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Diffstat (limited to 'gcc/ada/g-sechas.ads')
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diff --git a/gcc/ada/g-sechas.ads b/gcc/ada/g-sechas.ads new file mode 100644 index 00000000000..55180ac4ca4 --- /dev/null +++ b/gcc/ada/g-sechas.ads @@ -0,0 +1,187 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT LIBRARY COMPONENTS -- +-- -- +-- G N A T . S E C U R E _ H A S H E S -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 2009, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 3, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This package provides common suporting code for a family of secure +-- hash functions (including MD5 and the FIPS PUB 180-3 functions SHA-1, +-- SHA-224, SHA-256, SHA-384 and SHA-512). + +-- This is an internal unit and should be not used directly in applications. +-- Use GNAT.MD5 and GNAT.SHA* instead. + +with Ada.Streams; +with Interfaces; +with System; + +package GNAT.Secure_Hashes is + + type Buffer_Type is new String; + for Buffer_Type'Alignment use 8; + -- Secure hash functions use a string buffer that is also accessed as an + -- array of words, which may require up to 64 bit alignment. + + -- The function-independent part of processing state: A buffer of data + -- being accumulated until a complete block is ready for hashing. + + type Message_State (Block_Length : Natural) is record + Last : Natural := 0; + -- Index of last used element in Buffer + + Length : Interfaces.Unsigned_64 := 0; + -- Total length of processed data + + Buffer : Buffer_Type (1 .. Block_Length); + -- Data buffer + end record; + + -- The function-specific part of processing state: + + -- Each hash function maintains an internal state as an array of words, + -- which is ultimately converted to a stream representation with the + -- appropriate bit order. + + generic + type Word is mod <>; + -- Either 32 or 64 bits + + with procedure Swap (X : System.Address); + -- Byte swapping function for a Word at X + + Hash_Bit_Order : System.Bit_Order; + -- Bit order of the produced hash + + package Hash_Function_State is + + type State is array (Natural range <>) of Word; + -- Used to store a hash function's internal state + + procedure To_Hash + (H : State; + H_Bits : out Ada.Streams.Stream_Element_Array); + -- Convert H to stream representation with the given bit order. + -- If H_Bits is smaller than the internal hash state, then the state + -- is truncated. + + end Hash_Function_State; + + -- Generic hashing framework: + -- The user interface for each implemented secure hash function is an + -- instance of this generic package. + + generic + Block_Words : Natural; + -- Number of words in each block + + State_Words : Natural; + -- Number of words in internal state + + Hash_Words : Natural; + -- Number of words in the final hash (must be no greater than + -- State_Words). + + Hash_Bit_Order : System.Bit_Order; + -- Bit order used for conversion between bit representation and word + -- representation. + + with package Hash_State is new Hash_Function_State (<>); + -- Hash function state package + + Initial_State : Hash_State.State; + -- Initial value of the hash function state + + with procedure Transform + (H : in out Hash_State.State; + M : in out Message_State); + -- Transformation function updating H by processing a complete data + -- block from M. + + package H is + + -- The visible part of H is the interface to secure hashing functions + -- that is exposed to user applications, and is intended to remain + -- a stable interface. + + pragma Assert (Hash_Words <= State_Words); + + type Context is private; + -- The internal processing state of the hashing function + + Initial_Context : constant Context; + -- Initial value of a Context object. May be used to reinitialize + -- a Context value by simple assignment of this value to the object. + + procedure Update (C : in out Context; Input : String); + procedure Wide_Update (C : in out Context; Input : Wide_String); + procedure Update + (C : in out Context; + Input : Ada.Streams.Stream_Element_Array); + -- Update C to process the given input. Successive calls to Update are + -- equivalent to a single call with the concatenation of the inputs. For + -- the Wide_String version, each Wide_Character is processed low order + -- byte first. + + Word_Length : constant Natural := Hash_State.Word'Size / 8; + Hash_Length : constant Natural := Hash_Words * Word_Length; + + subtype Message_Digest is String (1 .. 2 * Hash_Length); + -- The fixed-length string returned by Digest, providing the hash in + -- hexadecimal representation. + + function Digest (C : Context) return Message_Digest; + -- Return hash for the data accumulated with C in hexadecimal + -- representation. + + function Digest (S : String) return Message_Digest; + function Wide_Digest (W : Wide_String) return Message_Digest; + function Digest + (A : Ada.Streams.Stream_Element_Array) return Message_Digest; + -- These functions are equivalent to the corresponding Update (or + -- Wide_Update) on a default initialized Context, followed by Digest + -- on the resulting Context. + + private + + Block_Length : constant Natural := Block_Words * Word_Length; + -- Length in bytes of a data block + + type Context is record + H_State : Hash_State.State (0 .. State_Words - 1) := Initial_State; + -- Function-specific state + + M_State : Message_State (Block_Length); + -- Function-independent state (block buffer) + end record; + + Initial_Context : constant Context := (others => <>); + -- Initial values are provided by default initialization of Context + + end H; + +end GNAT.Secure_Hashes; |