int adbd_tls_verify_cert(X509_STORE_CTX* ctx, std::string* auth_key) {
    if (!auth_required) {
        // Any key will do.
        LOG(INFO) << __func__ << ": auth not required";
        return 1;
    }

    bool authorized = false;
    X509* cert = X509_STORE_CTX_get0_cert(ctx);
    if (cert == nullptr) {
        LOG(INFO) << "got null x509 certificate";
        return 0;
    }
    bssl::UniquePtr<EVP_PKEY> evp_pkey(X509_get_pubkey(cert));
    if (evp_pkey == nullptr) {
        LOG(INFO) << "got null evp_pkey from x509 certificate";
        return 0;
    }

    IteratePublicKeys([&](std::string_view public_key) {
        // TODO: do we really have to support both ' ' and '\t'?
        std::vector<std::string> split = android::base::Split(std::string(public_key), " \t");
        uint8_t keybuf[ANDROID_PUBKEY_ENCODED_SIZE + 1];
        const std::string& pubkey = split[0];
        if (b64_pton(pubkey.c_str(), keybuf, sizeof(keybuf)) != ANDROID_PUBKEY_ENCODED_SIZE) {
            LOG(ERROR) << "Invalid base64 key " << pubkey;
            return true;
        }

        RSA* key = nullptr;
        if (!android_pubkey_decode(keybuf, ANDROID_PUBKEY_ENCODED_SIZE, &key)) {
            LOG(ERROR) << "Failed to parse key " << pubkey;
            return true;
        }

        bool verified = false;
        bssl::UniquePtr<EVP_PKEY> known_evp(EVP_PKEY_new());
        EVP_PKEY_set1_RSA(known_evp.get(), key);
        if (EVP_PKEY_cmp(known_evp.get(), evp_pkey.get())) {
            LOG(INFO) << "Matched auth_key=" << public_key;
            verified = true;
        } else {
            LOG(INFO) << "auth_key doesn't match [" << public_key << "]";
        }
        RSA_free(key);
        if (verified) {
            *auth_key = public_key;
            authorized = true;
            return false;
        }

        return true;
    });

    return authorized ? 1 : 0;
}