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L Willie
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Joined: Aug 10, 2008
Posts: 51
Error message "Exception:javax.crypto.IllegalBlockSizeException: Data must not be longer than 128 bytes" display when read the cipherMessage from ciphertext.txt* [ciphertext.txt can keep correct cipher message since the content same as System.out.println("Message encrypted with keystore public key:\n" + new String(ciphertextBytes) + "\n");]
and try to decrypt it.

NO such error message and decrypt properly ONLY IF direct read message from "ciphertextBytes " that i encrypt message,that is replace textBytes = cipher.doFinal(cipherMessageBytes); with textBytes = cipher.doFinal(ciphertextBytes);
moreover,the message also can not too long,otherwise it ll prompt another error message "Exception:javax.crypto.IllegalBlockSizeException: Data must not be longer than 117 bytes"

hence i guess might be wrong during read the "ciphertext.txt" especially convert the String cipherMessage to Byte[] cipherMessageBytes .am i wrong on this convert process??

Rob Spoor

Joined: Oct 27, 2005
Posts: 19656

That's the same question as this one. Let's continue in that thread, shall we?

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It is sorta covered in the JavaRanch Style Guide.
subject: IllegalBlockSizeException
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