Base64 Decode not working correctly along with Cipher.Decrypt in android

Question

Here's a string : ``` String msg="dpbqNszFN2cpmtlzPi3myV9M1ctlkSIQD95ue+T+9rz13T+Pe/aLZ8Pd5geI+PhEM/b0UeRS1cAzKybQsKICTBhh3ke5Jjw6BHWGESJWBnUT54lAlTvzkgOxpQ5stBh2cPPSn3KLyKmXifr8ClbV5s1k3Gy5C7HitA5KLw7hRxAmIGSWQG7PaiLNEVRbgicNfJ7Ic7VIdGA/UA51vK8mpywIR2YQUDPv30ThGq4DuclaJ3X4aVWVj8VYChcfM+82sViVU8HO3DF9CCU4EIADNET503olxiDZBp7WMYmJvWq0KhhZXkLSY3QFmcSMX6IThtdKKCcZp6hu3TtC+7aP7Q=="; ``` So the byte array is ``` [1] => 100 [2] => 112 [3] => 98 [4] => 113 [5] => 78 [6] => 115 [7] => 122 .. ``` Which should be decoded to [ I used PHP `base64_encode()` for encoding into the above form & `base64_decode()` for getting this output ] ``` [1] => 118 [2] => 150 [3] => 234 [4] => 54 [5] => 204 [6] => 197 7] => 55 ... ``` But the problem I'm facing is that ( In android , Using `Base64.decode(String)` ) it's getting decoded to : ``` [118, -106, -22, 54, -52, -59, 55, 103, 41, -102, -39, 115, 62, 45, -26, -55, 95, 76, -43, -53, 101, -111, 34, 16, 15, -34, 110, 123, -28, -2, -10, -68, -11, -35, 63, -113,…

Accepted Answer

All looks fine to me - you just need to remember that bytes are signed in Java. So a value of -106 in Java corresponds to an unsigned value of 150. Once you bear that in mind, I think you'll see that all the values in PHP correspond to the values in Java.

Note that you ought to distinguish between bytes and characters. So when you say:

As you can see , some characters ( which are not readable though) , are not getting decoded correctly.

You actually mean some bytes... and there's no such concept as a "readable" byte.

EDIT: I see no sign that you've actually decrypted the data at all.

You're converting the still encrypted result of the base64 decoding into text using the platform default encoding:

```
String tmpr=new String(baser);
```

You shouldn't be doing that - you should be using `baser` as the cipher-text to decrypt.

It's not at all clear where the `tmp` value you're passing to `doFinal` comes from at all...

Base64 Decode not working correctly along with Cipher.Decrypt in android

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