module Cryptokit: sig end
The Cryptokit library provides a variety of cryptographic primitives
that can be used to implement cryptographic protocols in
security-sensitive applications. The primitives provided include:
- Symmetric-key ciphers: AES, DES, Triple-DES, ARCfour,
in ECB, CBC, CFB and OFB modes.
- Public-key cryptography: RSA encryption, Diffie-Hellman key agreement.
- Hash functions and MACs: SHA-1, MD5, and MACs based on AES and DES.
- Random number generation.
- Encodings and compression: base 64, hexadecimal, Zlib compression.
To use this library, link with
ocamlc unix.cma nums.cma cryptokit.cma
or
ocamlopt unix.cmxa nums.cmxa cryptokit.cmxa.
General-purpose abstract interfaces
|
class type transform = object end
A transform is an arbitrary mapping from sequences of characters
to sequences of characters.
val transform_string : transform -> string -> string
transform_string t s runs the string s through the
transform t and returns the transformed string.
The transform t is wiped before returning, hence can
no longer be used for further transformations.
val transform_channel : transform ->
?len:int -> Pervasives.in_channel -> Pervasives.out_channel -> unit
transform_channel t ic oc reads characters from input channel ic,
runs them through the transform t, and writes the transformed
data to the output channel oc. If the optional len argument
is provided, exactly len characters are read from ic and
transformed; End_of_file is raised if ic does not contain
at least len characters. If len is not provided, ic is
read all the way to end of file.
The transform t is wiped before returning, hence can
no longer be used for further transformations.
val compose : transform -> transform -> transform
Compose two transforms, feeding the output of the first transform
to the input of the second transform.
class type hash = object end
A hash is a function that maps arbitrarily-long character
sequences to small, fixed-size strings.
val hash_string : hash -> string -> string
hash_string h s runs the string s through the hash function h
and returns the hash value of s.
The hash h is wiped before returning, hence can
no longer be used for further hash computations.
val hash_channel : hash -> ?len:int -> Pervasives.in_channel -> string
hash_channel h ic reads characters from the input channel ic,
computes their hash value and returns it.
If the optional len argument is provided, exactly len characters
are read from ic and hashed; End_of_file is raised if ic
does not contain at least len characters.
If len is not provided, ic is read all the way to end of file.
The hash h is wiped before returning, hence can
no longer be used for further hash computations.
Utilities: random numbers and padding schemes
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module Random: sig end
The Random module provides random and pseudo-random number generators
suitable for generating cryptographic keys, nonces, or challenges.
module Padding: sig end
The Padding module defines a generic interface
for padding input data to an integral number of blocks,
as well as two popular padding schemes.
Cryptographic primitives (simplified interface)
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module Cipher: sig end
The Cipher module implements the AES, DES, Triple-DES and ARCfour
symmetric ciphers.
module Hash: sig end
The Hash module implements unkeyed cryptographic hashes SHA-1
and MD5, also known as message digest functions.
module MAC: sig end
The MAC module implements message authentication codes, also
known as keyed hash functions.
module RSA: sig end
The RSA module implements RSA public-key cryptography.
module DH: sig end
The DH module implements Diffie-Hellman key agreement.
Advanced, compositional interface to block ciphers
and stream ciphers
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module Block: sig end
The Block module provides classes that implements
popular block ciphers, chaining modes, and wrapping of a block cipher
as a general transform or as a hash function.
module Stream: sig end
The Stream module provides classes that implement
the ARCfour stream cipher, and the wrapping of a stream cipher
as a general transform.
Encoding and compression of data
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module Base64: sig end
The Base64 module supports the encoding and decoding of
binary data in base 64 format, using only alphanumeric
characters that can safely be transmitted over e-mail or
in URLs.
module Hexa: sig end
The Hexa module supports the encoding and decoding of
binary data as hexadecimal strings.
module Zlib: sig end
The Zlib module supports the compression and decompression
of data, using the zlib library.
type error =
| |
Wrong_key_size |
(* | The key is too long or too short for the given cipher. | *) |
| |
Wrong_IV_size |
(* | The initialization vector does not have the same size as
the block size. | *) |
| |
Wrong_data_length |
(* | The total length of the input data for a transform is not an
integral multiple of the input block size. | *) |
| |
Bad_padding |
(* | Incorrect padding bytes were found after decryption. | *) |
| |
Output_buffer_overflow |
(* | The output buffer for a transform exceeds the maximal length
of a Caml string. | *) |
| |
Incompatible_block_size |
(* | A combination of two block ciphers was attempted whereby
the ciphers have different block sizes, while they must have
the same. | *) |
| |
Number_too_long |
(* | Denotes an internal error in RSA key generation or encryption. | *) |
| |
Seed_too_short |
(* | The seed given to a pseudo random number generator is too short. | *) |
| |
Message_too_long |
(* | The message passed to RSA encryption or decryption is greater
than the modulus of the RSA key | *) |
| |
Bad_encoding |
(* | Illegal characters were found in an encoding of binary data
such as base 64 or hexadecimal. | *) |
| |
Compression_error of string * string |
(* | Error during compression or decompression. | *) |
| |
No_entropy_source |
(* | No entropy source (/dev/random or EGD) was found for
Cryptokit.Random.secure_rng. | *) |
| |
Entropy_source_closed |
(* | End of file on a device or EGD entropy source. | *) |
Error codes for this library.
exception Error of error
Exception raised by functions in this library
to report error conditions.
val wipe_string : string -> unit
wipe_string s overwrites s with zeroes. Can be used
to reduce the memory lifetime of sensitive data.
val xor_string : string -> int -> string -> int -> int -> unit
xor_string src spos dst dpos len performs the xor (exclusive or)
of characters spos, ..., spos + len - 1 of src
with characters dpos, ..., dpos + len - 1 of dst,
storing the result in dst starting at position dpos.
val mod_power : string -> string -> string -> string
mod_power a b c computes a^b mod c, where the
strings a, b, c and the result string are viewed as
arbitrary-precision integers in big-endian format.
Requires a < c.
val mod_mult : string -> string -> string -> string
mod_mult a b c computes a*b mod c, where the
strings a, b, c and the result string are viewed as
arbitrary-precision integers in big-endian format.