Commit message: Fix length checks in X509_cmp_time to avoid out-of-bounds reads.

Also tighten X509_cmp_time to reject more than three fractional
seconds in the time; and to reject trailing garbage after the offset.

CVE-2015-1789

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
CVE: CVE-2015-1789
CWE: CWE-119
Vulnerability description: The X509_cmp_time function in crypto/x509/x509_vfy.c in OpenSSL before 0.9.8zg, 1.0.0 before 1.0.0s, 1.0.1 before 1.0.1n, and 1.0.2 before 1.0.2b allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via a crafted length field in ASN1_TIME data, as demonstrated by an attack against a server that supports client authentication with a custom verification callback.

Project: openssl

X509_CRL *X509_CRL_diff(X509_CRL *base, X509_CRL *newer,
                        EVP_PKEY *skey, const EVP_MD *md, unsigned int flags)
{
    X509_CRL *crl = NULL;
    int i;
    STACK_OF(X509_REVOKED) *revs = NULL;
    /* CRLs can't be delta already */
    if (base->base_crl_number || newer->base_crl_number) {
        X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_ALREADY_DELTA);
        return NULL;
    }
    /* Base and new CRL must have a CRL number */
    if (!base->crl_number || !newer->crl_number) {
        X509err(X509_F_X509_CRL_DIFF, X509_R_NO_CRL_NUMBER);
        return NULL;
    }
    /* Issuer names must match */
    if (X509_NAME_cmp(X509_CRL_get_issuer(base), X509_CRL_get_issuer(newer))) {
        X509err(X509_F_X509_CRL_DIFF, X509_R_ISSUER_MISMATCH);
        return NULL;
    }
    /* AKID and IDP must match */
    if (!crl_extension_match(base, newer, NID_authority_key_identifier)) {
        X509err(X509_F_X509_CRL_DIFF, X509_R_AKID_MISMATCH);
        return NULL;
    }
    if (!crl_extension_match(base, newer, NID_issuing_distribution_point)) {
        X509err(X509_F_X509_CRL_DIFF, X509_R_IDP_MISMATCH);
        return NULL;
    }
    /* Newer CRL number must exceed full CRL number */
    if (ASN1_INTEGER_cmp(newer->crl_number, base->crl_number) <= 0) {
        X509err(X509_F_X509_CRL_DIFF, X509_R_NEWER_CRL_NOT_NEWER);
        return NULL;
    }
    /* CRLs must verify */
    if (skey && (X509_CRL_verify(base, skey) <= 0 ||
                 X509_CRL_verify(newer, skey) <= 0)) {
        X509err(X509_F_X509_CRL_DIFF, X509_R_CRL_VERIFY_FAILURE);
        return NULL;
    }
    /* Create new CRL */
    crl = X509_CRL_new();
    if (!crl || !X509_CRL_set_version(crl, 1))
        goto memerr;
    /* Set issuer name */
    if (!X509_CRL_set_issuer_name(crl, X509_CRL_get_issuer(newer)))
        goto memerr;

    if (!X509_CRL_set_lastUpdate(crl, X509_CRL_get_lastUpdate(newer)))
        goto memerr;
    if (!X509_CRL_set_nextUpdate(crl, X509_CRL_get_nextUpdate(newer)))
        goto memerr;

    /* Set base CRL number: must be critical */

    if (!X509_CRL_add1_ext_i2d(crl, NID_delta_crl, base->crl_number, 1, 0))
        goto memerr;

    /*
     * Copy extensions across from newest CRL to delta: this will set CRL
     * number to correct value too.
     */

    for (i = 0; i < X509_CRL_get_ext_count(newer); i++) {
        X509_EXTENSION *ext;
        ext = X509_CRL_get_ext(newer, i);
        if (!X509_CRL_add_ext(crl, ext, -1))
            goto memerr;
    }

    /* Go through revoked entries, copying as needed */

    revs = X509_CRL_get_REVOKED(newer);

    for (i = 0; i < sk_X509_REVOKED_num(revs); i++) {
        X509_REVOKED *rvn, *rvtmp;
        rvn = sk_X509_REVOKED_value(revs, i);
        /*
         * Add only if not also in base. TODO: need something cleverer here
         * for some more complex CRLs covering multiple CAs.
         */
        if (!X509_CRL_get0_by_serial(base, &rvtmp, rvn->serialNumber)) {
            rvtmp = X509_REVOKED_dup(rvn);
            if (!rvtmp)
                goto memerr;
            if (!X509_CRL_add0_revoked(crl, rvtmp)) {
                X509_REVOKED_free(rvtmp);
                goto memerr;
            }
        }
    }
    /* TODO: optionally prune deleted entries */

    if (skey && md && !X509_CRL_sign(crl, skey, md))
        goto memerr;

    return crl;

 memerr:
    X509err(X509_F_X509_CRL_DIFF, ERR_R_MALLOC_FAILURE);
    X509_CRL_free(crl);
    return NULL;
}

Project: openssl

void X509_STORE_CTX_cleanup(X509_STORE_CTX *ctx)
{
    if (ctx->cleanup)
        ctx->cleanup(ctx);
    if (ctx->param != NULL) {
        if (ctx->parent == NULL)
            X509_VERIFY_PARAM_free(ctx->param);
        ctx->param = NULL;
    }
    X509_policy_tree_free(ctx->tree);
    ctx->tree = NULL;
    sk_X509_pop_free(ctx->chain, X509_free);
    ctx->chain = NULL;
    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx, &(ctx->ex_data));
    memset(&ctx->ex_data, 0, sizeof(ctx->ex_data));
}

Project: openssl

int X509_STORE_CTX_init(X509_STORE_CTX *ctx, X509_STORE *store, X509 *x509,
                        STACK_OF(X509) *chain)
{
    int ret = 1;
    ctx->ctx = store;
    ctx->current_method = 0;
    ctx->cert = x509;
    ctx->untrusted = chain;
    ctx->crls = NULL;
    ctx->last_untrusted = 0;
    ctx->other_ctx = NULL;
    ctx->valid = 0;
    ctx->chain = NULL;
    ctx->error = 0;
    ctx->explicit_policy = 0;
    ctx->error_depth = 0;
    ctx->current_cert = NULL;
    ctx->current_issuer = NULL;
    ctx->current_crl = NULL;
    ctx->current_crl_score = 0;
    ctx->current_reasons = 0;
    ctx->tree = NULL;
    ctx->parent = NULL;

    ctx->param = X509_VERIFY_PARAM_new();

    if (!ctx->param) {
        X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
        return 0;
    }

    /*
     * Inherit callbacks and flags from X509_STORE if not set use defaults.
     */

    if (store)
        ret = X509_VERIFY_PARAM_inherit(ctx->param, store->param);
    else
        ctx->param->inh_flags |= X509_VP_FLAG_DEFAULT | X509_VP_FLAG_ONCE;

    if (store) {
        ctx->verify_cb = store->verify_cb;
        ctx->cleanup = store->cleanup;
    } else
        ctx->cleanup = 0;

    if (ret)
        ret = X509_VERIFY_PARAM_inherit(ctx->param,
                                        X509_VERIFY_PARAM_lookup("default"));

    if (ret == 0) {
        X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
        return 0;
    }

    if (store && store->check_issued)
        ctx->check_issued = store->check_issued;
    else
        ctx->check_issued = check_issued;

    if (store && store->get_issuer)
        ctx->get_issuer = store->get_issuer;
    else
        ctx->get_issuer = X509_STORE_CTX_get1_issuer;

    if (store && store->verify_cb)
        ctx->verify_cb = store->verify_cb;
    else
        ctx->verify_cb = null_callback;

    if (store && store->verify)
        ctx->verify = store->verify;
    else
        ctx->verify = internal_verify;

    if (store && store->check_revocation)
        ctx->check_revocation = store->check_revocation;
    else
        ctx->check_revocation = check_revocation;

    if (store && store->get_crl)
        ctx->get_crl = store->get_crl;
    else
        ctx->get_crl = NULL;

    if (store && store->check_crl)
        ctx->check_crl = store->check_crl;
    else
        ctx->check_crl = check_crl;

    if (store && store->cert_crl)
        ctx->cert_crl = store->cert_crl;
    else
        ctx->cert_crl = cert_crl;

    if (store && store->lookup_certs)
        ctx->lookup_certs = store->lookup_certs;
    else
        ctx->lookup_certs = X509_STORE_get1_certs;

    if (store && store->lookup_crls)
        ctx->lookup_crls = store->lookup_crls;
    else
        ctx->lookup_crls = X509_STORE_get1_crls;

    ctx->check_policy = check_policy;

    /*
     * Since X509_STORE_CTX_cleanup does a proper "free" on the ex_data, we
     * put a corresponding "new" here.
     */
    if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_X509_STORE_CTX, ctx,
                            &(ctx->ex_data))) {
        OPENSSL_free(ctx);
        X509err(X509_F_X509_STORE_CTX_INIT, ERR_R_MALLOC_FAILURE);
        return 0;
    }
    return 1;
}

Project: openssl

X509_STORE_CTX *X509_STORE_CTX_new(void)
{
    X509_STORE_CTX *ctx = OPENSSL_malloc(sizeof(*ctx));

    if (!ctx) {
        X509err(X509_F_X509_STORE_CTX_NEW, ERR_R_MALLOC_FAILURE);
        return NULL;
    }
    memset(ctx, 0, sizeof(*ctx));
    return ctx;
}

Project: openssl

void X509_STORE_CTX_set0_param(X509_STORE_CTX *ctx, X509_VERIFY_PARAM *param)
{
    X509_VERIFY_PARAM_free(ctx->param);
    ctx->param = param;
}

Project: openssl

int X509_get_pubkey_parameters(EVP_PKEY *pkey, STACK_OF(X509) *chain)
{
    EVP_PKEY *ktmp = NULL, *ktmp2;
    int i, j;

    if ((pkey != NULL) && !EVP_PKEY_missing_parameters(pkey))
        return 1;

    for (i = 0; i < sk_X509_num(chain); i++) {
        ktmp = X509_get_pubkey(sk_X509_value(chain, i));
        if (ktmp == NULL) {
            X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,
                    X509_R_UNABLE_TO_GET_CERTS_PUBLIC_KEY);
            return 0;
        }
        if (!EVP_PKEY_missing_parameters(ktmp))
            break;
        EVP_PKEY_free(ktmp);
        ktmp = NULL;
    }
    if (ktmp == NULL) {
        X509err(X509_F_X509_GET_PUBKEY_PARAMETERS,
                X509_R_UNABLE_TO_FIND_PARAMETERS_IN_CHAIN);
        return 0;
    }

    /* first, populate the other certs */
    for (j = i - 1; j >= 0; j--) {
        ktmp2 = X509_get_pubkey(sk_X509_value(chain, j));
        EVP_PKEY_copy_parameters(ktmp2, ktmp);
        EVP_PKEY_free(ktmp2);
    }

    if (pkey != NULL)
        EVP_PKEY_copy_parameters(pkey, ktmp);
    EVP_PKEY_free(ktmp);
    return 1;
}

Project: openssl

int X509_verify_cert(X509_STORE_CTX *ctx)
{
    X509 *x, *xtmp, *xtmp2, *chain_ss = NULL;
    int bad_chain = 0;
    X509_VERIFY_PARAM *param = ctx->param;
    int depth, i, ok = 0;
    int num, j, retry;
    int (*cb) (int xok, X509_STORE_CTX *xctx);
    STACK_OF(X509) *sktmp = NULL;
    if (ctx->cert == NULL) {
        X509err(X509_F_X509_VERIFY_CERT, X509_R_NO_CERT_SET_FOR_US_TO_VERIFY);
        return -1;
    }

    cb = ctx->verify_cb;

    /*
     * first we make sure the chain we are going to build is present and that
     * the first entry is in place
     */
    if (ctx->chain == NULL) {
        if (((ctx->chain = sk_X509_new_null()) == NULL) ||
            (!sk_X509_push(ctx->chain, ctx->cert))) {
            X509err(X509_F_X509_VERIFY_CERT, ERR_R_MALLOC_FAILURE);
            goto end;
        }
        CRYPTO_add(&ctx->cert->references, 1, CRYPTO_LOCK_X509);
        ctx->last_untrusted = 1;
    }

    /* We use a temporary STACK so we can chop and hack at it */
    if (ctx->untrusted != NULL
        && (sktmp = sk_X509_dup(ctx->untrusted)) == NULL) {
        X509err(X509_F_X509_VERIFY_CERT, ERR_R_MALLOC_FAILURE);
        goto end;
    }

    num = sk_X509_num(ctx->chain);
    x = sk_X509_value(ctx->chain, num - 1);
    depth = param->depth;

    for (;;) {
        /* If we have enough, we break */
        if (depth < num)
            break;              /* FIXME: If this happens, we should take
                                 * note of it and, if appropriate, use the
                                 * X509_V_ERR_CERT_CHAIN_TOO_LONG error code
                                 * later. */

        /* If we are self signed, we break */
        if (cert_self_signed(x))
            break;
        /*
         * If asked see if we can find issuer in trusted store first
         */
        if (ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST) {
            ok = ctx->get_issuer(&xtmp, ctx, x);
            if (ok < 0)
                return ok;
            /*
             * If successful for now free up cert so it will be picked up
             * again later.
             */
            if (ok > 0) {
                X509_free(xtmp);
                break;
            }
        }

        /* If we were passed a cert chain, use it first */
        if (ctx->untrusted != NULL) {
            xtmp = find_issuer(ctx, sktmp, x);
            if (xtmp != NULL) {
                if (!sk_X509_push(ctx->chain, xtmp)) {
                    X509err(X509_F_X509_VERIFY_CERT, ERR_R_MALLOC_FAILURE);
                    goto end;
                }
                CRYPTO_add(&xtmp->references, 1, CRYPTO_LOCK_X509);
                (void)sk_X509_delete_ptr(sktmp, xtmp);
                ctx->last_untrusted++;
                x = xtmp;
                num++;
                /*
                 * reparse the full chain for the next one
                 */
                continue;
            }
        }
        break;
    }

    /* Remember how many untrusted certs we have */
    j = num;
    /*
     * at this point, chain should contain a list of untrusted certificates.
     * We now need to add at least one trusted one, if possible, otherwise we
     * complain.
     */

    do {
        /*
         * Examine last certificate in chain and see if it is self signed.
         */
        i = sk_X509_num(ctx->chain);
        x = sk_X509_value(ctx->chain, i - 1);
        if (cert_self_signed(x)) {
            /* we have a self signed certificate */
            if (sk_X509_num(ctx->chain) == 1) {
                /*
                 * We have a single self signed certificate: see if we can
                 * find it in the store. We must have an exact match to avoid
                 * possible impersonation.
                 */
                ok = ctx->get_issuer(&xtmp, ctx, x);
                if ((ok <= 0) || X509_cmp(x, xtmp)) {
                    ctx->error = X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT;
                    ctx->current_cert = x;
                    ctx->error_depth = i - 1;
                    if (ok == 1)
                        X509_free(xtmp);
                    bad_chain = 1;
                    ok = cb(0, ctx);
                    if (!ok)
                        goto end;
                } else {
                    /*
                     * We have a match: replace certificate with store
                     * version so we get any trust settings.
                     */
                    X509_free(x);
                    x = xtmp;
                    (void)sk_X509_set(ctx->chain, i - 1, x);
                    ctx->last_untrusted = 0;
                }
            } else {
                /*
                 * extract and save self signed certificate for later use
                 */
                chain_ss = sk_X509_pop(ctx->chain);
                ctx->last_untrusted--;
                num--;
                j--;
                x = sk_X509_value(ctx->chain, num - 1);
            }
        }
        /* We now lookup certs from the certificate store */
        for (;;) {
            /* If we have enough, we break */
            if (depth < num)
                break;
            /* If we are self signed, we break */
            if (cert_self_signed(x))
                break;
            ok = ctx->get_issuer(&xtmp, ctx, x);

            if (ok < 0)
                return ok;
            if (ok == 0)
                break;
            x = xtmp;
            if (!sk_X509_push(ctx->chain, x)) {
                X509_free(xtmp);
                X509err(X509_F_X509_VERIFY_CERT, ERR_R_MALLOC_FAILURE);
                return 0;
            }
            num++;
        }

        /* we now have our chain, lets check it... */
        i = check_trust(ctx);

        /* If explicitly rejected error */
        if (i == X509_TRUST_REJECTED)
            goto end;
        /*
         * If it's not explicitly trusted then check if there is an alternative
         * chain that could be used. We only do this if we haven't already
         * checked via TRUSTED_FIRST and the user hasn't switched off alternate
         * chain checking
         */
        retry = 0;
        if (i != X509_TRUST_TRUSTED
            && !(ctx->param->flags & X509_V_FLAG_TRUSTED_FIRST)
            && !(ctx->param->flags & X509_V_FLAG_NO_ALT_CHAINS)) {
            while (j-- > 1) {
                STACK_OF(X509) *chtmp = ctx->chain;
                xtmp2 = sk_X509_value(ctx->chain, j - 1);
                /*
                 * Temporarily set chain to NULL so we don't discount
                 * duplicates: the same certificate could be an untrusted
                 * CA found in the trusted store.
                 */
                ctx->chain = NULL;
                ok = ctx->get_issuer(&xtmp, ctx, xtmp2);
                ctx->chain = chtmp;
                if (ok < 0)
                    goto end;
                /* Check if we found an alternate chain */
                if (ok > 0) {
                    /*
                     * Free up the found cert we'll add it again later
                     */
                    X509_free(xtmp);

                    /*
                     * Dump all the certs above this point - we've found an
                     * alternate chain
                     */
                    while (num > j) {
                        xtmp = sk_X509_pop(ctx->chain);
                        X509_free(xtmp);
                        num--;
                        ctx->last_untrusted--;
                    }
                    retry = 1;
                    break;
                }
            }
        }
    } while (retry);

    /*
     * If not explicitly trusted then indicate error unless it's a single
     * self signed certificate in which case we've indicated an error already
     * and set bad_chain == 1
     */
    if (i != X509_TRUST_TRUSTED && !bad_chain) {
        if ((chain_ss == NULL) || !ctx->check_issued(ctx, x, chain_ss)) {
            if (ctx->last_untrusted >= num)
                ctx->error = X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY;
            else
                ctx->error = X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT;
            ctx->current_cert = x;
        } else {

            sk_X509_push(ctx->chain, chain_ss);
            num++;
            ctx->last_untrusted = num;
            ctx->current_cert = chain_ss;
            ctx->error = X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN;
            chain_ss = NULL;
        }

        ctx->error_depth = num - 1;
        bad_chain = 1;
        ok = cb(0, ctx);
        if (!ok)
            goto end;
    }

    /* We have the chain complete: now we need to check its purpose */
    ok = check_chain_extensions(ctx);

    if (!ok)
        goto end;

    /* Check name constraints */

    ok = check_name_constraints(ctx);

    if (!ok)
        goto end;

    ok = check_id(ctx);

    if (!ok)
        goto end;

    /* We may as well copy down any DSA parameters that are required */
    X509_get_pubkey_parameters(NULL, ctx->chain);

    /*
     * Check revocation status: we do this after copying parameters because
     * they may be needed for CRL signature verification.
     */

    ok = ctx->check_revocation(ctx);
    if (!ok)
        goto end;

    i = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain,
                                ctx->param->flags);
    if (i != X509_V_OK) {
        ctx->error = i;
        ctx->current_cert = sk_X509_value(ctx->chain, ctx->error_depth);
        ok = cb(0, ctx);
        if (!ok)
            goto end;
    }

    /* At this point, we have a chain and need to verify it */
    if (ctx->verify != NULL)
        ok = ctx->verify(ctx);
    else
        ok = internal_verify(ctx);
    if (!ok)
        goto end;

    /* RFC 3779 path validation, now that CRL check has been done */
    ok = v3_asid_validate_path(ctx);
    if (!ok)
        goto end;
    ok = v3_addr_validate_path(ctx);
    if (!ok)
        goto end;

    /* If we get this far evaluate policies */
    if (!bad_chain && (ctx->param->flags & X509_V_FLAG_POLICY_CHECK))
        ok = ctx->check_policy(ctx);
    if (ok)
        goto done;

 end:
    X509_get_pubkey_parameters(NULL, ctx->chain);
 done:
    sk_X509_free(sktmp);
    X509_free(chain_ss);
    return ok;
}

Project: openssl

static int check_cert(X509_STORE_CTX *ctx)
{
    X509_CRL *crl = NULL, *dcrl = NULL;
    X509 *x = NULL;
    int ok = 0, cnum = 0;
    unsigned int last_reasons = 0;
    cnum = ctx->error_depth;
    x = sk_X509_value(ctx->chain, cnum);
    ctx->current_cert = x;
    ctx->current_issuer = NULL;
    ctx->current_crl_score = 0;
    ctx->current_reasons = 0;
    while (ctx->current_reasons != CRLDP_ALL_REASONS) {
        last_reasons = ctx->current_reasons;
        /* Try to retrieve relevant CRL */
        if (ctx->get_crl)
            ok = ctx->get_crl(ctx, &crl, x);
        else
            ok = get_crl_delta(ctx, &crl, &dcrl, x);
        /*
         * If error looking up CRL, nothing we can do except notify callback
         */
        if (!ok) {
            ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
            ok = ctx->verify_cb(0, ctx);
            goto err;
        }
        ctx->current_crl = crl;
        ok = ctx->check_crl(ctx, crl);
        if (!ok)
            goto err;

        if (dcrl) {
            ok = ctx->check_crl(ctx, dcrl);
            if (!ok)
                goto err;
            ok = ctx->cert_crl(ctx, dcrl, x);
            if (!ok)
                goto err;
        } else
            ok = 1;

        /* Don't look in full CRL if delta reason is removefromCRL */
        if (ok != 2) {
            ok = ctx->cert_crl(ctx, crl, x);
            if (!ok)
                goto err;
        }

        X509_CRL_free(crl);
        X509_CRL_free(dcrl);
        crl = NULL;
        dcrl = NULL;
        /*
         * If reasons not updated we wont get anywhere by another iteration,
         * so exit loop.
         */
        if (last_reasons == ctx->current_reasons) {
            ctx->error = X509_V_ERR_UNABLE_TO_GET_CRL;
            ok = ctx->verify_cb(0, ctx);
            goto err;
        }
    }
 err:
    X509_CRL_free(crl);
    X509_CRL_free(dcrl);

    ctx->current_crl = NULL;
    return ok;

}

Project: openssl

static int check_hosts(X509 *x, X509_VERIFY_PARAM_ID *id)
{
    int i;
    int n = sk_OPENSSL_STRING_num(id->hosts);
    char *name;

    for (i = 0; i < n; ++i) {
        name = sk_OPENSSL_STRING_value(id->hosts, i);
        if (X509_check_host(x, name, 0, id->hostflags, &id->peername) > 0)
            return 1;
    }
    return n == 0;
}

Project: openssl

static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer)
{
    int ret;
    if (x == issuer)
        return cert_self_signed(x);
    ret = X509_check_issued(issuer, x);
    if (ret == X509_V_OK) {
        int i;
        X509 *ch;
        /* Special case: single self signed certificate */
        if (cert_self_signed(x) && sk_X509_num(ctx->chain) == 1)
            return 1;
        for (i = 0; i < sk_X509_num(ctx->chain); i++) {
            ch = sk_X509_value(ctx->chain, i);
            if (ch == issuer || !X509_cmp(ch, issuer)) {
                ret = X509_V_ERR_PATH_LOOP;
                break;
            }
        }
    }

    if (ret == X509_V_OK)
        return 1;
    /* If we haven't asked for issuer errors don't set ctx */
    if (!(ctx->param->flags & X509_V_FLAG_CB_ISSUER_CHECK))
        return 0;

    ctx->error = ret;
    ctx->current_cert = x;
    ctx->current_issuer = issuer;
    return ctx->verify_cb(0, ctx);
}

Project: openssl

static int check_revocation(X509_STORE_CTX *ctx)
{
    int i = 0, last = 0, ok = 0;
    if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK))
        return 1;
    if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL)
        last = sk_X509_num(ctx->chain) - 1;
    else {
        /* If checking CRL paths this isn't the EE certificate */
        if (ctx->parent)
            return 1;
        last = 0;
    }
    for (i = 0; i <= last; i++) {
        ctx->error_depth = i;
        ok = check_cert(ctx);
        if (!ok)
            return ok;
    }
    return 1;
}

Project: openssl

static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
{
    int i;
    X509 *issuer, *rv = NULL;;
    for (i = 0; i < sk_X509_num(sk); i++) {
        issuer = sk_X509_value(sk, i);
        if (ctx->check_issued(ctx, x, issuer)) {
            rv = issuer;
            if (x509_check_cert_time(ctx, rv, 1))
                break;
        }
    }
    return rv;
}

Project: openssl

static int get_crl_sk(X509_STORE_CTX *ctx, X509_CRL **pcrl, X509_CRL **pdcrl,
                      X509 **pissuer, int *pscore, unsigned int *preasons,
                      STACK_OF(X509_CRL) *crls)
{
    int i, crl_score, best_score = *pscore;
    unsigned int reasons, best_reasons = 0;
    X509 *x = ctx->current_cert;
    X509_CRL *crl, *best_crl = NULL;
    X509 *crl_issuer = NULL, *best_crl_issuer = NULL;

    for (i = 0; i < sk_X509_CRL_num(crls); i++) {
        crl = sk_X509_CRL_value(crls, i);
        reasons = *preasons;
        crl_score = get_crl_score(ctx, &crl_issuer, &reasons, crl, x);

        if (crl_score > best_score) {
            best_crl = crl;
            best_crl_issuer = crl_issuer;
            best_score = crl_score;
            best_reasons = reasons;
        }
    }

    if (best_crl) {
        X509_CRL_free(*pcrl);
        *pcrl = best_crl;
        *pissuer = best_crl_issuer;
        *pscore = best_score;
        *preasons = best_reasons;
        CRYPTO_add(&best_crl->references, 1, CRYPTO_LOCK_X509_CRL);
        X509_CRL_free(*pdcrl);
        *pdcrl = NULL;
        get_delta_sk(ctx, pdcrl, pscore, best_crl, crls);
    }

    if (best_score >= CRL_SCORE_VALID)
        return 1;

    return 0;
}

Project: openssl

static int internal_verify(X509_STORE_CTX *ctx)
{
    int ok = 0, n;
    X509 *xs, *xi;
    EVP_PKEY *pkey = NULL;
    int (*cb) (int xok, X509_STORE_CTX *xctx);

    cb = ctx->verify_cb;

    n = sk_X509_num(ctx->chain);
    ctx->error_depth = n - 1;
    n--;
    xi = sk_X509_value(ctx->chain, n);

    if (ctx->check_issued(ctx, xi, xi))
        xs = xi;
    else {
        if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
            xs = xi;
            goto check_cert;
        }
        if (n <= 0) {
            ctx->error = X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE;
            ctx->current_cert = xi;
            ok = cb(0, ctx);
            goto end;
        } else {
            n--;
            ctx->error_depth = n;
            xs = sk_X509_value(ctx->chain, n);
        }
    }

/*      ctx->error=0;  not needed */
    while (n >= 0) {
        ctx->error_depth = n;

        /*
         * Skip signature check for self signed certificates unless
         * explicitly asked for. It doesn't add any security and just wastes
         * time.
         */
        if (!xs->valid
            && (xs != xi
                || (ctx->param->flags & X509_V_FLAG_CHECK_SS_SIGNATURE))) {
            if ((pkey = X509_get_pubkey(xi)) == NULL) {
                ctx->error = X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY;
                ctx->current_cert = xi;
                ok = (*cb) (0, ctx);
                if (!ok)
                    goto end;
            } else if (X509_verify(xs, pkey) <= 0) {
                ctx->error = X509_V_ERR_CERT_SIGNATURE_FAILURE;
                ctx->current_cert = xs;
                ok = (*cb) (0, ctx);
                if (!ok) {
                    EVP_PKEY_free(pkey);
                    goto end;
                }
            }
            EVP_PKEY_free(pkey);
            pkey = NULL;
        }

        xs->valid = 1;

 check_cert:
        ok = x509_check_cert_time(ctx, xs, 0);
        if (!ok)
            goto end;

        /* The last error (if any) is still in the error value */
        ctx->current_issuer = xi;
        ctx->current_cert = xs;
        ok = (*cb) (1, ctx);
        if (!ok)
            goto end;

        n--;
        if (n >= 0) {
            xi = xs;
            xs = sk_X509_value(ctx->chain, n);
        }
    }
    ok = 1;
 end:
    return ok;
}