AES,MD5,BASE64,Paillier加密算法
1.AES：
import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
public class AES2Cryption {
public static String encrypt(String seed, String cleartext) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] result = encrypt(rawKey, cleartext.getBytes());
return toHex(result);
}
public static String decrypt(String seed, String encrypted) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] enc = toByte(encrypted);
byte[] result = decrypt(rawKey, enc);
return new String(result);
}
private static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed);
kgen.init(128, sr); // 192 and 256 bits may not be available
SecretKey skey = kgen.generateKey();
byte[] raw = skey.getEncoded();
return raw;
}
private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encrypted = cipher.doFinal(clear);
return encrypted;
}
private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception {
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, skeySpec);
byte[] decrypted = cipher.doFinal(encrypted);
return decrypted;
}
public static String toHex(String txt) {
return toHex(txt.getBytes());
}
public static String fromHex(String hex) {
return new String(toByte(hex));
}
public static byte[] toByte(String hexString) {
int len = hexString.length()/2;
byte[] result = new byte[len];
for (int i = 0; i < len; i++)
result[i] = Integer.valueOf(hexString.substring(2*i, 2*i+2), 16).byteValue();
return result;
}
public static String toHex(byte[] buf) {
if (buf == null)
return "";
StringBuffer result = new StringBuffer(2*buf.length);
for (int i = 0; i < buf.length; i++) {
appendHex(result, buf[i]);
}
return result.toString();
}
private final static String HEX = "0123456789ABCDEF";
private static void appendHex(StringBuffer sb, byte b) {
sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));
}
} 2.Paillier:
package edu.kxw.encryptionAlgorithm;
/**
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see
* References:
* [1] Pascal Paillier, "Public-Key Cryptosystems Based on Composite Degree Residuosity Classes," EUROCRYPT'99.
* URL: http://www.gemplus.com/smart/rd/publications/pdf/Pai99pai.pdf
*
* [2] Paillier cryptosystem from Wikipedia.
* URL: http://en.wikipedia.org/wiki/Paillier_cryptosystem
* @author Kun Liu ([email protected])
* @version 1.0
*/
public class Paillier {
/**
* p and q are two large primes.
* lambda = lcm(p-1, q-1) = (p-1)*(q-1)/gcd(p-1, q-1).
*/
private BigInteger p, q, lambda;
/**
* n = p*q, where p and q are two large primes.
*/
public BigInteger n;
/**
* nsquare = n*n
*/
public BigInteger nsquare;
/**
* a random integer in Z*_{n^2} where gcd (L(g^lambda mod n^2), n) = 1.
*/
private BigInteger g;
/**
* number of bits of modulus
*/
private int bitLength;
/**
* Constructs an instance of the Paillier cryptosystem.
* @param bitLengthVal number of bits of modulus
* @param certainty The probability that the new BigInteger represents a prime number will exceed (1 - 2^(-certainty)). The execution time of this constructor is proportional to the value of this parameter.
*/
public Paillier(int bitLengthVal, int certainty) {
KeyGeneration(bitLengthVal, certainty);
}
/**
* Constructs an instance of the Paillier cryptosystem with 512 bits of modulus and at least 1-2^(-64) certainty of primes generation.
*/
public Paillier() {
KeyGeneration(512, 64);
}
/**
* Sets up the public key and private key.
* @param bitLengthVal number of bits of modulus.
* @param certainty The probability that the new BigInteger represents a prime number will exceed (1 - 2^(-certainty)). The execution time of this constructor is proportional to the value of this parameter.
*/
public void KeyGeneration(int bitLengthVal, int certainty) {
bitLength = bitLengthVal;
/*Constructs two randomly generated positive BigIntegers that are probably prime, with the specified bitLength and certainty.*/
p = new BigInteger(bitLength / 2, certainty, new Random());
q = new BigInteger(bitLength / 2, certainty, new Random());
n = p.multiply(q);
nsquare = n.multiply(n);
g = new BigInteger("2");
lambda = p.subtract(BigInteger.ONE).multiply(q.subtract(BigInteger.ONE)).divide(
p.subtract(BigInteger.ONE).gcd(q.subtract(BigInteger.ONE)));
/* check whether g is good.*/
if (g.modPow(lambda, nsquare).subtract(BigInteger.ONE).divide(n).gcd(n).intValue() != 1) {
System.out.println("g is not good. Choose g again.");
System.exit(1);
}
}
/**
* Encrypts plaintext m. ciphertext c = g^m * r^n mod n^2. This function explicitly requires random input r to help with encryption.
* @param m plaintext as a BigInteger
* @param r random plaintext to help with encryption
* @return ciphertext as a BigInteger
*/
public BigInteger Encryption(BigInteger m, BigInteger r) {
return g.modPow(m, nsquare).multiply(r.modPow(n, nsquare)).mod(nsquare);
}
/**
* Encrypts plaintext m. ciphertext c = g^m * r^n mod n^2. This function automatically generates random input r (to help with encryption).
* @param m plaintext as a BigInteger
* @return ciphertext as a BigInteger
*/
public BigInteger Encryption(BigInteger m) {
BigInteger r = new BigInteger(bitLength, new Random());
return g.modPow(m, nsquare).multiply(r.modPow(n, nsquare)).mod(nsquare);
}
/**
* Decrypts ciphertext c. plaintext m = L(c^lambda mod n^2) * u mod n, where u = (L(g^lambda mod n^2))^(-1) mod n.
* @param c ciphertext as a BigInteger
* @return plaintext as a BigInteger
*/
public BigInteger Decryption(BigInteger c) {
BigInteger u = g.modPow(lambda, nsquare).subtract(BigInteger.ONE).divide(n).modInverse(n);
return c.modPow(lambda, nsquare).subtract(BigInteger.ONE).divide(n).multiply(u).mod(n);
}
/**
* main function
* @param str intput string
*/
public static void main(String[] str) {
/* instantiating an object of Paillier cryptosystem*/
Paillier paillier = new Paillier();
/* instantiating two plaintext msgs*/
BigInteger m1 = new BigInteger("20");
BigInteger m2 = new BigInteger("60");
/* encryption*/
BigInteger em1 = paillier.Encryption(m1);
BigInteger em2 = paillier.Encryption(m2);
/* printout encrypted text*/
System.out.println(em1);
System.out.println(em2);
/* printout decrypted text */
System.out.println(paillier.Decryption(em1).toString());
System.out.println(paillier.Decryption(em2).toString());
/* test homomorphic properties -> D(E(m1)*E(m2) mod n^2) = (m1 + m2) mod n */
BigInteger product_em1em2 = em1.multiply(em2).mod(paillier.nsquare);
BigInteger sum_m1m2 = m1.add(m2).mod(paillier.n);
System.out.println("original sum: " + sum_m1m2.toString());
System.out.println("decrypted sum: " + paillier.Decryption(product_em1em2).toString());
/* test homomorphic properties -> D(E(m1)^m2 mod n^2) = (m1*m2) mod n */
BigInteger expo_em1m2 = em1.modPow(m2, paillier.nsquare);
BigInteger prod_m1m2 = m1.multiply(m2).mod(paillier.n);
System.out.println("original product: " + prod_m1m2.toString());
System.out.println("decrypted product: " + paillier.Decryption(expo_em1m2).toString());
}
}3.Base64:
/**
*
*/
package com.gootrip.util;
/*
* Base64 encoding and decoding.
* Copyright (C) 2001-2004 Stephen Ostermiller
* http://ostermiller.org/contact.pl?regarding=Java+Utilities
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* See COPYING.TXT for details.
* http://www.jq-school.com
*/
import java.io.*;
import gnu.getopt.*;
import java.text.MessageFormat;
import java.util.ResourceBundle;
import java.util.Locale;
/**
* Implements Base64 encoding and decoding as defined by RFC 2045: "Multipurpose Internet
* Mail Extensions (MIME) Part One: Format of Internet Message Bodies" page 23.
* More information about this class is available from ostermiller.org.
*
*
* The Base64 Content-Transfer-Encoding is designed to represent
* arbitrary sequences of octets in a form that need not be humanly
* readable. The encoding and decoding algorithms are simple, but the
* encoded data are consistently only about 33 percent larger than the
* unencoded data. This encoding is virtually identical to the one used
* in Privacy Enhanced Mail (PEM) applications, as defined in RFC 1421.
*
* A 65-character subset of US-ASCII is used, enabling 6 bits to be
* represented per printable character. (The extra 65th character, "=",
* is used to signify a special processing function.)
*
* NOTE: This subset has the important property that it is represented
* identically in all versions of ISO 646, including US-ASCII, and all
* characters in the subset are also represented identically in all
* versions of EBCDIC. Other popular encodings, such as the encoding
* used by the uuencode utility, Macintosh binhex 4.0 [RFC-1741], and
* the base85 encoding specified as part of Level 2 PostScript, do no
* share these properties, and thus do not fulfill the portability
* requirements a binary transport encoding for mail must meet.
*
* The encoding process represents 24-bit groups of input bits as output
* strings of 4 encoded characters. Proceeding from left to right, a
* 24-bit input group is formed by concatenating 3 8bit input groups.
* These 24 bits are then treated as 4 concatenated 6-bit groups, each
* of which is translated into a single digit in the base64 alphabet.
* When encoding a bit stream via the base64 encoding, the bit stream
* must be presumed to be ordered with the most-significant-bit first.
* That is, the first bit in the stream will be the high-order bit in
* the first 8bit byte, and the eighth bit will be the low-order bit in
* the first 8bit byte, and so on.
*
* Each 6-bit group is used as an index into an array of 64 printable
* characters. The character referenced by the index is placed in the
* output string. These characters, identified in Table 1, below, are
* selected so as to be universally representable, and the set excludes
* characters with particular significance to SMTP (e.g., ".", CR, LF)
* and to the multipart boundary delimiters defined in RFC 2046 (e.g.,
* "-").
*
* Table 1: The Base64 Alphabet
*
* Value Encoding Value Encoding Value Encoding Value Encoding
* 0 A 17 R 34 i 51 z
* 1 B 18 S 35 j 52 0
* 2 C 19 T 36 k 53 1
* 3 D 20 U 37 l 54 2
* 4 E 21 V 38 m 55 3
* 5 F 22 W 39 n 56 4
* 6 G 23 X 40 o 57 5
* 7 H 24 Y 41 p 58 6
* 8 I 25 Z 42 q 59 7
* 9 J 26 a 43 r 60 8
* 10 K 27 b 44 s 61 9
* 11 L 28 c 45 t 62 +
* 12 M 29 d 46 u 63 /
* 13 N 30 e 47 v
* 14 O 31 f 48 w (pad) =
* 15 P 32 g 49 x
* 16 Q 33 h 50 y
*
* The encoded output stream must be represented in lines of no more
* than 76 characters each. All line breaks or other characters no
* found in Table 1 must be ignored by decoding software. In base64
* data, characters other than those in Table 1, line breaks, and other
* white space probably indicate a transmission error, about which a
* warning message or even a message rejection might be appropriate
* under some circumstances.
*
* Special processing is performed if fewer than 24 bits are available
* at the end of the data being encoded. A full encoding quantum is
* always completed at the end of a body. When fewer than 24 input bits
* are available in an input group, zero bits are added (on the right)
* to form an integral number of 6-bit groups. Padding at the end of
* the data is performed using the "=" character. Since all base64
* input is an integral number of octets, only the following cases can
* arise: (1) the final quantum of encoding input is an integral
* multiple of 24 bits; here, the final unit of encoded output will be
* an integral multiple of 4 characters with no "=" padding, (2) the
* final quantum of encoding input is exactly 8 bits; here, the final
* unit of encoded output will be two characters followed by two "="
* padding characters, or (3) the final quantum of encoding input is
* exactly 16 bits; here, the final unit of encoded output will be three
* characters followed by one "=" padding character.
*
* Because it is used only for padding at the end of the data, the
* occurrence of any "=" characters may be taken as evidence that the
* end of the data has been reached (without truncation in transit). No
* such assurance is possible, however, when the number of octets
* transmitted was a multiple of three and no "=" characters are
* present.
*
* Any characters outside of the base64 alphabet are to be ignored in
* base64-encoded data.
*
* Care must be taken to use the proper octets for line breaks if base64
* encoding is applied directly to text material that has not been
* converted to canonical form. In particular, text line breaks must be
* converted into CRLF sequences prior to base64 encoding. The
* important thing to note is that this may be done directly by the
* encoder rather than in a prior canonization step in some
* implementations.
*
* NOTE: There is no need to worry about quoting potential boundary
* delimiters within base64-encoded bodies within multipart entities
* because no hyphen characters are used in the base64 encoding.
*
*
* @author Stephen Ostermiller http://ostermiller.org/contact.pl?regarding=Java+Utilities
* @since ostermillerutils 1.00.00
*/
public class Base64 {
/**
* Symbol that represents the end of an input stream
*
* @since ostermillerutils 1.00.00
*/
private static final int END_OF_INPUT = -1;
/**
* A character that is not a valid base 64 character.
*
* @since ostermillerutils 1.00.00
*/
private static final int NON_BASE_64 = -1;
/**
* A character that is not a valid base 64 character.
*
* @since ostermillerutils 1.00.00
*/
private static final int NON_BASE_64_WHITESPACE = -2;
/**
* A character that is not a valid base 64 character.
*
* @since ostermillerutils 1.00.00
*/
private static final int NON_BASE_64_PADDING = -3;
/**
* This class need not be instantiated, all methods are static.
*
* @since ostermillerutils 1.00.00
*/
private Base64(){
}
/**
* Table of the sixty-four characters that are used as
* the Base64 alphabet: [A-Za-z0-9+/]
*
* @since ostermillerutils 1.00.00
*/
protected static final byte[] base64Chars = {
'A','B','C','D','E','F','G','H',
'I','J','K','L','M','N','O','P',
'Q','R','S','T','U','V','W','X',
'Y','Z','a','b','c','d','e','f',
'g','h','i','j','k','l','m','n',
'o','p','q','r','s','t','u','v',
'w','x','y','z','0','1','2','3',
'4','5','6','7','8','9','+','/',
};
/**
* Reverse lookup table for the Base64 alphabet.
* reversebase64Chars[byte] gives n for the nth Base64
* character or negative if a character is not a Base64 character.
*
* @since ostermillerutils 1.00.00
*/
protected static final byte[] reverseBase64Chars = new byte[0x100];
static {
// Fill in NON_BASE_64 for all characters to start with
for (int i=0; i",
"-f --" + labels.getString("force.option"),
"--" + labels.getString("noforce.option"),
"-v --" + labels.getString("verbose.option"),
"-q --" + labels.getString("quiet.option"),
"-Q --" + labels.getString("reallyquiet.option"),
"--" + labels.getString("file.option"),
"--" + labels.getString("string.option"),
"-n --" + labels.getString("newline.option"),
"--" + labels.getString("nonewline.option"),
};
int maxLength = 0;
for (int i=0; i\n" +
labels.getString("purpose.message") + "\n" +
" " + labels.getString("stdin.message") + "\n" +
" " + StringHelper.postpad(helpFlags[0] ,maxLength, ' ') + labels.getString("help.message") + "\n" +
" " + StringHelper.postpad(helpFlags[1] ,maxLength, ' ') + labels.getString("version.message") + "\n" +
" " + StringHelper.postpad(helpFlags[2] ,maxLength, ' ') + labels.getString("about.message") + "\n" +
" " + StringHelper.postpad(helpFlags[3] ,maxLength, ' ') + labels.getString("g.message") + " (" + labels.getString("default") + ")\n" +
" " + StringHelper.postpad(helpFlags[4] ,maxLength, ' ') + labels.getString("e.message") + "\n" +
" " + StringHelper.postpad(helpFlags[5] ,maxLength, ' ') + labels.getString("l.message") + " (" + labels.getString("default") + ")\n" +
" " + StringHelper.postpad(helpFlags[6] ,maxLength, ' ') + labels.getString("nolines.message") + "\n" +
" " + StringHelper.postpad(helpFlags[7] ,maxLength, ' ') + labels.getString("d.message") + "\n" +
" " + StringHelper.postpad(helpFlags[8] ,maxLength, ' ') + labels.getString("a.message") + "\n" +
" " + StringHelper.postpad(helpFlags[9] ,maxLength, ' ') + labels.getString("decodegood.message") + " (" + labels.getString("default") + ")\n" +
" " + StringHelper.postpad(helpFlags[10] ,maxLength, ' ') + labels.getString("x.message") + "\n" +
" " + StringHelper.postpad(helpFlags[11] ,maxLength, ' ') + labels.getString("f.message") + "\n" +
" " + StringHelper.postpad(helpFlags[12] ,maxLength, ' ') + labels.getString("noforce.message") + " (" + labels.getString("default") + ")\n" +
" " + StringHelper.postpad(helpFlags[13] ,maxLength, ' ') + labels.getString("v.message") + " (" + labels.getString("default") + ")\n" +
" " + StringHelper.postpad(helpFlags[14] ,maxLength, ' ') + labels.getString("q.message") + "\n" +
" " + StringHelper.postpad(helpFlags[15] ,maxLength, ' ') + labels.getString("Q.message") + "\n" +
" " + StringHelper.postpad(helpFlags[16] ,maxLength, ' ') + labels.getString("file.message") + "\n" +
" " + StringHelper.postpad(helpFlags[17] ,maxLength, ' ') + labels.getString("string.message") + "\n" +
" " + StringHelper.postpad(helpFlags[18] ,maxLength, ' ') + labels.getString("newline.message") + "\n" +
" " + StringHelper.postpad(helpFlags[19] ,maxLength, ' ') + labels.getString("nonewline.message") + "\n"
);
System.exit(0);
} break;
case 2:{
// print out the version message
System.out.println(MessageFormat.format(labels.getString("version"), (Object[])new String[] {version}));
System.exit(0);
} break;
case 3:{
System.out.println(
labels.getString("base64") + " -- " + labels.getString("purpose.message") + "\n" +
MessageFormat.format(labels.getString("copyright"), (Object[])new String[] {"2001-2002", "Stephen Ostermiller (http://ostermiller.org/contact.pl?regarding=Java+Utilities)"}) + "\n\n" +
labels.getString("license")
);
System.exit(0);
} break;
case 'd':{
action = ACTION_DECODE;
} break;
case 'a':{
forceDecode = true;
} break;
case 5:{
forceDecode = false;
} break;
case 'e':{
action = ACTION_ENCODE;
} break;
case 'l':{
lineBreaks = true;
} break;
case 6:{
lineBreaks = false;
} break;
case 'g':{
action = ACTION_GUESS;
} break;
case 'x':{
extension = opts.getOptarg();
if (extension == null) extension = "";
} break;
case 'f':{
force = true;
} break;
case 4:{
force = false;
} break;
case 'v':{
printMessages = true;
printErrors = true;
} break;
case 'q':{
printMessages = false;
printErrors = true;
} break;
case 'Q':{
printMessages = false;
printErrors = false;
} break;
case 7: {
argumentType = ARGUMENT_FILE;
} break;
case 8: {
argumentType = ARGUMENT_STRING;
} break;
case 'n': {
decodeEndLine = true;
} break;
case 9: {
decodeEndLine = false;
} break;
default:{
System.err.println(labels.getString("unknownarg"));
System.exit(1);
}
}
}
int exitCond = 0;
boolean done = false;
for (int i=opts.getOptind(); i 0){
if (fileAction == ACTION_ENCODE){
outName = args[i] + "." + extension;
} else {
if (args[i].endsWith("." + extension)){
outName = args[i].substring(0, args[i].length() - (extension.length() + 1));
}
}
}
File outFile = new File(outName);
if (!force && outFile.exists()){
if(printErrors){
System.err.println(MessageFormat.format(labels.getString("overwrite"), (Object[])new String[] {outName}));
}
exitCond = 1;
} else if (!(outFile.exists() || outFile.createNewFile()) || !outFile.canWrite()){
if(printErrors){
System.err.println(MessageFormat.format(labels.getString("cantwrite"), (Object[])new String[] {outName}));
}
exitCond = 1;
} else {
if (fileAction == ACTION_ENCODE){
if (printMessages){
System.out.println(MessageFormat.format(labels.getString("encoding"), (Object[])new String[] {args[i], outName}));
}
encode(source, outFile, lineBreaks);
} else {
if (printMessages){
System.out.println(MessageFormat.format(labels.getString("decoding"), (Object[])new String[] {args[i], outName}));
}
decode(source, outFile, !forceDecode);
}
}
} catch (Base64DecodingException x){
if(printErrors){
System.err.println(args[i] + ": " + x.getMessage() + " " + labels.getString("unexpectedcharforce"));
}
exitCond = 1;
} catch (IOException x){
if(printErrors){
System.err.println(args[i] + ": " + x.getMessage());
}
exitCond = 1;
}
}
}
if (!done){
try {
if (action == ACTION_GUESS){
if(printErrors){
System.err.println(labels.getString("cantguess"));
}
exitCond = 1;
} else if (action == ACTION_ENCODE){
encode(
new BufferedInputStream(System.in),
new BufferedOutputStream(System.out),
lineBreaks
);
} else {
decode(
new BufferedInputStream(System.in),
new BufferedOutputStream(System.out),
!forceDecode
);
if (decodeEndLine) System.out.println();
}
} catch (Base64DecodingException x){
if(printErrors){
System.err.println(x.getMessage() + " " + labels.getString("unexpectedcharforce"));
}
exitCond = 1;
} catch (IOException x){
if(printErrors){
System.err.println(x.getMessage());
}
exitCond = 1;
}
}
System.exit(exitCond);
}
/**
* Encode a String in Base64.
* The String is converted to and from bytes according to the platform's
* default character encoding.
* No line breaks or other white space are inserted into the encoded data.
*
* @param string The data to encode.
* @return An encoded String.
*
* @since ostermillerutils 1.00.00
*/
public static String encode(String string){
return new String(encode(string.getBytes()));
}
/**
* Encode a String in Base64.
* No line breaks or other white space are inserted into the encoded data.
*
* @param string The data to encode.
* @param enc Character encoding to use when converting to and from bytes.
* @throws UnsupportedEncodingException if the character encoding specified is not supported.
* @return An encoded String.
*
* @since ostermillerutils 1.00.00
*/
public static String encode(String string, String enc) throws UnsupportedEncodingException {
return new String(encode(string.getBytes(enc)), enc);
}
/**
* Encode bytes in Base64.
* No line breaks or other white space are inserted into the encoded data.
*
* @param bytes The data to encode.
* @return String with Base64 encoded data.
*
* @since ostermillerutils 1.04.00
*/
public static String encodeToString(byte[] bytes){
return encodeToString(bytes, false);
}
/**
* Encode bytes in Base64.
*
* @param bytes The data to encode.
* @param lineBreaks Whether to insert line breaks every 76 characters in the output.
* @return String with Base64 encoded data.
*
* @since ostermillerutils 1.04.00
*/
public static String encodeToString(byte[] bytes, boolean lineBreaks){
try {
return new String(encode(bytes, lineBreaks), "ASCII");
} catch (UnsupportedEncodingException iex){
// ASCII should be supported
throw new RuntimeException(iex);
}
}
/**
* Encode bytes in Base64.
* No line breaks or other white space are inserted into the encoded data.
*
* @param bytes The data to encode.
* @return Encoded bytes.
*
* @since ostermillerutils 1.00.00
*/
public static byte[] encode(byte[] bytes){
return encode(bytes, false);
}
/**
* Encode bytes in Base64.
*
* @param bytes The data to encode.
* @param lineBreaks Whether to insert line breaks every 76 characters in the output.
* @return Encoded bytes.
*
* @since ostermillerutils 1.04.00
*/
public static byte[] encode(byte[] bytes, boolean lineBreaks){
ByteArrayInputStream in = new ByteArrayInputStream(bytes);
// calculate the length of the resulting output.
// in general it will be 4/3 the size of the input
// but the input length must be divisible by three.
// If it isn't the next largest size that is divisible
// by three is used.
int mod;
int length = bytes.length;
if ((mod = length % 3) != 0){
length += 3 - mod;
}
length = length * 4 / 3;
ByteArrayOutputStream out = new ByteArrayOutputStream(length);
try {
encode(in, out, lineBreaks);
} catch (IOException x){
// This can't happen.
// The input and output streams were constructed
// on memory structures that don't actually use IO.
throw new RuntimeException(x);
}
return out.toByteArray();
}
/**
* Encode this file in Base64.
* Line breaks will be inserted every 76 characters.
*
* @param fIn File to be encoded (will be overwritten).
*
* @since ostermillerutils 1.00.00
*/
public static void encode(File fIn) throws IOException {
encode(fIn, fIn, true);
}
/**
* Encode this file in Base64.
*
* @param fIn File to be encoded (will be overwritten).
* @param lineBreaks Whether to insert line breaks every 76 characters in the output.
* @throws IOException if an input or output error occurs.
*
* @since ostermillerutils 1.00.00
*/
public static void encode(File fIn, boolean lineBreaks) throws IOException {
encode(fIn, fIn, lineBreaks);
}
/**
* Encode this file in Base64.
* Line breaks will be inserted every 76 characters.
*
* @param fIn File to be encoded.
* @param fOut File to which the results should be written (may be the same as fIn).
* @throws IOException if an input or output error occurs.
*
* @since ostermillerutils 1.00.00
*/
public static void encode(File fIn, File fOut) throws IOException {
encode(fIn, fOut, true);
}
/**
* Encode this file in Base64.
*
* @param fIn File to be encoded.
* @param fOut File to which the results should be written (may be the same as fIn).
* @param lineBreaks Whether to insert line breaks every 76 characters in the output.
* @throws IOException if an input or output error occurs.
*
* @since ostermillerutils 1.00.00
*/
public static void encode(File fIn, File fOut, boolean lineBreaks) throws IOException {
File temp = null;
InputStream in = null;
OutputStream out = null;
try {
in = new BufferedInputStream(new FileInputStream(fIn));
temp = File.createTempFile("Base64", null, null);
out = new BufferedOutputStream(new FileOutputStream(temp));
encode(in, out, lineBreaks);
in.close();
in = null;
out.flush();
out.close();
out = null;
FileHelper.move(temp, fOut, true);
} finally {
if (in != null){
in.close();
in = null;
}
if (out != null){
out.flush();
out.close();
out = null;
}
}
}
/**
* Encode data from the InputStream to the OutputStream in Base64.
* Line breaks are inserted every 76 characters in the output.
*
* @param in Stream from which to read data that needs to be encoded.
* @param out Stream to which to write encoded data.
* @throws IOException if there is a problem reading or writing.
*
* @since ostermillerutils 1.00.00
*/
public static void encode(InputStream in, OutputStream out) throws IOException {
encode(in, out, true);
}
/**
* Encode data from the InputStream to the OutputStream in Base64.
*
* @param in Stream from which to read data that needs to be encoded.
* @param out Stream to which to write encoded data.
* @param lineBreaks Whether to insert line breaks every 76 characters in the output.
* @throws IOException if there is a problem reading or writing.
*
* @since ostermillerutils 1.00.00
*/
public static void encode(InputStream in, OutputStream out, boolean lineBreaks) throws IOException {
// Base64 encoding converts three bytes of input to
// four bytes of output
int[] inBuffer = new int[3];
int lineCount = 0;
boolean done = false;
while (!done && (inBuffer[0] = in.read()) != END_OF_INPUT){
// Fill the buffer
inBuffer[1] = in.read();
inBuffer[2] = in.read();
// Calculate the out Buffer
// The first byte of our in buffer will always be valid
// but we must check to make sure the other two bytes
// are not END_OF_INPUT before using them.
// The basic idea is that the three bytes get split into
// four bytes along these lines:
// [AAAAAABB] [BBBBCCCC] [CCDDDDDD]
// [xxAAAAAA] [xxBBBBBB] [xxCCCCCC] [xxDDDDDD]
// bytes are considered to be zero when absent.
// the four bytes are then mapped to common ASCII symbols
// A's: first six bits of first byte
out.write(base64Chars[ inBuffer[0] >> 2 ]);
if (inBuffer[1] != END_OF_INPUT){
// B's: last two bits of first byte, first four bits of second byte
out.write(base64Chars [(( inBuffer[0] << 4 ) & 0x30) | (inBuffer[1] >> 4) ]);
if (inBuffer[2] != END_OF_INPUT){
// C's: last four bits of second byte, first two bits of third byte
out.write(base64Chars [((inBuffer[1] << 2) & 0x3c) | (inBuffer[2] >> 6) ]);
// D's: last six bits of third byte
out.write(base64Chars [inBuffer[2] & 0x3F]);
} else {
// C's: last four bits of second byte
out.write(base64Chars [((inBuffer[1] << 2) & 0x3c)]);
// an equals sign for a character that is not a Base64 character
out.write('=');
done = true;
}
} else {
// B's: last two bits of first byte
out.write(base64Chars [(( inBuffer[0] << 4 ) & 0x30)]);
// an equal signs for characters that is not a Base64 characters
out.write('=');
out.write('=');
done = true;
}
lineCount += 4;
if (lineBreaks && lineCount >= 76){
out.write('\n');
lineCount = 0;
}
}
if (lineBreaks && lineCount >= 1){
out.write('\n');
lineCount = 0;
}
out.flush();
}
/**
* Decode a Base64 encoded String.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
* The String is converted to and from bytes according to the platform's
* default character encoding.
*
* @param string The data to decode.
* @return A decoded String.
*
* @since ostermillerutils 1.00.00
*/
public static String decode(String string){
return new String(decode(string.getBytes()));
}
/**
* Decode a Base64 encoded String.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param string The data to decode.
* @param enc Character encoding to use when converting to and from bytes.
* @throws UnsupportedEncodingException if the character encoding specified is not supported.
* @return A decoded String.
*
* @since ostermillerutils 1.00.00
*/
public static String decode(String string, String enc) throws UnsupportedEncodingException {
return new String(decode(string.getBytes(enc)), enc);
}
/**
* Decode a Base64 encoded String.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param string The data to decode.
* @param encIn Character encoding to use when converting input to bytes (should not matter because Base64 data is designed to survive most character encodings)
* @param encOut Character encoding to use when converting decoded bytes to output.
* @throws UnsupportedEncodingException if the character encoding specified is not supported.
* @return A decoded String.
*
* @since ostermillerutils 1.00.00
*/
public static String decode(String string, String encIn, String encOut) throws UnsupportedEncodingException {
return new String(decode(string.getBytes(encIn)), encOut);
}
/**
* Decode a Base64 encoded String.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
* The String is converted to and from bytes according to the platform's
* default character encoding.
*
* @param string The data to decode.
* @return A decoded String.
*
* @since ostermillerutils 1.02.16
*/
public static String decodeToString(String string){
return new String(decode(string.getBytes()));
}
/**
* Decode a Base64 encoded String.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param string The data to decode.
* @param enc Character encoding to use when converting to and from bytes.
* @throws UnsupportedEncodingException if the character encoding specified is not supported.
* @return A decoded String.
*
* @since ostermillerutils 1.02.16
*/
public static String decodeToString(String string, String enc) throws UnsupportedEncodingException {
return new String(decode(string.getBytes(enc)), enc);
}
/**
* Decode a Base64 encoded String.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param string The data to decode.
* @param encIn Character encoding to use when converting input to bytes (should not matter because Base64 data is designed to survive most character encodings)
* @param encOut Character encoding to use when converting decoded bytes to output.
* @throws UnsupportedEncodingException if the character encoding specified is not supported.
* @return A decoded String.
*
* @since ostermillerutils 1.02.16
*/
public static String decodeToString(String string, String encIn, String encOut) throws UnsupportedEncodingException {
return new String(decode(string.getBytes(encIn)), encOut);
}
/**
* Decode a Base64 encoded String to an OutputStream.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
* The String is converted from bytes according to the platform's
* default character encoding.
*
* @param string The data to decode.
* @param out Stream to which to write decoded data.
* @throws IOException if an IO error occurs.
*
* @since ostermillerutils 1.02.16
*/
public static void decodeToStream(String string, OutputStream out) throws IOException {
decode(new ByteArrayInputStream(string.getBytes()), out);
}
/**
* Decode a Base64 encoded String to an OutputStream.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param string The data to decode.
* @param enc Character encoding to use when converting to and from bytes.
* @param out Stream to which to write decoded data.
* @throws UnsupportedEncodingException if the character encoding specified is not supported.
* @throws IOException if an IO error occurs.
*
* @since ostermillerutils 1.02.16
*/
public static void decodeToStream(String string, String enc, OutputStream out) throws UnsupportedEncodingException, IOException {
decode(new ByteArrayInputStream(string.getBytes(enc)), out);
}
/**
* Decode a Base64 encoded String.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
* The String is converted from bytes according to the platform's
* default character encoding.
*
* @param string The data to decode.
* @return decoded data.
*
* @since ostermillerutils 1.02.16
*/
public static byte[] decodeToBytes(String string){
return decode(string.getBytes());
}
/**
* Decode a Base64 encoded String.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param string The data to decode.
* @param enc Character encoding to use when converting from bytes.
* @throws UnsupportedEncodingException if the character encoding specified is not supported.
* @return decoded data.
*
* @since ostermillerutils 1.02.16
*/
public static byte[] decodeToBytes(String string, String enc) throws UnsupportedEncodingException {
return decode(string.getBytes(enc));
}
/**
* Decode Base64 encoded bytes.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
* The String is converted to bytes according to the platform's
* default character encoding.
*
* @param bytes The data to decode.
* @return A decoded String.
*
* @since ostermillerutils 1.02.16
*/
public static String decodeToString(byte[] bytes){
return new String(decode(bytes));
}
/**
* Decode Base64 encoded bytes.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param bytes The data to decode.
* @param enc Character encoding to use when converting to and from bytes.
* @throws UnsupportedEncodingException if the character encoding specified is not supported.
* @return A decoded String.
*
* @since ostermillerutils 1.02.16
*/
public static String decodeToString(byte[] bytes, String enc) throws UnsupportedEncodingException {
return new String(decode(bytes), enc);
}
/**
* Decode Base64 encoded bytes.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param bytes The data to decode.
* @return Decoded bytes.
*
* @since ostermillerutils 1.02.16
*/
public static byte[] decodeToBytes(byte[] bytes){
return decode(bytes);
}
/**
* Decode Base64 encoded bytes.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param bytes The data to decode.
* @return Decoded bytes.
*
* @since ostermillerutils 1.00.00
*/
public static byte[] decode(byte[] bytes){
ByteArrayInputStream in = new ByteArrayInputStream(bytes);
// calculate the length of the resulting output.
// in general it will be at most 3/4 the size of the input
// but the input length must be divisible by four.
// If it isn't the next largest size that is divisible
// by four is used.
int mod;
int length = bytes.length;
if ((mod = length % 4) != 0){
length += 4 - mod;
}
length = length * 3 / 4;
ByteArrayOutputStream out = new ByteArrayOutputStream(length);
try {
decode(in, out, false);
} catch (IOException x){
// This can't happen.
// The input and output streams were constructed
// on memory structures that don't actually use IO.
throw new RuntimeException(x);
}
return out.toByteArray();
}
/**
* Decode Base64 encoded bytes to the an OutputStream.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param bytes The data to decode.
* @param out Stream to which to write decoded data.
* @throws IOException if an IO error occurs.
*
* @since ostermillerutils 1.00.00
*/
public static void decode(byte[] bytes, OutputStream out) throws IOException {
ByteArrayInputStream in = new ByteArrayInputStream(bytes);
decode(in, out, false);
}
/**
* Decode Base64 encoded bytes to the an OutputStream.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param bytes The data to decode.
* @param out Stream to which to write decoded data.
* @throws IOException if an IO error occurs.
*
* @since ostermillerutils 1.02.16
*/
public static void decodeToStream(byte[] bytes, OutputStream out) throws IOException {
ByteArrayInputStream in = new ByteArrayInputStream(bytes);
decode(in, out, false);
}
/**
* Decode Base64 encoded data from one file to the other.
* Characters in the Base64 alphabet, white space and equals sign are
* expected to be in urlencoded data. The presence of other characters
* could be a sign that the data is corrupted.
*
* @param fIn File to be decoded (will be overwritten).
* @throws IOException if an IO error occurs.
* @throws Base64DecodingException if unexpected data is encountered.
*
* @since ostermillerutils 1.00.00
*/
public static void decode(File fIn) throws IOException {
decode(fIn, fIn, true);
}
/**
* Decode Base64 encoded data from one file to the other.
* Characters in the Base64 alphabet, white space and equals sign are
* expected to be in urlencoded data. The presence of other characters
* could be a sign that the data is corrupted.
*
* @param fIn File to be decoded (will be overwritten).
* @param throwExceptions Whether to throw exceptions when unexpected data is encountered.
* @throws IOException if an IO error occurs.
* @throws Base64DecodingException if unexpected data is encountered when throwExceptions is specified.
*
* @since ostermillerutils 1.00.00
*/
public static void decode(File fIn, boolean throwExceptions) throws IOException {
decode(fIn, fIn, throwExceptions);
}
/**
* Decode Base64 encoded data from one file to the other.
* Characters in the Base64 alphabet, white space and equals sign are
* expected to be in urlencoded data. The presence of other characters
* could be a sign that the data is corrupted.
*
* @param fIn File to be decoded.
* @param fOut File to which the results should be written (may be the same as fIn).
* @throws IOException if an IO error occurs.
* @throws Base64DecodingException if unexpected data is encountered.
*
* @since ostermillerutils 1.00.00
*/
public static void decode(File fIn, File fOut) throws IOException {
decode(fIn, fOut, true);
}
/**
* Decode Base64 encoded data from one file to the other.
* Characters in the Base64 alphabet, white space and equals sign are
* expected to be in urlencoded data. The presence of other characters
* could be a sign that the data is corrupted.
*
* @param fIn File to be decoded.
* @param fOut File to which the results should be written (may be the same as fIn).
* @param throwExceptions Whether to throw exceptions when unexpected data is encountered.
* @throws IOException if an IO error occurs.
* @throws Base64DecodingException if unexpected data is encountered when throwExceptions is specified.
*
* @since ostermillerutils 1.00.00
*/
public static void decode(File fIn, File fOut, boolean throwExceptions) throws IOException {
File temp = null;
InputStream in = null;
OutputStream out = null;
try {
in = new BufferedInputStream(new FileInputStream(fIn));
temp = File.createTempFile("Base64", null, null);
out = new BufferedOutputStream(new FileOutputStream(temp));
decode(in, out, throwExceptions);
in.close();
in = null;
out.flush();
out.close();
out = null;
FileHelper.move(temp, fOut, true);
} finally {
if (in != null){
try {
in.close();
} catch (IOException ignore){
if (throwExceptions) throw ignore;
}
in = null;
}
if (out != null){
try {
out.flush();
out.close();
} catch (IOException ignore){
if (throwExceptions) throw ignore;
}
out = null;
}
}
}
/**
* Reads the next (decoded) Base64 character from the input stream.
* Non Base64 characters are skipped.
*
* @param in Stream from which bytes are read.
* @param throwExceptions Throw an exception if an unexpected character is encountered.
* @return the next Base64 character from the stream or -1 if there are no more Base64 characters on the stream.
* @throws IOException if an IO Error occurs.
* @throws Base64DecodingException if unexpected data is encountered when throwExceptions is specified.
*
* @since ostermillerutils 1.00.00
*/
private static final int readBase64(InputStream in, boolean throwExceptions) throws IOException {
int read;
int numPadding = 0;
do {
read = in.read();
if (read == END_OF_INPUT) return END_OF_INPUT;
read = reverseBase64Chars[(byte)read];
if (throwExceptions && (read == NON_BASE_64 || (numPadding > 0 && read > NON_BASE_64))){
throw new Base64DecodingException (
MessageFormat.format(
labels.getString("unexpectedchar"),
(Object[])new String[] {
"'" + (char)read + "' (0x" + Integer.toHexString(read) + ")"
}
),
(char)read
);
}
if (read == NON_BASE_64_PADDING){
numPadding++;
}
} while (read <= NON_BASE_64);
return read;
}
/**
* Decode Base64 encoded data from the InputStream to a byte array.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param in Stream from which to read data that needs to be decoded.
* @return decoded data.
* @throws IOException if an IO error occurs.
*
* @since ostermillerutils 1.00.00
*/
public static byte[] decodeToBytes(InputStream in) throws IOException {
ByteArrayOutputStream out = new ByteArrayOutputStream();
decode(in, out, false);
return out.toByteArray();
}
/**
* Decode Base64 encoded data from the InputStream to a String.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
* Bytes are converted to characters in the output String according to the platform's
* default character encoding.
*
* @param in Stream from which to read data that needs to be decoded.
* @return decoded data.
* @throws IOException if an IO error occurs.
*
* @since ostermillerutils 1.02.16
*/
public static String decodeToString(InputStream in) throws IOException {
return new String(decodeToBytes(in));
}
/**
* Decode Base64 encoded data from the InputStream to a String.
* Characters that are not part of the Base64 alphabet are ignored
* in the input.
*
* @param in Stream from which to read data that needs to be decoded.
* @param enc Character encoding to use when converting bytes to characters.
* @return decoded data.
* @throws IOException if an IO error occurs.Throws:
* @throws UnsupportedEncodingException if the character encoding specified is not supported.
*
* @since ostermillerutils 1.02.16
*/
public static String decodeToString(InputStream in, String enc) throws IOException {
return new String(decodeToBytes(in), enc);
}
/**
* Decode Base64 encoded data from the InputStream to the OutputStream.
* Characters in the Base64 alphabet, white space and equals sign are
* expected to be in urlencoded data. The presence of other characters
* could be a sign that the data is corrupted.
*
* @param in Stream from which to read data that needs to be decoded.
* @param out Stream to which to write decoded data.
* @throws IOException if an IO error occurs.
* @throws Base64DecodingException if unexpected data is encountered.
*
* @since ostermillerutils 1.00.00
*/
public static void decode(InputStream in, OutputStream out) throws IOException {
decode(in, out, true);
}
/**
* Decode Base64 encoded data from the InputStream to the OutputStream.
* Characters in the Base64 alphabet, white space and equals sign are
* expected to be in urlencoded data. The presence of other characters
* could be a sign that the data is corrupted.
*
* @param in Stream from which to read data that needs to be decoded.
* @param out Stream to which to write decoded data.
* @param throwExceptions Whether to throw exceptions when unexpected data is encountered.
* @throws IOException if an IO error occurs.
* @throws Base64DecodingException if unexpected data is encountered when throwExceptions is specified.
*
* @since ostermillerutils 1.00.00
*/
public static void decode(InputStream in, OutputStream out, boolean throwExceptions) throws IOException {
// Base64 decoding converts four bytes of input to three bytes of output
int[] inBuffer = new int[4];
// read bytes unmapping them from their ASCII encoding in the process
// we must read at least two bytes to be able to output anything
boolean done = false;
while (!done && (inBuffer[0] = readBase64(in, throwExceptions)) != END_OF_INPUT
&& (inBuffer[1] = readBase64(in, throwExceptions)) != END_OF_INPUT){
// Fill the buffer
inBuffer[2] = readBase64(in, throwExceptions);
inBuffer[3] = readBase64(in, throwExceptions);
// Calculate the output
// The first two bytes of our in buffer will always be valid
// but we must check to make sure the other two bytes
// are not END_OF_INPUT before using them.
// The basic idea is that the four bytes will get reconstituted
// into three bytes along these lines:
// [xxAAAAAA] [xxBBBBBB] [xxCCCCCC] [xxDDDDDD]
// [AAAAAABB] [BBBBCCCC] [CCDDDDDD]
// bytes are considered to be zero when absent.
// six A and two B
out.write(inBuffer[0] << 2 | inBuffer[1] >> 4);
if (inBuffer[2] != END_OF_INPUT){
// four B and four C
out.write(inBuffer[1] << 4 | inBuffer[2] >> 2);
if (inBuffer[3] != END_OF_INPUT){
// two C and six D
out.write(inBuffer[2] << 6 | inBuffer[3]);
} else {
done = true;
}
} else {
done = true;
}
}
out.flush();
}
/**
* Determines if the byte array is in base64 format.
*
* Data will be considered to be in base64 format if it contains
* only base64 characters and whitespace with equals sign padding
* on the end so that the number of base64 characters is divisible
* by four.
*
* It is possible for data to be in base64 format but for it to not
* meet these stringent requirements. It is also possible for data
* to meet these requirements even though decoding it would not make
* any sense. This method should be used as a guide but it is not
* authoritative because of the possibility of these false positives
* and false negatives.
*
* Additionally, extra data such as headers or footers may throw
* this method off the scent and cause it to return false.
*
* @param bytes data that could be in base64 format.
*
* @since ostermillerutils 1.00.00
*/
public static boolean isBase64(byte[] bytes){
try {
return isBase64(new ByteArrayInputStream(bytes));
} catch (IOException x){
// This can't happen.
// The input and output streams were constructed
// on memory structures that don't actually use IO.
return false;
}
}
/**
* Determines if the String is in base64 format.
* The String is converted to and from bytes according to the platform's
* default character encoding.
*
* Data will be considered to be in base64 format if it contains
* only base64 characters and whitespace with equals sign padding
* on the end so that the number of base64 characters is divisible
* by four.
*
* It is possible for data to be in base64 format but for it to not
* meet these stringent requirements. It is also possible for data
* to meet these requirements even though decoding it would not make
* any sense. This method should be used as a guide but it is not
* authoritative because of the possibility of these false positives
* and false negatives.
*
* Additionally, extra data such as headers or footers may throw
* this method off the scent and cause it to return false.
*
* @param string String that may be in base64 format.
* @return Best guess as to whether the data is in base64 format.
*
* @since ostermillerutils 1.00.00
*/
public static boolean isBase64(String string){
return isBase64(string.getBytes());
}
/**
* Determines if the String is in base64 format.
*
* Data will be considered to be in base64 format if it contains
* only base64 characters and whitespace with equals sign padding
* on the end so that the number of base64 characters is divisible
* by four.
*
* It is possible for data to be in base64 format but for it to not
* meet these stringent requirements. It is also possible for data
* to meet these requirements even though decoding it would not make
* any sense. This method should be used as a guide but it is not
* authoritative because of the possibility of these false positives
* and false negatives.
*
* Additionally, extra data such as headers or footers may throw
* this method off the scent and cause it to return false.
*
* @param string String that may be in base64 format.
* @param enc Character encoding to use when converting to bytes.
* @return Best guess as to whether the data is in base64 format.
* @throws UnsupportedEncodingException if the character encoding specified is not supported.
*/
public static boolean isBase64(String string, String enc) throws UnsupportedEncodingException {
return isBase64(string.getBytes(enc));
}
/**
* Determines if the File is in base64 format.
*
* Data will be considered to be in base64 format if it contains
* only base64 characters and whitespace with equals sign padding
* on the end so that the number of base64 characters is divisible
* by four.
*
* It is possible for data to be in base64 format but for it to not
* meet these stringent requirements. It is also possible for data
* to meet these requirements even though decoding it would not make
* any sense. This method should be used as a guide but it is not
* authoritative because of the possibility of these false positives
* and false negatives.
*
* Additionally, extra data such as headers or footers may throw
* this method off the scent and cause it to return false.
*
* @param fIn File that may be in base64 format.
* @return Best guess as to whether the data is in base64 format.
* @throws IOException if an IO error occurs.
*
* @since ostermillerutils 1.00.00
*/
public static boolean isBase64(File fIn) throws IOException {
return isBase64(new BufferedInputStream(new FileInputStream(fIn)));
}
/**
* Reads data from the stream and determines if it is
* in base64 format.
*
* Data will be considered to be in base64 format if it contains
* only base64 characters and whitespace with equals sign padding
* on the end so that the number of base64 characters is divisible
* by four.
*
* It is possible for data to be in base64 format but for it to not
* meet these stringent requirements. It is also possible for data
* to meet these requirements even though decoding it would not make
* any sense. This method should be used as a guide but it is not
* authoritative because of the possibility of these false positives
* and false negatives.
*
* Additionally, extra data such as headers or footers may throw
* this method off the scent and cause it to return false.
*
* @param in Stream from which to read data to be tested.
* @return Best guess as to whether the data is in base64 format.
* @throws IOException if an IO error occurs.
*
* @since ostermillerutils 1.00.00
*/
public static boolean isBase64(InputStream in) throws IOException {
long numBase64Chars = 0;
int numPadding = 0;
int read;
while ((read = in.read()) != -1){
read = reverseBase64Chars[read];
if (read == NON_BASE_64){
return false;
} else if (read == NON_BASE_64_WHITESPACE){
} else if (read == NON_BASE_64_PADDING){
numPadding++;
numBase64Chars++;
} else if (numPadding > 0){
return false;
} else {
numBase64Chars++;
}
}
if (numBase64Chars == 0) return false;
if (numBase64Chars % 4 != 0) return false;
return true;
}
}
4.MD5:
MD5是一个安全的散列算法，有两个特点： 1、输入两个不同的明文（一段原始的数字信息）不会得到相同的输出值 2、根据输出值，不能得到原始的明文，即过程不可逆 所以要解密MD5没有现成的算法，只能用穷举法，把可能出现的明文，用MD5算法散列之后，把得到的散列值和原始的数据形成一个一对一的映射表，然后在所谓的解密的时候，都是通过这个映射表来查找其所对应的原始明文。 而绝对没有一种算法，可以通过输出加密后的散列值算出原始明文。http://zhidao.baidu.com/link?url=8GALGyzvERNGndKHHz-Ds54funzwR6PrUJ2NdXS55hNePcgRJEYc2Puh7o9-3x18F85aahGw0x5Z7NhjDUZJHq
package com.gootrip.util;
// Md5.java
// $Id: Md5.java,v 1.4 1999/12/06 13:13:58 ylafon Exp $
// (c) COPYRIGHT MIT and INRIA, 1996.
// Please first read the full copyright statement in file COPYRIGHT.html
// http://www.jq-school.com
//
// Add model hmac_Md5 ( String text , String key ) ;
//package md5java ;
import java.io.* ;
public class Md5 {
private static final int BUFFER_SIZE = 1024 ;
private static final int S11 = 7 ;
private static final int S12 = 12 ;
private static final int S13 = 17 ;
private static final int S14 = 22 ;
private static final int S21 = 5 ;
private static final int S22 = 9 ;
private static final int S23 = 14 ;
private static final int S24 = 20 ;
private static final int S31 = 4 ;
private static final int S32 = 11 ;
private static final int S33 = 16 ;
private static final int S34 = 23 ;
private static final int S41 = 6 ;
private static final int S42 = 10 ;
private static final int S43 = 15 ;
private static final int S44 = 21 ;
private static byte padding[] = {
(byte) 0x80, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
(byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0, (byte) 0,
(byte) 0, (byte) 0, (byte) 0, (byte) 0
} ;
private InputStream in = null ;
private boolean stringp = false ;
private int state[] = null ;
private long count = 0 ;
private byte buffer[] = null ;
private byte digest[] = null ;
public static String stringify (byte buf[]) {
StringBuffer sb = new StringBuffer(2*buf.length) ;
for (int i = 0 ; i < buf.length; i++) {
int h = (buf[i] & 0xf0) >> 4 ;
int l = (buf[i] & 0x0f) ;
sb.append (new Character((char)((h>9) ? 'a'+h-10 : '0'+h))) ;
sb.append (new Character((char)((l>9) ? 'a'+l-10 : '0'+l))) ;
}
return sb.toString() ;
}
private final int F(int x, int y, int z) {
return ((x & y) | ((~x) & z)) ;
}
private final int G(int x, int y, int z) {
return ((x & z) | (y & (~z))) ;
}
private final int H(int x, int y, int z) {
return (x ^ y ^ z) ;
}
private final int I(int x, int y, int z) {
return (y ^ (x | (~z))) ;
}
private final int rotate_left(int x, int n) {
return ((x << n) | (x >>> (32-n))) ;
}
private final int FF(int a,int b,int c,int d,int x,int s,int ac) {
a += (F(b, c, d) + x + ac) ;
a = rotate_left(a, s) ;
a += b ;
return a ;
}
private final int GG(int a,int b,int c,int d,int x,int s,int ac) {
a += (G(b, c, d) + x + ac) ;
a = rotate_left(a, s) ;
a += b ;
return a ;
}
private final int HH(int a,int b,int c,int d,int x,int s,int ac) {
a += (H(b, c, d) + x + ac) ;
a = rotate_left(a, s) ;
a += b ;
return a ;
}
private final int II(int a,int b,int c,int d,int x,int s,int ac) {
a += (I(b, c, d) + x + ac) ;
a = rotate_left(a, s) ;
a += b ;
return a;
}
private final void decode (int output[], byte input[], int off, int len) {
int i = 0 ;
int j = 0 ;
for ( ; j < len; i++, j += 4) {
output[i] = (((int) (input[off+j]&0xff))
| (((int) (input[off+j+1] & 0xff)) << 8)
| (((int) (input[off+j+2] & 0xff)) << 16)
| (((int) (input[off+j+3] & 0xff)) << 24)) ;
}
}
private final void transform (byte block[], int offset) {
int a = state[0] ;
int b = state[1] ;
int c = state[2] ;
int d = state[3] ;
int x[] = new int[16] ;
decode (x, block, offset, 64);
/* Round 1 */
a = FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
d = FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
c = FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
b = FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
a = FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
d = FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
c = FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
b = FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
a = FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
d = FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
c = FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
b = FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
a = FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
d = FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
c = FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
b = FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
/* Round 2 */
a = GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
d = GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
c = GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
b = GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
a = GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
d = GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
c = GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
b = GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
a = GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
d = GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
c = GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
b = GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
a = GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
d = GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
c = GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
b = GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
/* Round 3 */
a = HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
d = HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
c = HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
b = HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
a = HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
d = HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
c = HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
b = HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
a = HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
d = HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
c = HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
b = HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */
a = HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
d = HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
c = HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
b = HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
/* Round 4 */
a = II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
d = II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
c = II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
b = II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
a = II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
d = II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
c = II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
b = II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
a = II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
d = II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
c = II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
b = II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
a = II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
d = II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
c = II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
b = II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
state[0] += a;
state[1] += b;
state[2] += c;
state[3] += d;
}
private final void update (byte input[], int len) {
int index = ((int) (count >> 3)) & 0x3f ;
count += (len << 3) ;
int partLen = 64 - index ;
int i = 0 ;
if ( len >= partLen ) {
System.arraycopy (input, 0, buffer, index, partLen) ;
transform (buffer, 0) ;
for (i = partLen ; i + 63 < len ; i+= 64)
transform (input, i) ;
index = 0 ;
} else {
i = 0 ;
}
System.arraycopy (input, i, buffer, index, len - i) ;
}
private byte[] end () {
byte bits[] = new byte[8] ;
for (int i = 0 ; i < 8 ; i++)
bits[i] = (byte) ((count>>>(i*8)) & 0xff) ;
int index = ((int) (count >> 3)) & 0x3f ;
int padlen = (index < 56) ? (56 - index) : (120 - index) ;
update (padding, padlen) ;
update (bits, 8) ;
return encode(state, 16) ;
}
// Encode the content.state array into 16 bytes array
private byte[] encode (int input[], int len) {
byte output[] = new byte[len] ;
int i = 0 ;
int j = 0 ;
for ( ; j < len ; i++, j+= 4) {
output[j] = (byte) ((input[i] ) & 0xff) ;
output[j+1] = (byte) ((input[i] >> 8 ) & 0xff) ;
output[j+2] = (byte) ((input[i] >> 16) & 0xff) ;
output[j+3] = (byte) ((input[i] >> 24) & 0xff) ;
}
return output ;
}
/**
* Get the digest for our input stream.
* This method constructs the input stream digest, and return it, as a
* a String, following the MD5 (rfc1321) algorithm,
* @return An instance of String, giving the message digest.
* @exception IOException Thrown if the digestifier was unable to read the
* input stream.
*/
public byte[] getDigest ()
throws IOException
{
byte buffer[] = new byte[BUFFER_SIZE] ;
int got = -1 ;
if ( digest != null )
return digest ;
while ((got = in.read(buffer)) > 0 )
update (buffer, got) ;
this.digest = end () ;
return digest ;
}
/**
* Get the digest, for this string digestifier.
* This method doesn't throw any IOException, since it knows that the
* underlying stream ws built from a String.
*/
public byte[] processString () {
if ( ! stringp )
throw new RuntimeException (this.getClass().getName()
+ "[processString]"
+ " not a string.") ;
try {
return getDigest() ;
} catch (IOException ex) {
}
throw new RuntimeException (this.getClass().getName()
+ "[processString]"
+ ": implementation error.") ;
}
/**
* Get the digest, as a proper string.
*/
public String getStringDigest() {
if ( digest == null )
throw new RuntimeException (this.getClass().getName()
+ "[getStringDigest]"
+ ": called before processing.") ;
return stringify (digest) ;
}
/**
* Construct a digestifier for the given string.
* @param input The string to be digestified.
* @param encoding the encoding name used (such as UTF8)
*/
public Md5 (String input, String enc) {
byte bytes [] = null;
try {
bytes = input.getBytes (enc);
} catch(UnsupportedEncodingException e){
throw new RuntimeException("no "+enc+" encoding!!!");
}
this.stringp = true ;
this.in = new ByteArrayInputStream (bytes) ;
this.state = new int[4] ;
this.buffer = new byte[64] ;
this.count = 0 ;
state[0] = 0x67452301;
state[1] = 0xefcdab89;
state[2] = 0x98badcfe;
state[3] = 0x10325476;
}
/**
* Construct a digestifier for the given string.
* @param input The string to be digestified.
*/
public Md5 (String input) {
this(input, "UTF8");
}
/**
* Construct a digestifier for the given input stream.
* @param in The input stream to be digestified.
*/
public Md5 (InputStream in) {
this.stringp = false ;
this.in = in ;
this.state = new int[4] ;
this.buffer = new byte[64] ;
this.count = 0 ;
state[0] = 0x67452301;
state[1] = 0xefcdab89;
state[2] = 0x98badcfe;
state[3] = 0x10325476;
}
public void hmac_Md5 ( String text , String key )
throws IOException {
//byte disgest[] = new byte[16] ;
//byte output[] = new byte[32] ;
//output[33] = ( byte ) '\0' ;
byte k_ipad[] = new byte[64] ;
byte k_opad[] = new byte[64] ;
//byte tk[] = new byte[16] ;
byte key1 [] ;
int i ;
int text_len = text.getBytes().length ;
int key_len = key.getBytes().length ;
key1 = key.getBytes() ;
if ( key_len > 64 ) {
key1 = new Md5( key ).getDigest() ;
key_len = 16 ;
}
for ( i = 0 ; i < 64 ; i++ )
k_ipad[i] = ( byte ) 0 ;
for ( i = 0 ; i < 64 ; i++ )
k_opad[i] = ( byte ) 0 ;
for ( i = 0 ; i < key_len ; i++ ) {
k_ipad[i] = ( byte ) key1[i] ;
k_opad[i] = ( byte ) key1[i] ;
}
for ( i = 0 ; i < 64 ; i++ ) {
k_ipad[i] ^= 0x36 ;
k_opad[i] ^= 0x5c ;
}
Md5 md5 = new Md5( "" ) ;
md5.update( k_ipad , 64 ) ;
md5.update( text.getBytes() , text_len ) ;
digest = md5.getDigest() ;
Md5 md51 = new Md5( "" ) ;
md51.update( k_opad , 64 ) ;
md51.update( digest , 16 ) ;
digest = md51.getDigest() ;
}
}