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Diffstat (limited to 'src/libstrongswan/crypto/crl.c')
-rwxr-xr-x | src/libstrongswan/crypto/crl.c | 470 |
1 files changed, 470 insertions, 0 deletions
diff --git a/src/libstrongswan/crypto/crl.c b/src/libstrongswan/crypto/crl.c new file mode 100755 index 000000000..644fb2cd2 --- /dev/null +++ b/src/libstrongswan/crypto/crl.c @@ -0,0 +1,470 @@ +/** + * @file crl.c + * + * @brief Implementation of crl_t. + * + */ + +/* + * Copyright (C) 2006 Andreas Steffen + * Hochschule fuer Technik Rapperswil + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#include <sys/stat.h> +#include <unistd.h> +#include <string.h> + +#include <types.h> +#include <definitions.h> +#include <asn1/oid.h> +#include <asn1/asn1.h> +#include <asn1/pem.h> +#include <utils/logger_manager.h> +#include <utils/linked_list.h> +#include <utils/identification.h> + +#include "crl.h" +#include "x509.h" + +#define CRL_WARNING_INTERVAL 7 /* days */ + +static logger_t *logger; + +/* access structure for a revoked certificate */ + +typedef struct revokedCert_t revokedCert_t; + +struct revokedCert_t { + chunk_t userCertificate; + time_t revocationDate; + crl_reason_t revocationReason; +}; + +typedef struct private_crl_t private_crl_t; + +/** + * Private data of a crl_t object. + */ +struct private_crl_t { + /** + * Public interface for this crl. + */ + crl_t public; + + /** + * Time when crl was installed + */ + time_t installed; + + /** + * List of crlDistributionPoints + */ + linked_list_t *crlDistributionPoints; + + /** + * X.509 crl in DER format + */ + chunk_t certificateList; + + /** + * X.509 crl body over which signature is computed + */ + chunk_t tbsCertList; + + /** + * Version of the X.509 crl + */ + u_int version; + + /** + * Signature algorithm + */ + int sigAlg; + + /** + * ID representing the crl issuer + */ + identification_t *issuer; + + /** + * Time when the crl was generated + */ + time_t thisUpdate; + + /** + * Time when an update crl will be available + */ + time_t nextUpdate; + + /** + * List of identification_t's representing subjectAltNames + */ + linked_list_t *revokedCertificates; + + /** + * Authority Key Identifier + */ + chunk_t authKeyID; + + /** + * Authority Key Serial Number + */ + chunk_t authKeySerialNumber; + + /** + * Signature algorithm (must be identical to sigAlg) + */ + int algorithm; + + /** + * Signature + */ + chunk_t signature; +}; + +/* ASN.1 definition of an X.509 certificate revocation list */ + +static const asn1Object_t crlObjects[] = { + { 0, "certificateList", ASN1_SEQUENCE, ASN1_OBJ }, /* 0 */ + { 1, "tbsCertList", ASN1_SEQUENCE, ASN1_OBJ }, /* 1 */ + { 2, "version", ASN1_INTEGER, ASN1_OPT | + ASN1_BODY }, /* 2 */ + { 2, "end opt", ASN1_EOC, ASN1_END }, /* 3 */ + { 2, "signature", ASN1_EOC, ASN1_RAW }, /* 4 */ + { 2, "issuer", ASN1_SEQUENCE, ASN1_OBJ }, /* 5 */ + { 2, "thisUpdate", ASN1_EOC, ASN1_RAW }, /* 6 */ + { 2, "nextUpdate", ASN1_EOC, ASN1_RAW }, /* 7 */ + { 2, "revokedCertificates", ASN1_SEQUENCE, ASN1_OPT | + ASN1_LOOP }, /* 8 */ + { 3, "certList", ASN1_SEQUENCE, ASN1_NONE }, /* 9 */ + { 4, "userCertificate", ASN1_INTEGER, ASN1_BODY }, /* 10 */ + { 4, "revocationDate", ASN1_EOC, ASN1_RAW }, /* 11 */ + { 4, "crlEntryExtensions", ASN1_SEQUENCE, ASN1_OPT | + ASN1_LOOP }, /* 12 */ + { 5, "extension", ASN1_SEQUENCE, ASN1_NONE }, /* 13 */ + { 6, "extnID", ASN1_OID, ASN1_BODY }, /* 14 */ + { 6, "critical", ASN1_BOOLEAN, ASN1_DEF | + ASN1_BODY }, /* 15 */ + { 6, "extnValue", ASN1_OCTET_STRING, ASN1_BODY }, /* 16 */ + { 4, "end opt or loop", ASN1_EOC, ASN1_END }, /* 17 */ + { 2, "end opt or loop", ASN1_EOC, ASN1_END }, /* 18 */ + { 2, "optional extensions", ASN1_CONTEXT_C_0, ASN1_OPT }, /* 19 */ + { 3, "crlExtensions", ASN1_SEQUENCE, ASN1_LOOP }, /* 20 */ + { 4, "extension", ASN1_SEQUENCE, ASN1_NONE }, /* 21 */ + { 5, "extnID", ASN1_OID, ASN1_BODY }, /* 22 */ + { 5, "critical", ASN1_BOOLEAN, ASN1_DEF | + ASN1_BODY }, /* 23 */ + { 5, "extnValue", ASN1_OCTET_STRING, ASN1_BODY }, /* 24 */ + { 3, "end loop", ASN1_EOC, ASN1_END }, /* 25 */ + { 2, "end opt", ASN1_EOC, ASN1_END }, /* 26 */ + { 1, "signatureAlgorithm", ASN1_EOC, ASN1_RAW }, /* 27 */ + { 1, "signatureValue", ASN1_BIT_STRING, ASN1_BODY } /* 28 */ + }; + +#define CRL_OBJ_CERTIFICATE_LIST 0 +#define CRL_OBJ_TBS_CERT_LIST 1 +#define CRL_OBJ_VERSION 2 +#define CRL_OBJ_SIG_ALG 4 +#define CRL_OBJ_ISSUER 5 +#define CRL_OBJ_THIS_UPDATE 6 +#define CRL_OBJ_NEXT_UPDATE 7 +#define CRL_OBJ_USER_CERTIFICATE 10 +#define CRL_OBJ_REVOCATION_DATE 11 +#define CRL_OBJ_CRL_ENTRY_EXTN_ID 14 +#define CRL_OBJ_CRL_ENTRY_CRITICAL 15 +#define CRL_OBJ_CRL_ENTRY_EXTN_VALUE 16 +#define CRL_OBJ_EXTN_ID 22 +#define CRL_OBJ_CRITICAL 23 +#define CRL_OBJ_EXTN_VALUE 24 +#define CRL_OBJ_ALGORITHM 27 +#define CRL_OBJ_SIGNATURE 28 +#define CRL_OBJ_ROOF 29 + +/** + * Parses a CRL revocation reason code + */ +static crl_reason_t parse_crl_reasonCode(chunk_t object) +{ + crl_reason_t reason = REASON_UNSPECIFIED; + + if (*object.ptr == ASN1_ENUMERATED && asn1_length(&object) == 1) + { + reason = *object.ptr; + } + /* TODO logger->log(logger, CONTROL|LEVEL2, " '%s'", enum_name(&crl_reason_names, reason)) */ + return reason; +} + +/** + * Parses an X.509 Certificate Revocation List (CRL) + */ +bool parse_x509crl(chunk_t blob, u_int level0, private_crl_t *crl) +{ + u_char buf[BUF_LEN]; + asn1_ctx_t ctx; + bool critical; + chunk_t extnID; + chunk_t userCertificate; + revokedCert_t *revokedCert; + chunk_t object; + u_int level; + int objectID = 0; + + asn1_init(&ctx, blob, level0, FALSE); + + while (objectID < CRL_OBJ_ROOF) + { + if (!extract_object(crlObjects, &objectID, &object, &level, &ctx)) + return FALSE; + + /* those objects which will parsed further need the next higher level */ + level++; + + switch (objectID) + { + case CRL_OBJ_CERTIFICATE_LIST: + crl->certificateList = object; + break; + case CRL_OBJ_TBS_CERT_LIST: + crl->tbsCertList = object; + break; + case CRL_OBJ_VERSION: + crl->version = (object.len) ? (1+(u_int)*object.ptr) : 1; + logger->log(logger, CONTROL|LEVEL2, " v%d", crl->version); + break; + case CRL_OBJ_SIG_ALG: + crl->sigAlg = parse_algorithmIdentifier(object, level, NULL); + break; + case CRL_OBJ_ISSUER: + crl->issuer = identification_create_from_encoding(ID_DER_ASN1_DN, object); + logger->log(logger, CONTROL|LEVEL1, " '%s'", crl->issuer->get_string(crl->issuer)); + break; + case CRL_OBJ_THIS_UPDATE: + crl->thisUpdate = parse_time(object, level); + break; + case CRL_OBJ_NEXT_UPDATE: + crl->nextUpdate = parse_time(object, level); + break; + case CRL_OBJ_USER_CERTIFICATE: + userCertificate = object; + break; + case CRL_OBJ_REVOCATION_DATE: + revokedCert = malloc_thing(revokedCert_t); + revokedCert->userCertificate = userCertificate; + revokedCert->revocationDate = parse_time(object, level); + revokedCert->revocationReason = REASON_UNSPECIFIED; + crl->revokedCertificates->insert_last(crl->revokedCertificates, (void *)revokedCert); + break; + case CRL_OBJ_CRL_ENTRY_EXTN_ID: + case CRL_OBJ_EXTN_ID: + extnID = object; + break; + case CRL_OBJ_CRL_ENTRY_CRITICAL: + case CRL_OBJ_CRITICAL: + critical = object.len && *object.ptr; + logger->log(logger, CONTROL|LEVEL2, " %s",(critical)?"TRUE":"FALSE"); + break; + case CRL_OBJ_CRL_ENTRY_EXTN_VALUE: + case CRL_OBJ_EXTN_VALUE: + { + int extn_oid = known_oid(extnID); + + if (extn_oid == OID_CRL_REASON_CODE) + { + revokedCert->revocationReason = parse_crl_reasonCode(object); + } + else if (extn_oid == OID_AUTHORITY_KEY_ID) + { + parse_authorityKeyIdentifier(object, level, &crl->authKeyID, &crl->authKeySerialNumber); + } + } + break; + case CRL_OBJ_ALGORITHM: + crl->algorithm = parse_algorithmIdentifier(object, level, NULL); + break; + case CRL_OBJ_SIGNATURE: + crl->signature = object; + break; + default: + break; + } + objectID++; + } + time(&crl->installed); + return TRUE; +} + +/** + * Implements crl_t.is_valid + */ +static err_t is_valid(const private_crl_t *this, time_t *until, bool strict) +{ + char buf[TIMETOA_BUF]; + + time_t current_time = time(NULL); + + timetoa(buf, BUF_LEN, &this->thisUpdate, TRUE); + logger->log(logger, CONTROL|LEVEL1, " this update : %s", buf); + timetoa(buf, BUF_LEN, ¤t_time, TRUE); + logger->log(logger, CONTROL|LEVEL1, " current time: %s", buf); + timetoa(buf, BUF_LEN, &this->nextUpdate, TRUE); + logger->log(logger, CONTROL|LEVEL1, " next update: %s", buf); + + if (strict && until != NULL + && (*until == UNDEFINED_TIME || this->nextUpdate < *until)) + { + *until = this->nextUpdate; + } + if (current_time > this->nextUpdate) + return "has expired"; + logger->log(logger, CONTROL|LEVEL1, " crl is valid", buf); + return NULL; +} + +/** + * Implements crl_t.get_issuer + */ +static identification_t *get_issuer(const private_crl_t *this) +{ + return this->issuer; +} + +/** + * Implements crl_t.equals_issuer + */ +static bool equals_issuer(const private_crl_t *this, const private_crl_t *other) +{ + return (this->authKeyID.ptr) + ? chunk_equals(this->authKeyID, other->authKeyID) + : (this->issuer->equals(this->issuer, other->issuer) + && chunk_equals_or_null(this->authKeySerialNumber, other->authKeySerialNumber)); +} + +/** + * destroy + */ +static void destroy(private_crl_t *this) +{ + revokedCert_t *revokedCert; + identification_t *id; + + while (this->revokedCertificates->remove_last(this->revokedCertificates, (void**)&revokedCert) == SUCCESS) + { + free(revokedCert); + } + this->revokedCertificates->destroy(this->revokedCertificates); + + while (this->crlDistributionPoints->remove_last(this->crlDistributionPoints, (void**)&id) == SUCCESS) + { + id->destroy(id); + } + this->crlDistributionPoints->destroy(this->crlDistributionPoints); + + if (this->issuer) + this->issuer->destroy(this->issuer); + + free(this->certificateList.ptr); + free(this); +} + +/** + * log crl + */ +static void log_crl(const private_crl_t *this, logger_t *logger, bool utc, bool strict) +{ + identification_t *issuer = this->issuer; + linked_list_t *crlDistributionPoints = this->crlDistributionPoints; + linked_list_t *revokedCertificates = this->revokedCertificates; + + char buf[BUF_LEN]; + + /* determine the current time */ + time_t now = time(NULL); + + timetoa(buf, BUF_LEN, &this->installed, utc); + logger->log(logger, CONTROL, "%s, revoked certs: %d", + buf, revokedCertificates->get_count(revokedCertificates)); + + logger->log(logger, CONTROL, " issuer: '%s'", issuer->get_string(issuer)); + + timetoa(buf, BUF_LEN, &this->thisUpdate, utc); + logger->log(logger, CONTROL, " updates: this %s", buf); + + timetoa(buf, BUF_LEN, &this->nextUpdate, utc); + logger->log(logger, CONTROL, " next %s %s", buf, + check_expiry(this->nextUpdate, CRL_WARNING_INTERVAL, strict)); + + if (this->authKeyID.ptr != NULL) + { + chunk_to_hex(buf, BUF_LEN, this->authKeyID); + logger->log(logger, CONTROL, " authkey: %s", buf); + } + if (this->authKeySerialNumber.ptr != NULL) + { + chunk_to_hex(buf, BUF_LEN, this->authKeySerialNumber); + logger->log(logger, CONTROL, " aserial: %s", buf); + } +} + +/* + * Described in header. + */ +crl_t *crl_create_from_chunk(chunk_t chunk) +{ + private_crl_t *this = malloc_thing(private_crl_t); + + /* initialize */ + this->crlDistributionPoints = linked_list_create(); + this->tbsCertList = CHUNK_INITIALIZER; + this->issuer = NULL; + this->revokedCertificates = linked_list_create(); + this->authKeyID = CHUNK_INITIALIZER; + this->authKeySerialNumber = CHUNK_INITIALIZER; + + /* public functions */ + this->public.is_valid = (err_t (*) (const crl_t*,time_t*))is_valid; + this->public.destroy = (void (*) (crl_t*))destroy; + this->public.get_issuer = (identification_t* (*) (const crl_t*))get_issuer; + this->public.equals_issuer = (bool (*) (const crl_t*, const crl_t*))equals_issuer; + this->public.log_crl = (void (*) (const crl_t*,logger_t*,bool,bool))log_crl; + + /* we do not use a per-instance logger right now, since its not always accessible */ + logger = logger_manager->get_logger(logger_manager, ASN1); + + if (!parse_x509crl(chunk, 0, this)) + { + destroy(this); + return NULL; + } + + return &this->public; +} + +/* + * Described in header. + */ +crl_t *crl_create_from_file(const char *filename) +{ + bool pgp = FALSE; + chunk_t chunk = CHUNK_INITIALIZER; + crl_t *crl = NULL; + + if (!pem_asn1_load_file(filename, "", "crl", &chunk, &pgp)) + return NULL; + + crl = crl_create_from_chunk(chunk); + + if (crl == NULL) + free(chunk.ptr); + return crl; +} |