/* ocsp_cl.c */
/*
 * Written by Tom Titchener <Tom_Titchener@groove.net> for the OpenSSL
 * project.
 */

/*
 * History: This file was transfered to Richard Levitte from CertCo by Kathy
 * Weinhold in mid-spring 2000 to be included in OpenSSL or released as a
 * patch kit.
 */

/* ====================================================================
 * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <stdio.h>
#include <time.h>
#include <cryptlib.h>
#include <openssl/objects.h>
#include <openssl/rand.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/x509v3.h>
#include <openssl/ocsp.h>
#include "ocsp_lcl.h"

/*
 * Utility functions related to sending OCSP requests and extracting relevant
 * information from the response.
 */

/*
 * Add an OCSP_CERTID to an OCSP request. Return new OCSP_ONEREQ pointer:
 * useful if we want to add extensions.
 */

OCSP_ONEREQ *OCSP_request_add0_id(OCSP_REQUEST *req, OCSP_CERTID *cid)
{
    OCSP_ONEREQ *one = NULL;

    if (!(one = OCSP_ONEREQ_new()))
        goto err;
    if (one->reqCert)
        OCSP_CERTID_free(one->reqCert);
    one->reqCert = cid;
    if (req && !sk_OCSP_ONEREQ_push(req->tbsRequest->requestList, one))
        goto err;
    return one;
 err:
    OCSP_ONEREQ_free(one);
    return NULL;
}

/* Set requestorName from an X509_NAME structure */

int OCSP_request_set1_name(OCSP_REQUEST *req, X509_NAME *nm)
{
    GENERAL_NAME *gen;
    gen = GENERAL_NAME_new();
    if (gen == NULL)
        return 0;
    if (!X509_NAME_set(&gen->d.directoryName, nm)) {
        GENERAL_NAME_free(gen);
        return 0;
    }
    gen->type = GEN_DIRNAME;
    if (req->tbsRequest->requestorName)
        GENERAL_NAME_free(req->tbsRequest->requestorName);
    req->tbsRequest->requestorName = gen;
    return 1;
}

/* Add a certificate to an OCSP request */

int OCSP_request_add1_cert(OCSP_REQUEST *req, X509 *cert)
{
    OCSP_SIGNATURE *sig;
    if (!req->optionalSignature)
        req->optionalSignature = OCSP_SIGNATURE_new();
    sig = req->optionalSignature;
    if (!sig)
        return 0;
    if (!cert)
        return 1;
    if (!sig->certs && !(sig->certs = sk_X509_new_null()))
        return 0;

    if (!sk_X509_push(sig->certs, cert))
        return 0;
    CRYPTO_add(&cert->references, 1, CRYPTO_LOCK_X509);
    return 1;
}

/*
 * Sign an OCSP request set the requestorName to the subjec name of an
 * optional signers certificate and include one or more optional certificates
 * in the request. Behaves like PKCS7_sign().
 */

int OCSP_request_sign(OCSP_REQUEST *req,
                      X509 *signer,
                      EVP_PKEY *key,
                      const EVP_MD *dgst,
                      STACK_OF(X509) *certs, unsigned long flags)
{
    int i;
    X509 *x;

    if (!OCSP_request_set1_name(req, X509_get_subject_name(signer)))
        goto err;

    if (!(req->optionalSignature = OCSP_SIGNATURE_new()))
        goto err;
    if (key) {
        if (!X509_check_private_key(signer, key)) {
            OCSPerr(OCSP_F_OCSP_REQUEST_SIGN,
                    OCSP_R_PRIVATE_KEY_DOES_NOT_MATCH_CERTIFICATE);
            goto err;
        }
        if (!OCSP_REQUEST_sign(req, key, dgst))
            goto err;
    }

    if (!(flags & OCSP_NOCERTS)) {
        if (!OCSP_request_add1_cert(req, signer))
            goto err;
        for (i = 0; i < sk_X509_num(certs); i++) {
            x = sk_X509_value(certs, i);
            if (!OCSP_request_add1_cert(req, x))
                goto err;
        }
    }

    return 1;
 err:
    OCSP_SIGNATURE_free(req->optionalSignature);
    req->optionalSignature = NULL;
    return 0;
}

/* Get response status */

int OCSP_response_status(OCSP_RESPONSE *resp)
{
    return ASN1_ENUMERATED_get(resp->responseStatus);
}

/*
 * Extract basic response from OCSP_RESPONSE or NULL if no basic response
 * present.
 */

OCSP_BASICRESP *OCSP_response_get1_basic(OCSP_RESPONSE *resp)
{
    OCSP_RESPBYTES *rb;
    rb = resp->responseBytes;
    if (!rb) {
        OCSPerr(OCSP_F_OCSP_RESPONSE_GET1_BASIC, OCSP_R_NO_RESPONSE_DATA);
        return NULL;
    }
    if (OBJ_obj2nid(rb->responseType) != NID_id_pkix_OCSP_basic) {
        OCSPerr(OCSP_F_OCSP_RESPONSE_GET1_BASIC, OCSP_R_NOT_BASIC_RESPONSE);
        return NULL;
    }

    return ASN1_item_unpack(rb->response, ASN1_ITEM_rptr(OCSP_BASICRESP));
}

ASN1_OCTET_STRING *OCSP_resp_get0_signature(OCSP_BASICRESP *bs)
{
    return bs->signature;
}

/*
 * Return number of OCSP_SINGLERESP reponses present in a basic response.
 */

int OCSP_resp_count(OCSP_BASICRESP *bs)
{
    if (!bs)
        return -1;
    return sk_OCSP_SINGLERESP_num(bs->tbsResponseData->responses);
}

/* Extract an OCSP_SINGLERESP response with a given index */

OCSP_SINGLERESP *OCSP_resp_get0(OCSP_BASICRESP *bs, int idx)
{
    if (!bs)
        return NULL;
    return sk_OCSP_SINGLERESP_value(bs->tbsResponseData->responses, idx);
}

/* Look single response matching a given certificate ID */

int OCSP_resp_find(OCSP_BASICRESP *bs, OCSP_CERTID *id, int last)
{
    int i;
    STACK_OF(OCSP_SINGLERESP) *sresp;
    OCSP_SINGLERESP *single;
    if (!bs)
        return -1;
    if (last < 0)
        last = 0;
    else
        last++;
    sresp = bs->tbsResponseData->responses;
    for (i = last; i < sk_OCSP_SINGLERESP_num(sresp); i++) {
        single = sk_OCSP_SINGLERESP_value(sresp, i);
        if (!OCSP_id_cmp(id, single->certId))
            return i;
    }
    return -1;
}

/*
 * Extract status information from an OCSP_SINGLERESP structure. Note: the
 * revtime and reason values are only set if the certificate status is
 * revoked. Returns numerical value of status.
 */

int OCSP_single_get0_status(OCSP_SINGLERESP *single, int *reason,
                            ASN1_GENERALIZEDTIME **revtime,
                            ASN1_GENERALIZEDTIME **thisupd,
                            ASN1_GENERALIZEDTIME **nextupd)
{
    int ret;
    OCSP_CERTSTATUS *cst;
    if (!single)
        return -1;
    cst = single->certStatus;
    ret = cst->type;
    if (ret == V_OCSP_CERTSTATUS_REVOKED) {
        OCSP_REVOKEDINFO *rev = cst->value.revoked;
        if (revtime)
            *revtime = rev->revocationTime;
        if (reason) {
            if (rev->revocationReason)
                *reason = ASN1_ENUMERATED_get(rev->revocationReason);
            else
                *reason = -1;
        }
    }
    if (thisupd)
        *thisupd = single->thisUpdate;
    if (nextupd)
        *nextupd = single->nextUpdate;
    return ret;
}

/*
 * This function combines the previous ones: look up a certificate ID and if
 * found extract status information. Return 0 is successful.
 */

int OCSP_resp_find_status(OCSP_BASICRESP *bs, OCSP_CERTID *id, int *status,
                          int *reason,
                          ASN1_GENERALIZEDTIME **revtime,
                          ASN1_GENERALIZEDTIME **thisupd,
                          ASN1_GENERALIZEDTIME **nextupd)
{
    int i;
    OCSP_SINGLERESP *single;
    i = OCSP_resp_find(bs, id, -1);
    /* Maybe check for multiple responses and give an error? */
    if (i < 0)
        return 0;
    single = OCSP_resp_get0(bs, i);
    i = OCSP_single_get0_status(single, reason, revtime, thisupd, nextupd);
    if (status)
        *status = i;
    return 1;
}

/*
 * Check validity of thisUpdate and nextUpdate fields. It is possible that
 * the request will take a few seconds to process and/or the time wont be
 * totally accurate. Therefore to avoid rejecting otherwise valid time we
 * allow the times to be within 'nsec' of the current time. Also to avoid
 * accepting very old responses without a nextUpdate field an optional maxage
 * parameter specifies the maximum age the thisUpdate field can be.
 */

int OCSP_check_validity(ASN1_GENERALIZEDTIME *thisupd,
                        ASN1_GENERALIZEDTIME *nextupd, long nsec, long maxsec)
{
    int ret = 1;
    time_t t_now, t_tmp;
    time(&t_now);
    /* Check thisUpdate is valid and not more than nsec in the future */
    if (!ASN1_GENERALIZEDTIME_check(thisupd)) {
        OCSPerr(OCSP_F_OCSP_CHECK_VALIDITY, OCSP_R_ERROR_IN_THISUPDATE_FIELD);
        ret = 0;
    } else {
        t_tmp = t_now + nsec;
        if (X509_cmp_time(thisupd, &t_tmp) > 0) {
            OCSPerr(OCSP_F_OCSP_CHECK_VALIDITY, OCSP_R_STATUS_NOT_YET_VALID);
            ret = 0;
        }

        /*
         * If maxsec specified check thisUpdate is not more than maxsec in
         * the past
         */
        if (maxsec >= 0) {
            t_tmp = t_now - maxsec;
            if (X509_cmp_time(thisupd, &t_tmp) < 0) {
                OCSPerr(OCSP_F_OCSP_CHECK_VALIDITY, OCSP_R_STATUS_TOO_OLD);
                ret = 0;
            }
        }
    }

    if (!nextupd)
        return ret;

    /* Check nextUpdate is valid and not more than nsec in the past */
    if (!ASN1_GENERALIZEDTIME_check(nextupd)) {
        OCSPerr(OCSP_F_OCSP_CHECK_VALIDITY, OCSP_R_ERROR_IN_NEXTUPDATE_FIELD);
        ret = 0;
    } else {
        t_tmp = t_now - nsec;
        if (X509_cmp_time(nextupd, &t_tmp) < 0) {
            OCSPerr(OCSP_F_OCSP_CHECK_VALIDITY, OCSP_R_STATUS_EXPIRED);
            ret = 0;
        }
    }

    /* Also don't allow nextUpdate to precede thisUpdate */
    if (ASN1_STRING_cmp(nextupd, thisupd) < 0) {
        OCSPerr(OCSP_F_OCSP_CHECK_VALIDITY,
                OCSP_R_NEXTUPDATE_BEFORE_THISUPDATE);
        ret = 0;
    }

    return ret;
}