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- RC4属于对称可逆加密(就是加密解密的密钥一样), U& y7 Z+ w- f0 ~/ |
- 使用方法:
$ c+ }( P: ? B V - try
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- String encryStr = RC4Util.encryRC4String("测试", "123456", "UTF-8");
' j/ i" h! `- I" q) ]; R' w& n - System.out.println("加密后得到得字符串:" + encryStr);
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- catch (UnsupportedEncodingException e)( j( o9 ]" h/ G" Q' W
- {}
+ n9 D% K+ t0 D -
) }( F7 p ~& E+ C - String decryStr = RC4Util.decryRC4(encryStr, "123456");
: r3 f" e/ H/ {0 X - System.out.println("解密后得到得字符串:"+decryStr);
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- 工具类:# Q+ t; z! U3 @4 @7 u
- class RC4Util {
! {/ r& c {7 E - public static String encryRC4String(String data, String key, String chartSet) throws UnsupportedEncodingException {
; |+ C- P$ w$ E. v6 y - if (data == null || key == null) {
# j; {* J. Y0 ]6 f3 g6 f% ^ A - return null;
- h) X) U' [; F8 { - }
+ v; P& M, J% i& P% i - return toHexString(asString(encryRC4Byte(data, key, chartSet)));; G g0 A5 _ M1 f+ y0 y7 b! x. g
- }
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9 P& `; W- c% O$ T. \9 ]1 @- public static byte[] encryRC4Byte(String data, String key, String chartSet) throws UnsupportedEncodingException {
, k& M( P' X( S: B4 u8 D, |9 N, F( h( Z - if (data == null || key == null) {
% H0 N' g( [, d( v" e* U# c* h! c - return null;
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- if (chartSet == null || chartSet.isEmpty()) {
0 F2 s7 _" D, L6 u0 b0 T' K - byte bData[] = data.getBytes();. ?' K3 B" n0 E
- return RC4Base(bData, key);$ P. e$ q; K$ I( x4 D
- } else {: s- Q* U! w* W8 g' _' g
- byte bData[] = data.getBytes(chartSet);$ r6 ~ w+ d t
- return RC4Base(bData, key);
+ t/ h. ^' H# | - }
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- }0 P4 @/ i$ r# o9 k" J% J
- ! m# M! y) M8 K' c s3 D+ J% V
- public static String decryRC4(String data, String key) {
8 a; N6 J" V! Y - if (data == null || key == null) {9 d( I$ G2 ~* w
- return null;2 G* H- x% h& ]5 b5 T& O7 Z
- }
. F6 l4 V1 e3 `# T( \ - return new String(RC4Base(HexString2Bytes(data), key), StandardCharsets.UTF_8);
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- public static String decryRC4(byte[] data, String key) {
" h& g ^) t* x' S1 p - if (data == null || key == null) {
* @+ ?- S$ S/ {, Z# k! t - return null;
- u( P% K% v5 ]% C) n; R9 Z - }
. D( W2 |+ x& x4 R: {& I - return asString(RC4Base(data, key));& @6 s- C9 j0 z3 |
- }
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- private static String asString(byte[] buf) {# H# B& H( B( ^ I7 e
- StringBuffer strbuf = new StringBuffer(buf.length);
( W; @' U- d7 Q" \0 ^" y- T - for (byte b : buf) {
* v8 U( D1 X2 e5 B - strbuf.append((char) b);
4 t9 q# L7 H1 O& _" v7 j4 N: ]" A - }
' ^- u5 O7 n7 n. H) z - return strbuf.toString();
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- private static byte[] initKey(String aKey) {5 y2 h" P4 e& z( w' A9 ]
- byte[] bkey = aKey.getBytes();, z2 y" K! C% D; s5 w
- byte state[] = new byte[256];
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/ a6 m, R4 k4 U; j- for (int i = 0; i < 256; i++) {
3 b9 y' ?, q: O5 | - state[i] = (byte) i;
+ o1 G ]: S$ i+ g D7 E - }
8 E, T6 ^# M% I$ y5 F6 w - int index1 = 0;2 l) r) F6 f! K
- int index2 = 0;
8 `0 L" D( j) K4 F! h - if (bkey.length == 0) {$ Q" h, u2 i: u$ Z8 ?
- return null;
0 e: J) f0 Z" Q7 e/ s [$ f; n3 W7 g - }
9 a! W8 |7 l7 h, ?7 C - for (int i = 0; i < 256; i++) {6 o3 z4 I7 O$ `
- index2 = ((bkey[index1] & 0xff) + (state[i] & 0xff) + index2) & 0xff;
5 X8 x# V e; W4 }1 I: L - byte tmp = state[i];
g2 X0 i+ e9 ?# ?2 L - state[i] = state[index2];' R. z8 `5 |3 S
- state[index2] = tmp;1 C' k p4 U0 T. g
- index1 = (index1 + 1) % bkey.length;7 a8 Z) S' O; s- }1 z4 r8 g9 A
- }
4 a: S. X x2 X) Q1 N - return state;8 L/ q% V2 m: H4 a
- }
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! V4 R; g* f( C ~2 `( l! y- private static String toHexString(String s) {7 Q3 r* c Q9 b. h; r
- String str = "";
# X3 R% {) a' [% o6 p" N - for (int i = 0; i < s.length(); i++) {2 D* B+ _9 D6 h! `- K4 s, Q1 [
- int ch = (int) s.charAt(i);( x9 {# E) R% s! z1 f% U0 |
- String s4 = Integer.toHexString(ch & 0xFF);7 E$ F, C# F- p! Z* E
- if (s4.length() == 1) {1 ? t0 |' m2 J4 U/ A" m6 K
- s4 = '0' + s4;6 a1 L, W9 N- m% ~$ K
- }
$ G* v# X: b& g2 `7 M - str = str + s4;2 a# k9 l( h! x9 h7 R; J
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- return str;' f m* H' V8 r$ W; T$ W( L$ c0 t! l
- }, w3 z. }3 T, M; A D9 k' z
- / `+ i! M8 x2 X$ \& {
- private static byte[] HexString2Bytes(String src) {, W$ F* |5 O$ c
- int size = src.length();7 F L" o, N- Z( }1 j% k
- byte[] ret = new byte[size / 2];' p1 M6 j5 ^/ y1 U( ?3 F, Z% y; h2 Z
- byte[] tmp = src.getBytes(StandardCharsets.UTF_8);
$ A Z ~, H) e2 y: f9 g - for (int i = 0; i < size / 2; i++) {6 ^& \9 C9 z( T' @8 m2 M; g
- ret[i] = uniteBytes(tmp[i * 2], tmp[i * 2 + 1]);( m8 |- r7 T$ \% Y; B0 l- T
- }
6 s5 s* j4 Q( k* `0 ~ - return ret; r/ z0 n, w: j% P3 n
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- # f# P& o6 Z4 i. @$ k7 e9 p! _2 P" h
- private static byte uniteBytes(byte src0, byte src1) {
. `$ _) `4 W# g$ o2 _ - char _b0 = (char) Byte.decode("0x" + new String(new byte[]{src0})).byteValue();4 S& d) ?( p. o/ E/ s7 f' q; x
- _b0 = (char) (_b0 << 4);6 w+ Z D, w9 t8 z }( l( K
- char _b1 = (char) Byte.decode("0x" + new String(new byte[]{src1})).byteValue();
& a/ s5 Q- F5 c% U5 } - return (byte) (_b0 ^ _b1);- s- |$ M& d1 M N( x5 K
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- 9 [& b- a+ @9 ]
- private static byte[] RC4Base(byte[] input, String mKkey) {' `# P2 j( A1 H) T* m) Y6 M
- int x = 0;6 y% g) T/ d! ^6 {
- int y = 0;4 m( ]$ {- x! h2 P7 \: q- F
- byte key[] = initKey(mKkey);
/ S& d1 I# F8 M" p9 z! U3 D - int xorIndex;$ [9 H0 x! o1 l; |8 Y, ~
- byte[] result = new byte[input.length];
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1 A1 X, B5 D; J$ G% e- E- for (int i = 0; i < input.length; i++) {
# F1 u! i/ ^) R7 o - x = (x + 1) & 0xff;& H h; [: M/ b' Q
- y = ((key[x] & 0xff) + y) & 0xff;' `6 S8 n% x0 t, d, k( ~! F
- byte tmp = key[x];
( Z9 h+ g: O) b6 H - key[x] = key[y];
8 F9 X! D( N) A, d: J - key[y] = tmp;& W- z- k, \* \" Z' ^
- xorIndex = ((key[x] & 0xff) + (key[y] & 0xff)) & 0xff;$ m3 _8 q/ }" _* c
- result[i] = (byte) (input[i] ^ key[xorIndex]);
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- return result;2 \' Y5 c! ]% j3 y% P8 K
- }9 y+ R& u5 U* }; d
- }
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