微信退款回调解密 pad block corrupted

以下是相关代码

public static String decryptData(String base64Data) throws Exception { Security.addProvider(new BouncyCastleProvider()); Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC"); cipher.init(Cipher.DECRYPT_MODE, key); byte[] decode = Base64Util.decode(base64Data); return new String(cipher.doFinal(decode)); } public static byte[] decode(String data) { char ibuf[] = new char[4]; int ibufcount = 0; byte obuf[] = new byte[(data.length() / 4) * 3 + 3]; int obufcount = 0; for (int i = 0; i < data.length(); i++) { char ch = data.charAt(i); if (ch != '=' && (ch >= S_DECODETABLE.length || S_DECODETABLE[ch] == 127)) continue; ibuf[ibufcount++] = ch; if (ibufcount == ibuf.length) { ibufcount = 0; obufcount += decode0(ibuf, obuf, obufcount); } } if (obufcount == obuf.length) { return obuf; } else { byte ret[] = new byte[obufcount]; System.arraycopy(obuf, 0, ret, 0, obufcount); return ret; } } public static String md5Encode(String origin, String charsetname) { String resultString = null; try { resultString = new String(origin); MessageDigest md = MessageDigest.getInstance("MD5"); if (charsetname == null || "".equals(charsetname)) resultString = byteArrayToHexString(md.digest(resultString.getBytes())); else resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname))); } catch (Exception exception) { } return resultString; }