<转载>实现android的AES加密技术
原文地址：实现android的AES加密技术作者：大牛

java类文件：

import?java.security.SecureRandom; ?? ?? import?javax.crypto.Cipher; ?? import?javax.crypto.KeyGenerator; ?? import?javax.crypto.SecretKey; ?? import?javax.crypto.spec.SecretKeySpec; ?? ?? ?? public?class?SimpleCrypto?{ ?? ?? ????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).bytue(); ?? ????????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)); ?? ????} ?? ???? ?? }?

?加密：String encryptingCode = SimpleCrypto.encrypt(masterPassword,originalText);

解密：String originalText = SimpleCrypto.decrypt(masterpassword, encryptingCode);