• Stephan Mueller's avatar
    crypto: keywrap - add key wrapping block chaining mode · e28facde
    Stephan Mueller authored
    This patch implements the AES key wrapping as specified in
    NIST SP800-38F and RFC3394.
    
    The implementation covers key wrapping without padding.
    
    IV handling: The caller does not provide an IV for encryption,
    but must obtain the IV after encryption which would serve as the first
    semblock in the ciphertext structure defined by SP800-38F. Conversely,
    for decryption, the caller must provide the first semiblock of the data
    as the IV and the following blocks as ciphertext.
    
    The key wrapping is an authenticated decryption operation. The caller
    will receive EBADMSG during decryption if the authentication failed.
    
    Albeit the standards define the key wrapping for AES only, the template
    can be used with any other block cipher that has a block size of 16
    bytes. During initialization of the template, that condition is checked.
    Any cipher not having a block size of 16 bytes will cause the
    initialization to fail.
    Signed-off-by: Stephan Mueller's avatarStephan Mueller <smueller@chronox.de>
    Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
    e28facde
keywrap.c 12.6 KB