Docs GODI Archive
Projects Blog Knowledge

Look up function:

(e.g. "List.find" or "keysym")
More options

Module Netmech_scram.Cryptosystem


module Cryptosystem: sig .. end
This is the cryptosystem as defined in RFC 3961, so far needed here. This uses AES_CTS as cipher, and SHA1-96 for signing.

exception Integrity_error
val derive_keys : string -> int -> Netmech_scram.specific_keys
derive_keys protocol_key usage: Returns the specific keys for this protocol_key and this usage numbers. See RFC 4121 for applicable usage numbers
val encrypt_and_sign : Netmech_scram.specific_keys -> string -> string
Encrypts the plaintext message and adds a signature to the ciphertext.

Returns ciphertext_with_signature.

val encrypt_and_sign_mstrings : Netmech_scram.specific_keys ->
Xdr_mstring.mstring list -> Xdr_mstring.mstring list
Same, but with data representation as mstring list
val decrypt_and_verify : Netmech_scram.specific_keys -> string -> string
Decrypts the ciphertext and verifies the attached signature. Returns the restored plaintext.

For very short plaintexts (< 16 bytes) there will be some padding at the end ("residue"), as returned as ec above. We ignore this problem generally, because GSS-API adds a 16-byte header to the plaintext anyway, so these short messages do not occur.

If the signature is not valid, the exception Integrity_error is raised.

val decrypt_and_verify_mstrings : Netmech_scram.specific_keys ->
Xdr_mstring.mstring list -> Xdr_mstring.mstring list
Same, but with data representation as mstring list
val get_ec : Netmech_scram.specific_keys -> int -> int
let ec = get_ec e_keys n: Returns the required value for the "extra count" field of RFC 4121 if the plaintext message has size n. Here, n is the size of the payload message plus the token header of 16 bytes, i.e. the function is always called with n >= 16.

Here, the returned ec value is always 0.

val get_mic : Netmech_scram.specific_keys -> string -> string
Returns a message integrity code
val get_mic_mstrings : Netmech_scram.specific_keys -> Xdr_mstring.mstring list -> string
Same, but with data representation as mstring list
This web site is published by Informatikbüro Gerd Stolpmann
Powered by Caml