C/C++ Problem when trying to decryp encryped file with CryptoPP (C++)

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The discussion revolves around a decryption issue involving AES128 encryption. The user successfully encrypted a text file using a binary key and Base64 encoding but encounters an error when attempting to decrypt it. The error message indicates a problem with the passphrase during decryption. The user has verified that their own encryption and decryption processes work correctly with the same binary key. Potential causes for the decryption failure include differences in encryption algorithms, padding schemes, or the mode of operation (such as ECB, CBC, or CTR) used during encryption. The user seeks clarification on these aspects to resolve the decryption issue.
CMV123
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Hi all,

I have a problem.

Someone I know encrypted a text file using AES128 by using binary key file, (He generate the binary key).
After that he uses "base64Encode" over the encryped file

I have the private binary key file.
Now, when I'm trying to decrypt the file, I do as follow:
1. Use "Base64Decoder" to get the encrypted file --> Pass successfully
2. Use the following:

Try using both functions:
FileSource f(in, true, new DefaultDecryptorWithMAC(passPhrase, new FileSink(out)));

FileSource f(in, true, new DefaultDecryptor(passPhrase, new FileSink(out)));

where:
in - is the input file (encrypted file)
passPharse - char* - location of the key file


but I always getting the following error:
terminate called after throwing an instance of 'CryptoPP::DefaultDecryptor::KeyBadErr'
what(): DefaultDecryptor: cannot decrypt message with this passphrase


Now when I'm trying to encrypt and decrypt by myself it works fine,
(I'm using the binary key he gave me)

1. FileSource f(in, true, new DefaultEncryptorWithMAC(passPhrase, new FileSink(out)));
2. FileSource(in, true, new Base64Encoder(new FileSink(out)));
3. FileSource(in, true, new Base64Decoder(new FileSink(out)));
4. FileSource f(in, true, new DefaultDecryptorWithMAC(passPhrase, new FileSink(out)));


Could anyone help me to understand what is my problem?
I'm guessing that the problem could be from 2 reasons:
1. Because this is a different algorithm form java AES128
2. There is a problem in the key, It can't read it right
 
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I don't know anything about the implementation you are using so I don't know whether your code is correct, but from my experience such problems are usually the result of using different padding schemes.

Also, since it's AES, make sure you are using the same mode (ECB, CBC, CTR...) and initialization vector, if appropriate.

I'm pretty sure one of these two is the problem if your program correctly decrypts the stuff it encrypts.
 
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