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ipxe/src/crypto/x509.c

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/*
* Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
*
* 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 any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <ipxe/list.h>
#include <ipxe/base16.h>
#include <ipxe/asn1.h>
#include <ipxe/crypto.h>
#include <ipxe/md5.h>
#include <ipxe/sha1.h>
#include <ipxe/sha256.h>
#include <ipxe/rsa.h>
#include <ipxe/rootcert.h>
#include <ipxe/certstore.h>
#include <ipxe/socket.h>
#include <ipxe/in.h>
#include <ipxe/image.h>
#include <ipxe/x509.h>
#include <config/crypto.h>
/** @file
*
* X.509 certificates
*
* The structure of X.509v3 certificates is documented in RFC 5280
* section 4.1.
*/
/* Disambiguate the various error causes */
#define ENOTSUP_ALGORITHM \
__einfo_error ( EINFO_ENOTSUP_ALGORITHM )
#define EINFO_ENOTSUP_ALGORITHM \
__einfo_uniqify ( EINFO_ENOTSUP, 0x01, "Unsupported algorithm" )
#define ENOTSUP_EXTENSION \
__einfo_error ( EINFO_ENOTSUP_EXTENSION )
#define EINFO_ENOTSUP_EXTENSION \
__einfo_uniqify ( EINFO_ENOTSUP, 0x02, "Unsupported extension" )
#define EINVAL_ALGORITHM \
__einfo_error ( EINFO_EINVAL_ALGORITHM )
#define EINFO_EINVAL_ALGORITHM \
__einfo_uniqify ( EINFO_EINVAL, 0x01, "Invalid algorithm type" )
#define EINVAL_ALGORITHM_MISMATCH \
__einfo_error ( EINFO_EINVAL_ALGORITHM_MISMATCH )
#define EINFO_EINVAL_ALGORITHM_MISMATCH \
__einfo_uniqify ( EINFO_EINVAL, 0x04, "Signature algorithm mismatch" )
#define EINVAL_PATH_LEN \
__einfo_error ( EINFO_EINVAL_PATH_LEN )
#define EINFO_EINVAL_PATH_LEN \
__einfo_uniqify ( EINFO_EINVAL, 0x05, "Invalid pathLenConstraint" )
#define EINVAL_VERSION \
__einfo_error ( EINFO_EINVAL_VERSION )
#define EINFO_EINVAL_VERSION \
__einfo_uniqify ( EINFO_EINVAL, 0x06, "Invalid version" )
#define EACCES_WRONG_ISSUER \
__einfo_error ( EINFO_EACCES_WRONG_ISSUER )
#define EINFO_EACCES_WRONG_ISSUER \
__einfo_uniqify ( EINFO_EACCES, 0x01, "Wrong issuer" )
#define EACCES_NOT_CA \
__einfo_error ( EINFO_EACCES_NOT_CA )
#define EINFO_EACCES_NOT_CA \
__einfo_uniqify ( EINFO_EACCES, 0x02, "Not a CA certificate" )
#define EACCES_KEY_USAGE \
__einfo_error ( EINFO_EACCES_KEY_USAGE )
#define EINFO_EACCES_KEY_USAGE \
__einfo_uniqify ( EINFO_EACCES, 0x03, "Incorrect key usage" )
#define EACCES_EXPIRED \
__einfo_error ( EINFO_EACCES_EXPIRED )
#define EINFO_EACCES_EXPIRED \
__einfo_uniqify ( EINFO_EACCES, 0x04, "Expired (or not yet valid)" )
#define EACCES_PATH_LEN \
__einfo_error ( EINFO_EACCES_PATH_LEN )
#define EINFO_EACCES_PATH_LEN \
__einfo_uniqify ( EINFO_EACCES, 0x05, "Maximum path length exceeded" )
#define EACCES_UNTRUSTED \
__einfo_error ( EINFO_EACCES_UNTRUSTED )
#define EINFO_EACCES_UNTRUSTED \
__einfo_uniqify ( EINFO_EACCES, 0x06, "Untrusted root certificate" )
#define EACCES_OUT_OF_ORDER \
__einfo_error ( EINFO_EACCES_OUT_OF_ORDER )
#define EINFO_EACCES_OUT_OF_ORDER \
__einfo_uniqify ( EINFO_EACCES, 0x07, "Validation out of order" )
#define EACCES_EMPTY \
__einfo_error ( EINFO_EACCES_EMPTY )
#define EINFO_EACCES_EMPTY \
__einfo_uniqify ( EINFO_EACCES, 0x08, "Empty certificate chain" )
#define EACCES_OCSP_REQUIRED \
__einfo_error ( EINFO_EACCES_OCSP_REQUIRED )
#define EINFO_EACCES_OCSP_REQUIRED \
__einfo_uniqify ( EINFO_EACCES, 0x09, "OCSP check required" )
#define EACCES_WRONG_NAME \
__einfo_error ( EINFO_EACCES_WRONG_NAME )
#define EINFO_EACCES_WRONG_NAME \
__einfo_uniqify ( EINFO_EACCES, 0x0a, "Incorrect certificate name" )
#define EACCES_USELESS \
__einfo_error ( EINFO_EACCES_USELESS )
#define EINFO_EACCES_USELESS \
__einfo_uniqify ( EINFO_EACCES, 0x0b, "No usable certificates" )
/**
* Get X.509 certificate display name
*
* @v cert X.509 certificate
* @ret name Display name
*/
const char * x509_name ( struct x509_certificate *cert ) {
struct asn1_cursor *common_name = &cert->subject.common_name;
struct digest_algorithm *digest = &sha1_algorithm;
static char buf[64];
uint8_t fingerprint[ digest->digestsize ];
size_t len;
len = common_name->len;
if ( len ) {
/* Certificate has a commonName: use that */
if ( len > ( sizeof ( buf ) - 1 /* NUL */ ) )
len = ( sizeof ( buf ) - 1 /* NUL */ );
memcpy ( buf, common_name->data, len );
buf[len] = '\0';
} else {
/* Certificate has no commonName: use SHA-1 fingerprint */
x509_fingerprint ( cert, digest, fingerprint );
base16_encode ( fingerprint, sizeof ( fingerprint ),
buf, sizeof ( buf ) );
}
return buf;
}
/** "commonName" object identifier */
static uint8_t oid_common_name[] = { ASN1_OID_COMMON_NAME };
/** "commonName" object identifier cursor */
static struct asn1_cursor oid_common_name_cursor =
ASN1_OID_CURSOR ( oid_common_name );
/**
* Parse X.509 certificate version
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_version ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct asn1_cursor cursor;
int version;
int rc;
/* Enter version */
memcpy ( &cursor, raw, sizeof ( cursor ) );
asn1_enter ( &cursor, ASN1_EXPLICIT_TAG ( 0 ) );
/* Parse integer */
if ( ( rc = asn1_integer ( &cursor, &version ) ) != 0 ) {
DBGC ( cert, "X509 %p cannot parse version: %s\n",
cert, strerror ( rc ) );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return rc;
}
/* Sanity check */
if ( version < 0 ) {
DBGC ( cert, "X509 %p invalid version %d\n", cert, version );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return -EINVAL_VERSION;
}
/* Record version */
cert->version = version;
DBGC2 ( cert, "X509 %p is a version %d certificate\n",
cert, ( cert->version + 1 ) );
return 0;
}
/**
* Parse X.509 certificate serial number
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_serial ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct x509_serial *serial = &cert->serial;
int rc;
/* Record raw serial number */
memcpy ( &serial->raw, raw, sizeof ( serial->raw ) );
if ( ( rc = asn1_shrink ( &serial->raw, ASN1_INTEGER ) ) != 0 ) {
DBGC ( cert, "X509 %p cannot shrink serialNumber: %s\n",
cert, strerror ( rc ) );
return rc;
}
DBGC2 ( cert, "X509 %p issuer is:\n", cert );
DBGC2_HDA ( cert, 0, serial->raw.data, serial->raw.len );
return 0;
}
/**
* Parse X.509 certificate issuer
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_issuer ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct x509_issuer *issuer = &cert->issuer;
int rc;
/* Record raw issuer */
memcpy ( &issuer->raw, raw, sizeof ( issuer->raw ) );
if ( ( rc = asn1_shrink ( &issuer->raw, ASN1_SEQUENCE ) ) != 0 ) {
DBGC ( cert, "X509 %p cannot shrink issuer: %s\n",
cert, strerror ( rc ) );
return rc;
}
DBGC2 ( cert, "X509 %p issuer is:\n", cert );
DBGC2_HDA ( cert, 0, issuer->raw.data, issuer->raw.len );
return 0;
}
/**
* Parse X.509 certificate validity
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_validity ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct x509_validity *validity = &cert->validity;
struct x509_time *not_before = &validity->not_before;
struct x509_time *not_after = &validity->not_after;
struct asn1_cursor cursor;
int rc;
/* Enter validity */
memcpy ( &cursor, raw, sizeof ( cursor ) );
asn1_enter ( &cursor, ASN1_SEQUENCE );
/* Parse notBefore */
if ( ( rc = asn1_generalized_time ( &cursor,
&not_before->time ) ) != 0 ) {
DBGC ( cert, "X509 %p cannot parse notBefore: %s\n",
cert, strerror ( rc ) );
return rc;
}
DBGC2 ( cert, "X509 %p valid from time %lld\n",
cert, not_before->time );
asn1_skip_any ( &cursor );
/* Parse notAfter */
if ( ( rc = asn1_generalized_time ( &cursor,
&not_after->time ) ) != 0 ) {
DBGC ( cert, "X509 %p cannot parse notAfter: %s\n",
cert, strerror ( rc ) );
return rc;
}
DBGC2 ( cert, "X509 %p valid until time %lld\n",
cert, not_after->time );
return 0;
}
/**
* Parse X.509 certificate common name
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_common_name ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct asn1_cursor cursor;
struct asn1_cursor oid_cursor;
struct asn1_cursor name_cursor;
int rc;
/* Enter name */
memcpy ( &cursor, raw, sizeof ( cursor ) );
asn1_enter ( &cursor, ASN1_SEQUENCE );
/* Scan through name list */
for ( ; cursor.len ; asn1_skip_any ( &cursor ) ) {
/* Check for "commonName" OID */
memcpy ( &oid_cursor, &cursor, sizeof ( oid_cursor ) );
asn1_enter ( &oid_cursor, ASN1_SET );
asn1_enter ( &oid_cursor, ASN1_SEQUENCE );
memcpy ( &name_cursor, &oid_cursor, sizeof ( name_cursor ) );
asn1_enter ( &oid_cursor, ASN1_OID );
if ( asn1_compare ( &oid_common_name_cursor, &oid_cursor ) != 0)
continue;
asn1_skip_any ( &name_cursor );
if ( ( rc = asn1_enter_any ( &name_cursor ) ) != 0 ) {
DBGC ( cert, "X509 %p cannot locate name:\n", cert );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return rc;
}
/* Record common name */
memcpy ( &cert->subject.common_name, &name_cursor,
sizeof ( cert->subject.common_name ) );
return 0;
}
/* Certificates may not have a commonName */
DBGC2 ( cert, "X509 %p no commonName found:\n", cert );
return 0;
}
/**
* Parse X.509 certificate subject
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_subject ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct x509_subject *subject = &cert->subject;
int rc;
/* Record raw subject */
memcpy ( &subject->raw, raw, sizeof ( subject->raw ) );
asn1_shrink_any ( &subject->raw );
DBGC2 ( cert, "X509 %p subject is:\n", cert );
DBGC2_HDA ( cert, 0, subject->raw.data, subject->raw.len );
/* Parse common name */
if ( ( rc = x509_parse_common_name ( cert, raw ) ) != 0 )
return rc;
DBGC2 ( cert, "X509 %p common name is \"%s\":\n", cert,
x509_name ( cert ) );
return 0;
}
/**
* Parse X.509 certificate public key information
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_public_key ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct x509_public_key *public_key = &cert->subject.public_key;
struct asn1_algorithm **algorithm = &public_key->algorithm;
struct asn1_bit_string *raw_bits = &public_key->raw_bits;
struct asn1_cursor cursor;
int rc;
/* Record raw subjectPublicKeyInfo */
memcpy ( &cursor, raw, sizeof ( cursor ) );
asn1_shrink_any ( &cursor );
memcpy ( &public_key->raw, &cursor, sizeof ( public_key->raw ) );
DBGC2 ( cert, "X509 %p public key is:\n", cert );
DBGC2_HDA ( cert, 0, public_key->raw.data, public_key->raw.len );
/* Enter subjectPublicKeyInfo */
asn1_enter ( &cursor, ASN1_SEQUENCE );
/* Parse algorithm */
if ( ( rc = asn1_pubkey_algorithm ( &cursor, algorithm ) ) != 0 ) {
DBGC ( cert, "X509 %p could not parse public key algorithm: "
"%s\n", cert, strerror ( rc ) );
return rc;
}
DBGC2 ( cert, "X509 %p public key algorithm is %s\n",
cert, (*algorithm)->name );
asn1_skip_any ( &cursor );
/* Parse bit string */
if ( ( rc = asn1_bit_string ( &cursor, raw_bits ) ) != 0 ) {
DBGC ( cert, "X509 %p could not parse public key bits: %s\n",
cert, strerror ( rc ) );
return rc;
}
return 0;
}
/**
* Parse X.509 certificate basic constraints
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_basic_constraints ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct x509_basic_constraints *basic = &cert->extensions.basic;
struct asn1_cursor cursor;
int ca = 0;
int path_len;
int rc;
/* Enter basicConstraints */
memcpy ( &cursor, raw, sizeof ( cursor ) );
asn1_enter ( &cursor, ASN1_SEQUENCE );
/* Parse "cA", if present */
if ( asn1_type ( &cursor ) == ASN1_BOOLEAN ) {
ca = asn1_boolean ( &cursor );
if ( ca < 0 ) {
rc = ca;
DBGC ( cert, "X509 %p cannot parse cA: %s\n",
cert, strerror ( rc ) );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return rc;
}
asn1_skip_any ( &cursor );
}
basic->ca = ca;
DBGC2 ( cert, "X509 %p is %sa CA certificate\n",
cert, ( basic->ca ? "" : "not " ) );
/* Ignore everything else unless "cA" is true */
if ( ! ca )
return 0;
/* Parse "pathLenConstraint", if present and applicable */
basic->path_len = X509_PATH_LEN_UNLIMITED;
if ( asn1_type ( &cursor ) == ASN1_INTEGER ) {
if ( ( rc = asn1_integer ( &cursor, &path_len ) ) != 0 ) {
DBGC ( cert, "X509 %p cannot parse pathLenConstraint: "
"%s\n", cert, strerror ( rc ) );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return rc;
}
if ( path_len < 0 ) {
DBGC ( cert, "X509 %p invalid pathLenConstraint %d\n",
cert, path_len );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return -EINVAL;
}
basic->path_len = path_len;
DBGC2 ( cert, "X509 %p path length constraint is %d\n",
cert, basic->path_len );
}
return 0;
}
/**
* Parse X.509 certificate key usage
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_key_usage ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct x509_key_usage *usage = &cert->extensions.usage;
struct asn1_bit_string bit_string;
const uint8_t *bytes;
size_t len;
unsigned int i;
int rc;
/* Mark extension as present */
usage->present = 1;
/* Parse bit string */
if ( ( rc = asn1_bit_string ( raw, &bit_string ) ) != 0 ) {
DBGC ( cert, "X509 %p could not parse key usage: %s\n",
cert, strerror ( rc ) );
return rc;
}
/* Parse key usage bits */
bytes = bit_string.data;
len = bit_string.len;
if ( len > sizeof ( usage->bits ) )
len = sizeof ( usage->bits );
for ( i = 0 ; i < len ; i++ ) {
usage->bits |= ( *(bytes++) << ( 8 * i ) );
}
DBGC2 ( cert, "X509 %p key usage is %08x\n", cert, usage->bits );
return 0;
}
/** "id-kp-codeSigning" object identifier */
static uint8_t oid_code_signing[] = { ASN1_OID_CODESIGNING };
/** "id-kp-OCSPSigning" object identifier */
static uint8_t oid_ocsp_signing[] = { ASN1_OID_OCSPSIGNING };
/** Supported key purposes */
static struct x509_key_purpose x509_key_purposes[] = {
{
.name = "codeSigning",
.bits = X509_CODE_SIGNING,
.oid = ASN1_OID_CURSOR ( oid_code_signing ),
},
{
.name = "ocspSigning",
.bits = X509_OCSP_SIGNING,
.oid = ASN1_OID_CURSOR ( oid_ocsp_signing ),
},
};
/**
* Parse X.509 certificate key purpose identifier
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_key_purpose ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct x509_extended_key_usage *ext_usage = &cert->extensions.ext_usage;
struct x509_key_purpose *purpose;
struct asn1_cursor cursor;
unsigned int i;
int rc;
/* Enter keyPurposeId */
memcpy ( &cursor, raw, sizeof ( cursor ) );
if ( ( rc = asn1_enter ( &cursor, ASN1_OID ) ) != 0 ) {
DBGC ( cert, "X509 %p invalid keyPurposeId:\n", cert );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return rc;
}
/* Identify key purpose */
for ( i = 0 ; i < ( sizeof ( x509_key_purposes ) /
sizeof ( x509_key_purposes[0] ) ) ; i++ ) {
purpose = &x509_key_purposes[i];
if ( asn1_compare ( &cursor, &purpose->oid ) == 0 ) {
DBGC2 ( cert, "X509 %p has key purpose %s\n",
cert, purpose->name );
ext_usage->bits |= purpose->bits;
return 0;
}
}
/* Ignore unrecognised key purposes */
return 0;
}
/**
* Parse X.509 certificate extended key usage
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_extended_key_usage ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct asn1_cursor cursor;
int rc;
/* Enter extKeyUsage */
memcpy ( &cursor, raw, sizeof ( cursor ) );
asn1_enter ( &cursor, ASN1_SEQUENCE );
/* Parse each extended key usage in turn */
while ( cursor.len ) {
if ( ( rc = x509_parse_key_purpose ( cert, &cursor ) ) != 0 )
return rc;
asn1_skip_any ( &cursor );
}
return 0;
}
/**
* Parse X.509 certificate OCSP access method
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_ocsp ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct x509_ocsp_responder *ocsp = &cert->extensions.auth_info.ocsp;
struct asn1_cursor *uri = &ocsp->uri;
int rc;
/* Enter accessLocation */
memcpy ( uri, raw, sizeof ( *uri ) );
if ( ( rc = asn1_enter ( uri, X509_GENERAL_NAME_URI ) ) != 0 ) {
DBGC ( cert, "X509 %p OCSP does not contain "
"uniformResourceIdentifier:\n", cert );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return rc;
}
DBGC2 ( cert, "X509 %p OCSP URI is:\n", cert );
DBGC2_HDA ( cert, 0, uri->data, uri->len );
return 0;
}
/** "id-ad-ocsp" object identifier */
static uint8_t oid_ad_ocsp[] = { ASN1_OID_OCSP };
/** Supported access methods */
static struct x509_access_method x509_access_methods[] = {
{
.name = "OCSP",
.oid = ASN1_OID_CURSOR ( oid_ad_ocsp ),
.parse = x509_parse_ocsp,
},
};
/**
* Identify X.509 access method by OID
*
* @v oid OID
* @ret method Access method, or NULL
*/
static struct x509_access_method *
x509_find_access_method ( const struct asn1_cursor *oid ) {
struct x509_access_method *method;
unsigned int i;
for ( i = 0 ; i < ( sizeof ( x509_access_methods ) /
sizeof ( x509_access_methods[0] ) ) ; i++ ) {
method = &x509_access_methods[i];
if ( asn1_compare ( &method->oid, oid ) == 0 )
return method;
}
return NULL;
}
/**
* Parse X.509 certificate access description
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_access_description ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct asn1_cursor cursor;
struct asn1_cursor subcursor;
struct x509_access_method *method;
int rc;
/* Enter keyPurposeId */
memcpy ( &cursor, raw, sizeof ( cursor ) );
asn1_enter ( &cursor, ASN1_SEQUENCE );
/* Try to identify access method */
memcpy ( &subcursor, &cursor, sizeof ( subcursor ) );
asn1_enter ( &subcursor, ASN1_OID );
method = x509_find_access_method ( &subcursor );
asn1_skip_any ( &cursor );
DBGC2 ( cert, "X509 %p found access method %s\n",
cert, ( method ? method->name : "<unknown>" ) );
/* Parse access location, if applicable */
if ( method && ( ( rc = method->parse ( cert, &cursor ) ) != 0 ) )
return rc;
return 0;
}
/**
* Parse X.509 certificate authority information access
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_authority_info_access ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct asn1_cursor cursor;
int rc;
/* Enter authorityInfoAccess */
memcpy ( &cursor, raw, sizeof ( cursor ) );
asn1_enter ( &cursor, ASN1_SEQUENCE );
/* Parse each access description in turn */
while ( cursor.len ) {
if ( ( rc = x509_parse_access_description ( cert,
&cursor ) ) != 0 )
return rc;
asn1_skip_any ( &cursor );
}
return 0;
}
/**
* Parse X.509 certificate subject alternative name
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_subject_alt_name ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct x509_subject_alt_name *alt_name = &cert->extensions.alt_name;
struct asn1_cursor *names = &alt_name->names;
int rc;
/* Enter subjectAltName */
memcpy ( names, raw, sizeof ( *names ) );
if ( ( rc = asn1_enter ( names, ASN1_SEQUENCE ) ) != 0 ) {
DBGC ( cert, "X509 %p invalid subjectAltName: %s\n",
cert, strerror ( rc ) );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return rc;
}
DBGC2 ( cert, "X509 %p has subjectAltName:\n", cert );
DBGC2_HDA ( cert, 0, names->data, names->len );
return 0;
}
/** "id-ce-basicConstraints" object identifier */
static uint8_t oid_ce_basic_constraints[] =
{ ASN1_OID_BASICCONSTRAINTS };
/** "id-ce-keyUsage" object identifier */
static uint8_t oid_ce_key_usage[] =
{ ASN1_OID_KEYUSAGE };
/** "id-ce-extKeyUsage" object identifier */
static uint8_t oid_ce_ext_key_usage[] =
{ ASN1_OID_EXTKEYUSAGE };
/** "id-pe-authorityInfoAccess" object identifier */
static uint8_t oid_pe_authority_info_access[] =
{ ASN1_OID_AUTHORITYINFOACCESS };
/** "id-ce-subjectAltName" object identifier */
static uint8_t oid_ce_subject_alt_name[] =
{ ASN1_OID_SUBJECTALTNAME };
/** Supported certificate extensions */
static struct x509_extension x509_extensions[] = {
{
.name = "basicConstraints",
.oid = ASN1_OID_CURSOR ( oid_ce_basic_constraints ),
.parse = x509_parse_basic_constraints,
},
{
.name = "keyUsage",
.oid = ASN1_OID_CURSOR ( oid_ce_key_usage ),
.parse = x509_parse_key_usage,
},
{
.name = "extKeyUsage",
.oid = ASN1_OID_CURSOR ( oid_ce_ext_key_usage ),
.parse = x509_parse_extended_key_usage,
},
{
.name = "authorityInfoAccess",
.oid = ASN1_OID_CURSOR ( oid_pe_authority_info_access ),
.parse = x509_parse_authority_info_access,
},
{
.name = "subjectAltName",
.oid = ASN1_OID_CURSOR ( oid_ce_subject_alt_name ),
.parse = x509_parse_subject_alt_name,
},
};
/**
* Identify X.509 extension by OID
*
* @v oid OID
* @ret extension Extension, or NULL
*/
static struct x509_extension *
x509_find_extension ( const struct asn1_cursor *oid ) {
struct x509_extension *extension;
unsigned int i;
for ( i = 0 ; i < ( sizeof ( x509_extensions ) /
sizeof ( x509_extensions[0] ) ) ; i++ ) {
extension = &x509_extensions[i];
if ( asn1_compare ( &extension->oid, oid ) == 0 )
return extension;
}
return NULL;
}
/**
* Parse X.509 certificate extension
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_extension ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct asn1_cursor cursor;
struct asn1_cursor subcursor;
struct x509_extension *extension;
int is_critical = 0;
int rc;
/* Enter extension */
memcpy ( &cursor, raw, sizeof ( cursor ) );
asn1_enter ( &cursor, ASN1_SEQUENCE );
/* Try to identify extension */
memcpy ( &subcursor, &cursor, sizeof ( subcursor ) );
asn1_enter ( &subcursor, ASN1_OID );
extension = x509_find_extension ( &subcursor );
asn1_skip_any ( &cursor );
DBGC2 ( cert, "X509 %p found extension %s\n",
cert, ( extension ? extension->name : "<unknown>" ) );
/* Identify criticality */
if ( asn1_type ( &cursor ) == ASN1_BOOLEAN ) {
is_critical = asn1_boolean ( &cursor );
if ( is_critical < 0 ) {
rc = is_critical;
DBGC ( cert, "X509 %p cannot parse extension "
"criticality: %s\n", cert, strerror ( rc ) );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return rc;
}
asn1_skip_any ( &cursor );
}
/* Handle unknown extensions */
if ( ! extension ) {
if ( is_critical ) {
/* Fail if we cannot handle a critical extension */
DBGC ( cert, "X509 %p cannot handle critical "
"extension:\n", cert );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return -ENOTSUP_EXTENSION;
} else {
/* Ignore unknown non-critical extensions */
return 0;
}
};
/* Extract extnValue */
if ( ( rc = asn1_enter ( &cursor, ASN1_OCTET_STRING ) ) != 0 ) {
DBGC ( cert, "X509 %p extension missing extnValue:\n", cert );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return rc;
}
/* Parse extension */
if ( ( rc = extension->parse ( cert, &cursor ) ) != 0 )
return rc;
return 0;
}
/**
* Parse X.509 certificate extensions, if present
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_extensions ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct asn1_cursor cursor;
int rc;
/* Enter extensions, if present */
memcpy ( &cursor, raw, sizeof ( cursor ) );
asn1_enter ( &cursor, ASN1_EXPLICIT_TAG ( 3 ) );
asn1_enter ( &cursor, ASN1_SEQUENCE );
/* Parse each extension in turn */
while ( cursor.len ) {
if ( ( rc = x509_parse_extension ( cert, &cursor ) ) != 0 )
return rc;
asn1_skip_any ( &cursor );
}
return 0;
}
/**
* Parse X.509 certificate tbsCertificate
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
static int x509_parse_tbscertificate ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct asn1_algorithm **algorithm = &cert->signature_algorithm;
struct asn1_cursor cursor;
int rc;
/* Record raw tbsCertificate */
memcpy ( &cursor, raw, sizeof ( cursor ) );
asn1_shrink_any ( &cursor );
memcpy ( &cert->tbs, &cursor, sizeof ( cert->tbs ) );
/* Enter tbsCertificate */
asn1_enter ( &cursor, ASN1_SEQUENCE );
/* Parse version, if present */
if ( asn1_type ( &cursor ) == ASN1_EXPLICIT_TAG ( 0 ) ) {
if ( ( rc = x509_parse_version ( cert, &cursor ) ) != 0 )
return rc;
asn1_skip_any ( &cursor );
}
/* Parse serialNumber */
if ( ( rc = x509_parse_serial ( cert, &cursor ) ) != 0 )
return rc;
asn1_skip_any ( &cursor );
/* Parse signature */
if ( ( rc = asn1_signature_algorithm ( &cursor, algorithm ) ) != 0 ) {
DBGC ( cert, "X509 %p could not parse signature algorithm: "
"%s\n", cert, strerror ( rc ) );
return rc;
}
DBGC2 ( cert, "X509 %p tbsCertificate signature algorithm is %s\n",
cert, (*algorithm)->name );
asn1_skip_any ( &cursor );
/* Parse issuer */
if ( ( rc = x509_parse_issuer ( cert, &cursor ) ) != 0 )
return rc;
asn1_skip_any ( &cursor );
/* Parse validity */
if ( ( rc = x509_parse_validity ( cert, &cursor ) ) != 0 )
return rc;
asn1_skip_any ( &cursor );
/* Parse subject */
if ( ( rc = x509_parse_subject ( cert, &cursor ) ) != 0 )
return rc;
asn1_skip_any ( &cursor );
/* Parse subjectPublicKeyInfo */
if ( ( rc = x509_parse_public_key ( cert, &cursor ) ) != 0 )
return rc;
asn1_skip_any ( &cursor );
/* Parse extensions, if present */
if ( ( rc = x509_parse_extensions ( cert, &cursor ) ) != 0 )
return rc;
return 0;
}
/**
* Parse X.509 certificate from ASN.1 data
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @ret rc Return status code
*/
int x509_parse ( struct x509_certificate *cert,
const struct asn1_cursor *raw ) {
struct x509_signature *signature = &cert->signature;
struct asn1_algorithm **signature_algorithm = &signature->algorithm;
struct asn1_bit_string *signature_value = &signature->value;
struct asn1_cursor cursor;
int rc;
/* Record raw certificate */
memcpy ( &cursor, raw, sizeof ( cursor ) );
memcpy ( &cert->raw, &cursor, sizeof ( cert->raw ) );
/* Enter certificate */
asn1_enter ( &cursor, ASN1_SEQUENCE );
/* Parse tbsCertificate */
if ( ( rc = x509_parse_tbscertificate ( cert, &cursor ) ) != 0 )
return rc;
asn1_skip_any ( &cursor );
/* Parse signatureAlgorithm */
if ( ( rc = asn1_signature_algorithm ( &cursor,
signature_algorithm ) ) != 0 ) {
DBGC ( cert, "X509 %p could not parse signature algorithm: "
"%s\n", cert, strerror ( rc ) );
return rc;
}
DBGC2 ( cert, "X509 %p signatureAlgorithm is %s\n",
cert, (*signature_algorithm)->name );
asn1_skip_any ( &cursor );
/* Parse signatureValue */
if ( ( rc = asn1_integral_bit_string ( &cursor,
signature_value ) ) != 0 ) {
DBGC ( cert, "X509 %p could not parse signature value: %s\n",
cert, strerror ( rc ) );
return rc;
}
DBGC2 ( cert, "X509 %p signatureValue is:\n", cert );
DBGC2_HDA ( cert, 0, signature_value->data, signature_value->len );
/* Check that algorithm in tbsCertificate matches algorithm in
* signature
*/
if ( signature->algorithm != (*signature_algorithm) ) {
DBGC ( cert, "X509 %p signature algorithm %s does not match "
"signatureAlgorithm %s\n",
cert, signature->algorithm->name,
(*signature_algorithm)->name );
return -EINVAL_ALGORITHM_MISMATCH;
}
return 0;
}
/**
* Create X.509 certificate
*
* @v data Raw certificate data
* @v len Length of raw data
* @ret cert X.509 certificate
* @ret rc Return status code
*
* On success, the caller holds a reference to the X.509 certificate,
* and is responsible for ultimately calling x509_put().
*/
int x509_certificate ( const void *data, size_t len,
struct x509_certificate **cert ) {
struct asn1_cursor cursor;
void *raw;
int rc;
/* Initialise cursor */
cursor.data = data;
cursor.len = len;
asn1_shrink_any ( &cursor );
/* Return stored certificate, if present */
if ( ( *cert = certstore_find ( &cursor ) ) != NULL ) {
/* Add caller's reference */
x509_get ( *cert );
return 0;
}
/* Allocate and initialise certificate */
*cert = zalloc ( sizeof ( **cert ) + cursor.len );
if ( ! *cert )
return -ENOMEM;
ref_init ( &(*cert)->refcnt, NULL );
raw = ( *cert + 1 );
/* Copy raw data */
memcpy ( raw, cursor.data, cursor.len );
cursor.data = raw;
/* Parse certificate */
if ( ( rc = x509_parse ( *cert, &cursor ) ) != 0 ) {
x509_put ( *cert );
*cert = NULL;
return rc;
}
/* Add certificate to store */
certstore_add ( *cert );
return 0;
}
/**
* Check X.509 certificate signature
*
* @v cert X.509 certificate
* @v public_key X.509 public key
* @ret rc Return status code
*/
static int x509_check_signature ( struct x509_certificate *cert,
struct x509_public_key *public_key ) {
struct x509_signature *signature = &cert->signature;
struct asn1_algorithm *algorithm = signature->algorithm;
struct digest_algorithm *digest = algorithm->digest;
struct pubkey_algorithm *pubkey = algorithm->pubkey;
uint8_t digest_ctx[ digest->ctxsize ];
uint8_t digest_out[ digest->digestsize ];
uint8_t pubkey_ctx[ pubkey->ctxsize ];
int rc;
/* Sanity check */
assert ( cert->signature_algorithm == cert->signature.algorithm );
/* Calculate certificate digest */
digest_init ( digest, digest_ctx );
digest_update ( digest, digest_ctx, cert->tbs.data, cert->tbs.len );
digest_final ( digest, digest_ctx, digest_out );
DBGC2 ( cert, "X509 %p \"%s\" digest:\n", cert, x509_name ( cert ) );
DBGC2_HDA ( cert, 0, digest_out, sizeof ( digest_out ) );
/* Check that signature public key algorithm matches signer */
if ( public_key->algorithm->pubkey != pubkey ) {
DBGC ( cert, "X509 %p \"%s\" signature algorithm %s does not "
"match signer's algorithm %s\n",
cert, x509_name ( cert ), algorithm->name,
public_key->algorithm->name );
rc = -EINVAL_ALGORITHM_MISMATCH;
goto err_mismatch;
}
/* Verify signature using signer's public key */
if ( ( rc = pubkey_init ( pubkey, pubkey_ctx, public_key->raw.data,
public_key->raw.len ) ) != 0 ) {
DBGC ( cert, "X509 %p \"%s\" cannot initialise public key: "
"%s\n", cert, x509_name ( cert ), strerror ( rc ) );
goto err_pubkey_init;
}
if ( ( rc = pubkey_verify ( pubkey, pubkey_ctx, digest, digest_out,
signature->value.data,
signature->value.len ) ) != 0 ) {
DBGC ( cert, "X509 %p \"%s\" signature verification failed: "
"%s\n", cert, x509_name ( cert ), strerror ( rc ) );
goto err_pubkey_verify;
}
/* Success */
rc = 0;
err_pubkey_verify:
pubkey_final ( pubkey, pubkey_ctx );
err_pubkey_init:
err_mismatch:
return rc;
}
/**
* Check X.509 certificate against issuer certificate
*
* @v cert X.509 certificate
* @v issuer X.509 issuer certificate
* @ret rc Return status code
*/
int x509_check_issuer ( struct x509_certificate *cert,
struct x509_certificate *issuer ) {
struct x509_public_key *public_key = &issuer->subject.public_key;
int rc;
/* Check issuer. In theory, this should be a full X.500 DN
* comparison, which would require support for a plethora of
* abominations such as TeletexString (which allows the
* character set to be changed mid-string using escape codes).
* In practice, we assume that anyone who deliberately changes
* the encoding of the issuer DN is probably a masochist who
* will rather enjoy the process of figuring out exactly why
* their certificate doesn't work.
*
* See http://www.cs.auckland.ac.nz/~pgut001/pubs/x509guide.txt
* for some enjoyable ranting on this subject.
*/
if ( asn1_compare ( &cert->issuer.raw, &issuer->subject.raw ) != 0 ) {
DBGC ( cert, "X509 %p \"%s\" issuer does not match ",
cert, x509_name ( cert ) );
DBGC ( cert, "X509 %p \"%s\" subject\n",
issuer, x509_name ( issuer ) );
DBGC_HDA ( cert, 0, cert->issuer.raw.data,
cert->issuer.raw.len );
DBGC_HDA ( issuer, 0, issuer->subject.raw.data,
issuer->subject.raw.len );
return -EACCES_WRONG_ISSUER;
}
/* Check that issuer is allowed to sign certificates */
if ( ! issuer->extensions.basic.ca ) {
DBGC ( issuer, "X509 %p \"%s\" cannot sign ",
issuer, x509_name ( issuer ) );
DBGC ( issuer, "X509 %p \"%s\": not a CA certificate\n",
cert, x509_name ( cert ) );
return -EACCES_NOT_CA;
}
if ( issuer->extensions.usage.present &&
( ! ( issuer->extensions.usage.bits & X509_KEY_CERT_SIGN ) ) ) {
DBGC ( issuer, "X509 %p \"%s\" cannot sign ",
issuer, x509_name ( issuer ) );
DBGC ( issuer, "X509 %p \"%s\": no keyCertSign usage\n",
cert, x509_name ( cert ) );
return -EACCES_KEY_USAGE;
}
/* Check signature */
if ( ( rc = x509_check_signature ( cert, public_key ) ) != 0 )
return rc;
return 0;
}
/**
* Calculate X.509 certificate fingerprint
*
* @v cert X.509 certificate
* @v digest Digest algorithm
* @v fingerprint Fingerprint buffer
*/
void x509_fingerprint ( struct x509_certificate *cert,
struct digest_algorithm *digest,
void *fingerprint ) {
uint8_t ctx[ digest->ctxsize ];
/* Calculate fingerprint */
digest_init ( digest, ctx );
digest_update ( digest, ctx, cert->raw.data, cert->raw.len );
digest_final ( digest, ctx, fingerprint );
}
/**
* Check X.509 root certificate
*
* @v cert X.509 certificate
* @v root X.509 root certificate list
* @ret rc Return status code
*/
int x509_check_root ( struct x509_certificate *cert, struct x509_root *root ) {
struct digest_algorithm *digest = root->digest;
uint8_t fingerprint[ digest->digestsize ];
const uint8_t *root_fingerprint = root->fingerprints;
unsigned int i;
/* Calculate certificate fingerprint */
x509_fingerprint ( cert, digest, fingerprint );
/* Check fingerprint against all root certificates */
for ( i = 0 ; i < root->count ; i++ ) {
if ( memcmp ( fingerprint, root_fingerprint,
sizeof ( fingerprint ) ) == 0 ) {
DBGC ( cert, "X509 %p \"%s\" is a root certificate\n",
cert, x509_name ( cert ) );
return 0;
}
root_fingerprint += sizeof ( fingerprint );
}
DBGC2 ( cert, "X509 %p \"%s\" is not a root certificate\n",
cert, x509_name ( cert ) );
return -ENOENT;
}
/**
* Check X.509 certificate validity period
*
* @v cert X.509 certificate
* @v time Time at which to check certificate
* @ret rc Return status code
*/
int x509_check_time ( struct x509_certificate *cert, time_t time ) {
struct x509_validity *validity = &cert->validity;
/* Check validity period */
if ( validity->not_before.time > ( time + TIMESTAMP_ERROR_MARGIN ) ) {
DBGC ( cert, "X509 %p \"%s\" is not yet valid (at time %lld)\n",
cert, x509_name ( cert ), time );
return -EACCES_EXPIRED;
}
if ( validity->not_after.time < ( time - TIMESTAMP_ERROR_MARGIN ) ) {
DBGC ( cert, "X509 %p \"%s\" has expired (at time %lld)\n",
cert, x509_name ( cert ), time );
return -EACCES_EXPIRED;
}
DBGC2 ( cert, "X509 %p \"%s\" is valid (at time %lld)\n",
cert, x509_name ( cert ), time );
return 0;
}
/**
* Validate X.509 certificate
*
* @v cert X.509 certificate
* @v issuer Issuing X.509 certificate (or NULL)
* @v time Time at which to validate certificate
* @v root Root certificate list, or NULL to use default
* @ret rc Return status code
*
* The issuing certificate must have already been validated.
*
* Validation results are cached: if a certificate has already been
* successfully validated then @c issuer, @c time, and @c root will be
* ignored.
*/
int x509_validate ( struct x509_certificate *cert,
struct x509_certificate *issuer,
time_t time, struct x509_root *root ) {
unsigned int max_path_remaining;
int rc;
/* Use default root certificate store if none specified */
if ( ! root )
root = &root_certificates;
/* Return success if certificate has already been validated */
if ( x509_is_valid ( cert ) )
return 0;
/* Fail if certificate is invalid at specified time */
if ( ( rc = x509_check_time ( cert, time ) ) != 0 )
return rc;
/* Succeed if certificate is a trusted root certificate */
if ( x509_check_root ( cert, root ) == 0 ) {
cert->flags |= X509_FL_VALIDATED;
cert->path_remaining = ( cert->extensions.basic.path_len + 1 );
return 0;
}
/* Fail unless we have an issuer */
if ( ! issuer ) {
DBGC2 ( cert, "X509 %p \"%s\" has no issuer\n",
cert, x509_name ( cert ) );
return -EACCES_UNTRUSTED;
}
/* Fail unless issuer has already been validated */
if ( ! x509_is_valid ( issuer ) ) {
DBGC ( cert, "X509 %p \"%s\" ", cert, x509_name ( cert ) );
DBGC ( cert, "issuer %p \"%s\" has not yet been validated\n",
issuer, x509_name ( issuer ) );
return -EACCES_OUT_OF_ORDER;
}
/* Fail if issuing certificate cannot validate this certificate */
if ( ( rc = x509_check_issuer ( cert, issuer ) ) != 0 )
return rc;
/* Fail if path length constraint is violated */
if ( issuer->path_remaining == 0 ) {
DBGC ( cert, "X509 %p \"%s\" ", cert, x509_name ( cert ) );
DBGC ( cert, "issuer %p \"%s\" path length exceeded\n",
issuer, x509_name ( issuer ) );
return -EACCES_PATH_LEN;
}
/* Fail if OCSP is required */
if ( cert->extensions.auth_info.ocsp.uri.len &&
( ! cert->extensions.auth_info.ocsp.good ) ) {
DBGC ( cert, "X509 %p \"%s\" requires an OCSP check\n",
cert, x509_name ( cert ) );
return -EACCES_OCSP_REQUIRED;
}
/* Calculate effective path length */
cert->path_remaining = ( issuer->path_remaining - 1 );
max_path_remaining = ( cert->extensions.basic.path_len + 1 );
if ( cert->path_remaining > max_path_remaining )
cert->path_remaining = max_path_remaining;
/* Mark certificate as valid */
cert->flags |= X509_FL_VALIDATED;
DBGC ( cert, "X509 %p \"%s\" successfully validated using ",
cert, x509_name ( cert ) );
DBGC ( cert, "issuer %p \"%s\"\n", issuer, x509_name ( issuer ) );
return 0;
}
/**
* Check X.509 certificate alternative dNSName
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @v name Name
* @ret rc Return status code
*/
static int x509_check_dnsname ( struct x509_certificate *cert,
const struct asn1_cursor *raw,
const char *name ) {
const char *fullname = name;
const char *dnsname = raw->data;
size_t len = raw->len;
/* Check for wildcards */
if ( ( len >= 2 ) && ( dnsname[0] == '*' ) && ( dnsname[1] == '.' ) ) {
/* Skip initial "*." */
dnsname += 2;
len -= 2;
/* Skip initial portion of name to be tested */
name = strchr ( name, '.' );
if ( ! name )
return -ENOENT;
name++;
}
/* Compare names */
if ( ! ( ( strlen ( name ) == len ) &&
( memcmp ( name, dnsname, len ) == 0 ) ) )
return -ENOENT;
if ( name != fullname ) {
DBGC2 ( cert, "X509 %p \"%s\" found wildcard match for "
"\"*.%s\"\n", cert, x509_name ( cert ), name );
}
return 0;
}
/**
* Check X.509 certificate alternative iPAddress
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @v name Name
* @ret rc Return status code
*/
static int x509_check_ipaddress ( struct x509_certificate *cert,
const struct asn1_cursor *raw,
const char *name ) {
struct sockaddr sa;
sa_family_t family;
const void *address;
int rc;
/* Determine address family */
if ( raw->len == sizeof ( struct in_addr ) ) {
struct sockaddr_in *sin = ( ( struct sockaddr_in * ) &sa );
family = AF_INET;
address = &sin->sin_addr;
} else if ( raw->len == sizeof ( struct in6_addr ) ) {
struct sockaddr_in6 *sin6 = ( ( struct sockaddr_in6 * ) &sa );
family = AF_INET6;
address = &sin6->sin6_addr;
} else {
DBGC ( cert, "X509 %p \"%s\" has iPAddress with unexpected "
"length %zd\n", cert, x509_name ( cert ), raw->len );
DBGC_HDA ( cert, 0, raw->data, raw->len );
return -EINVAL;
}
/* Attempt to convert name to a socket address */
if ( ( rc = sock_aton ( name, &sa ) ) != 0 ) {
DBGC2 ( cert, "X509 %p \"%s\" cannot parse \"%s\" as "
"iPAddress: %s\n", cert, x509_name ( cert ), name,
strerror ( rc ) );
return rc;
}
if ( sa.sa_family != family )
return -ENOENT;
/* Compare addresses */
if ( memcmp ( address, raw->data, raw->len ) != 0 )
return -ENOENT;
DBGC2 ( cert, "X509 %p \"%s\" found iPAddress match for \"%s\"\n",
cert, x509_name ( cert ), sock_ntoa ( &sa ) );
return 0;
}
/**
* Check X.509 certificate alternative name
*
* @v cert X.509 certificate
* @v raw ASN.1 cursor
* @v name Name
* @ret rc Return status code
*/
static int x509_check_alt_name ( struct x509_certificate *cert,
const struct asn1_cursor *raw,
const char *name ) {
struct asn1_cursor alt_name;
unsigned int type;
/* Enter generalName */
memcpy ( &alt_name, raw, sizeof ( alt_name ) );
type = asn1_type ( &alt_name );
asn1_enter_any ( &alt_name );
/* Check this name */
switch ( type ) {
case X509_GENERAL_NAME_DNS :
return x509_check_dnsname ( cert, &alt_name, name );
case X509_GENERAL_NAME_IP :
return x509_check_ipaddress ( cert, &alt_name, name );
default:
DBGC2 ( cert, "X509 %p \"%s\" unknown name of type %#02x:\n",
cert, x509_name ( cert ), type );
DBGC2_HDA ( cert, 0, alt_name.data, alt_name.len );
return -ENOTSUP;
}
}
/**
* Check X.509 certificate name
*
* @v cert X.509 certificate
* @v name Name
* @ret rc Return status code
*/
int x509_check_name ( struct x509_certificate *cert, const char *name ) {
struct asn1_cursor *common_name = &cert->subject.common_name;
struct asn1_cursor alt_name;
int rc;
/* Check commonName */
if ( x509_check_dnsname ( cert, common_name, name ) == 0 ) {
DBGC2 ( cert, "X509 %p \"%s\" commonName matches \"%s\"\n",
cert, x509_name ( cert ), name );
return 0;
}
/* Check any subjectAlternativeNames */
memcpy ( &alt_name, &cert->extensions.alt_name.names,
sizeof ( alt_name ) );
for ( ; alt_name.len ; asn1_skip_any ( &alt_name ) ) {
if ( ( rc = x509_check_alt_name ( cert, &alt_name,
name ) ) == 0 ) {
DBGC2 ( cert, "X509 %p \"%s\" subjectAltName matches "
"\"%s\"\n", cert, x509_name ( cert ), name );
return 0;
}
}
DBGC ( cert, "X509 %p \"%s\" does not match name \"%s\"\n",
cert, x509_name ( cert ), name );
return -EACCES_WRONG_NAME;
}
/**
* Free X.509 certificate chain
*
* @v refcnt Reference count
*/
static void x509_free_chain ( struct refcnt *refcnt ) {
struct x509_chain *chain =
container_of ( refcnt, struct x509_chain, refcnt );
struct x509_link *link;
struct x509_link *tmp;
DBGC2 ( chain, "X509 chain %p freed\n", chain );
/* Free each link in the chain */
list_for_each_entry_safe ( link, tmp, &chain->links, list ) {
x509_put ( link->cert );
list_del ( &link->list );
free ( link );
}
/* Free chain */
free ( chain );
}
/**
* Allocate X.509 certificate chain
*
* @ret chain X.509 certificate chain, or NULL
*/
struct x509_chain * x509_alloc_chain ( void ) {
struct x509_chain *chain;
/* Allocate chain */
chain = zalloc ( sizeof ( *chain ) );
if ( ! chain )
return NULL;
/* Initialise chain */
ref_init ( &chain->refcnt, x509_free_chain );
INIT_LIST_HEAD ( &chain->links );
DBGC2 ( chain, "X509 chain %p allocated\n", chain );
return chain;
}
/**
* Append X.509 certificate to X.509 certificate chain
*
* @v chain X.509 certificate chain
* @v cert X.509 certificate
* @ret rc Return status code
*/
int x509_append ( struct x509_chain *chain, struct x509_certificate *cert ) {
struct x509_link *link;
/* Allocate link */
link = zalloc ( sizeof ( *link ) );
if ( ! link )
return -ENOMEM;
/* Add link to chain */
link->cert = x509_get ( cert );
list_add_tail ( &link->list, &chain->links );
DBGC ( chain, "X509 chain %p added X509 %p \"%s\"\n",
chain, cert, x509_name ( cert ) );
return 0;
}
/**
* Append X.509 certificate to X.509 certificate chain
*
* @v chain X.509 certificate chain
* @v data Raw certificate data
* @v len Length of raw data
* @ret rc Return status code
*/
int x509_append_raw ( struct x509_chain *chain, const void *data,
size_t len ) {
struct x509_certificate *cert;
int rc;
/* Parse certificate */
if ( ( rc = x509_certificate ( data, len, &cert ) ) != 0 )
goto err_parse;
/* Append certificate to chain */
if ( ( rc = x509_append ( chain, cert ) ) != 0 )
goto err_append;
/* Drop reference to certificate */
x509_put ( cert );
return 0;
err_append:
x509_put ( cert );
err_parse:
return rc;
}
/**
* Identify X.509 certificate by subject
*
* @v certs X.509 certificate list
* @v subject Subject
* @ret cert X.509 certificate, or NULL if not found
*/
static struct x509_certificate *
x509_find_subject ( struct x509_chain *certs,
const struct asn1_cursor *subject ) {
struct x509_link *link;
struct x509_certificate *cert;
/* Scan through certificate list */
list_for_each_entry ( link, &certs->links, list ) {
/* Check subject */
cert = link->cert;
if ( asn1_compare ( subject, &cert->subject.raw ) == 0 )
return cert;
}
return NULL;
}
/**
* Append X.509 certificates to X.509 certificate chain
*
* @v chain X.509 certificate chain
* @v certs X.509 certificate list
* @ret rc Return status code
*
* Certificates will be automatically appended to the chain based upon
* the subject and issuer names.
*/
int x509_auto_append ( struct x509_chain *chain, struct x509_chain *certs ) {
struct x509_certificate *cert;
struct x509_certificate *previous;
int rc;
/* Get current certificate */
cert = x509_last ( chain );
if ( ! cert ) {
DBGC ( chain, "X509 chain %p has no certificates\n", chain );
return -EACCES_EMPTY;
}
/* Append certificates, in order */
while ( 1 ) {
/* Find issuing certificate */
previous = cert;
cert = x509_find_subject ( certs, &cert->issuer.raw );
if ( ! cert )
break;
if ( cert == previous )
break;
/* Append certificate to chain */
if ( ( rc = x509_append ( chain, cert ) ) != 0 )
return rc;
}
return 0;
}
/**
* Validate X.509 certificate chain
*
* @v chain X.509 certificate chain
* @v time Time at which to validate certificates
* @v store Certificate store, or NULL to use default
* @v root Root certificate list, or NULL to use default
* @ret rc Return status code
*/
int x509_validate_chain ( struct x509_chain *chain, time_t time,
struct x509_chain *store, struct x509_root *root ) {
struct x509_certificate *issuer = NULL;
struct x509_link *link;
int rc;
/* Use default certificate store if none specified */
if ( ! store )
store = &certstore;
/* Append any applicable certificates from the certificate store */
if ( ( rc = x509_auto_append ( chain, store ) ) != 0 )
return rc;
/* Find first certificate that can be validated as a
* standalone (i.e. is already valid, or can be validated as
* a trusted root certificate).
*/
list_for_each_entry ( link, &chain->links, list ) {
/* Try validating this certificate as a standalone */
if ( ( rc = x509_validate ( link->cert, NULL, time,
root ) ) != 0 )
continue;
/* Work back up to start of chain, performing pairwise
* validation.
*/
issuer = link->cert;
list_for_each_entry_continue_reverse ( link, &chain->links,
list ) {
/* Validate this certificate against its issuer */
if ( ( rc = x509_validate ( link->cert, issuer, time,
root ) ) != 0 )
return rc;
issuer = link->cert;
}
return 0;
}
DBGC ( chain, "X509 chain %p found no usable certificates\n", chain );
return -EACCES_USELESS;
}
/**
* Extract X.509 certificate object from image
*
* @v image Image
* @v offset Offset within image
* @ret cert X.509 certificate
* @ret next Offset to next image, or negative error
*
* On success, the caller holds a reference to the X.509 certificate,
* and is responsible for ultimately calling x509_put().
*/
int image_x509 ( struct image *image, size_t offset,
struct x509_certificate **cert ) {
struct asn1_cursor *cursor;
int next;
int rc;
/* Get ASN.1 object */
next = image_asn1 ( image, offset, &cursor );
if ( next < 0 ) {
rc = next;
goto err_asn1;
}
/* Parse certificate */
if ( ( rc = x509_certificate ( cursor->data, cursor->len,
cert ) ) != 0 )
goto err_certificate;
/* Free ASN.1 object */
free ( cursor );
return next;
x509_put ( *cert );
err_certificate:
free ( cursor );
err_asn1:
return rc;
}
/* Drag in objects via x509_validate() */
REQUIRING_SYMBOL ( x509_validate );
/* Drag in certificate store */
REQUIRE_OBJECT ( certstore );
/* Drag in crypto configuration */
REQUIRE_OBJECT ( config_crypto );
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