22 lines
758 B
Go
22 lines
758 B
Go
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// Copyright (c) 2015 The btcsuite developers
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// Copyright (c) 2015-2023 The Decred developers
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// Use of this source code is governed by an ISC
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// license that can be found in the LICENSE file.
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package secp256k1
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// GenerateSharedSecret generates a shared secret based on a private key and a
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// public key using Diffie-Hellman key exchange (ECDH) (RFC 5903).
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// RFC5903 Section 9 states we should only return x.
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//
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// It is recommended to securely hash the result before using as a cryptographic
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// key.
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func GenerateSharedSecret(privkey *PrivateKey, pubkey *PublicKey) []byte {
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var point, result JacobianPoint
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pubkey.AsJacobian(&point)
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ScalarMultNonConst(&privkey.Key, &point, &result)
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result.ToAffine()
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xBytes := result.X.Bytes()
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return xBytes[:]
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}
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