[multiple changes]

2014-08-04  Robert Dewar  <dewar@adacore.com>

	* sem_prag.adb, osint.adb, osint.ads: Minor reformatting.

2014-08-04  Yannick Moy  <moy@adacore.com>

	* sem_ch3.adb (Derive_Type_Declaration,
	Process_Discriminants): Remove SPARK-specific legality checks.

2014-08-04  Thomas Quinot  <quinot@adacore.com>

	* g-sechas.ads, g-sechas.adb (HMAC_Initial_Context): New subprogram.
	* gnat_rm.texi (GNAT.MD5/SHA1/SHA224/SHA256/SHA512): Document support
	for HMAC.

From-SVN: r213577

1 files changed, 70 insertions, 4 deletions

diff --git a/gcc/ada/g-sechas.adb b/gcc/ada/g-sechas.adb
index 4b396f1..0e70b5d 100644
--- a/gcc/ada/g-sechas.adb
+++ b/gcc/ada/g-sechas.adb
@@ -6,7 +6,7 @@
 --                                                                          --
 --                                 B o d y                                  --
 --                                                                          --
---          Copyright (C) 2009-2012, Free Software Foundation, Inc.         --
+--          Copyright (C) 2009-2014, 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- --
@@ -218,8 +218,8 @@ package body GNAT.Secure_Hashes is
       --  the message size in bits (excluding padding).
 
       procedure Final
-        (C          : Context;
-         Hash_Bits  : out Stream_Element_Array)
+        (C         : Context;
+         Hash_Bits : out Stream_Element_Array)
       is
          FC : Context := C;
 
@@ -274,8 +274,73 @@ package body GNAT.Secure_Hashes is
          pragma Assert (FC.M_State.Last = 0);
 
          Hash_State.To_Hash (FC.H_State, Hash_Bits);
+
+         --  HMAC case: hash outer pad
+
+         if C.KL /= 0 then
+            declare
+               Outer_C : Context;
+               Opad    : Stream_Element_Array :=
+                 (1 .. Stream_Element_Offset (Block_Length) => 16#5c#);
+
+            begin
+               for J in C.Key'Range loop
+                  Opad (J) := Opad (J) xor C.Key (J);
+               end loop;
+
+               Update (Outer_C, Opad);
+               Update (Outer_C, Hash_Bits);
+
+               Final (Outer_C, Hash_Bits);
+            end;
+         end if;
       end Final;
 
+      --------------------------
+      -- HMAC_Initial_Context --
+      --------------------------
+
+      function HMAC_Initial_Context (Key : String) return Context is
+      begin
+         if Key'Length = 0 then
+            raise Constraint_Error with "null key";
+         end if;
+
+         return C : Context (KL => (if Key'Length <= Key_Length'Last
+                                    then Key'Length
+                                    else Stream_Element_Offset (Hash_Length)))
+         do
+            --  Set Key (if longer than block length, first hash it)
+
+            if C.KL = Key'Length then
+               declare
+                  SK : String (1 .. Key'Length);
+                  for SK'Address use C.Key'Address;
+                  pragma Import (Ada, SK);
+               begin
+                  SK := Key;
+               end;
+
+            else
+               C.Key := Digest (Key);
+            end if;
+
+            --  Hash inner pad
+
+            declare
+               Ipad : Stream_Element_Array :=
+                 (1 .. Stream_Element_Offset (Block_Length) => 16#36#);
+
+            begin
+               for J in C.Key'Range loop
+                  Ipad (J) := Ipad (J) xor C.Key (J);
+               end loop;
+
+               Update (C, Ipad);
+            end;
+         end return;
+      end HMAC_Initial_Context;
+
       ------------
       -- Update --
       ------------
@@ -285,11 +350,12 @@ package body GNAT.Secure_Hashes is
          S           : String;
          Fill_Buffer : Fill_Buffer_Access)
       is
-         Last : Natural := S'First - 1;
+         Last : Natural;
 
       begin
          C.M_State.Length := C.M_State.Length + S'Length;
 
+         Last := S'First - 1;
          while Last < S'Last loop
             Fill_Buffer (C.M_State, S, Last + 1, Last);