/*

 * Copyright 1995-2025 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include <stdio.h>

#include "internal/cryptlib.h"

#include <openssl/asn1t.h>

#include <openssl/x509.h>

#include "crypto/x509.h"

#include <openssl/x509v3.h>

#include "x509_local.h"

static int X509_REVOKED_cmp(const X509_REVOKED *const *a,

    const X509_REVOKED *const *b);

static int setup_idp(X509_CRL *crl, ISSUING_DIST_POINT *idp);

ASN1_SEQUENCE(X509_REVOKED) = {

    ASN1_EMBED(X509_REVOKED, serialNumber, ASN1_INTEGER),

    ASN1_SIMPLE(X509_REVOKED, revocationDate, ASN1_TIME),

    ASN1_SEQUENCE_OF_OPT(X509_REVOKED, extensions, X509_EXTENSION)

} ASN1_SEQUENCE_END(X509_REVOKED)

static int def_crl_verify(X509_CRL *crl, EVP_PKEY *r);

static int def_crl_lookup(X509_CRL *crl,

    X509_REVOKED **ret, const ASN1_INTEGER *serial,

    const X509_NAME *issuer);

static X509_CRL_METHOD int_crl_meth = {

    0,

    0, 0,

    def_crl_lookup,

    def_crl_verify

};

static const X509_CRL_METHOD *default_crl_method = &int_crl_meth;

/*

 * The X509_CRL_INFO structure needs a bit of customisation. Since we cache

 * the original encoding the signature won't be affected by reordering of the

 * revoked field.

 */

static int crl_inf_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,

    void *exarg)

{

    X509_CRL_INFO *a = (X509_CRL_INFO *)*pval;

    if (!a || !a->revoked)

        return 1;

    switch (operation) {

        /*

         * Just set cmp function here. We don't sort because that would

         * affect the output of X509_CRL_print().

         */

    case ASN1_OP_D2I_POST:

        (void)sk_X509_REVOKED_set_cmp_func(a->revoked, X509_REVOKED_cmp);

        break;

    }

    return 1;

}

ASN1_SEQUENCE_enc(X509_CRL_INFO, enc, crl_inf_cb) = {

    ASN1_OPT(X509_CRL_INFO, version, ASN1_INTEGER),

    ASN1_EMBED(X509_CRL_INFO, sig_alg, X509_ALGOR),

    ASN1_SIMPLE(X509_CRL_INFO, issuer, X509_NAME),

    ASN1_SIMPLE(X509_CRL_INFO, lastUpdate, ASN1_TIME),

    ASN1_OPT(X509_CRL_INFO, nextUpdate, ASN1_TIME),

    ASN1_SEQUENCE_OF_OPT(X509_CRL_INFO, revoked, X509_REVOKED),

    ASN1_EXP_SEQUENCE_OF_OPT(X509_CRL_INFO, extensions, X509_EXTENSION, 0)

} ASN1_SEQUENCE_END_enc(X509_CRL_INFO, X509_CRL_INFO)

/*

 * Set CRL entry issuer according to CRL certificate issuer extension. Check

 * for unhandled critical CRL entry extensions.

 */

static int crl_set_issuers(X509_CRL *crl)

{

    int i, j;

    GENERAL_NAMES *most_recent_issuer, *gtmp;

    STACK_OF(X509_REVOKED) *revoked;

    /*

     * The CRL's nextUpdate field is optional, but we will still verify

     * lastUpdate and treat missing or invalid values as a failure.

     */

    if (crl->crl.lastUpdate == NULL) {

        crl->flags |= EXFLAG_INVALID;

        return 0;

    }

    revoked = X509_CRL_get_REVOKED(crl);

    /*

     * If this extension is not present on the first entry in an indirect CRL,

     * the certificate issuer defaults to the CRL issuer. Subsequent entries in

     * an indirect CRL, if this extension is not present, the certificate issuer

     * for the entry is the same as that for the preceding entry.

     * https://datatracker.ietf.org/doc/html/rfc5280#section-5.3.3

     */

    most_recent_issuer = NULL;

    for (i = 0; i < sk_X509_REVOKED_num(revoked); i++) {

        X509_REVOKED *rev = sk_X509_REVOKED_value(revoked, i);

        STACK_OF(X509_EXTENSION) *exts;

        ASN1_ENUMERATED *reason;

        X509_EXTENSION *ext;

        const ASN1_TIME *rev_date;

        ASN1_GENERALIZEDTIME *inv_date;

        int nid;

        /*

         * The revocation date is a mandatory attribute. If we get NULL here, it

         * means the validation has failed and an error has been pushed onto the

         * error stack.

         */

        if ((rev_date = X509_REVOKED_get0_revocationDate(rev)) == NULL) {

            crl->flags |= EXFLAG_INVALID;

            return 0;

        }

        gtmp = X509_REVOKED_get_ext_d2i(rev, NID_certificate_issuer, &j, NULL);

        if (gtmp == NULL && j != -1) {

            crl->flags |= EXFLAG_INVALID;

            return 1;

        }

        if (gtmp != NULL) {

            /*

             * Validation to ensure Certificate Issuer extensions in CRL

             * entries only appear when the Indirect CRL flag is TRUE in the

             * Issuing Distribution Point (IDP) extension, as required by

             * https://datatracker.ietf.org/doc/html/rfc5280#section-5.3.3

             */

            if (crl->idp == NULL || !crl->idp->indirectCRL) {

                crl->flags |= EXFLAG_INVALID;

                GENERAL_NAMES_free(gtmp);

                return 0;

            }

            if (crl->issuers == NULL) {

                crl->issuers = sk_GENERAL_NAMES_new_null();

                if (crl->issuers == NULL) {

                    GENERAL_NAMES_free(gtmp);

                    return 0;

                }

            }

            if (!sk_GENERAL_NAMES_push(crl->issuers, gtmp)) {

                GENERAL_NAMES_free(gtmp);

                return 0;

            }

            most_recent_issuer = gtmp;

        }

        rev->issuer = most_recent_issuer;

        reason = X509_REVOKED_get_ext_d2i(rev, NID_crl_reason, &j, NULL);

        if (reason == NULL && j != -1) {

            crl->flags |= EXFLAG_INVALID;

            return 1;

        }

        if (reason != NULL) {

            rev->reason = ASN1_ENUMERATED_get(reason);

            ASN1_ENUMERATED_free(reason);

        } else

            rev->reason = CRL_REASON_NONE;

        /* Check for critical CRL entry extensions and validate time. */

        exts = rev->extensions;

        for (j = 0; j < sk_X509_EXTENSION_num(exts); j++) {

            ext = sk_X509_EXTENSION_value(exts, j);

            nid = OBJ_obj2nid(X509_EXTENSION_get_object(ext));

            /*

             * If we obtain the extension but the time is NULL, it means that

             * the validation has failed and the reason will be pushed onto the

             * error stack.

             */

            if (nid == NID_invalidity_date) {

                if ((inv_date = X509V3_EXT_d2i(ext)) == NULL) {

                    crl->flags |= EXFLAG_INVALID;

                    return 0;

                }

                ASN1_GENERALIZEDTIME_free(inv_date);

            }

            if (X509_EXTENSION_get_critical(ext)) {

                if (nid == NID_certificate_issuer)

                    continue;

                crl->flags |= EXFLAG_CRITICAL;

            }

        }

    }

    return 1;

}

/*

 * The X509_CRL structure needs a bit of customisation. Cache some extensions

 * and hash of the whole CRL or set EXFLAG_NO_FINGERPRINT if this fails.

 */

static int crl_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,

    void *exarg)

{

    X509_CRL *crl = (X509_CRL *)*pval;

    STACK_OF(X509_EXTENSION) *exts;

    X509_EXTENSION *ext;

    int idx, i;

    switch (operation) {

    case ASN1_OP_D2I_PRE:

        if (crl->meth->crl_free) {

            if (!crl->meth->crl_free(crl))

                return 0;

        }

        AUTHORITY_KEYID_free(crl->akid);

        ISSUING_DIST_POINT_free(crl->idp);

        ASN1_INTEGER_free(crl->crl_number);

        ASN1_INTEGER_free(crl->base_crl_number);

        sk_GENERAL_NAMES_pop_free(crl->issuers, GENERAL_NAMES_free);

        /* fall through */

    case ASN1_OP_NEW_POST:

        crl->idp = NULL;

        crl->akid = NULL;

        crl->flags = 0;

        crl->idp_flags = 0;

        crl->idp_reasons = CRLDP_ALL_REASONS;

        crl->meth = default_crl_method;

        crl->meth_data = NULL;

        crl->issuers = NULL;

        crl->crl_number = NULL;

        crl->base_crl_number = NULL;

        break;

    case ASN1_OP_D2I_POST:

        if (!X509_CRL_digest(crl, EVP_sha1(), crl->sha1_hash, NULL))

            crl->flags |= EXFLAG_NO_FINGERPRINT;

        crl->idp = X509_CRL_get_ext_d2i(crl,

            NID_issuing_distribution_point, &i,

            NULL);

        if (crl->idp != NULL) {

            if (!setup_idp(crl, crl->idp))

                crl->flags |= EXFLAG_INVALID;

        } else if (i != -1) {

            crl->flags |= EXFLAG_INVALID;

        }

        crl->akid = X509_CRL_get_ext_d2i(crl,

            NID_authority_key_identifier, &i,

            NULL);

        if (crl->akid == NULL && i != -1)

            crl->flags |= EXFLAG_INVALID;

        crl->crl_number = X509_CRL_get_ext_d2i(crl,

            NID_crl_number, &i, NULL);

        if (crl->crl_number == NULL && i != -1)

            crl->flags |= EXFLAG_INVALID;

        crl->base_crl_number = X509_CRL_get_ext_d2i(crl,

            NID_delta_crl, &i,

            NULL);

        if (crl->base_crl_number == NULL && i != -1)

            crl->flags |= EXFLAG_INVALID;

        /* Delta CRLs must have CRL number */

        if (crl->base_crl_number && !crl->crl_number)

            crl->flags |= EXFLAG_INVALID;

        /*

         * See if we have any unhandled critical CRL extensions and indicate

         * this in a flag. We only currently handle IDP so anything else

         * critical sets the flag. This code accesses the X509_CRL structure

         * directly: applications shouldn't do this.

         */

        exts = crl->crl.extensions;

        for (idx = 0; idx < sk_X509_EXTENSION_num(exts); idx++) {

            int nid;

            ext = sk_X509_EXTENSION_value(exts, idx);

            nid = OBJ_obj2nid(X509_EXTENSION_get_object(ext));

            if (nid == NID_freshest_crl)

                crl->flags |= EXFLAG_FRESHEST;

            if (X509_EXTENSION_get_critical(ext)) {

                /* We handle IDP and deltas */

                if ((nid == NID_issuing_distribution_point)

                    || (nid == NID_authority_key_identifier)

                    || (nid == NID_delta_crl))

                    continue;

                crl->flags |= EXFLAG_CRITICAL;

                break;

            }

        }

        if (!crl_set_issuers(crl))

            return 0;

        if (crl->meth->crl_init) {

            if (crl->meth->crl_init(crl) == 0)

                return 0;

        }

        crl->flags |= EXFLAG_SET;

        break;

    case ASN1_OP_FREE_POST:

        if (crl->meth != NULL && crl->meth->crl_free != NULL) {

            if (!crl->meth->crl_free(crl))

                return 0;

        }

        AUTHORITY_KEYID_free(crl->akid);

        ISSUING_DIST_POINT_free(crl->idp);

        ASN1_INTEGER_free(crl->crl_number);

        ASN1_INTEGER_free(crl->base_crl_number);

        sk_GENERAL_NAMES_pop_free(crl->issuers, GENERAL_NAMES_free);

        OPENSSL_free(crl->propq);

        break;

    case ASN1_OP_DUP_POST: {

        X509_CRL *old = exarg;

        if (!ossl_x509_crl_set0_libctx(crl, old->libctx, old->propq))

            return 0;

    } break;

    }

    return 1;

}

/* Convert IDP into a more convenient form */

static int setup_idp(X509_CRL *crl, ISSUING_DIST_POINT *idp)

{

    int idp_only = 0;

    int ret = 0;

    /* Set various flags according to IDP */

    crl->idp_flags |= IDP_PRESENT;

    if (idp->onlyuser > 0) {

        idp_only++;

        crl->idp_flags |= IDP_ONLYUSER;

    }

    if (idp->onlyCA > 0) {

        idp_only++;

        crl->idp_flags |= IDP_ONLYCA;

    }

    if (idp->onlyattr > 0) {

        idp_only++;

        crl->idp_flags |= IDP_ONLYATTR;

    }

    if (idp_only > 1)

        crl->idp_flags |= IDP_INVALID;

    if (idp->indirectCRL > 0)

        crl->idp_flags |= IDP_INDIRECT;

    if (idp->onlysomereasons) {

        crl->idp_flags |= IDP_REASONS;

        if (idp->onlysomereasons->length > 0)

            crl->idp_reasons = idp->onlysomereasons->data[0];

        if (idp->onlysomereasons->length > 1)

            crl->idp_reasons |= (idp->onlysomereasons->data[1] << 8);

        crl->idp_reasons &= CRLDP_ALL_REASONS;

    }

    ret = DIST_POINT_set_dpname(idp->distpoint, X509_CRL_get_issuer(crl));

    /*

     * RFC5280 specifies that if onlyContainsUserCerts, onlyContainsCACerts,

     * indirectCRL, and OnlyContainsAttributeCerts are all FALSE, there must

     * be either a distributionPoint field or an onlySomeReasons field present.

     */

    if (crl->idp_flags == IDP_PRESENT && idp->distpoint == NULL)

        crl->idp_flags |= IDP_INVALID;

    return ret;

}

ASN1_SEQUENCE_ref(X509_CRL, crl_cb) = {

    ASN1_EMBED(X509_CRL, crl, X509_CRL_INFO),

    ASN1_EMBED(X509_CRL, sig_alg, X509_ALGOR),

    ASN1_EMBED(X509_CRL, signature, ASN1_BIT_STRING)

} ASN1_SEQUENCE_END_ref(X509_CRL, X509_CRL)

IMPLEMENT_ASN1_FUNCTIONS(X509_REVOKED)

IMPLEMENT_ASN1_DUP_FUNCTION(X509_REVOKED)

IMPLEMENT_ASN1_FUNCTIONS(X509_CRL_INFO)

IMPLEMENT_ASN1_FUNCTIONS(X509_CRL)

IMPLEMENT_ASN1_DUP_FUNCTION(X509_CRL)

static int X509_REVOKED_cmp(const X509_REVOKED *const *a,

    const X509_REVOKED *const *b)

{

    return (ASN1_STRING_cmp((ASN1_STRING *)&(*a)->serialNumber,

        (ASN1_STRING *)&(*b)->serialNumber));

}

X509_CRL *X509_CRL_new_ex(OSSL_LIB_CTX *libctx, const char *propq)

{

    X509_CRL *crl = NULL;

    crl = (X509_CRL *)ASN1_item_new((X509_CRL_it()));

    if (!ossl_x509_crl_set0_libctx(crl, libctx, propq)) {

        X509_CRL_free(crl);

        crl = NULL;

    }

    return crl;

}

int X509_CRL_add0_revoked(X509_CRL *crl, X509_REVOKED *rev)

{

    X509_CRL_INFO *inf;

    inf = &crl->crl;

    if (inf->revoked == NULL)

        inf->revoked = sk_X509_REVOKED_new(X509_REVOKED_cmp);

    if (inf->revoked == NULL || !sk_X509_REVOKED_push(inf->revoked, rev)) {

        ERR_raise(ERR_LIB_ASN1, ERR_R_CRYPTO_LIB);

        return 0;

    }

    inf->enc.modified = 1;

    return 1;

}

int X509_CRL_verify(X509_CRL *crl, EVP_PKEY *r)

{

    if (crl->meth->crl_verify)

        return crl->meth->crl_verify(crl, r);

    return 0;

}

int X509_CRL_get0_by_serial(X509_CRL *crl,

    X509_REVOKED **ret, const ASN1_INTEGER *serial)

{

    if (crl->meth->crl_lookup)

        return crl->meth->crl_lookup(crl, ret, serial, NULL);

    return 0;

}

int X509_CRL_get0_by_cert(X509_CRL *crl, X509_REVOKED **ret, X509 *x)

{

    if (crl->meth->crl_lookup)

        return crl->meth->crl_lookup(crl, ret,

            X509_get0_serialNumber(x),

            X509_get_issuer_name(x));

    return 0;

}

static int def_crl_verify(X509_CRL *crl, EVP_PKEY *r)

{

    return ASN1_item_verify_ex(ASN1_ITEM_rptr(X509_CRL_INFO),

        &crl->sig_alg, &crl->signature, &crl->crl, NULL,

        r, crl->libctx, crl->propq);

}

static int crl_revoked_issuer_match(X509_CRL *crl, const X509_NAME *nm,

    X509_REVOKED *rev)

{

    int i;

    if (!rev->issuer) {

        if (!nm)

            return 1;

        if (!X509_NAME_cmp(nm, X509_CRL_get_issuer(crl)))

            return 1;

        return 0;

    }

    if (!nm)

        nm = X509_CRL_get_issuer(crl);

    for (i = 0; i < sk_GENERAL_NAME_num(rev->issuer); i++) {

        GENERAL_NAME *gen = sk_GENERAL_NAME_value(rev->issuer, i);

        if (gen->type != GEN_DIRNAME)

            continue;

        if (!X509_NAME_cmp(nm, gen->d.directoryName))

            return 1;

    }

    return 0;

}

static int def_crl_lookup(X509_CRL *crl,

    X509_REVOKED **ret, const ASN1_INTEGER *serial,

    const X509_NAME *issuer)

{

    X509_REVOKED rtmp, *rev;

    int idx, num;

    if (crl->crl.revoked == NULL)

        return 0;

    /*

     * Sort revoked into serial number order if not already sorted. Do this

     * under a lock to avoid race condition.

     */

    if (!sk_X509_REVOKED_is_sorted(crl->crl.revoked)) {

        if (!CRYPTO_THREAD_write_lock(crl->lock))

            return 0;

        sk_X509_REVOKED_sort(crl->crl.revoked);

        CRYPTO_THREAD_unlock(crl->lock);

    }

    rtmp.serialNumber = *serial;

    idx = sk_X509_REVOKED_find(crl->crl.revoked, &rtmp);

    if (idx < 0)

        return 0;

    /* Need to look for matching name */

    for (num = sk_X509_REVOKED_num(crl->crl.revoked); idx < num; idx++) {

        rev = sk_X509_REVOKED_value(crl->crl.revoked, idx);

        if (ASN1_INTEGER_cmp(&rev->serialNumber, serial))

            return 0;

        if (crl_revoked_issuer_match(crl, issuer, rev)) {

            if (ret)

                *ret = rev;

            if (rev->reason == CRL_REASON_REMOVE_FROM_CRL)

                return 2;

            return 1;

        }

    }

    return 0;

}

void X509_CRL_set_default_method(const X509_CRL_METHOD *meth)

{

    if (meth == NULL)

        default_crl_method = &int_crl_meth;

    else

        default_crl_method = meth;

}

X509_CRL_METHOD *X509_CRL_METHOD_new(int (*crl_init)(X509_CRL *crl),

    int (*crl_free)(X509_CRL *crl),

    int (*crl_lookup)(X509_CRL *crl,

        X509_REVOKED **ret,

        const ASN1_INTEGER *ser,

        const X509_NAME *issuer),

    int (*crl_verify)(X509_CRL *crl,

        EVP_PKEY *pk))

{

    X509_CRL_METHOD *m = OPENSSL_malloc(sizeof(*m));

    if (m == NULL)

        return NULL;

    m->crl_init = crl_init;

    m->crl_free = crl_free;

    m->crl_lookup = crl_lookup;

    m->crl_verify = crl_verify;

    m->flags = X509_CRL_METHOD_DYNAMIC;

    return m;

}

void X509_CRL_METHOD_free(X509_CRL_METHOD *m)

{

    if (m == NULL || !(m->flags & X509_CRL_METHOD_DYNAMIC))

        return;

    OPENSSL_free(m);

}

void X509_CRL_set_meth_data(X509_CRL *crl, void *dat)

{

    crl->meth_data = dat;

}

void *X509_CRL_get_meth_data(X509_CRL *crl)

{

    return crl->meth_data;

}

int ossl_x509_crl_set0_libctx(X509_CRL *x, OSSL_LIB_CTX *libctx,

    const char *propq)

{

    if (x != NULL) {

        x->libctx = libctx;

        OPENSSL_free(x->propq);

        x->propq = NULL;

        if (propq != NULL) {

            x->propq = OPENSSL_strdup(propq);

            if (x->propq == NULL)

                return 0;

        }

    }

    return 1;

}