md5.java

文件验证

        a += ((b & d) | (c & ~d)) + x[ 1] + 0xf61e2562; /* 17 */
        a = ((a << 5) | (a >>> 27)) + b;
        d += ((a & c) | (b & ~c)) + x[ 6] + 0xc040b340; /* 18 */
        d = ((d << 9) | (d >>> 23)) + a;
        c += ((d & b) | (a & ~b)) + x[11] + 0x265e5a51; /* 19 */
        c = ((c << 14) | (c >>> 18)) + d;
        b += ((c & a) | (d & ~a)) + x[ 0] + 0xe9b6c7aa; /* 20 */
        b = ((b << 20) | (b >>> 12)) + c;
        
        a += ((b & d) | (c & ~d)) + x[ 5] + 0xd62f105d; /* 21 */
        a = ((a << 5) | (a >>> 27)) + b;
        d += ((a & c) | (b & ~c)) + x[10] + 0x02441453; /* 22 */
        d = ((d << 9) | (d >>> 23)) + a;
        c += ((d & b) | (a & ~b)) + x[15] + 0xd8a1e681; /* 23 */
        c = ((c << 14) | (c >>> 18)) + d;
        b += ((c & a) | (d & ~a)) + x[ 4] + 0xe7d3fbc8; /* 24 */
        b = ((b << 20) | (b >>> 12)) + c;
        
        a += ((b & d) | (c & ~d)) + x[ 9] + 0x21e1cde6; /* 25 */
        a = ((a << 5) | (a >>> 27)) + b;
        d += ((a & c) | (b & ~c)) + x[14] + 0xc33707d6; /* 26 */
        d = ((d << 9) | (d >>> 23)) + a;
        c += ((d & b) | (a & ~b)) + x[ 3] + 0xf4d50d87; /* 27 */
        c = ((c << 14) | (c >>> 18)) + d;
        b += ((c & a) | (d & ~a)) + x[ 8] + 0x455a14ed; /* 28 */
        b = ((b << 20) | (b >>> 12)) + c;
        
        a += ((b & d) | (c & ~d)) + x[13] + 0xa9e3e905; /* 29 */
        a = ((a << 5) | (a >>> 27)) + b;
        d += ((a & c) | (b & ~c)) + x[ 2] + 0xfcefa3f8; /* 30 */
        d = ((d << 9) | (d >>> 23)) + a;
        c += ((d & b) | (a & ~b)) + x[ 7] + 0x676f02d9; /* 31 */
        c = ((c << 14) | (c >>> 18)) + d;
        b += ((c & a) | (d & ~a)) + x[12] + 0x8d2a4c8a; /* 32 */
        b = ((b << 20) | (b >>> 12)) + c;
        
        
        /* Round 3 */
        a += (b ^ c ^ d) + x[ 5] + 0xfffa3942;      /* 33 */
        a = ((a << 4) | (a >>> 28)) + b;
        d += (a ^ b ^ c) + x[ 8] + 0x8771f681;      /* 34 */
        d = ((d << 11) | (d >>> 21)) + a;
        c += (d ^ a ^ b) + x[11] + 0x6d9d6122;      /* 35 */
        c = ((c << 16) | (c >>> 16)) + d;
        b += (c ^ d ^ a) + x[14] + 0xfde5380c;      /* 36 */
        b = ((b << 23) | (b >>> 9)) + c;
        
        a += (b ^ c ^ d) + x[ 1] + 0xa4beea44;      /* 37 */
        a = ((a << 4) | (a >>> 28)) + b;
        d += (a ^ b ^ c) + x[ 4] + 0x4bdecfa9;      /* 38 */
        d = ((d << 11) | (d >>> 21)) + a;
        c += (d ^ a ^ b) + x[ 7] + 0xf6bb4b60;      /* 39 */
        c = ((c << 16) | (c >>> 16)) + d;
        b += (c ^ d ^ a) + x[10] + 0xbebfbc70;      /* 40 */
        b = ((b << 23) | (b >>> 9)) + c;
        
        a += (b ^ c ^ d) + x[13] + 0x289b7ec6;      /* 41 */
        a = ((a << 4) | (a >>> 28)) + b;
        d += (a ^ b ^ c) + x[ 0] + 0xeaa127fa;      /* 42 */
        d = ((d << 11) | (d >>> 21)) + a;
        c += (d ^ a ^ b) + x[ 3] + 0xd4ef3085;      /* 43 */
        c = ((c << 16) | (c >>> 16)) + d;
        b += (c ^ d ^ a) + x[ 6] + 0x04881d05;      /* 44 */
        b = ((b << 23) | (b >>> 9)) + c;
        
        a += (b ^ c ^ d) + x[ 9] + 0xd9d4d039;      /* 33 */
        a = ((a << 4) | (a >>> 28)) + b;
        d += (a ^ b ^ c) + x[12] + 0xe6db99e5;      /* 34 */
        d = ((d << 11) | (d >>> 21)) + a;
        c += (d ^ a ^ b) + x[15] + 0x1fa27cf8;      /* 35 */
        c = ((c << 16) | (c >>> 16)) + d;
        b += (c ^ d ^ a) + x[ 2] + 0xc4ac5665;      /* 36 */
        b = ((b << 23) | (b >>> 9)) + c;
        
        
        /* Round 4 */
        a += (c ^ (b | ~d)) + x[ 0] + 0xf4292244; /* 49 */
        a = ((a << 6) | (a >>> 26)) + b;
        d += (b ^ (a | ~c)) + x[ 7] + 0x432aff97; /* 50 */
        d = ((d << 10) | (d >>> 22)) + a;
        c += (a ^ (d | ~b)) + x[14] + 0xab9423a7; /* 51 */
        c = ((c << 15) | (c >>> 17)) + d;
        b += (d ^ (c | ~a)) + x[ 5] + 0xfc93a039; /* 52 */
        b = ((b << 21) | (b >>> 11)) + c;
        
        a += (c ^ (b | ~d)) + x[12] + 0x655b59c3; /* 53 */
        a = ((a << 6) | (a >>> 26)) + b;
        d += (b ^ (a | ~c)) + x[ 3] + 0x8f0ccc92; /* 54 */
        d = ((d << 10) | (d >>> 22)) + a;
        c += (a ^ (d | ~b)) + x[10] + 0xffeff47d; /* 55 */
        c = ((c << 15) | (c >>> 17)) + d;
        b += (d ^ (c | ~a)) + x[ 1] + 0x85845dd1; /* 56 */
        b = ((b << 21) | (b >>> 11)) + c;
        
        a += (c ^ (b | ~d)) + x[ 8] + 0x6fa87e4f; /* 57 */
        a = ((a << 6) | (a >>> 26)) + b;
        d += (b ^ (a | ~c)) + x[15] + 0xfe2ce6e0; /* 58 */
        d = ((d << 10) | (d >>> 22)) + a;
        c += (a ^ (d | ~b)) + x[ 6] + 0xa3014314; /* 59 */
        c = ((c << 15) | (c >>> 17)) + d;
        b += (d ^ (c | ~a)) + x[13] + 0x4e0811a1; /* 60 */
        b = ((b << 21) | (b >>> 11)) + c;
        
        a += (c ^ (b | ~d)) + x[ 4] + 0xf7537e82; /* 61 */
        a = ((a << 6) | (a >>> 26)) + b;
        d += (b ^ (a | ~c)) + x[11] + 0xbd3af235; /* 62 */
        d = ((d << 10) | (d >>> 22)) + a;
        c += (a ^ (d | ~b)) + x[ 2] + 0x2ad7d2bb; /* 63 */
        c = ((c << 15) | (c >>> 17)) + d;
        b += (d ^ (c | ~a)) + x[ 9] + 0xeb86d391; /* 64 */
        b = ((b << 21) | (b >>> 11)) + c;
        
        state.state[0] += a;
        state.state[1] += b;
        state.state[2] += c;
        state.state[3] += d;
    }
    
    /**
     * Updates hash with the bytebuffer given (using at maximum length bytes from
     * that buffer)
     *
     * @param stat   Which state is updated
     * @param buffer Array of bytes to be hashed
     * @param offset Offset to buffer array
     * @param length Use at maximum `length' bytes (absolute
     *               maximum is buffer.length)
     */
    public void Update (MD5State stat, byte buffer[], int offset, int length) {
        int index, partlen, i, start;
        finals = null;
        
        /* Length can be told to be shorter, but not inter */
        if ((length - offset)> buffer.length)
            length = buffer.length - offset;
        
        /* compute number of bytes mod 64 */
        
        index = (int) (stat.count & 0x3f);
        stat.count += length;
        
        partlen = 64 - index;
        
        if (length >= partlen) {
            
            // update state (using native method) to reflect input
            
            if (native_lib_loaded) {
                if (partlen == 64) {
                    partlen = 0;
                } else {
                    for (i = 0; i < partlen; i++)
                        stat.buffer[i + index] = buffer[i + offset];
                    Transform_native(stat.state, stat.buffer, 0, 64);
                }
                i = partlen + ((length - partlen) / 64) * 64;
                
                // break into chunks to guard against stack overflow in JNI
                
                int transformLength = length - partlen;
                int transformOffset = partlen + offset;
                final int MAX_LENGTH = 65536; // prevent stack overflow in JNI
                while (true) {
                    if (transformLength > MAX_LENGTH) {
                        Transform_native(stat.state, buffer, transformOffset, MAX_LENGTH);
                        transformLength -= MAX_LENGTH;
                        transformOffset += MAX_LENGTH;
                    } else {
                        Transform_native(stat.state, buffer, transformOffset, transformLength);
                        break;
                    }
                }
            }
            
            // update state (using only Java) to reflect input
            
            else {
                int[] decode_buf = new int[16];
                if (partlen == 64) {
                    partlen = 0;
                } else {
                    for (i = 0; i < partlen; i++)
                        stat.buffer[i + index] = buffer[i + offset];
                    Transform(stat, stat.buffer, 0, decode_buf);
                }
                for (i = partlen; (i + 63) < length; i+= 64) {
                    Transform(stat, buffer, i + offset, decode_buf);
                }
            }
            index = 0;
        } else {
            i = 0;
        }
        
        /* buffer remaining input */
        if (i < length) {
            start = i;
            for (; i < length; i++) {
                stat.buffer[index + i - start] = buffer[i + offset];
            }
        }
    }
    
    /* 
     * Update()s for other datatypes than byte[] also. Update(byte[], int)
     * is only the main driver.
     */
    
    /**
     * Plain update, updates this object
     **/
    public void Update (byte buffer[], int offset, int length) {
        Update(this.state, buffer, offset, length);
    }
    
    public void Update (byte buffer[], int length) {
        Update(this.state, buffer, 0, length);
    }
    
    /**
     * Updates hash with given array of bytes
     *
     * @param buffer Array of bytes to use for updating the hash
     **/
    public void Update (byte buffer[]) {
        Update(buffer, 0, buffer.length);
    }
    
    /**
     * Updates hash with a single byte
     *
     * @param b Single byte to update the hash
     **/
    public void Update (byte b) {
        byte buffer[] = new byte[1];
        buffer[0] = b;
        
        Update(buffer, 1);
    }
    
    /**
     * Update buffer with given string.  Note that because the version of
     * the s.getBytes() method without parameters is used to convert the
     * string to a byte array, the results of this method may be different
     * on different platforms.  The s.getBytes() method converts the string
     * into a byte array using the current platform's default character set
     * and may therefore have different results on platforms with different
     * default character sets.  If a version that works consistently
     * across platforms with different default character sets is desired,
     * use the overloaded version of the Update() method which takes a
     * string and a character encoding.
     *
     * @param s String to be update to hash (is used as s.getBytes())
     **/
    public void Update (String s) {
        byte chars[] = s.getBytes();
        Update(chars, chars.length);
    }
    
    /**
     * Update buffer with given string using the given encoding.  If the
     * given encoding is null, the encoding "ISO8859_1" is used.
     *
     * @param s            String to be update to hash (is used as
     *                     s.getBytes(charset_name))
     * @param charset_name The character set to use to convert s to a
     *                     byte array, or null if the "ISO8859_1"
     *                     character set is desired.
     * @exception          java.io.UnsupportedEncodingException If the named
     *                     charset is not supported.
     **/
    public void Update (String s, String charset_name) throws java.io.UnsupportedEncodingException {
        if (charset_name == null) charset_name = "ISO8859_1";
        byte chars[] = s.getBytes(charset_name);
        Update(chars, chars.length);
    }