mirror of https://gogs.blitter.com/RLabs/xs
60 lines
1.9 KiB
Go
60 lines
1.9 KiB
Go
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// Copryright (C) 2019 Yawning Angel
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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 Affero General Public License as
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// published by the Free Software Foundation, either version 3 of the
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// License, or (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 Affero General Public License for more details.
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//
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// You should have received a copy of the GNU Affero General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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// Package api provides the ChaCha20 implementation abstract interface.
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package api
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const (
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// BlockSize is the size of a ChaCha20 block in bytes.
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BlockSize = 64
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// StateSize is the size of the ChaCha20 state as 32 bit unsigned words.
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StateSize = 16
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// HashSize is the size of the HChaCha output in bytes.
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HashSize = 32
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// HNonceSize is the HChaCha20 nonce size in bytes.
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HNonceSize = 16
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// Sigma0 is the first word of the ChaCha constant.
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Sigma0 = uint32(0x61707865)
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// Sigma1 is the second word of the ChaCha constant.
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Sigma1 = uint32(0x3320646e)
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// Sigma2 is the third word of the ChaCha constant.
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Sigma2 = uint32(0x79622d32)
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// Sigma3 is the fourth word of the ChaCha constant.
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Sigma3 = uint32(0x6b206574)
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)
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// Implementation is a ChaCha20 implementation
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type Implementation interface {
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// Name returns the name of the implementation.
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Name() string
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// Blocks calculates the ChaCha20 blocks. If src is not nil, dst will
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// be set to the XOR of src with the key stream, otherwise dst will be
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// set to the key stream.
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Blocks(x *[StateSize]uint32, dst, src []byte, nrBlocks int)
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// HChaCha calculates the HChaCha20 hash.
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//
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// Note: `dst` is guaranteed to be HashSize bytes.
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HChaCha(key, nonce []byte, dst []byte)
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}
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