x509.c

This a good VPN source

/* Support of X.509 certificates and CRLs
 * 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 1.23 2004/09/08 17:16:52 ken Exp $
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <dirent.h>
#include <time.h>
#include <sys/types.h>

#include <openswan.h>
#include <openswan/ipsec_policy.h>

#include <sys/queue.h>

#include "constants.h"
#include "oswlog.h"

#include "defs.h"
#include "log.h"
#include "id.h"
#include "asn1.h"
#include "oid.h"
#include "x509.h"
#include "pgp.h"
#include "certs.h"
#include "keys.h"
#include "packet.h"
#include "demux.h"	/* needs packet.h */
#include "connections.h"
#include "state.h"
#include "md2.h"
#include "md5.h"
#include "sha1.h"
#include "whack.h"
#include "fetch.h"
#include "ocsp.h"
#include "pkcs.h"
#include "x509more.h"
#include "paths.h"

/* chained lists of X.509 host/user and ca certificates and crls */

static x509cert_t *x509certs   = NULL;
static x509cert_t *x509authcerts = NULL;
static x509crl_t  *x509crls    = 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 definiton of an algorithmIdentifier */

static const asn1Object_t algorithmIdentifierObjects[] = {
  { 0, "algorithmIdentifier",		ASN1_SEQUENCE,	   ASN1_NONE }, /*  0 */
  { 1,   "algorithm",			ASN1_OID,	   ASN1_BODY }  /*  1 */
};

#define ALGORITHM_IDENTIFIER_ALG	1
#define ALGORITHM_IDENTIFIER_ROOF	2

/* 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 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_NONE }, /* 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_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


/* ASN.1 definition of an X.509 certificate list */

static const asn1Object_t crlObjects[] = {
  { 0, "certificateList",		ASN1_SEQUENCE,     ASN1_OBJ  }, /*  0 */
  { 1,   "tbsCertList",			ASN1_SEQUENCE,     ASN1_OBJ  }, /*  1 */
  { 2,     "version",			ASN1_INTEGER,      ASN1_OPT |
							   ASN1_BODY }, /*  2 */
  { 2,     "end opt",			ASN1_EOC,          ASN1_END  }, /*  3 */
  { 2,     "signature",			ASN1_EOC,          ASN1_RAW  }, /*  4 */
  { 2,     "issuer",			ASN1_SEQUENCE,     ASN1_OBJ  }, /*  5 */
  { 2,     "thisUpdate",		ASN1_EOC,          ASN1_RAW  }, /*  6 */
  { 2,     "nextUpdate",		ASN1_EOC,          ASN1_RAW  }, /*  7 */
  { 2,     "revokedCertificates",	ASN1_SEQUENCE,     ASN1_OPT |
							   ASN1_LOOP }, /*  8 */
  { 3,       "certList",		ASN1_SEQUENCE,     ASN1_NONE }, /*  9 */
  { 4,         "userCertificate",	ASN1_INTEGER,      ASN1_BODY }, /* 10 */
  { 4,         "revocationDate",	ASN1_EOC,          ASN1_RAW  }, /* 11 */
  { 4,         "crlEntryExtensions",	ASN1_SEQUENCE,     ASN1_OPT |
							   ASN1_LOOP }, /* 12 */
  { 5,           "extension",		ASN1_SEQUENCE,     ASN1_NONE }, /* 13 */
  { 6,             "extnID",		ASN1_OID,          ASN1_BODY }, /* 14 */
  { 6,             "critical",		ASN1_BOOLEAN,      ASN1_DEF |
							   ASN1_BODY }, /* 15 */
  { 6,             "extnValue",		ASN1_OCTET_STRING, ASN1_BODY }, /* 16 */
  { 4,         "end opt or loop",	ASN1_EOC,          ASN1_END  }, /* 17 */
  { 2,     "end opt or loop",		ASN1_EOC,          ASN1_END  }, /* 18 */
  { 2,     "optional extensions",	ASN1_CONTEXT_C_0,  ASN1_OPT  }, /* 19 */
  { 3,       "crlExtensions",		ASN1_SEQUENCE,     ASN1_LOOP }, /* 20 */
  { 4,         "extension",		ASN1_SEQUENCE,     ASN1_NONE }, /* 21 */
  { 5,           "extnID",		ASN1_OID,          ASN1_BODY }, /* 22 */
  { 5,           "critical",		ASN1_BOOLEAN,      ASN1_DEF |
							   ASN1_BODY }, /* 23 */
  { 5,           "extnValue",		ASN1_OCTET_STRING, ASN1_BODY }, /* 24 */
  { 3,       "end loop",		ASN1_EOC,          ASN1_END  }, /* 25 */
  { 2,     "end opt",			ASN1_EOC,          ASN1_END  }, /* 26 */
  { 1,   "signatureAlgorithm",		ASN1_EOC,          ASN1_RAW  }, /* 27 */
  { 1,   "signatureValue",		ASN1_BIT_STRING,   ASN1_BODY }  /* 28 */
 };

#define CRL_OBJ_CERTIFICATE_LIST		 0
#define CRL_OBJ_TBS_CERT_LIST			 1
#define CRL_OBJ_VERSION				 2
#define CRL_OBJ_SIG_ALG				 4
#define CRL_OBJ_ISSUER				 5
#define CRL_OBJ_THIS_UPDATE			 6
#define CRL_OBJ_NEXT_UPDATE			 7
#define CRL_OBJ_USER_CERTIFICATE		10
#define CRL_OBJ_REVOCATION_DATE			11
#define CRL_OBJ_CRL_ENTRY_CRITICAL		15
#define CRL_OBJ_EXTN_ID				22
#define CRL_OBJ_CRITICAL			23
#define CRL_OBJ_EXTN_VALUE			24
#define CRL_OBJ_ALGORITHM			27
#define CRL_OBJ_SIGNATURE			28
#define CRL_OBJ_ROOF				29


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 */
                    /*       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 */
};

const x509crl_t empty_x509crl = {
      NULL        , /* *next */
    UNDEFINED_TIME, /* installed */
      NULL        , /* distributionPoints */
    { NULL, 0 }   , /* certificateList */
    { NULL, 0 }   , /*   tbsCertList */
            1     , /*     version */
    OID_UNKNOWN   , /*     sigAlg */
    { NULL, 0 }   , /*     issuer */
    UNDEFINED_TIME, /*     thisUpdate */
    UNDEFINED_TIME, /*     nextUpdate */
      NULL        , /*     revokedCertificates */
                    /*     crlExtensions */
                    /*       extension */
                    /*         extnID */
                    /*         critical */
                    /*         extnValue */
    { NULL, 0 }   , /*           authKeyID */
    { NULL, 0 }   , /*           authKeySerialNumber */
    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_E[]   = {0x2A, 0x86, 0x48, 0x86, 0xF7,
			   0x0D, 0x01, 0x09, 0x01};
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},
  {"E"            , {oid_E,      9}, ASN1_IA5STRING},
  {"Email"        , {oid_E,      9}, ASN1_IA5STRING},
  {"emailAddress" , {oid_E,      9}, ASN1_IA5STRING},
  {"TCGID"        , {oid_TCGID, 12}, ASN1_PRINTABLESTRING}
};

#define X501_RDN_ROOF   22

/* Maximum length of ASN.1 distinquished name */

#define BUF_LEN	      512

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 ? */