static int check_trust(X509_STORE_CTX *ctx, int num_untrusted)
{
    int i;
    X509 *x = NULL;
    X509 *mx;
    SSL_DANE *dane = ctx->dane;
    int num = sk_X509_num(ctx->chain);
    int trust;
    if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) {
        switch (trust = check_dane_issuer(ctx, num_untrusted)) {
        case X509_TRUST_TRUSTED:
        case X509_TRUST_REJECTED:
            return trust;
        }
    }
    for (i = num_untrusted; i < num; i++) {
        x = sk_X509_value(ctx->chain, i);
        trust = X509_check_trust(x, ctx->param->trust, 0);
        if (trust == X509_TRUST_TRUSTED)
            goto trusted;
        if (trust == X509_TRUST_REJECTED)
            goto rejected;
    }
    if (num_untrusted < num) {
        if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN)
            goto trusted;
        return X509_TRUST_UNTRUSTED;
    }
    if (num_untrusted == num && ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
        i = 0;
        x = sk_X509_value(ctx->chain, i);
        mx = lookup_cert_match(ctx, x);
        if (!mx)
            return X509_TRUST_UNTRUSTED;
        trust = X509_check_trust(mx, ctx->param->trust, 0);
        if (trust == X509_TRUST_REJECTED) {
            X509_free(mx);
            goto rejected;
        }
        (void) sk_X509_set(ctx->chain, 0, mx);
        X509_free(x);
        ctx->num_untrusted = 0;
        goto trusted;
    }
    return X509_TRUST_UNTRUSTED;
 rejected:
    if (!verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED))
        return X509_TRUST_REJECTED;
    return X509_TRUST_UNTRUSTED;
 trusted:
    if (!DANETLS_ENABLED(dane))
        return X509_TRUST_TRUSTED;
    if (dane->pdpth < 0)
        dane->pdpth = num_untrusted;
    if (dane->mdpth >= 0)
        return X509_TRUST_TRUSTED;
    return X509_TRUST_UNTRUSTED;
}
['static int check_trust(X509_STORE_CTX *ctx, int num_untrusted)\n{\n    int i;\n    X509 *x = NULL;\n    X509 *mx;\n    SSL_DANE *dane = ctx->dane;\n    int num = sk_X509_num(ctx->chain);\n    int trust;\n    if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) {\n        switch (trust = check_dane_issuer(ctx, num_untrusted)) {\n        case X509_TRUST_TRUSTED:\n        case X509_TRUST_REJECTED:\n            return trust;\n        }\n    }\n    for (i = num_untrusted; i < num; i++) {\n        x = sk_X509_value(ctx->chain, i);\n        trust = X509_check_trust(x, ctx->param->trust, 0);\n        if (trust == X509_TRUST_TRUSTED)\n            goto trusted;\n        if (trust == X509_TRUST_REJECTED)\n            goto rejected;\n    }\n    if (num_untrusted < num) {\n        if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN)\n            goto trusted;\n        return X509_TRUST_UNTRUSTED;\n    }\n    if (num_untrusted == num && ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {\n        i = 0;\n        x = sk_X509_value(ctx->chain, i);\n        mx = lookup_cert_match(ctx, x);\n        if (!mx)\n            return X509_TRUST_UNTRUSTED;\n        trust = X509_check_trust(mx, ctx->param->trust, 0);\n        if (trust == X509_TRUST_REJECTED) {\n            X509_free(mx);\n            goto rejected;\n        }\n        (void) sk_X509_set(ctx->chain, 0, mx);\n        X509_free(x);\n        ctx->num_untrusted = 0;\n        goto trusted;\n    }\n    return X509_TRUST_UNTRUSTED;\n rejected:\n    if (!verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED))\n        return X509_TRUST_REJECTED;\n    return X509_TRUST_UNTRUSTED;\n trusted:\n    if (!DANETLS_ENABLED(dane))\n        return X509_TRUST_TRUSTED;\n    if (dane->pdpth < 0)\n        dane->pdpth = num_untrusted;\n    if (dane->mdpth >= 0)\n        return X509_TRUST_TRUSTED;\n    return X509_TRUST_UNTRUSTED;\n}', 'DEFINE_STACK_OF(X509)', 'int OPENSSL_sk_num(const OPENSSL_STACK *st)\n{\n    if (st == NULL)\n        return -1;\n    return st->num;\n}', 'void *OPENSSL_sk_value(const OPENSSL_STACK *st, int i)\n{\n    if (st == NULL || i < 0 || i >= st->num)\n        return NULL;\n    return (void *)st->data[i];\n}', 'static X509 *lookup_cert_match(X509_STORE_CTX *ctx, X509 *x)\n{\n    STACK_OF(X509) *certs;\n    X509 *xtmp = NULL;\n    int i;\n    certs = ctx->lookup_certs(ctx, X509_get_subject_name(x));\n    if (certs == NULL)\n        return NULL;\n    for (i = 0; i < sk_X509_num(certs); i++) {\n        xtmp = sk_X509_value(certs, i);\n        if (!X509_cmp(xtmp, x))\n            break;\n    }\n    if (i < sk_X509_num(certs))\n        X509_up_ref(xtmp);\n    else\n        xtmp = NULL;\n    sk_X509_pop_free(certs, X509_free);\n    return xtmp;\n}', 'X509_NAME *X509_get_subject_name(const X509 *a)\n{\n    return (a->cert_info.subject);\n}']