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strongswan/src/pluto/x509.c

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/* 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);
}
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