/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.conscrypt;

import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * Provides an interface to OpenSSL's BIO system directly from a Java
 * InputStream. It allows an OpenSSL API to read directly from something more
 * flexible interface than a byte array.
 */
public class OpenSSLBIOInputStream extends FilterInputStream {
    private long ctx;

    public OpenSSLBIOInputStream(InputStream is) {
        super(is);

        ctx = NativeCrypto.create_BIO_InputStream(this);
    }

    public long getBioContext() {
        return ctx;
    }

    public void release() {
        NativeCrypto.BIO_free_all(ctx);
    }

    /**
     * Similar to a {@code readLine} method, but matches what OpenSSL expects
     * from a {@code BIO_gets} method.
     */
    public int gets(byte[] buffer) throws IOException {
        if (buffer == null || buffer.length == 0) {
            return 0;
        }

        int offset = 0;
        int inputByte = 0;
        while (offset < buffer.length) {
            inputByte = read();
            if (inputByte == -1) {
                // EOF
                break;
            }
            if (inputByte == '\n') {
                if (offset == 0) {
                    // If we haven't read anything yet, ignore CRLF.
                    continue;
                } else {
                    break;
                }
            }

            buffer[offset++] = (byte) inputByte;
        }

        return offset;
    }
}