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[SOLVED] javax.crypto.BadPaddingException: Given final block not properly padded

Error added: 2009-11-02T22:59:10Z

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Answer 2502 (100.0% helpful)

If you try to decrypt PKCS5-padded data with the wrong key, and then unpad it (which is done by the Cipher class automatically), you most likely will get the BadPaddingException (with probably of slightly less than 255/256, around 99.61%), because the padding has a special structure which is validated during unpad and very few keys would produce a valid padding.

So, if you get this exception, catch it and treat it as "wrong key".
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