I have no idea if this is an issue with D, or OpenSSL, or if I'm
just doing something completely wrong. I'm writing a program that
will either encrypt or decrypt a string using AES in ECB mode
(for a school assignment) and it's giving me a very strange bug.
encrypt and decrypt are both bools, either one or the other is
set based on command-line arguments passed to the program. aesKey
is a 128-bit value hashed from user input, and is (obviously)
used as the key for encryption. inputStr is either the string to
be encrypted or decrypted (also passed in as a command-line
argument). I grabbed the OpenSSL bindings from Deimos to do this.
if(encrypt)
{
AES_KEY encKey;
auto encOut = new ubyte[inputStr.length];
// Encrypt and convert to base64
AES_set_encrypt_key(aesKey.ptr, aesKey.sizeof * 8, &encKey);
AES_ecb_encrypt(inputStr.ptr, encOut.ptr, &encKey,
AES_ENCRYPT);
writeln(Base64.encode(encOut));
}
else if(decrypt) // I'd leave this as else, but it's here for
explanation purposes
{
AES_KEY decKey;
auto decLength = Base64.decodeLength(inputStr.length);
auto decB64 = new ubyte[decLength], decOut = new
ubyte[decLength];
// convert back from base64 and decrypt
decB64 = Base64.decode(inputStr); // Yes I checked, and
decB64 has exact the same contents as encOut from the if block
AES_set_decrypt_key(aesKey.ptr, aesKey.sizeof * 8, &decKey);
AES_ecb_encrypt(decB64.ptr, decOut.ptr, &decKey, AES_DECRYPT);
writeln(cast(char[]) decOut);
}
However, this isn't working for a very strange reason (spits back
garbage instead of the string I originally encrypted).
Here's the problem. I tried running this without the if-else
statements (i.e. encrypting and decrypting all in one run of the
program, code below). If I leave in the base64 encoding and
decoding, and use decB64 as the input to decrypt, it still
doesn't work. However, if I decrypt with encOut directly, or
assign encOut to decB64, it somehow works.
AES_KEY encKey;
auto encOut = new ubyte[inputStr.length];
// Encrypt and convert to base64
AES_set_encrypt_key(aesKey.ptr, aesKey.sizeof * 8, &encKey);
AES_ecb_encrypt(inputStr.ptr, encOut.ptr, &encKey, AES_ENCRYPT);
auto decLength =
Base64.decodeLength(Base64.encode(encOut).length);
AES_KEY decKey;
auto decB64 = new ubyte[decLength], decOut = new ubyte[decLength];
// convert back from base64 and decrypt
decB64 = Base64.decode(Base64.encode(encOut));
// doesn't work unless I uncomment out the following line, or
just use encOut directly
//decB64 = encOut;
AES_set_decrypt_key(aesKey.ptr, aesKey.sizeof * 8, &decKey);
AES_ecb_encrypt(decB64.ptr, decOut.ptr, &decKey, AES_DECRYPT);
writeln(cast(char[]) decOut);
tl;dr The decryption doesn't work unless I pass it the exact same
buffer (including not only contents, but apparently the exact
same memory address) that I used to receive output from encryption
Does anyone have any idea where the issue may lie, or how I could
fix this?
Here's the full program if you want to take a look
http://pastebin.com/KyY103Ac
