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Diffstat (limited to 'gcc-4.8.3/gcc/ada/g-shshco.adb')
| -rw-r--r-- | gcc-4.8.3/gcc/ada/g-shshco.adb | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/gcc-4.8.3/gcc/ada/g-shshco.adb b/gcc-4.8.3/gcc/ada/g-shshco.adb new file mode 100644 index 000000000..dcdb23690 --- /dev/null +++ b/gcc-4.8.3/gcc/ada/g-shshco.adb @@ -0,0 +1,135 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT LIBRARY COMPONENTS -- +-- -- +-- G N A T . S E C U R E _ H A S H E S . S H A 2 _ C O M M O N -- +-- -- +-- B o d y -- +-- -- +-- 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. -- +-- -- +------------------------------------------------------------------------------ + +package body GNAT.Secure_Hashes.SHA2_Common is + + --------------- + -- Transform -- + --------------- + + procedure Transform + (H_St : in out Hash_State.State; + M_St : in out Message_State) + is + use System; + + subtype Word is Hash_State.Word; + use type Hash_State.Word; + + function Ch (X, Y, Z : Word) return Word; + function Maj (X, Y, Z : Word) return Word; + pragma Inline (Ch, Maj); + -- Elementary functions from FIPS PUB 180-3 + + -------- + -- Ch -- + -------- + + function Ch (X, Y, Z : Word) return Word is + begin + return (X and Y) xor ((not X) and Z); + end Ch; + + --------- + -- Maj -- + --------- + + function Maj (X, Y, Z : Word) return Word is + begin + return (X and Y) xor (X and Z) xor (Y and Z); + end Maj; + + type Words is array (Natural range <>) of Word; + + X : Words (0 .. 15); + for X'Address use M_St.Buffer'Address; + pragma Import (Ada, X); + + W : Words (0 .. Rounds - 1); + + A, B, C, D, E, F, G, H, T1, T2 : Word; + + -- Start of processing for Transform + + begin + if Default_Bit_Order /= High_Order_First then + for J in X'Range loop + Hash_State.Swap (X (J)'Address); + end loop; + end if; + + -- 1. Prepare message schedule + + W (0 .. 15) := X; + + for T in 16 .. Rounds - 1 loop + W (T) := S1 (W (T - 2)) + W (T - 7) + S0 (W (T - 15)) + W (T - 16); + end loop; + + -- 2. Initialize working variables + + A := H_St (0); + B := H_St (1); + C := H_St (2); + D := H_St (3); + E := H_St (4); + F := H_St (5); + G := H_St (6); + H := H_St (7); + + -- 3. Perform transformation rounds + + for T in 0 .. Rounds - 1 loop + T1 := H + Sigma1 (E) + Ch (E, F, G) + K (T) + W (T); + T2 := Sigma0 (A) + Maj (A, B, C); + H := G; + G := F; + F := E; + E := D + T1; + D := C; + C := B; + B := A; + A := T1 + T2; + end loop; + + -- 4. Update hash state + + H_St (0) := A + H_St (0); + H_St (1) := B + H_St (1); + H_St (2) := C + H_St (2); + H_St (3) := D + H_St (3); + H_St (4) := E + H_St (4); + H_St (5) := F + H_St (5); + H_St (6) := G + H_St (6); + H_St (7) := H + H_St (7); + end Transform; + +end GNAT.Secure_Hashes.SHA2_Common; |