diff options
Diffstat (limited to 'qemu/roms/ipxe/src/crypto/x509.c')
| -rw-r--r-- | qemu/roms/ipxe/src/crypto/x509.c | 1765 |
1 files changed, 1765 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/crypto/x509.c b/qemu/roms/ipxe/src/crypto/x509.c new file mode 100644 index 000000000..4a02dad14 --- /dev/null +++ b/qemu/roms/ipxe/src/crypto/x509.c @@ -0,0 +1,1765 @@ +/* + * 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. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#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/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 name (for debugging) + * + * @v cert X.509 certificate + * @ret name Name (for debugging) + */ +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 ); + } + 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, + ¬_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, + ¬_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 ( cert->valid ) + 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->valid = 1; + 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 ( ! issuer->valid ) { + 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->valid = 1; + + 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; +} + +/* Drag in certificate store */ +REQUIRE_OBJECT ( certstore ); |