JavaAES256位加密解密
Java AES解密加密算法默认是⽀持128位的，但是，最近，做了登录练习，是从数据库⾥的⽤户表提取⽤户账号和密码来进⾏验证登录，因为⽤户表⾥的密码是经过256位加密进⾏储存的，⽽且是⽤PKCS7Padding的填充⽅式来存储，所以Java默认的128位解密加密读出来的数据与数据库中的数据不匹配，⽽且Java默认⽀持的填充⽅式是PKCS5Padding，所以需要引⽤第三⽅jar包bouncycastle组件来让Java⾥⾯⽀持PKCS7Padding填充⽅式，获取jar包：
提取码：jj7o
然后还需要下载jce⽆限制权限策略⽂件，覆盖到JDK和JRE中，如：
C:\Program Files\Java\jdk1.7.0_80\jre\lib\curity
C:\Program Files\Java\jre7\lib\curity
根据⾃⼰的JAVA_HOME路径
相关⽂件下载地址：
然后具体相应代码如下：
先封装⼀个源码，Ba64.java：
import java.io.UnsupportedEncodingException;
public class Ba64 {
/**
* Default values for encoder/decoder flags.
*/
public static final int DEFAULT = 0;
/**
* Encoder flag bit to omit the padding '=' characters at the end
* of the output (if any).
*/
北京德语培训学校
public static final int NO_PADDING = 1;
/**
* Encoder flag bit to omit all line terminators (i.e., the output
* will be on one long line).
*/
public static final int NO_WRAP = 2;
/**
* Encoder flag bit to indicate lines should be terminated with a
* CRLF pair instead of just an LF. Has no effect if {@code
* NO_WRAP} is specified as well.
*/
public static final int CRLF = 4;
/**
* Encoder/decoder flag bit to indicate using the "URL and
* filename safe" variant of Ba64 (e RFC 3548 ction 4) where
* {@code -} and {@code _} are ud in place of {@code +} and
* {@code /}.
*/
public static final int URL_SAFE = 8;
/**
* Flag to pass to {@link Ba64OutputStream} to indicate that it
* should not clo the output stream it is wrapping when it
usarmy
* itlf is clod.
*/5023
public static final int NO_CLOSE = 16;
// --------------------------------------------------------
// shared code
// --------------------------------------------------------
/* package */ static abstract class Coder {
public byte[] output;
public int op;
/**
* Encode/decode another block of input data. this.output is
* provided by the caller, and must be big enough to hold all
* the coded data. On exit, this.opwill be t to the length
* of the coded data.
*
* @param finish true if this is the final call to process for
* this object. Will finalize the coder state and
* include any final bytes in the output.
*
* @return true if the input so far is good; fal if some
* error has been detected in the input stream..icpo
*/
public abstract boolean process(byte[] input, int offt, int len, boolean finish);
/**
* @return the maximum number of bytes a call to process()
* could produce for the given number of input bytes. This may
homework什么意思* be an overestimate.
*/
public abstract int maxOutputSize(int len);
}
// --------------------------------------------------------
// decoding
// --------------------------------------------------------
/grails
**
* Decode the Ba64-encoded data in input and return the data in
* a new byte array.
*
* <p>The padding '=' characters at the end are considered optional, but
* if any are prent, there must be the correct number of them.
*
* @param str the input String to decode, which is converted to
* bytes using the default chart
* @param flags controls certain features of the decoded output.
* Pass {@code DEFAULT} to decode standard Ba64.
*
* @throws IllegalArgumentException if the input contains
* incorrect padding
*/
public static byte[] decode(String str, int flags) {
return Bytes(), flags);
}
/**
* Decode the Ba64-encoded data in input and return the data in
* a new byte array.
*
* <p>The padding '=' characters at the end are considered optional, but
* if any are prent, there must be the correct number of them.
*
* @param input the input array to decode
* @param flags controls certain features of the decoded output.
* Pass {@code DEFAULT} to decode standard Ba64.
* @throws IllegalArgumentException if the input contains
* incorrect padding
*/
public static byte[] decode(byte[] input, int flags) {
return decode(input, 0, input.length, flags);
}
/**
* Decode the Ba64-encoded data in input and return the data in
* a new byte array.
*
* <p>The padding '=' characters at the end are considered optional, but * if any are prent, there must be the correct number of them.
*
* @param input the data to decode
* @param offt the position within the input array at which to start
* @param len the number of bytes of input to decode
* @param flags controls certain features of the decoded output.
* Pass {@code DEFAULT} to decode standard Ba64.
*
* @throws IllegalArgumentException if the input contains
* incorrect padding
*/
public static byte[] decode(byte[] input, int offt, int len, int flags) {
// Allocate space for the most data the input could reprent.
// (It could contain less if it contains whitespace, etc.)
Decoder decoder = new Decoder(flags, new byte[len*3/4]);
if (!decoder.process(input, offt, len, true)) {
throw new IllegalArgumentException("bad ba-64");
}
// Maybe we got lucky and allocated exactly enough output space.
if (decoder.op == decoder.output.length) {
return decoder.output;
}
// Need to shorten the array, so allocate a new one of the
// right size and copy.
byte[] temp = new byte[decoder.op];
System.arraycopy(decoder.output, 0, temp, 0, decoder.op);
return temp;
}
/
* package */ static class Decoder extends Coder {
/**
* Lookup table for turning bytes into their position in the
* Ba64 alphabet.
*/
private static final int DECODE[] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -2, -1, -1,
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-
1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};
/**
* Decode lookup table for the "web safe" variant (RFC 3548
* c. 4) where - and _ replace + and /.
*/
private static final int DECODE_WEBSAFE[] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -2, -1, -1,
-
1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63,
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-
1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};
/** Non-data values in the DECODE arrays. */
private static final int SKIP = -1;
private static final int EQUALS = -2;
/**
* States 0-3 are reading through the next input tuple.wirelessfidelity
津津有味的近义词
* State 4 is having read one '=' and expecting exactly
* one more.
* State 5 is expecting no more data or padding characters
* in the input.
* State 6 is the error state; an error has been detected
* in the input and no future input can "fix" it.
*/
private int state; // state number (0 to 6)
private int value;
final private int[] alphabet;
public Decoder(int flags, byte[] output) {
this.output = output;
alphabet = ((flags & URL_SAFE) == 0) ? DECODE : DECODE_WEBSAFE; state = 0;
value = 0;
}
/
**
* @return an overestimate for the number of bytes {@code
* len} bytes could decode to.
*/
public int maxOutputSize(int len) {
return len * 3/4 + 10;
}
/**
* Decode another block of input data.
*
* @return true if the state machine is still healthy. fal if
* bad ba-64 data has been detected in the input stream.
* bad ba-64 data has been detected in the input stream.
*/
public boolean process(byte[] input, int offt, int len, boolean finish) { if (this.state == 6) return fal;
int p = offt;
len += offt;
// Using local variables makes the decoder about 12%
// faster than if we manipulate the member variables in
// the loop. (Even alphabet makes a measurable
// difference, which is somewhat surprising to me since
// the member variable is final.)
int state = this.state;
int value = this.value;
int op = 0;
final byte[] output = this.output;
final int[] alphabet = this.alphabet;
while (p < len) {
// Try the fast path: we're starting a new tuple and the
// next four bytes of the input stream are all data
// bytes. This corresponds to going through states
// 0-1-2-3-0. We expect to u this method for most of
// the data.
/
/
// If any of the next four bytes of input are non-data
// (whitespace, etc.), value will end up negative. (All
// the non-data values in decode are small negative
// numbers, so shifting any of them up and or'ing them
// together will result in a value with its top bit t.)
//
// You can remove this whole block and the output should
// be the same, just slower.
if (state == 0) {
while (p+4 <= len &&
(value = ((alphabet[input[p] & 0xff] << 18) |
(alphabet[input[p+1] & 0xff] << 12) |
(alphabet[input[p+2] & 0xff] << 6) |
(alphabet[input[p+3] & 0xff]))) >= 0) {
output[op+2] = (byte) value;
output[op+1] = (byte) (value >> 8);
output[op] = (byte) (value >> 16);
op += 3;
p += 4;
}
if (p >= len) break;
}
// The fast path isn't available -- either we've read a
// partial tuple, or the next four input bytes aren't all
// data, or whatever. Fall back to the slower state
// machine implementation.石家庄心理
int d = alphabet[input[p++] & 0xff];
switch (state) {
肯塔基大学
ca 0:
if (d >= 0) {
value = d;
++state;
} el if (d != SKIP) {
this.state = 6;
return fal;
}
break;
