package MD5 is --==================================================================== -- Authors Rolf Ebert (no known address), -- Christoph Grein <Christ-Usch.Grein@T-Online.de> -- Version 1.1 -- Date 16 January 1999 --==================================================================== -- The Message-Digest MD5 Algorithm of RSA Data Security, Inc. -- -- The official description of this algorithm can be found on the -- site of the RSA Data Security, Inc. The following is a quote from -- this description. -- -- The algorithm takes as input a message of arbitrary length and -- produces as output a 128-bit "fingerprint" or "message digest" -- of the input. It is conjectured that it is computationally -- infeasible to produce two messages having the same message -- digest, or to produce any message having a given prespecified -- target message digest. The MD5 algorithm is intended for digital -- signature applications, where a large file must be "compressed" -- in a secure manner before being encrypted with a private -- (secret) key under a public-key cryptosystem such as RSA. -- -- The official description of the MD5 algorithm can be found at -- <ftp://ftp.rsa.com/pub/md5.txt> -- License is granted by RSA Data Security, Inc. <http://www.rsa.com> -- to make and use derivative works provided that such works are -- identified as "derived from the RSA Data Security, Inc. MD5 -- Message-Digest Algorithm" in all material mentioning or referencing -- the derived work. (See the copyright notice in the official -- description.) -- -- Usage: -- - First call Init. -- - Call Update (repeatedly) until all input has been digested. -- Long messages may be digested in chunks of any length (the -- reference implementation uses chunks of 1024 bits). -- - Call Final. -- For text output, the fingerprint may be converted to a hexadecimal -- string. --==================================================================== -- History -- Author Version Date Reason for change -- R.E. 1.0 04.06.1997 Original as found in internet -- C.G. 1.1 16.01.1999 Minor code changes; commented to make -- publication legal --==================================================================== type Byte is mod 2**8; type Byte_Array is array (Long_Integer range <>) of Byte; pragma Pack (Byte_Array); subtype Fingerprint is Byte_Array (1 .. 16); -- 128 bits subtype Digest_String is String (1 .. 32); -- Fingerprint in hex -- Create a fingerprint type Context is private; procedure Init (Ctx: out Context); procedure Update (Ctx: in out Context; Data : in Byte_Array); procedure Update (Ctx: in out Context; Data : in String); procedure Final (Ctx: in out Context; Digest: out Fingerprint); -- Conversions Malformed: exception; -- may be raised in Digest_From_Text function Digest_From_Text (S: Digest_String) return Fingerprint; function Digest_To_Text (A: Fingerprint) return Digest_String; private type Word is mod 2**32; type Word_Array is array (Long_Integer range <>) of Word; pragma Pack (Word_Array); subtype ABCD_State is Word_Array (1 .. 4); subtype Count_T is Word_Array (1 .. 2); subtype Buffer_T is Byte_Array (1 .. 64); type Context is record State : ABCD_State; Count : Count_T; Buffer: Buffer_T; end record; end MD5;
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