forked from TrueCloudLab/tzhash
51 lines
1.3 KiB
Go
51 lines
1.3 KiB
Go
package gf127
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import (
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"encoding/binary"
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"encoding/hex"
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)
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// GF127x2 represents a pair of elements of GF(2^127) stored together.
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type GF127x2 [2]GF127
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func mul10x2Generic(a, b *GF127x2) {
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mul10Generic(&a[0], &b[0])
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mul10Generic(&a[1], &b[1])
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}
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func mul11x2Generic(a, b *GF127x2) {
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mul11Generic(&a[0], &b[0])
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mul11Generic(&a[1], &b[1])
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}
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// Split returns 2 components of pair without additional allocations.
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func Split(a *GF127x2) (*GF127, *GF127) {
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return &a[0], &a[1]
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}
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// CombineTo 2 elements of GF(2^127) to the respective components of pair.
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func CombineTo(a *GF127, b *GF127, c *GF127x2) {
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c[0] = *a
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c[1] = *b
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}
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// Equal checks if both elements of GF(2^127) pair are equal.
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func (a *GF127x2) Equal(b *GF127x2) bool {
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return a[0] == b[0] && a[1] == b[1]
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}
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// String returns hex-encoded representation, starting with MSB.
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// Elements of pair are separated by comma.
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func (a *GF127x2) String() string {
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b := a.Bytes()
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return hex.EncodeToString(b[:16]) + " , " + hex.EncodeToString(b[16:])
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}
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// Bytes represents element of GF(2^127) as byte array of length 32.
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func (a *GF127x2) Bytes() (buf [32]byte) {
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binary.BigEndian.PutUint64(buf[:], a[0][1])
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binary.BigEndian.PutUint64(buf[8:], a[0][0])
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binary.BigEndian.PutUint64(buf[16:], a[1][1])
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binary.BigEndian.PutUint64(buf[24:], a[1][0])
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return
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}
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