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crypto/ot/base/simplest/util.go

@@ -1,53 +0,0 @@
-package simplest
-
-import (
-	"io"
-)
-
-// xorBytes computes c = a xor b.
-func xorBytes(a, b [DigestSize]byte) (c [DigestSize]byte) {
-	for i := 0; i < DigestSize; i++ {
-		c[i] = a[i] ^ b[i]
-	}
-	return
-}
-
-// initChoice initializes the receiver's choice array from the PackedRandomChoiceBits array
-func (receiver *Receiver) initChoice() {
-	// unpack the random values in PackedRandomChoiceBits into bits in Choice
-	receiver.Output.RandomChoiceBits = make([]int, receiver.batchSize)
-	for i := 0; i < len(receiver.Output.RandomChoiceBits); i++ {
-		receiver.Output.RandomChoiceBits[i] = int(ExtractBitFromByteVector(receiver.Output.PackedRandomChoiceBits, i))
-	}
-}
-
-// ExtractBitFromByteVector interprets the byte-vector `vector` as if it were a _bit_-vector with len(vector) * 8 bits.
-// it extracts the `index`th such bit, interpreted in the little-endian way (i.e., both across bytes and within bytes).
-func ExtractBitFromByteVector(vector []byte, index int) byte {
-	// the bitwise tricks index >> 3 == index // 8 and index & 0x07 == index % 8 are designed to avoid CPU division.
-	return vector[index>>3] >> (index & 0x07) & 0x01
-}
-
-type pipeWrapper struct {
-	r         *io.PipeReader
-	w         *io.PipeWriter
-	exchanged int // used this during testing, to track bytes exchanged
-}
-
-func (wrapper *pipeWrapper) Write(p []byte) (n int, err error) {
-	n, err = wrapper.w.Write(p)
-	wrapper.exchanged += n
-	return
-}
-
-func (wrapper *pipeWrapper) Read(p []byte) (n int, err error) {
-	n, err = wrapper.r.Read(p)
-	wrapper.exchanged += n
-	return
-}
-
-func NewPipeWrappers() (*pipeWrapper, *pipeWrapper) {
-	leftOut, leftIn := io.Pipe()
-	rightOut, rightIn := io.Pipe()
-	return &pipeWrapper{r: leftOut, w: rightIn}, &pipeWrapper{r: rightOut, w: leftIn}
-}