Hey,
First of all I'm new to OpenSSL and EVP functions. I've been using them in a project in order to encrypt/decrypt files using 256-bit AES in CBC mode, and using these functions to entirely encrypt/decrypt a file I've found any problem. Now, I've been asked to decrypt a file partially, and the problem we've found is that when decrypting it block by block, if the block to be decrypted is not the first one I have rubbish characters. But when decrypting all the content of the file, starting by the beginning block these characters does not appear.
So, my question is if it is possible to decrypt a file partially, and I will be very grateful if you could help me.
I also want to mention that when decrypting the file block by block (block chunks of 1024), the outlen variable on EVP_CipherUpdate(...) is always less than the inlen variable passed, though the outbuf contains more than outlen characters decrypted. Is it also normal?
Thank you all for your time,
Eudald
First of all I'm new to OpenSSL and EVP functions. I've been using them in a project in order to encrypt/decrypt files using 256-bit AES in CBC mode, and using these functions to entirely encrypt/decrypt a file I've found any problem. Now, I've been asked to decrypt a file partially, and the problem we've found is that when decrypting it block by block, if the block to be decrypted is not the first one I have rubbish characters. But when decrypting all the content of the file, starting by the beginning block these characters does not appear.
So, my question is if it is possible to decrypt a file partially, and I will be very grateful if you could help me.
I also want to mention that when decrypting the file block by block (block chunks of 1024), the outlen variable on EVP_CipherUpdate(...) is always less than the inlen variable passed, though the outbuf contains more than outlen characters decrypted. Is it also normal?
Thank you all for your time,
Eudald
-- openssl-users mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users
