END  }, /*  9 */
+  { 0,   "ediPartyName",		ASN1_CONTEXT_C_5,  ASN1_OPT |
+							   ASN1_BODY }, /* 10 */
+  { 0,   "end choice",			ASN1_EOC,          ASN1_END  }, /* 11 */
+  { 0,   "uniformResourceIdentifier",	ASN1_CONTEXT_S_6,  ASN1_OPT |
+							   ASN1_BODY }, /* 12 */
+  { 0,   "end choice",			ASN1_EOC,          ASN1_END  }, /* 13 */
+  { 0,   "ipAddress",			ASN1_CONTEXT_S_7,  ASN1_OPT |
+							   ASN1_BODY }, /* 14 */
+  { 0,   "end choice",			ASN1_EOC,          ASN1_END  }, /* 15 */
+  { 0,   "registeredID",		ASN1_CONTEXT_S_8,  ASN1_OPT |
+							   ASN1_BODY }, /* 16 */
+  { 0,   "end choice",			ASN1_EOC,          ASN1_END  }  /* 17 */
+};
+
+#define GN_OBJ_OTHER_NAME	 0
+#define GN_OBJ_RFC822_NAME	 2
+#define GN_OBJ_DNS_NAME		 4
+#define GN_OBJ_X400_ADDRESS	 6
+#define GN_OBJ_DIRECTORY_NAME	 8
+#define GN_OBJ_EDI_PARTY_NAME	10
+#define GN_OBJ_URI		12
+#define GN_OBJ_IP_ADDRESS	14
+#define GN_OBJ_REGISTERED_ID	16
+#define GN_OBJ_ROOF		18
+
+/* ASN.1 definition of otherName */
+
+static const asn1Object_t otherNameObjects[] = {
+  {0, "type-id",			ASN1_OID,          ASN1_BODY }, /*  0 */
+  {0, "value",				ASN1_CONTEXT_C_0,  ASN1_BODY }  /*  1 */
+};
+
+#define ON_OBJ_ID_TYPE		0
+#define ON_OBJ_VALUE		1
+#define ON_OBJ_ROOF		2
+
+/* ASN.1 definition of crlDistributionPoints */
+
+static const asn1Object_t crlDistributionPointsObjects[] = {
+  { 0, "crlDistributionPoints",		ASN1_SEQUENCE,     ASN1_LOOP }, /*  0 */
+  { 1,   "DistributionPoint",		ASN1_SEQUENCE,     ASN1_NONE }, /*  1 */
+  { 2,     "distributionPoint",		ASN1_CONTEXT_C_0,  ASN1_OPT |
+							   ASN1_LOOP }, /*  2 */
+  { 3,       "fullName",		ASN1_CONTEXT_C_0,  ASN1_OPT |
+							   ASN1_OBJ  }, /*  3 */
+  { 3,       "end choice",		ASN1_EOC,          ASN1_END  }, /*  4 */
+  { 3,       "nameRelativeToCRLIssuer",	ASN1_CONTEXT_C_1,  ASN1_OPT |
+							   ASN1_BODY }, /*  5 */
+  { 3,       "end choice",		ASN1_EOC,          ASN1_END  }, /*  6 */
+  { 2,     "end opt",			ASN1_EOC,          ASN1_END  }, /*  7 */
+  { 2,     "reasons",			ASN1_CONTEXT_C_1,  ASN1_OPT |
+							   ASN1_BODY }, /*  8 */
+  { 2,     "end opt",			ASN1_EOC,          ASN1_END  }, /*  9 */
+  { 2,     "crlIssuer",			ASN1_CONTEXT_C_2,  ASN1_OPT |
+							   ASN1_BODY }, /* 10 */
+  { 2,     "end opt",			ASN1_EOC,          ASN1_END  }, /* 11 */
+  { 0, "end loop",			ASN1_EOC,          ASN1_END  }, /* 12 */
+};
+
+#define CRL_DIST_POINTS_FULLNAME	 3
+#define CRL_DIST_POINTS_ROOF		13
+
+/* ASN.1 definition of an X.509v3 certificate */
+
+static const asn1Object_t certObjects[] = {
+  { 0, "certificate",			ASN1_SEQUENCE,     ASN1_OBJ  }, /*  0 */
+  { 1,   "tbsCertificate",		ASN1_SEQUENCE,     ASN1_OBJ  }, /*  1 */
+  { 2,     "DEFAULT v1",		ASN1_CONTEXT_C_0,  ASN1_DEF  }, /*  2 */
+  { 3,       "version",			ASN1_INTEGER,      ASN1_BODY }, /*  3 */
+  { 2,     "serialNumber",		ASN1_INTEGER,      ASN1_BODY }, /*  4 */
+  { 2,     "signature",			ASN1_EOC,          ASN1_RAW  }, /*  5 */
+  { 2,     "issuer",			ASN1_SEQUENCE,     ASN1_OBJ  }, /*  6 */
+  { 2,     "validity",			ASN1_SEQUENCE,     ASN1_NONE }, /*  7 */
+  { 3,       "notBefore",		ASN1_EOC,          ASN1_RAW  }, /*  8 */
+  { 3,       "notAfter",		ASN1_EOC,          ASN1_RAW  }, /*  9 */
+  { 2,     "subject",			ASN1_SEQUENCE,     ASN1_OBJ  }, /* 10 */
+  { 2,     "subjectPublicKeyInfo",	ASN1_SEQUENCE,     ASN1_NONE }, /* 11 */
+  { 3,       "algorithm",		ASN1_EOC,          ASN1_RAW  }, /* 12 */
+  { 3,       "subjectPublicKey",	ASN1_BIT_STRING,   ASN1_NONE }, /* 13 */
+  { 4,         "RSAPublicKey",		ASN1_SEQUENCE,     ASN1_OBJ  }, /* 14 */
+  { 5,           "modulus",		ASN1_INTEGER,      ASN1_BODY }, /* 15 */
+  { 5,           "publicExponent",	ASN1_INTEGER,      ASN1_BODY }, /* 16 */
+  { 2,     "issuerUniqueID",		ASN1_CONTEXT_C_1,  ASN1_OPT  }, /* 17 */
+  { 2,     "end opt",			ASN1_EOC,          ASN1_END  }, /* 18 */
+  { 2,     "subjectUniqueID",		ASN1_CONTEXT_C_2,  ASN1_OPT  }, /* 19 */
+  { 2,     "end opt",			ASN1_EOC,          ASN1_END  }, /* 20 */
+  { 2,     "optional extensions",	ASN1_CONTEXT_C_3,  ASN1_OPT  }, /* 21 */
+  { 3,       "extensions",		ASN1_SEQUENCE,     ASN1_LOOP }, /* 22 */
+  { 4,         "extension",		ASN1_SEQUENCE,     ASN1_NONE }, /* 23 */
+  { 5,           "extnID",		ASN1_OID,          ASN1_BODY }, /* 24 */
+  { 5,           "critical",		ASN1_BOOLEAN,      ASN1_DEF |
+							   ASN1_BODY }, /* 25 */
+  { 5,           "extnValue",		ASN1_OCTET_STRING, ASN1_BODY }, /* 26 */
+  { 3,       "end loop",		ASN1_EOC,          ASN1_END  }, /* 27 */
+  { 2,     "end opt",			ASN1_EOC,          ASN1_END  }, /* 28 */
+  { 1,   "signatureAlgorithm",		ASN1_EOC,          ASN1_RAW  }, /* 29 */
+  { 1,   "signatureValue",		ASN1_BIT_STRING,   ASN1_BODY }  /* 30 */
+};
+
+#define X509_OBJ_CERTIFICATE			 0
+#define X509_OBJ_TBS_CERTIFICATE		 1
+#define X509_OBJ_VERSION			 3
+#define X509_OBJ_SERIAL_NUMBER			 4
+#define X509_OBJ_SIG_ALG			 5
+#define X509_OBJ_ISSUER 			 6
+#define X509_OBJ_NOT_BEFORE			 8
+#define X509_OBJ_NOT_AFTER			 9
+#define X509_OBJ_SUBJECT			10
+#define X509_OBJ_SUBJECT_PUBLIC_KEY_ALGORITHM	12
+#define X509_OBJ_SUBJECT_PUBLIC_KEY		13
+#define X509_OBJ_RSA_PUBLIC_KEY			14
+#define X509_OBJ_MODULUS			15
+#define X509_OBJ_PUBLIC_EXPONENT		16
+#define X509_OBJ_EXTN_ID			24
+#define X509_OBJ_CRITICAL			25
+#define X509_OBJ_EXTN_VALUE			26
+#define X509_OBJ_ALGORITHM			29
+#define X509_OBJ_SIGNATURE			30
+#define X509_OBJ_ROOF				31
+
+
+const x509cert_t empty_x509cert = {
+      NULL        , /* *next */
+    UNDEFINED_TIME, /* installed */
+            0     , /* count */
+      FALSE       , /* smartcard */
+     AUTH_NONE    , /* authority_flags */
+    { NULL, 0 }   , /* certificate */
+    { NULL, 0 }   , /*   tbsCertificate */
+            1	  , /*     version */
+    { NULL, 0 }   , /*     serialNumber */
+    OID_UNKNOWN   , /*     sigAlg */
+    { NULL, 0 }   , /*     issuer */
+                    /*     validity */
+            0     , /*       notBefore */
+            0     , /*       notAfter */
+    { NULL, 0 }   , /*     subject */
+                    /*     subjectPublicKeyInfo */
+    OID_UNKNOWN   , /*       subjectPublicKeyAlgorithm */
+    { NULL, 0 }   , /*       subjectPublicKey */
+    { NULL, 0 }   , /*         modulus */
+    { NULL, 0 }   , /*         publicExponent */
+                    /*     issuerUniqueID */
+                    /*     subjectUniqueID */
+                    /*     extensions */
+                    /*       extension */
+                    /*         extnID */
+                    /*         critical */
+                    /*         extnValue */
+      FALSE       , /*           isCA */
+      FALSE       , /*           isOcspSigner */
+    { NULL, 0 }   , /*           subjectKeyID */
+    { NULL, 0 }   , /*           authKeyID */
+    { NULL, 0 }   , /*           authKeySerialNumber */
+    { NULL, 0 }   , /*           accessLocation */
+      NULL        , /*           subjectAltName */
+      NULL        , /*           crlDistributionPoints */
+    OID_UNKNOWN   , /*   algorithm */
+    { NULL, 0 }     /*   signature */
+};
+
+/* coding of X.501 distinguished name */
+
+typedef struct {
+    const u_char *name;
+    chunk_t oid;
+    u_char type;
+} x501rdn_t;
+
+/* X.501 acronyms for well known object identifiers (OIDs) */
+
+static u_char oid_ND[]  = {0x02, 0x82, 0x06, 0x01,
+			   0x0A, 0x07, 0x14};
+static u_char oid_UID[] = {0x09, 0x92, 0x26, 0x89, 0x93,
+			   0xF2, 0x2C, 0x64, 0x01, 0x01};
+static u_char oid_DC[]  = {0x09, 0x92, 0x26, 0x89, 0x93,
+			   0xF2, 0x2C, 0x64, 0x01, 0x19};
+static u_char oid_CN[]  = {0x55, 0x04, 0x03};
+static u_char oid_S[]   = {0x55, 0x04, 0x04};
+static u_char oid_SN[]  = {0x55, 0x04, 0x05};
+static u_char oid_C[]   = {0x55, 0x04, 0x06};
+static u_char oid_L[]   = {0x55, 0x04, 0x07};
+static u_char oid_ST[]  = {0x55, 0x04, 0x08};
+static u_char oid_O[]   = {0x55, 0x04, 0x0A};
+static u_char oid_OU[]  = {0x55, 0x04, 0x0B};
+static u_char oid_T[]   = {0x55, 0x04, 0x0C};
+static u_char oid_D[]   = {0x55, 0x04, 0x0D};
+static u_char oid_N[]   = {0x55, 0x04, 0x29};
+static u_char oid_G[]   = {0x55, 0x04, 0x2A};
+static u_char oid_I[]   = {0x55, 0x04, 0x2B};
+static u_char oid_ID[]  = {0x55, 0x04, 0x2D};
+static u_char oid_EN[]  = {0x60, 0x86, 0x48, 0x01, 0x86,
+			   0xF8, 0x42, 0x03, 0x01, 0x03};
+static u_char oid_E[]   = {0x2A, 0x86, 0x48, 0x86, 0xF7,
+			   0x0D, 0x01, 0x09, 0x01};
+static u_char oid_UN[]  = {0x2A, 0x86, 0x48, 0x86, 0xF7,
+			   0x0D, 0x01, 0x09, 0x02};
+static u_char oid_TCGID[] = {0x2B, 0x06, 0x01, 0x04, 0x01, 0x89,
+			     0x31, 0x01, 0x01, 0x02, 0x02, 0x4B};
+
+static const x501rdn_t x501rdns[] = {
+  {"ND"              , {oid_ND,     7}, ASN1_PRINTABLESTRING},
+  {"UID"             , {oid_UID,   10}, ASN1_PRINTABLESTRING},
+  {"DC"              , {oid_DC,    10}, ASN1_PRINTABLESTRING},
+  {"CN"              , {oid_CN,     3}, ASN1_PRINTABLESTRING},
+  {"S"               , {oid_S,      3}, ASN1_PRINTABLESTRING},
+  {"SN"              , {oid_SN,     3}, ASN1_PRINTABLESTRING},
+  {"serialNumber"    , {oid_SN,     3}, ASN1_PRINTABLESTRING},
+  {"C"               , {oid_C,      3}, ASN1_PRINTABLESTRING},
+  {"L"               , {oid_L,      3}, ASN1_PRINTABLESTRING},
+  {"ST"              , {oid_ST,     3}, ASN1_PRINTABLESTRING},
+  {"O"               , {oid_O,      3}, ASN1_PRINTABLESTRING},
+  {"OU"              , {oid_OU,     3}, ASN1_PRINTABLESTRING},
+  {"T"               , {oid_T,      3}, ASN1_PRINTABLESTRING},
+  {"D"               , {oid_D,      3}, ASN1_PRINTABLESTRING},
+  {"N"               , {oid_N,      3}, ASN1_PRINTABLESTRING},
+  {"G"               , {oid_G,      3}, ASN1_PRINTABLESTRING},
+  {"I"               , {oid_I,      3}, ASN1_PRINTABLESTRING},
+  {"ID"              , {oid_ID,     3}, ASN1_PRINTABLESTRING},
+  {"EN"              , {oid_EN,    10}, ASN1_PRINTABLESTRING},
+  {"employeeNumber"  , {oid_EN,    10}, ASN1_PRINTABLESTRING},
+  {"E"               , {oid_E,      9}, ASN1_IA5STRING},
+  {"Email"           , {oid_E,      9}, ASN1_IA5STRING},
+  {"emailAddress"    , {oid_E,      9}, ASN1_IA5STRING},
+  {"UN"              , {oid_UN,     9}, ASN1_IA5STRING},
+  {"unstructuredName", {oid_UN,     9}, ASN1_IA5STRING},
+  {"TCGID"           , {oid_TCGID, 12}, ASN1_PRINTABLESTRING}
+};
+
+#define X501_RDN_ROOF   26
+
+static u_char ASN1_subjectAltName_oid_str[] = {
+    0x06, 0x03, 0x55, 0x1D, 0x11
+};
+
+static const chunk_t ASN1_subjectAltName_oid = strchunk(ASN1_subjectAltName_oid_str);
+
+static void
+update_chunk(chunk_t *ch, int n)
+{
+    n = (n > -1 && n < (int)ch->len)? n : (int)ch->len-1;
+    ch->ptr += n; ch->len -= n;
+}
+
+
+/*
+ *  Pointer is set to the first RDN in a DN
+ */
+static err_t
+init_rdn(chunk_t dn, chunk_t *rdn, chunk_t *attribute, bool *next)
+{
+    *rdn = empty_chunk;
+    *attribute = empty_chunk;
+
+    /* a DN is a SEQUENCE OF RDNs */
+
+    if (*dn.ptr != ASN1_SEQUENCE)
+    {
+	return "DN is not a SEQUENCE";
+    }
+
+    rdn->len = asn1_length(&dn);
+
+    if (rdn->len == ASN1_INVALID_LENGTH)
+	return "Invalid RDN length";
+
+    rdn->ptr = dn.ptr;
+
+    /* are there any RDNs ? */
+    *next = rdn->len > 0;
+
+    return NULL;
+}
+
+/*
+ *  Fetches the next RDN in a DN
+ */
+static err_t
+get_next_rdn(chunk_t *rdn, chunk_t * attribute, chunk_t *oid, chunk_t *value
+, asn1_t *type, bool *next)
+{
+    chunk_t body;
+
+    /* initialize return values */
+    *oid   = empty_chunk;
+    *value = empty_chunk;
+
+    /* if all attributes have been parsed, get next rdn */
+    if (attribute->len <= 0)
+    {
+	/* an RDN is a SET OF attributeTypeAndValue */
+	if (*rdn->ptr != ASN1_SET)
+	    return "RDN is not a SET";
+
+	attribute->len = asn1_length(rdn);
+	
+	if (attribute->len == ASN1_INVALID_LENGTH)
+	    return "Invalid attribute length";
+
+	attribute->ptr = rdn->ptr;
+
+	/* advance to start of next RDN */
+	rdn->ptr += attribute->len;
+	rdn->len -= attribute->len;
+    }
+
+    /* an attributeTypeAndValue is a SEQUENCE */
+    if (*attribute->ptr != ASN1_SEQUENCE)
+ 	return "attributeTypeAndValue is not a SEQUENCE";
+
+    /* extract the attribute body */
+    body.len = asn1_length(attribute);
+    
+    if (body.len == ASN1_INVALID_LENGTH)
+	return "Invalid attribute body length";
+
+    body.ptr = attribute->ptr;
+    
+    /* advance to start of next attribute */
+    attribute->ptr += body.len;
+    attribute->len -= body.len;
+
+    /* attribute type is an OID */
+    if (*body.ptr != ASN1_OID)
+	return "attributeType is not an OID";
+
+    /* extract OID */
+    oid->len = asn1_length(&body);
+    
+    if (oid->len == ASN1_INVALID_LENGTH)
+	return "Invalid attribute OID length";
+
+    oid->ptr = body.ptr;
+
+    /* advance to the attribute value */
+    body.ptr += oid->len;
+    body.len -= oid->len;
+
+    /* extract string type */
+    *type = *body.ptr;
+
+    /* extract string value */
+    value->len = asn1_length(&body);
+    
+    if (value->len == ASN1_INVALID_LENGTH)
+	return "Invalid attribute string length";
+
+    value->ptr = body.ptr;
+
+    /* are there any RDNs left? */
+    *next = rdn->len > 0 || attribute->len > 0;
+
+    return NULL;
+}
+
+/*
+ *  Parses an ASN.1 distinguished name int its OID/value pairs
+ */
+static err_t
+dn_parse(chunk_t dn, chunk_t *str)
+{
+    chunk_t rdn, oid, attribute, value;
+    asn1_t type;
+    int oid_code;
+    bool next;
+    bool first = TRUE;
+
+    err_t ugh = init_rdn(dn, &rdn, &attribute, &next);
+
+    if (ugh != NULL) /* a parsing error has occured */
+        return ugh;
+
+    while (next)
+    {
+	ugh = get_next_rdn(&rdn, &attribute, &oid, &value, &type, &next);
+
+	if (ugh != NULL) /* a parsing error has occured */
+	    return ugh;
+
+	if (first)		/* first OID/value pair */
+	    first = FALSE;
+	else			/* separate OID/value pair by a comma */
+	    update_chunk(str, snprintf(str->ptr,str->len,", "));
+
+	/* print OID */
+	oid_code = known_oid(oid);
+	if (oid_code == OID_UNKNOWN)	/* OID not found in list */
+	    hex_str(oid, str);
+	else
+	    update_chunk(str, snprintf(str->ptr,str->len,"%s",
+			      oid_names[oid_code].name));
+
+	/* print value */
+	update_chunk(str, snprintf(str->ptr,str->len,"=%.*s",
+			      (int)value.len,value.ptr));
+    }
+    return NULL;
+}
+
+/*
+ *  Count the number of wildcard RDNs in a distinguished name
+ */
+int
+dn_count_wildcards(chunk_t dn)
+{
+    chunk_t rdn, attribute, oid, value;
+    asn1_t type;
+    bool next;
+    int wildcards = 0;
+
+    err_t ugh = init_rdn(dn, &rdn, &attribute, &next);
+
+    if (ugh != NULL) /* a parsing error has occured */
+        return -1;
+
+    while (next)
+    {
+	ugh = get_next_rdn(&rdn, &attribute, &oid, &value, &type, &next);
+
+	if (ugh != NULL) /* a parsing error has occured */
+	    return -1;
+	if (value.len == 1 && *value.ptr == '*')
+	    wildcards++; /* we have found a wildcard RDN */
+    }
+    return wildcards;
+}
+
+/*
+ * Prints a binary string in hexadecimal form
+ */
+void
+hex_str(chunk_t bin, chunk_t *str)
+{
+    u_int i;
+    update_chunk(str, snprintf(str->ptr,str->len,"0x"));
+    for (i=0; i < bin.len; i++)
+	update_chunk(str, snprintf(str->ptr,str->len,"%02X",*bin.ptr++));
+}
+
+
+/*  Converts a binary DER-encoded ASN.1 distinguished name
+ *  into LDAP-style human-readable ASCII format
+ */
+int
+dntoa(char *dst, size_t dstlen, chunk_t dn)
+{
+    err_t ugh = NULL;
+    chunk_t str;
+
+    str.ptr = dst;
+    str.len = dstlen;
+    ugh = dn_parse(dn, &str);
+
+    if (ugh != NULL) /* error, print DN as hex string */
+    {
+	DBG(DBG_PARSING,
+	    DBG_log("error in DN parsing: %s", ugh)
+	)
+	str.ptr = dst;
+	str.len = dstlen;
+	hex_str(dn, &str);
+    }
+    return (int)(dstlen - str.len);
+}
+
+/*
+ * Same as dntoa but prints a special string for a null dn
+ */
+int
+dntoa_or_null(char *dst, size_t dstlen, chunk_t dn, const char* null_dn)
+{
+    if (dn.ptr == NULL)
+	return snprintf(dst, dstlen, "%s", null_dn);
+    else
+	return dntoa(dst, dstlen, dn);
+}
+
+/*  Converts an LDAP-style human-readable ASCII-encoded
+ *  ASN.1 distinguished name into binary DER-encoded format
+ */
+err_t
+atodn(char *src, chunk_t *dn)
+{
+  /* finite state machine for atodn */
+
+    typedef enum {
+	SEARCH_OID =	0,
+	READ_OID =	1,
+	SEARCH_NAME =	2,
+	READ_NAME =	3,
+        UNKNOWN_OID =	4
+    } state_t;
+
+    u_char oid_len_buf[3];
+    u_char name_len_buf[3];
+    u_char rdn_seq_len_buf[3];
+    u_char rdn_set_len_buf[3];
+    u_char dn_seq_len_buf[3];
+
+    chunk_t asn1_oid_len     = { oid_len_buf,     0 };
+    chunk_t asn1_name_len    = { name_len_buf,    0 };
+    chunk_t asn1_rdn_seq_len = { rdn_seq_len_buf, 0 };
+    chunk_t asn1_rdn_set_len = { rdn_set_len_buf, 0 };
+    chunk_t asn1_dn_seq_len  = { dn_seq_len_buf,  0 };
+    chunk_t oid  = empty_chunk;
+    chunk_t name = empty_chunk;
+
+    int whitespace  = 0;
+    int rdn_seq_len = 0;
+    int rdn_set_len = 0;
+    int dn_seq_len  = 0;
+    int pos         = 0;
+
+    err_t ugh = NULL;
+
+    u_char *dn_ptr = dn->ptr + 4;
+
+    state_t state = SEARCH_OID;
+
+    do
+    {
+        switch (state)
+	{
+	case SEARCH_OID:
+	    if (*src != ' ' && *src != '/' && *src !=  ',')
+	    {
+		oid.ptr = src;
+		oid.len = 1;
+		state = READ_OID;
+	    }
+	    break;
+	case READ_OID:
+	    if (*src != ' ' && *src != '=')
+		oid.len++;
+	    else
+	    {
+		for (pos = 0; pos < X501_RDN_ROOF; pos++)
+		{
+		    if (strlen(x501rdns[pos].name) == oid.len &&
+			strncasecmp(x501rdns[pos].name, oid.ptr, oid.len) == 0)
+			break; /* found a valid OID */
+		}
+		if (pos == X501_RDN_ROOF)
+		{
+		    ugh = "unknown OID in distinguished name";
+		    state = UNKNOWN_OID;
+		    break;
+		}
+		code_asn1_length(x501rdns[pos].oid.len, &asn1_oid_len);
+
+		/* reset oid and change state */
+		oid = empty_chunk;
+		state = SEARCH_NAME;
+	    }
+	    break;
+	case SEARCH_NAME:
+	    if (*src != ' ' && *src != '=')
+	    {
+		name.ptr = src;
+		name.len = 1;
+		whitespace = 0;
+		state = READ_NAME;
+	    }
+	    break;
+	case READ_NAME:
+	    if (*src != ',' && *src != '/' && *src != '\0')
+	    {
+		name.len++;
+		if (*src == ' ')
+		    whitespace++;
+		else
+		    whitespace = 0;
+	    }
+	    else
+	    {
+		name.len -= whitespace;
+		code_asn1_length(name.len, &asn1_name_len);
+
+		/* compute the length of the relative distinguished name sequence */
+		rdn_seq_len = 1 + asn1_oid_len.len + x501rdns[pos].oid.len +
+			      1 + asn1_name_len.len + name.len;
+		code_asn1_length(rdn_seq_len, &asn1_rdn_seq_len);
+
+		/* compute the length of the relative distinguished name set */
+		rdn_set_len = 1 + asn1_rdn_seq_len.len + rdn_seq_len;
+		code_asn1_length(rdn_set_len, &asn1_rdn_set_len);
+
+		/* encode the relative distinguished name */
+		*dn_ptr++ = ASN1_SET;
+		chunkcpy(dn_ptr, asn1_rdn_set_len);
+		*dn_ptr++ = ASN1_SEQUENCE;
+		chunkcpy(dn_ptr, asn1_rdn_seq_len);
+		*dn_ptr++ = ASN1_OID;
+		chunkcpy(dn_ptr, asn1_oid_len);
+		chunkcpy(dn_ptr, x501rdns[pos].oid);
+		/* encode the ASN.1 character string type of the name */
+		*dn_ptr++ = (x501rdns[pos].type == ASN1_PRINTABLESTRING
+		    && !is_printablestring(name))? ASN1_T61STRING : x501rdns[pos].type;
+		chunkcpy(dn_ptr, asn1_name_len);
+		chunkcpy(dn_ptr, name);
+
+		/* accumulate the length of the distinguished name sequence */
+		dn_seq_len += 1 + asn1_rdn_set_len.len + rdn_set_len;
+
+		/* reset name and change state */
+		name = empty_chunk;
+		state = SEARCH_OID;
+	    }
+	    break;
+	case UNKNOWN_OID:
+	    break;
+	}
+    } while (*src++ != '\0');
+
+    /* complete the distinguished name sequence*/
+    code_asn1_length(dn_seq_len, &asn1_dn_seq_len);
+    dn->ptr += 3 - asn1_dn_seq_len.len;
+    dn->len =  1 + asn1_dn_seq_len.len + dn_seq_len;
+    dn_ptr = dn->ptr;
+    *dn_ptr++ = ASN1_SEQUENCE;
+    chunkcpy(dn_ptr, asn1_dn_seq_len);
+    return ugh;
+}
+
+/*  compare two distinguished names by
+ *  comparing the individual RDNs
+ */
+bool
+same_dn(chunk_t a, chunk_t b)
+{
+    chunk_t rdn_a, rdn_b, attribute_a, attribute_b;
+    chunk_t oid_a, oid_b, value_a, value_b;
+    asn1_t type_a, type_b;
+    bool next_a, next_b;
+
+    /* same lengths for the DNs */
+    if (a.len != b.len)
+	return FALSE;
+
+    /* try a binary comparison first */
+    if (memcmp(a.ptr, b.ptr, b.len) == 0)
+	return TRUE;
+ 
+    /* initialize DN parsing */
+    if (init_rdn(a, &rdn_a, &attribute_a, &next_a) != NULL
+    ||  init_rdn(b, &rdn_b, &attribute_b, &next_b) != NULL)
+	return FALSE;
+
+    /* fetch next RDN pair */
+    while (next_a && next_b)
+    {
+	/* parse next RDNs and check for errors */
+	if (get_next_rdn(&rdn_a, &attribute_a, &oid_a, &value_a, &type_a, &next_a) != NULL
+	||  get_next_rdn(&rdn_b, &attribute_b, &oid_b, &value_b, &type_b, &next_b) != NULL)
+	{
+	    return FALSE;
+	}
+
+	/* OIDs must agree */
+	if (oid_a.len != oid_b.len || memcmp(oid_a.ptr, oid_b.ptr, oid_b.len) != 0)
+	    return FALSE;
+
+	/* same lengths for values */
+	if (value_a.len != value_b.len)
+	    return FALSE;
+
+	/* printableStrings and email RDNs require uppercase comparison */
+	if (type_a == type_b && (type_a == ASN1_PRINTABLESTRING ||
+	   (type_a == ASN1_IA5STRING && known_oid(oid_a) == OID_PKCS9_EMAIL)))
+	{
+	    if (strncasecmp(value_a.ptr, value_b.ptr, value_b.len) != 0)
+		return FALSE;
+	}
+	else
+	{
+	    if (strncmp(value_a.ptr, value_b.ptr, value_b.len) != 0)
+		return FALSE;
+	}
+    }
+    /* both DNs must have same number of RDNs */
+    if (next_a || next_b)
+	return FALSE;
+
+    /* the two DNs are equal! */
+    return TRUE;
+}
+
+
+/*  compare two distinguished names by comparing the individual RDNs.
+ *  A single'*' character designates a wildcard RDN in DN b.
+ */
+bool
+match_dn(chunk_t a, chunk_t b, int *wildcards)
+{
+    chunk_t rdn_a, rdn_b, attribute_a, attribute_b;
+    chunk_t oid_a, oid_b, value_a, value_b;
+    asn1_t type_a,  type_b;
+    bool next_a, next_b;
+
+    /* initialize wildcard counter */
+    *wildcards = 0;
+
+    /* initialize DN parsing */
+    if (init_rdn(a, &rdn_a, &attribute_a, &next_a) != NULL
+    ||  init_rdn(b, &rdn_b, &attribute_b, &next_b) != NULL)
+    	return FALSE;
+
+    /* fetch next RDN pair */
+    while (next_a && next_b)
+    {
+	/* parse next RDNs and check for errors */
+	if (get_next_rdn(&rdn_a, &attribute_a, &oid_a, &value_a, &type_a, &next_a) != NULL
+	||  get_next_rdn(&rdn_b, &attribute_b, &oid_b, &value_b, &type_b, &next_b) != NULL)
+	{
+	    return FALSE;
+	}
+
+	/* OIDs must agree */
+	if (oid_a.len != oid_b.len || memcmp(oid_a.ptr, oid_b.ptr, oid_b.len) != 0)
+	    return FALSE;
+
+	/* does rdn_b contain a wildcard? */
+	if (value_b.len == 1 && *value_b.ptr == '*')
+	{
+	    (*wildcards)++;
+	    continue;
+	}
+
+	/* same lengths for values */
+	if (value_a.len != value_b.len)
+	    return FALSE;
+
+	/* printableStrings and email RDNs require uppercase comparison */
+	if (type_a == type_b && (type_a == ASN1_PRINTABLESTRING ||
+	   (type_a == ASN1_IA5STRING && known_oid(oid_a) == OID_PKCS9_EMAIL)))
+	{
+	    if (strncasecmp(value_a.ptr, value_b.ptr, value_b.len) != 0)
+		return FALSE;
+	}
+	else
+	{
+	    if (strncmp(value_a.ptr, value_b.ptr, value_b.len) != 0)
+		return FALSE;
+	}
+    }
+    /* both DNs must have same number of RDNs */
+    if (next_a || next_b)
+	return FALSE;
+
+    /* the two DNs match! */
+    return TRUE;
+}
+
+/*
+ *  compare two X.509 certificates by comparing their signatures
+ */
+bool
+same_x509cert(const x509cert_t *a, const x509cert_t *b)
+{
+    return same_chunk(a->signature, b->signature);
+}
+
+/*  for each link pointing to the certificate
+ "  increase the count by one
+ */
+void
+share_x509cert(x509cert_t *cert)
+{
+    if (cert != NULL)
+ 	cert->count++;
+}
+
+/*
+ *  add a X.509 user/host certificate to the chained list
+ */
+x509cert_t*
+add_x509cert(x509cert_t *cert)
+{
+    x509cert_t *c = x509certs;
+
+    while (c != NULL)
+    {
+	if (same_x509cert(c, cert)) /* already in chain, free cert */
+	{
+	    free_x509cert(cert);
+	    return c;
+	}
+	c = c->next;
+    }
+
+    /* insert new cert at the root of the chain */
+    lock_certs_and_keys("add_x509cert");
+    cert->next = x509certs;
+    x509certs = cert;
+    DBG(DBG_CONTROL | DBG_PARSING,
+	DBG_log("  x509 cert inserted")
+    )
+    unlock_certs_and_keys("add_x509cert");
+    return cert;
+}
+
+/*
+ * choose either subject DN or a subjectAltName as connection end ID
+ */
+void
+select_x509cert_id(x509cert_t *cert, struct id *end_id)
+{
+    bool copy_subject_dn = TRUE;	 /* ID is subject DN */
+
+    if (end_id->kind != ID_NONE) /* check for matching subjectAltName */
+    {
+	generalName_t *gn = cert->subjectAltName;
+
+	while (gn != NULL)
+	{
+	    struct id id = empty_id;
+
+	    gntoid(&id, gn);
+	    if (same_id(&id, end_id))
+	    {
+		copy_subject_dn = FALSE; /* take subjectAltName instead */
+		break;
+	    }
+	    gn = gn->next;
+	}
+    }
+
+    if (copy_subject_dn)
+    {
+	if (end_id->kind != ID_NONE && end_id->kind != ID_DER_ASN1_DN)
+	{
+	     char buf[BUF_LEN];
+
+	     idtoa(end_id, buf, BUF_LEN);
+	     plog("  no subjectAltName matches ID '%s', replaced by subject DN", buf);
+	}
+	end_id->kind = ID_DER_ASN1_DN;
+	end_id->name.len = cert->subject.len;
+	end_id->name.ptr = temporary_cyclic_buffer();
+	memcpy(end_id->name.ptr, cert->subject.ptr, cert->subject.len);
+    }
+}
+
+/*
+ * check for equality between two key identifiers
+ */
+bool
+same_keyid(chunk_t a, chunk_t b)
+{
+    if (a.ptr == NULL || b.ptr == NULL)
+	return FALSE;
+
+    return same_chunk(a, b);
+}
+
+/*
+ * check for equality between two serial numbers
+ */
+bool
+same_serial(chunk_t a, chunk_t b)
+{
+    /* do not compare serial numbers if one of them is not defined */
+    if (a.ptr == NULL || b.ptr == NULL)
+	return TRUE;
+
+    return same_chunk(a, b);
+}
+
+/*
+ *  get a X.509 certificate with a given issuer found at a certain position
+ */
+x509cert_t*
+get_x509cert(chunk_t issuer, chunk_t serial, chunk_t keyid, x509cert_t *chain)
+{
+    x509cert_t *cert = (chain != NULL)? chain->next : x509certs;
+
+    while (cert != NULL)
+    {
+	if ((keyid.ptr != NULL) ? same_keyid(keyid, cert->authKeyID)
+	    : (same_dn(issuer, cert->issuer)
+	       && same_serial(serial, cert->authKeySerialNumber)))
+	{
+	    return cert;
+	}
+	cert = cert->next;
+    }
+    return NULL;
+}
+
+/*
+ * encode a linked list of subjectAltNames
+ */
+chunk_t
+build_subjectAltNames(generalName_t *subjectAltNames)
+{
+    u_char *pos;
+    chunk_t names;
+    size_t len = 0;
+    generalName_t *gn = subjectAltNames;
+	
+   /* compute the total size of the ASN.1 attributes object */
+    while (gn != NULL)
+    {
+	len += gn->name.len;
+	gn = gn->next;
+    }
+
+    pos = build_asn1_object(&names, ASN1_SEQUENCE, len);
+
+    gn = subjectAltNames;
+    while (gn != NULL)
+    {
+	chunkcpy(pos, gn->name);
+	gn = gn->next;
+    }
+
+    return asn1_wrap(ASN1_SEQUENCE, "cm"
+		, ASN1_subjectAltName_oid
+		, asn1_wrap(ASN1_OCTET_STRING, "m", names));
+}
+
+/*
+ * build a to-be-signed X.509 certificate body
+ */
+static chunk_t
+build_tbs_x509cert(x509cert_t *cert, const RSA_public_key_t *rsa)
+{
+    /* version is always X.509v3 */
+    chunk_t version = asn1_simple_object(ASN1_CONTEXT_C_0, ASN1_INTEGER_2);
+
+    chunk_t extensions = empty_chunk;
+
+    if (cert->subjectAltName != NULL)
+    {
+	extensions = asn1_wrap(ASN1_CONTEXT_C_3, "m"
+		, asn1_wrap(ASN1_SEQUENCE, "m"
+		, build_subjectAltNames(cert->subjectAltName)));
+    }
+
+    return asn1_wrap(ASN1_SEQUENCE, "mmccmcmm"
+		, version
+		, asn1_simple_object(ASN1_INTEGER, cert->serialNumber)
+		, asn1_algorithmIdentifier(cert->sigAlg)
+		, cert->issuer
+		, asn1_wrap(ASN1_SEQUENCE, "mm"
+		    , timetoasn1(&cert->notBefore, ASN1_UTCTIME) 
+		    , timetoasn1(&cert->notAfter,  ASN1_UTCTIME)
+		  )
+		, cert->subject
+		, pkcs1_build_publicKeyInfo(rsa)
+		, extensions
+	   );
+}
+
+/*
+ * build a DER-encoded X.509 certificate
+ */
+void
+build_x509cert(x509cert_t *cert, const RSA_public_key_t *cert_key
+, const RSA_private_key_t *signer_key)
+{
+    chunk_t tbs_cert = build_tbs_x509cert(cert, cert_key);
+
+    chunk_t signature = pkcs1_build_signature(tbs_cert, cert->sigAlg
+			    , signer_key, TRUE);
+
+    cert->certificate = asn1_wrap(ASN1_SEQUENCE, "mcm"
+				, tbs_cert
+				, asn1_algorithmIdentifier(cert->sigAlg)
+				, signature);
+}
+
+/*
+ *  free the dynamic memory used to store generalNames
+ */
+void
+free_generalNames(generalName_t* gn, bool free_name)
+{
+    while (gn != NULL)
+    {
+	generalName_t *gn_top = gn;
+	if (free_name)
+	{
+	    pfree(gn->name.ptr);
+	}
+	gn = gn->next;
+	pfree(gn_top);
+    }
+}
+
+/*
+ *  free a X.509 certificate
+ */
+void
+free_x509cert(x509cert_t *cert)
+{
+    if (cert != NULL)
+    {
+	free_generalNames(cert->subjectAltName, FALSE);
+	free_generalNames(cert->crlDistributionPoints, FALSE);
+	pfreeany(cert->certificate.ptr);
+	pfree(cert);
+	cert = NULL;
+    }
+}
+
+/*  release of a certificate decreases the count by one
+ "  the certificate is freed when the counter reaches zero
+ */
+void
+release_x509cert(x509cert_t *cert)
+{
+    if (cert != NULL && --cert->count == 0)
+    {
+	x509cert_t **pp = &x509certs;
+	while (*pp != cert)
+	    pp = &(*pp)->next;
+        *pp = cert->next;
+	free_x509cert(cert);
+    }
+}
+
+
+/*
+ * stores a chained list of end certs and CA certs
+ */
+void
+store_x509certs(x509cert_t **firstcert, bool strict)
+{
+    x509cert_t *cacerts = NULL;
+    x509cert_t **pp = firstcert;
+
+    /* first extract CA certs, discarding root CA certs */
+
+    while (*pp != NULL)
+    {
+	x509cert_t *cert = *pp;
+
+	if (cert->isCA)
+	{
+	    *pp = cert->next;
+	    
+	    /* we don't accept self-signed CA certs */
+	    if (same_dn(cert->issuer, cert->subject))
+	    {
+		plog("self-signed cacert rejected");
+		free_x509cert(cert);
+	    }
+	    else
+	    {
+		/* insertion into temporary chain of candidate CA certs */
+		cert->next = cacerts;
+		cacerts = cert;
+	    }
+	}
+	else
+	    pp = &cert->next;
+    }
+
+    /* now verify the candidate CA certs */
+    
+    while (cacerts != NULL)
+    {
+	x509cert_t *cert = cacerts;
+	
+	cacerts = cacerts->next;
+
+	if (trust_authcert_candidate(cert, cacerts))
+	{
+	    add_authcert(cert, AUTH_CA);
+	}
+	else
+	{
+	    plog("intermediate cacert rejected");
+	    free_x509cert(cert);
+	}
+    }
+    
+    /* now verify the end certificates */
+
+    pp = firstcert;
+
+    while (*pp != NULL)
+    {
+	time_t valid_until;
+	x509cert_t *cert = *pp;
+
+	if (verify_x509cert(cert, strict, &valid_until))
+	{
+	    DBG(DBG_CONTROL | DBG_PARSING,
+		DBG_log("public key validated")
+	    )
+	    add_x509_public_key(cert, valid_until, DAL_SIGNED);
+	}
+	else
+	{
+	    plog("X.509 certificate rejected");
+	}
+	*pp = cert->next;
+	free_x509cert(cert);
+    }
+}
+
+/*
+ *  decrypts an RSA signature using the issuer's certificate
+ */
+static bool
+decrypt_sig(chunk_t sig, int alg, const x509cert_t *issuer_cert,
+	    chunk_t *digest)
+{
+    switch (alg)
+    {
+	chunk_t decrypted;
+
+	case OID_RSA_ENCRYPTION:
+	case OID_MD2_WITH_RSA:
+	case OID_MD5_WITH_RSA:
+	case OID_SHA1_WITH_RSA:
+	case OID_SHA1_WITH_RSA_OIW:
+	case OID_SHA256_WITH_RSA:
+	case OID_SHA384_WITH_RSA:
+	case OID_SHA512_WITH_RSA:
+	{
+	    mpz_t s;
+	    RSA_public_key_t rsa;
+
+	    init_RSA_public_key(&rsa, issuer_cert->publicExponent
+				    , issuer_cert->modulus);
+
+	    /* decrypt the signature s = s^e mod n */
+	    n_to_mpz(s, sig.ptr, sig.len);
+	    mpz_powm(s, s, &rsa.e, &rsa.n);
+
+	    /* convert back to bytes */
+	    decrypted = mpz_to_n(s, rsa.k);
+	    DBG(DBG_PARSING,
+		DBG_dump_chunk("  decrypted signature: ", decrypted)
+	    )
+
+	    /*  copy the least significant bits of decrypted signature
+	     *  into the digest string
+	    */
+	    memcpy(digest->ptr, decrypted.ptr + decrypted.len - digest->len,
+		   digest->len);
+
+	    /* free memory */
+	    free_RSA_public_content(&rsa);
+	    pfree(decrypted.ptr);
+	    mpz_clear(s);
+	    return TRUE;
+	}
+	default:
+	    digest->len = 0;
+	    return FALSE;
+    }
+}
+
+/*
+ *   Check if a signature over binary blob is genuine
+ */
+bool
+check_signature(chunk_t tbs, chunk_t sig, int digest_alg, int enc_alg
+, const x509cert_t *issuer_cert)
+{
+    u_char digest_buf[MAX_DIGEST_LEN];
+    u_char decrypted_buf[MAX_DIGEST_LEN];
+    chunk_t digest = {digest_buf, MAX_DIGEST_LEN};
+    chunk_t decrypted = {decrypted_buf, MAX_DIGEST_LEN};
+
+    DBG(DBG_PARSING,
+	if (digest_alg != OID_UNKNOWN)
+	    DBG_log("signature digest algorithm: '%s'",oid_names[digest_alg].name);
+	else
+	    DBG_log("unknown signature digest algorithm");
+    )
+
+    if (!compute_digest(tbs, digest_alg, &digest))
+    {
+	plog("  digest algorithm not supported");
+	return FALSE;
+    }
+
+    DBG(DBG_PARSING,
+	DBG_dump_chunk("  digest:", digest)
+    )
+
+    decrypted.len = digest.len; /* we want the same digest length */
+
+    DBG(DBG_PARSING,
+	if (enc_alg != OID_UNKNOWN)
+	    DBG_log("signature encryption algorithm: '%s'",oid_names[enc_alg].name);
+	else
+	    DBG_log("unknown signature encryption algorithm");
+    )
+
+    if (!decrypt_sig(sig, enc_alg, issuer_cert, &decrypted))
+    {
+    	plog("  decryption algorithm not supported");
+	return FALSE;
+    }
+
+    /* check if digests are equal */
+    return !memcmp(decrypted.ptr, digest.ptr, digest.len);
+}
+
+/*
+ * extracts the basicConstraints extension
+ */
+static bool
+parse_basicConstraints(chunk_t blob, int level0)
+{
+    asn1_ctx_t ctx;
+    chunk_t object;
+    u_int level;
+    int objectID = 0;
+    bool isCA = FALSE;
+
+    asn1_init(&ctx, blob, level0, FALSE, DBG_RAW);
+
+    while (objectID < BASIC_CONSTRAINTS_ROOF) {
+
+	if (!extract_object(basicConstraintsObjects, &objectID,
+			    &object,&level, &ctx))
+	     break;
+
+	if (objectID == BASIC_CONSTRAINTS_CA)
+	{
+	    isCA = object.len && *object.ptr;
+	    DBG(DBG_PARSING,
+		DBG_log("  %s",(isCA)?"TRUE":"FALSE");
+	    )
+	}
+	objectID++;
+    }
+    return isCA;
+}
+
+/*
+ *  Converts a X.500 generalName into an ID
+ */
+void
+gntoid(struct id *id, const generalName_t *gn)
+{
+    switch(gn->kind)
+    {
+    case GN_DNS_NAME:		/* ID type: ID_FQDN */
+	id->kind = ID_FQDN;
+	id->name = gn->name;
+	break;
+    case GN_IP_ADDRESS:		/* ID type: ID_IPV4_ADDR */
+	{
+	    const struct af_info *afi = &af_inet4_info;
+	    err_t ugh = NULL;
+
+	    id->kind = afi->id_addr;
+	    ugh = initaddr(gn->name.ptr, gn->name.len, afi->af, &id->ip_addr);
+	}
+	break;
+    case GN_RFC822_NAME:	/* ID type: ID_USER_FQDN */
+	id->kind = ID_USER_FQDN;
+	id->name = gn->name;
+	break;
+    default:
+	id->kind = ID_NONE;
+	id->name = empty_chunk;
+    }
+}
+
+/* compute the subjectKeyIdentifier according to section 4.2.1.2 of RFC 3280
+ * as the 160 bit SHA-1 hash of the public key
+ */
+void
+compute_subjectKeyID(x509cert_t *cert, chunk_t subjectKeyID)
+{
+    SHA1_CTX context;
+
+    SHA1Init(&context);
+    SHA1Update(&context
+	      , cert->subjectPublicKey.ptr
+	      , cert->subjectPublicKey.len);
+    SHA1Final(subjectKeyID.ptr, &context);
+    subjectKeyID.len = SHA1_DIGEST_SIZE;
+}
+
+/*
+ * extracts an otherName
+ */
+static bool
+parse_otherName(chunk_t blob, int level0)
+{
+    asn1_ctx_t ctx;
+    chunk_t object;
+    int objectID = 0;
+    u_int level;
+    int oid = OID_UNKNOWN;
+
+    asn1_init(&ctx, blob, level0, FALSE, DBG_RAW);
+
+    while (objectID < ON_OBJ_ROOF)
+    {
+	if (!extract_object(otherNameObjects, &objectID, &object, &level, &ctx))
+	     return FALSE;
+
+	switch (objectID)
+	{
+	case ON_OBJ_ID_TYPE:
+	    oid = known_oid(object);
+	    break;
+	case ON_OBJ_VALUE:
+	    if (oid == OID_XMPP_ADDR)
+	    {
+		if (!parse_asn1_simple_object(&object, ASN1_UTF8STRING
+					     , level + 1, "xmppAddr"))
+		{
+		    return FALSE;
+		}
+	    }
+	    break;
+	default:
+	    break;
+	}
+	objectID++;
+    }
+    return TRUE;
+}
+
+
+/*
+ * extracts a generalName
+ */
+static generalName_t*
+parse_generalName(chunk_t blob, int level0)
+{
+    u_char buf[BUF_LEN];
+    asn1_ctx_t ctx;
+    chunk_t object;
+    int objectID = 0;
+    u_int level;
+
+    asn1_init(&ctx, blob, level0, FALSE, DBG_RAW);
+
+    while (objectID < GN_OBJ_ROOF)
+    {
+	bool valid_gn = FALSE;
+	
+	if (!extract_object(generalNameObjects, &objectID, &object, &level, &ctx))
+	     return NULL;
+
+	switch (objectID) {
+	case GN_OBJ_RFC822_NAME:
+	case GN_OBJ_DNS_NAME:
+	case GN_OBJ_URI:
+	    DBG(DBG_PARSING,
+		DBG_log("  '%.*s'", (int)object.len, object.ptr);
+	    )
+	    valid_gn = TRUE;
+	    break;
+	case GN_OBJ_DIRECTORY_NAME:
+	    DBG(DBG_PARSING,
+		dntoa(buf, BUF_LEN, object);
+		DBG_log("  '%s'", buf)
+	    )
+	    valid_gn = TRUE;
+	    break;
+	case GN_OBJ_IP_ADDRESS:
+	    DBG(DBG_PARSING,
+		DBG_log("  '%d.%d.%d.%d'", *object.ptr, *(object.ptr+1),
+				      *(object.ptr+2), *(object.ptr+3));
+	    )
+	    valid_gn = TRUE;
+	    break;
+	case GN_OBJ_OTHER_NAME:
+	    if (!parse_otherName(object, level + 1))
+		return NULL;
+	    break;
+	case GN_OBJ_X400_ADDRESS:
+	case GN_OBJ_EDI_PARTY_NAME:
+	case GN_OBJ_REGISTERED_ID:
+	    break;
+	default:
+	    break;
+	}
+
+	if (valid_gn)
+	{
+	    generalName_t *gn = alloc_thing(generalName_t, "generalName");
+	    gn->kind = (objectID - GN_OBJ_OTHER_NAME) / 2;
+	    gn->name = object;
+	    gn->next = NULL;
+	    return gn;
+        }
+	objectID++;
+    }
+    return NULL;
+}
+
+
+/*
+ * extracts one or several GNs and puts them into a chained list
+ */
+static generalName_t*
+parse_generalNames(chunk_t blob, int level0, bool implicit)
+{
+    asn1_ctx_t ctx;
+    chunk_t object;
+    u_int level;
+    int objectID = 0;
+
+    generalName_t *top_gn = NULL;
+
+    asn1_init(&ctx, blob, level0, implicit, DBG_RAW);
+
+    while (objectID < GENERAL_NAMES_ROOF)
+    {
+	if (!extract_object(generalNamesObjects, &objectID, &object, &level, &ctx))
+	     return NULL;
+	     
+	if (objectID == GENERAL_NAMES_GN)
+	{
+	    generalName_t *gn = parse_generalName(object, level+1);
+	    if (gn != NULL)
+	    {
+		gn->next = top_gn;
+		top_gn = gn;
+	    }
+	}
+	objectID++;
+    }
+    return top_gn;
+}
+
+/*
+ * returns a directoryName
+ */
+chunk_t get_directoryName(chunk_t blob, int level, bool implicit)
+{
+    chunk_t name = empty_chunk;
+    generalName_t * gn = parse_generalNames(blob, level, implicit);
+
+    if (gn != NULL && gn->kind == GN_DIRECTORY_NAME)
+	name= gn->name;
+
+    free_generalNames(gn, FALSE);
+
+    return name;
+}
+
+/*
+ * extracts and converts a UTCTIME or GENERALIZEDTIME object
+ */
+time_t
+parse_time(chunk_t blob, int level0)
+{
+    asn1_ctx_t ctx;
+    chunk_t object;
+    u_int level;
+    int objectID = 0;
+
+    asn1_init(&ctx, blob, level0, FALSE, DBG_RAW);
+
+    while (objectID < TIME_ROOF)
+    {
+	if (!extract_object(timeObjects, &objectID, &object, &level, &ctx))
+	     return UNDEFINED_TIME;
+
+	if (objectID == TIME_UTC || objectID == TIME_GENERALIZED)
+	{
+	    return asn1totime(&object, (objectID == TIME_UTC)
+			? ASN1_UTCTIME : ASN1_GENERALIZEDTIME);
+	}
+	objectID++;
+    }
+    return UNDEFINED_TIME;
+ }
+
+/*
+ * extracts a keyIdentifier
+ */
+static chunk_t
+parse_keyIdentifier(chunk_t blob, int level0, bool implicit)
+{
+    asn1_ctx_t ctx;
+    chunk_t object;
+    u_int level;
+    int objectID = 0;
+
+    asn1_init(&ctx, blob, level0, implicit, DBG_RAW);
+
+    extract_object(keyIdentifierObjects, &objectID, &object, &level, &ctx);
+    return object;
+}
+
+/*
+ * extracts an authoritykeyIdentifier
+ */
+void
+parse_authorityKeyIdentifier(chunk_t blob, int level0
+    , chunk_t *authKeyID, chunk_t *authKeySerialNumber)
+{
+    asn1_ctx_t ctx;
+    chunk_t object;
+    u_int level;
+    int objectID = 0;
+
+    asn1_init(&ctx, blob, level0, FALSE, DBG_RAW);
+
+    while (objectID < AUTH_KEY_ID_ROOF)
+    {
+	if (!extract_object(authorityKeyIdentifierObjects, &objectID, &object, &level, &ctx))
+	     return;
+
+	switch (objectID) {
+	case AUTH_KEY_ID_KEY_ID:
+	    *authKeyID = parse_keyIdentifier(object, level+1, TRUE);
+	    break;
+	case AUTH_KEY_ID_CERT_ISSUER:
+	    {
+		generalName_t * gn = parse_generalNames(object, level+1, TRUE);
+
+		free_generalNames(gn, FALSE);
+	    }
+	    break;
+	case AUTH_KEY_ID_CERT_SERIAL:
+	    *authKeySerialNumber = object;
+	    break;
+	default:
+	    break;
+	}
+	objectID++;
+    }
+}
+
+/*
+ * extracts an authorityInfoAcess location
+ */
+static void
+parse_authorityInfoAccess(chunk_t blob, int level0, chunk_t *accessLocation)
+{
+    asn1_ctx_t ctx;
+    chunk_t object;
+    u_int level;
+    int objectID = 0;
+
+    u_int accessMethod = OID_UNKNOWN;
+
+    asn1_init(&ctx, blob, level0, FALSE, DBG_RAW);
+
+    while (objectID < AUTH_INFO_ACCESS_ROOF)
+    {
+	if (!extract_object(authorityInfoAccessObjects, &objectID, &object, &level, &ctx))
+	     return;
+
+	switch (objectID) {
+	case AUTH_INFO_ACCESS_METHOD:
+	    accessMethod = known_oid(object);
+	    break;
+	case AUTH_INFO_ACCESS_LOCATION:
+	    {
+		switch (accessMethod)
+		{
+		case OID_OCSP:
+		    if (*object.ptr == ASN1_CONTEXT_S_6)
+		    {
+			if (asn1_length(&object) == ASN1_INVALID_LENGTH)
+			    return;
+
+			DBG(DBG_PARSING,
+			    DBG_log("  '%.*s'",(int)object.len, object.ptr)
+			)
+
+			/* only HTTP(S) URIs accepted */
+			if (strncasecmp(object.ptr, "http", 4) == 0)
+			{
+			    *accessLocation = object;
+			    return;
+			}
+		    }
+		    plog("warning: ignoring OCSP InfoAccessLocation with unkown protocol");
+		    break;
+		default:
+		    /* unkown accessMethod, ignoring */
+		    break;
+		}
+	    }
+	    break;
+	default:
+	    break;
+	}
+	objectID++;
+    }
+
+}
+
+/*
+ * extracts extendedKeyUsage OIDs
+ */
+static bool
+parse_extendedKeyUsage(chunk_t blob, int level0)
+{
+    asn1_ctx_t ctx;
+    chunk_t object;
+    u_int level;
+    int objectID = 0;
+
+    asn1_init(&ctx, blob, level0, FALSE, DBG_RAW);
+
+    while (objectID < EXT_KEY_USAGE_ROOF)
+    {
+	if (!extract_object(extendedKeyUsageObjects, &objectID
+			    , &object, &level, &ctx))
+	     return FALSE;
+
+	if (objectID == EXT_KEY_USAGE_PURPOSE_ID
+	&& known_oid(object) == OID_OCSP_SIGNING)
+	    return TRUE;
+	objectID++;
+    }
+    return FALSE;
+}
+
+/*  extracts one or several crlDistributionPoints and puts them into
+ *  a chained list
+ */
+static generalName_t*
+parse_crlDistributionPoints(chunk_t blob, int level0)
+{
+    asn1_ctx_t ctx;
+    chunk_t object;
+    u_int level;
+    int objectID = 0;
+
+    generalName_t *top_gn = NULL;      /* top of the chained list */
+    generalName_t **tail_gn = &top_gn; /* tail of the chained list */
+
+    asn1_init(&ctx, blob, level0, FALSE, DBG_RAW);
+
+    while (objectID < CRL_DIST_POINTS_ROOF)
+    {
+	if (!extract_object(crlDistributionPointsObjects, &objectID,
+			    &object, &level, &ctx))
+	     return NULL;
+
+	if (objectID == CRL_DIST_POINTS_FULLNAME)
+	{
+	    generalName_t *gn = parse_generalNames(object, level+1, TRUE);
+	    /* append extracted generalNames to existing chained list */
+	    *tail_gn = gn;
+	    /* find new tail of the chained list */
+            while (gn != NULL)
+	    {
+		tail_gn = &gn->next;  gn = gn->next;
+	    }
+	}
+	objectID++;
+    }
+    return top_gn;
+}
+
+
+/*
+ *  Parses an X.509v3 certificate
+ */
+bool
+parse_x509cert(chunk_t blob, u_int level0, x509cert_t *cert)
+{
+    u_char  buf[BUF_LEN];
+    asn1_ctx_t ctx;
+    bool critical;
+    chunk_t object;
+    u_int level;
+    u_int extn_oid = OID_UNKNOWN;
+    int objectID = 0;
+
+    asn1_init(&ctx, blob, level0, FALSE, DBG_RAW);
+
+    while (objectID < X509_OBJ_ROOF)
+    {
+	if (!extract_object(certObjects, &objectID, &object, &level, &ctx))
+	     return FALSE;
+
+	/* those objects which will parsed further need the next higher level */
+	level++;
+
+	switch (objectID) {
+	case X509_OBJ_CERTIFICATE:
+	    cert->certificate = object;
+	    break;
+	case X509_OBJ_TBS_CERTIFICATE:
+	    cert->tbsCertificate = object;
+	    break;
+	case X509_OBJ_VERSION:
+	    cert->version = (object.len) ? (1+(u_int)*object.ptr) : 1;
+	    DBG(DBG_PARSING,
+		DBG_log("  v%d", cert->version);
+	    )
+	    break;
+	case X509_OBJ_SERIAL_NUMBER:
+	    cert->serialNumber = object;
+	    break;
+	case X509_OBJ_SIG_ALG:
+	    cert->sigAlg = parse_algorithmIdentifier(object, level, NULL);
+	    break;
+	case X509_OBJ_ISSUER:
+	    cert->issuer = object;
+	    DBG(DBG_PARSING,
+		dntoa(buf, BUF_LEN, object);
+		DBG_log("  '%s'",buf)
+	    )
+	    break;
+	case X509_OBJ_NOT_BEFORE:
+	    cert->notBefore = parse_time(object, level);
+	    break;
+	case X509_OBJ_NOT_AFTER:
+	    cert->notAfter = parse_time(object, level);
+	    break;
+	case X509_OBJ_SUBJECT:
+	    cert->subject = object;
+	    DBG(DBG_PARSING,
+		dntoa(buf, BUF_LEN, object);
+		DBG_log("  '%s'",buf)
+	    )
+	    break;
+	case X509_OBJ_SUBJECT_PUBLIC_KEY_ALGORITHM:
+	    if (parse_algorithmIdentifier(object, level, NULL) == OID_RSA_ENCRYPTION)
+		cert->subjectPublicKeyAlgorithm = PUBKEY_ALG_RSA;
+	    else
+	    {
+		plog("  unsupported public key algorithm");
+		return FALSE;
+	    }
+	    break;
+	case X509_OBJ_SUBJECT_PUBLIC_KEY:
+	    if (ctx.blobs[4].len > 0 && *ctx.blobs[4].ptr == 0x00)
+	    {
+		/* skip initial bit string octet defining 0 unused bits */
+		ctx.blobs[4].ptr++; ctx.blobs[4].len--;
+	    }
+	    else
+	    {
+		plog("  invalid RSA public key format");
+		return FALSE;
+	    }
+	    break;
+	case X509_OBJ_RSA_PUBLIC_KEY:
+	    cert->subjectPublicKey = object;
+	    break;
+	case X509_OBJ_MODULUS:
+	    if (object.len < RSA_MIN_OCTETS + 1)
+	    {
+		plog("  " RSA_MIN_OCTETS_UGH);
+		return FALSE;
+	    }
+	    if (object.len > RSA_MAX_OCTETS + (size_t)(*object.ptr == 0x00))
+	    {
+		plog("  " RSA_MAX_OCTETS_UGH);
+		return FALSE;
+	    }
+	    cert->modulus = object;
+	    break;
+	case X509_OBJ_PUBLIC_EXPONENT:
+	    cert->publicExponent = object;
+	    break;
+	case X509_OBJ_EXTN_ID:
+	    extn_oid = known_oid(object);
+	    break;
+	case X509_OBJ_CRITICAL:
+	    critical = object.len && *object.ptr;
+	    DBG(DBG_PARSING,
+		DBG_log("  %s",(critical)?"TRUE":"FALSE");
+	    )
+	    break;
+	case X509_OBJ_EXTN_VALUE:
+	    {
+		switch (extn_oid) {
+		case OID_SUBJECT_KEY_ID:
+		    cert->subjectKeyID =
+			parse_keyIdentifier(object, level, FALSE);
+		    break;
+		case OID_SUBJECT_ALT_NAME:
+		    cert->subjectAltName =
+			parse_generalNames(object, level, FALSE);
+		    break;
+		case OID_BASIC_CONSTRAINTS:
+		    cert->isCA =
+			parse_basicConstraints(object, level);
+		    break;
+		case OID_CRL_DISTRIBUTION_POINTS:
+		    cert->crlDistributionPoints =
+			parse_crlDistributionPoints(object, level);
+		    break;
+		 case OID_AUTHORITY_KEY_ID:
+		    parse_authorityKeyIdentifier(object, level
+			, &cert->authKeyID, &cert->authKeySerialNumber);
+		    break;
+		case OID_AUTHORITY_INFO_ACCESS:
+		    parse_authorityInfoAccess(object, level, &cert->accessLocation);
+		    break;
+		case OID_EXTENDED_KEY_USAGE:
+		    cert->isOcspSigner = parse_extendedKeyUsage(object, level);
+		    break;
+		case OID_NS_REVOCATION_URL:
+		case OID_NS_CA_REVOCATION_URL:
+		case OID_NS_CA_POLICY_URL:
+		case OID_NS_COMMENT:
+		    if (!parse_asn1_simple_object(&object, ASN1_IA5STRING
+		    , level, oid_names[extn_oid].name))
+		    {
+			return FALSE;
+		    }
+		    break;
+		default:
+		    break;
+		}
+	    }
+	    break;
+	case X509_OBJ_ALGORITHM:
+	    cert->algorithm = parse_algorithmIdentifier(object, level, NULL);
+	    break;
+	case X509_OBJ_SIGNATURE:
+	    cert->signature = object;
+	    break;
+	default:
+	    break;
+	}
+	objectID++;
+    }
+    time(&cert->installed);
+    return TRUE;
+}
+
+/* verify the validity of a certificate by
+ * checking the notBefore and notAfter dates
+ */
+err_t
+check_validity(const x509cert_t *cert, time_t *until)
+{
+    time_t current_time;
+
+    time(&current_time);
+    DBG(DBG_CONTROL | DBG_PARSING ,
+	DBG_log("  not before  : %s", timetoa(&cert->notBefore, TRUE));
+	DBG_log("  current time: %s", timetoa(&current_time, TRUE));
+	DBG_log("  not after   : %s", timetoa(&cert->notAfter, TRUE));
+    )
+
+    if (cert->notAfter < *until) *until = cert->notAfter;
+
+    if (current_time < cert->notBefore)
+	return "certificate is not valid yet";
+    if (current_time > cert->notAfter)
+	return "certificate has expired";
+    else
+	return NULL;
+}
+
+/*
+ *  verifies a X.509 certificate
+ */
+bool
+verify_x509cert(const x509cert_t *cert, bool strict, time_t *until)
+{
+    int pathlen;
+
+    *until = cert->notAfter;
+
+    for (pathlen = 0; pathlen < MAX_CA_PATH_LEN; pathlen++)
+    {
+	x509cert_t *issuer_cert;
+	u_char buf[BUF_LEN];
+	err_t ugh = NULL;
+
+	DBG(DBG_CONTROL,
+	    dntoa(buf, BUF_LEN, cert->subject);
+	    DBG_log("subject: '%s'",buf);
+	    dntoa(buf, BUF_LEN, cert->issuer);
+	    DBG_log("issuer:  '%s'",buf);
+	    if (cert->authKeyID.ptr != NULL)
+	    {
+		datatot(cert->authKeyID.ptr, cert->authKeyID.len, ':'
+		    , buf, BUF_LEN);
+		DBG_log("authkey:  %s", buf);
+	    }
+	)
+
+	ugh = check_validity(cert, until);
+
+	if (ugh != NULL)
+	{
+	    plog("%s", ugh);
+	    return FALSE;
+	}
+
+	DBG(DBG_CONTROL,
+	    DBG_log("certificate is valid")
+	)
+
+	lock_authcert_list("verify_x509cert");
+	issuer_cert = get_authcert(cert->issuer, cert->authKeySerialNumber
+	    , cert->authKeyID, AUTH_CA);
+
+	if (issuer_cert == NULL)
+	{
+	    plog("issuer cacert not found");
+	    unlock_authcert_list("verify_x509cert");
+	    return FALSE;
+	}
+	DBG(DBG_CONTROL,
+	    DBG_log("issuer cacert found")
+	)
+
+	if (!check_signature(cert->tbsCertificate, cert->signature
+			   , cert->algorithm, cert->algorithm, issuer_cert))
+	{
+	    plog("certificate signature is invalid");
+	    unlock_authcert_list("verify_x509cert");
+	    return FALSE;
+	}
+	DBG(DBG_CONTROL,
+	    DBG_log("certificate signature is valid")
+	)
+	unlock_authcert_list("verify_x509cert");
+
+	/* check if cert is a self-signed root ca */
+	if (pathlen > 0 && same_dn(cert->issuer, cert->subject))
+	{
+	    DBG(DBG_CONTROL,
+		DBG_log("reached self-signed root ca")
+	    )
+	    return TRUE;
+	}
+	else
+	{
+	    time_t nextUpdate = *until;
+	    time_t revocationDate = UNDEFINED_TIME;
+	    crl_reason_t revocationReason = REASON_UNSPECIFIED;
+
+	    /* first check certificate revocation using ocsp */
+	    cert_status_t status = verify_by_ocsp(cert, &nextUpdate
+		, &revocationDate, &revocationReason);
+
+	    /* if ocsp service is not available then fall back to crl */
+	    if ((status == CERT_UNDEFINED)
+	    ||  (status == CERT_UNKNOWN && strict))
+	    {
+		status = verify_by_crl(cert, &nextUpdate, &revocationDate
+		    , &revocationReason);
+	    }
+ 
+	    switch (status)
+	    {
+	    case CERT_GOOD:
+		/* if status information is stale */
+		if (strict && nextUpdate < time(NULL))
+		{
+		    DBG(DBG_CONTROL,
+			DBG_log("certificate is good but status is stale")
+		    )
+		    remove_x509_public_key(cert);
+		    return FALSE;
+		}
+		DBG(DBG_CONTROL,
+		    DBG_log("certificate is good")
+		)
+		
+		/* with strict crl policy the public key must have the same
+		 * lifetime as the validity of the ocsp status or crl lifetime
+		 */
+		if (strict && nextUpdate < *until)
+		    *until = nextUpdate;
+		break;
+	    case CERT_REVOKED:
+		plog("certificate was revoked on %s, reason: %s"
+		    , timetoa(&revocationDate, TRUE)
+		    , enum_name(&crl_reason_names, revocationReason));
+		remove_x509_public_key(cert);
+		return FALSE;
+	    case CERT_UNKNOWN:
+	    case CERT_UNDEFINED:
+	    default:
+		plog("certificate status unknown");
+		if (strict)
+		{
+		    remove_x509_public_key(cert);
+		    return FALSE;
+		}
+		break;
+	    }
+	}
+
+	/* go up one step in the trust chain */
+	cert = issuer_cert;
+    }
+    plog("maximum ca path length of %d levels exceeded", MAX_CA_PATH_LEN);
+    return FALSE;
+}
+
+/*
+ *  list all X.509 certs in a chained list
+ */
+void
+list_x509cert_chain(const char *caption, x509cert_t* cert, u_char auth_flags
+ , bool utc)
+{
+    bool first = TRUE;
+    time_t now;
+
+    /* determine the current time */
+    time(&now);
+
+    while (cert != NULL)
+    {
+	if (auth_flags == AUTH_NONE || (auth_flags & cert->authority_flags))
+	{
+	    unsigned keysize;
+	    char keyid[KEYID_BUF];
+	    u_char buf[BUF_LEN];
+	    cert_t c;
+
+	    c.type = CERT_X509_SIGNATURE;
+	    c.u.x509 = cert;
+
+	    if (first)
+	    {
+		whack_log(RC_COMMENT, " ");
+		whack_log(RC_COMMENT, "List of X.509 %s Certificates:", caption);
+		whack_log(RC_COMMENT, " ");
+		first = FALSE;
+	    }
+
+	    whack_log(RC_COMMENT, "%s, count: %d", timetoa(&cert->installed, utc),
+		cert->count);
+	    dntoa(buf, BUF_LEN, cert->subject);
+	    whack_log(RC_COMMENT, "       subject:  '%s'", buf);
+	    dntoa(buf, BUF_LEN, cert->issuer);
+	    whack_log(RC_COMMENT, "       issuer:   '%s'", buf);
+	    datatot(cert->serialNumber.ptr, cert->serialNumber.len, ':'
+		, buf, BUF_LEN);
+	    whack_log(RC_COMMENT, "       serial:    %s", buf);
+	    form_keyid(cert->publicExponent, cert->modulus, keyid, &keysize);
+	    whack_log(RC_COMMENT, "       pubkey:    %4d RSA Key %s%s"
+		, 8*keysize, keyid
+		, cert->smartcard ? ", on smartcard" :
+		(has_private_key(c)? ", has private key" : ""));
+	    whack_log(RC_COMMENT, "       validity:  not before %s %s",
+		timetoa(&cert->notBefore, utc),
+		(cert->notBefore < now)?"ok":"fatal (not valid yet)");
+	    whack_log(RC_COMMENT, "                  not after  %s %s",
+		timetoa(&cert->notAfter, utc),
+		check_expiry(cert->notAfter, CA_CERT_WARNING_INTERVAL, TRUE));
+	    if (cert->subjectKeyID.ptr != NULL)
+	    {
+		datatot(cert->subjectKeyID.ptr, cert->subjectKeyID.len, ':'
+		    , buf, BUF_LEN);
+		whack_log(RC_COMMENT, "       subjkey:   %s", buf);
+	    }
+	    if (cert->authKeyID.ptr != NULL)
+	    {
+		datatot(cert->authKeyID.ptr, cert->authKeyID.len, ':'
+		    , buf, BUF_LEN);
+		whack_log(RC_COMMENT, "       authkey:   %s", buf);
+	    }
+	    if (cert->authKeySerialNumber.ptr != NULL)
+	    {
+		datatot(cert->authKeySerialNumber.ptr, cert->authKeySerialNumber.len
+		    , ':', buf, BUF_LEN);
+		whack_log(RC_COMMENT, "       aserial:   %s", buf);
+	    }
+	}
+	cert = cert->next;
+    }
+}
+
+/*
+ *  list all X.509 end certificates in a chained list
+ */
+void
+list_x509_end_certs(bool utc)
+{
+    list_x509cert_chain("End", x509certs, AUTH_NONE, utc);
+}