forked from TrueCloudLab/frostfs-crypto
35 lines
683 B
Go
35 lines
683 B
Go
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// +build go1.15
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package crypto
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import (
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"crypto/elliptic"
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"math/big"
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)
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func encodePoint(x, y *big.Int) []byte {
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return elliptic.MarshalCompressed(curve, x, y)
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}
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func decodePoint(data []byte) (x *big.Int, y *big.Int) {
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// empty data
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if len(data) == 0 {
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return
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}
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// tries to unmarshal compressed form
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// returns (nil, nil) when:
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// - wrong len(data)
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// - data[0] != 2 && data[0] != 3
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if x, y = elliptic.UnmarshalCompressed(curve, data); x != nil && y != nil {
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return x, y
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}
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// tries to unmarshal uncompressed form and check that points on curve
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if x, y = unmarshalXY(data); x == nil || y == nil || !curve.IsOnCurve(x, y) {
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x, y = nil, nil
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}
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return x, y
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}
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