121 lines
3.8 KiB
Ada
121 lines
3.8 KiB
Ada
-- Copyright (C) 2015 Daniel Otte <bg@nerilex.org>
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--
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-- This program is free software: you can redistribute it and/or modify
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-- it under the terms of the GNU General Public License as published by
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-- the Free Software Foundation, either version 3 of the License, or
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-- (at your option) any later version.
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--
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-- This program is distributed in the hope that it will be useful,
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-- but WITHOUT ANY WARRANTY; without even the implied warranty of
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-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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-- GNU General Public License for more details.
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--
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-- You should have received a copy of the GNU General Public License
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-- along with this program. If not, see <http://www.gnu.org/licenses/>.
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package body Spritz_AEAD is
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procedure Initialize (ctx : out Context; key : in u8_Array) is
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begin
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Spritz.Initialize(ctx.ctx);
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Spritz.Absorb(ctx.ctx, key);
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Spritz.AbsorbStop(ctx.ctx);
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ctx.state := pre_nonce;
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end Initialize;
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procedure Initialize (ctx : out Context; key : in String) is
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begin
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Spritz.Initialize(ctx.ctx);
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Spritz.Absorb(ctx.ctx, key);
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Spritz.AbsorbStop(ctx.ctx);
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ctx.state := pre_nonce;
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end Initialize;
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procedure Set_Nonce (ctx : in out Context; nonce : in u8_Array) is
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begin
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if ctx.state /= pre_nonce then
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raise Wrong_Opertaion_Order;
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end if;
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Spritz.Absorb(ctx.ctx, nonce);
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Spritz.AbsorbStop(ctx.ctx);
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ctx.state := pre_header;
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end Set_Nonce;
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procedure Set_Nonce (ctx : in out Context; nonce : in String) is
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begin
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if ctx.state /= pre_nonce then
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raise Wrong_Opertaion_Order;
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end if;
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Spritz.Absorb(ctx.ctx, nonce);
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Spritz.AbsorbStop(ctx.ctx);
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ctx.state := pre_header;
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end Set_Nonce;
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procedure Add_Header (ctx : in out Context; header : in u8_Array) is
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begin
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if ctx.state /= pre_header then
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raise Wrong_Opertaion_Order;
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end if;
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Spritz.Absorb(ctx.ctx, header);
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end Add_Header;
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procedure Encrypt_Data (ctx : in out Context; data : in out u8_Array) is
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c : Integer := data'First;
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begin
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if ctx.state /= pre_header then
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Spritz.AbsorbStop(ctx.ctx);
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ctx.state := pre_data;
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end if;
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if ctx.state /= pre_data then
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raise Wrong_Opertaion_Order;
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end if;
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while c <= data'Last loop
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if ctx.offset = 0 then
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Spritz.Squeeze(ctx.ctx, ctx.buffer);
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end if;
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data(c) := data(c) + ctx.buffer(ctx.offset);
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ctx.buffer(ctx.offset) := data(c);
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c := c + 1;
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ctx.offset := (ctx.offset + 1) mod (Spritz.N / 4);
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if ctx.offset = 0 then
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Spritz.Absorb(ctx.ctx, ctx.buffer);
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end if;
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end loop;
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end Encrypt_Data;
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procedure Extract_Tag (ctx : in out Context; tag : out u8_Array) is
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begin
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if ctx.state /= pre_data then
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raise Wrong_Opertaion_Order;
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end if;
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Spritz.AbsorbStop(ctx.ctx);
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Spritz.Absorb(ctx.ctx, Natural(tag'Length));
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Spritz.Squeeze(ctx.ctx, tag);
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ctx.state := post_tag;
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end;
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procedure Decrypt_Data (ctx : in out Context; data : in out u8_Array) is
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c : Integer := data'First;
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begin
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if ctx.state /= pre_header then
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Spritz.AbsorbStop(ctx.ctx);
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ctx.state := pre_data;
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end if;
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if ctx.state /= pre_data then
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raise Wrong_Opertaion_Order;
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end if;
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while c <= data'Last loop
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if ctx.offset = 0 then
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Spritz.Squeeze(ctx.ctx, ctx.buffer);
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end if;
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data(c) := data(c) - ctx.buffer(ctx.offset);
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ctx.buffer(ctx.offset) := data(c);
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c := c + 1;
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ctx.offset := (ctx.offset + 1) mod (Spritz.N / 4);
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if ctx.offset = 0 then
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Spritz.Absorb(ctx.ctx, ctx.buffer);
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end if;
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end loop;
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end Decrypt_Data;
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end Spritz_AEAD; |