> -----Original Message----- > From: [email protected] [mailto:owner-openssl- > [email protected]] On Behalf Of Tayade, Nilesh > Sent: Friday, March 08, 2013 9:26 PM > To: [email protected] > Subject: Extra bytes before the decrypted data. > > Hi, > > On performing the AES128 decryption, I see the decrypted data is > preceded by a block of 16bytes. > E.g. Below, 0x48 to 0x5a is the extra 16bytes block. And the actual > 'GET' request starts from 0x47 onwards. > > 48 3f c4 99 fa f0 75 0e 51 b8 3b 58 aa 1f 4a 5a > 47 45 54 20 2f 20 48 54 54 50 2f 31 2e 31 0d 0a > ... > 5b 28 c4 52 4e f9 53 2c 08 04 94 04 04 04 04 04 > > There is a padding of 5bytes in the end, which I can detect. Any > pointers on how to detect the initial 16bytes block? > This causes the output to be some junk followed by actual data. > > I cannot use EVP* APIs for some reason, so I am using the low level > aes_cbc_encrypt() function. > Any pointers will be appreciated. Forwarding the email to dev community. I apologize if this has some obvious answer and I overlooked it. These bytes might be IV. But I am trying to understand why these preceding bytes are there in specific data I decrypted and not in every decrypted data.
> -- > Thanks, > Nilesh ______________________________________________________________________ OpenSSL Project http://www.openssl.org Development Mailing List [email protected] Automated List Manager [email protected]
