Format files and add further optimization

Author: Keelan10

kem/ntruprime/doc.go

@@ -5,4 +5,6 @@
 // competition and described in
 //
 //	https://ntruprime.cr.yp.to/nist/ntruprime-20201007.pdf
+//
+// The code is translated from the C reference implementation.
 package ntruprime

kem/ntruprime/gen.go

@@ -131,7 +131,7 @@ func generateKAT() {
 		if offset == -1 {
 			panic("Missing template warning in pkg.templ.go")
 		}
-		err = ioutil.WriteFile(mode.Pkg()+"/kat_test.go", []byte(res[offset:]), 0o644)
+		err = ioutil.WriteFile(mode.Pkg()+"/kat_test.go", []byte(res[offset:]), 0o600)
 		if err != nil {
 			panic(err)
 		}

kem/ntruprime/internal/Decode.go

@@ -1,5 +1,6 @@
 package internal
 
+// TO DO: Optimize the Decode function
 /* Decode(R,s,M,len) */
 /* assumes 0 < M[i] < 16384 */
 /* produces 0 <= R[i] < M[i] */
@@ -9,9 +10,9 @@ func Decode(out []uint16, S []uint8, M []uint16, len int) {
 		if M[0] == 1 {
 			out[index] = 0
 		} else if M[0] <= 256 {
-			out[index] = Uint32_mod_uint14(uint32(S[0]), M[0])
+			out[index] = Uint32ModUint14(uint32(S[0]), M[0])
 		} else {
-			out[index] = Uint32_mod_uint14(uint32(uint16(S[0])+((uint16(S[1]))<<8)), M[0])
+			out[index] = Uint32ModUint14(uint32(uint16(S[0])+((uint16(S[1]))<<8)), M[0])
 		}
 	}
 	if len > 1 {
@@ -33,7 +34,6 @@ func Decode(out []uint16, S []uint8, M []uint16, len int) {
 				bottomr[i/2] = uint16(S[0])
 				S = S[1:]
 				M2[i/2] = uint16((m + 255) >> 8)
-
 			} else {
 				bottomt[i/2] = 1
 				bottomr[i/2] = 0
@@ -47,24 +47,21 @@ func Decode(out []uint16, S []uint8, M []uint16, len int) {
 		Decode(R2, S, M2, (len+1)/2)
 
 		for i = 0; i < len-1; i += 2 {
-			var r uint32 = uint32(bottomr[i/2])
+			r := uint32(bottomr[i/2])
 			var r1 uint32
 			var r0 uint16
 
 			r += bottomt[i/2] * uint32(R2[i/2])
-			Uint32_divmod_uint14(&r1, &r0, r, M[i])
-			r1 = uint32(Uint32_mod_uint14(r1, M[i+1])) /* only needed for invalid inputs */
+			Uint32DivmodUint14(&r1, &r0, r, M[i])
+			r1 = uint32(Uint32ModUint14(r1, M[i+1])) /* only needed for invalid inputs */
 
 			out[index] = r0
 			index++
 			out[index] = uint16(r1)
 			index++
-
 		}
 		if i < len {
 			out[index] = R2[i/2]
-			index++
 		}
-
 	}
 }

kem/ntruprime/internal/Divmod.go

@@ -10,14 +10,14 @@ There could also be compiler issues.
 */
 // q, r = x/m
 // Returns quotient and remainder
-func Uint32_divmod_uint14(q *uint32, r *uint16, x uint32, m uint16) {
+func Uint32DivmodUint14(q *uint32, r *uint16, x uint32, m uint16) {
 	var v uint32 = 0x80000000
 
 	v /= uint32(m)
 
 	*q = 0
 
-	var qpart uint32 = uint32(uint64(x) * uint64(v) >> 31)
+	qpart := uint32(uint64(x) * uint64(v) >> 31)
 
 	x -= qpart * uint32(m)
 	*q += qpart
@@ -28,38 +28,37 @@ func Uint32_divmod_uint14(q *uint32, r *uint16, x uint32, m uint16) {
 
 	x -= uint32(m)
 	*q += 1
-	var mask uint32 = -(x >> 31)
+	mask := -(x >> 31)
 	x += mask & uint32(m)
 	*q += mask
 
 	*r = uint16(x)
-
 }
 
 // Returns the quotient of x/m
-func Uint32_div_uint14(x uint32, m uint16) uint32 {
+func Uint32DivUint14(x uint32, m uint16) uint32 {
 	var q uint32
 	var r uint16
-	Uint32_divmod_uint14(&q, &r, x, m)
+	Uint32DivmodUint14(&q, &r, x, m)
 	return q
 }
 
 // Returns the remainder of x/m
-func Uint32_mod_uint14(x uint32, m uint16) uint16 {
+func Uint32ModUint14(x uint32, m uint16) uint16 {
 	var q uint32
 	var r uint16
-	Uint32_divmod_uint14(&q, &r, x, m)
+	Uint32DivmodUint14(&q, &r, x, m)
 	return r
 }
 
 // Calculates quotient and remainder
-func Int32_divmod_uint14(q *int32, r *uint16, x int32, m uint16) {
+func Int32DivmodUint14(q *int32, r *uint16, x int32, m uint16) {
 	var uq, uq2 uint32
 	var ur, ur2 uint16
 	var mask uint32
 
-	Uint32_divmod_uint14(&uq, &ur, 0x80000000+uint32(x), m)
-	Uint32_divmod_uint14(&uq2, &ur2, 0x80000000, m)
+	Uint32DivmodUint14(&uq, &ur, 0x80000000+uint32(x), m)
+	Uint32DivmodUint14(&uq2, &ur2, 0x80000000, m)
 
 	ur -= ur2
 	uq -= uq2
@@ -71,34 +70,33 @@ func Int32_divmod_uint14(q *int32, r *uint16, x int32, m uint16) {
 }
 
 // Returns quotient of x/m
-func Int32_div_uint14(x int32, m uint16) int32 {
+func Int32DivUint14(x int32, m uint16) int32 {
 	var q int32
 	var r uint16
-	Int32_divmod_uint14(&q, &r, x, m)
+	Int32DivmodUint14(&q, &r, x, m)
 	return q
 }
 
 // Returns remainder of x/m
-func Int32_mod_uint14(x int32, m uint16) uint16 {
+func Int32ModUint14(x int32, m uint16) uint16 {
 	var q int32
 	var r uint16
-	Int32_divmod_uint14(&q, &r, x, m)
+	Int32DivmodUint14(&q, &r, x, m)
 	return r
-
 }
 
 // Returns -1 if x!=0; else return 0
-func Int16_nonzero_mask(x int16) int {
-	var u uint16 = uint16(x) /* 0, else 1...65535 */
-	var v uint32 = uint32(u) /* 0, else 1...65535 */
-	v = -v                   /* 0, else 2^32-65535...2^32-1 */
-	v >>= 31                 /* 0, else 1 */
-	return -int(v)           /* 0, else -1 */
+func Int16NonzeroMask(x int16) int {
+	u := uint16(x) /* 0, else 1...65535 */
+	v := uint32(u) /* 0, else 1...65535 */
+	v = -v         /* 0, else 2^32-65535...2^32-1 */
+	v >>= 31       /* 0, else 1 */
+	return -int(v) /* 0, else -1 */
 }
 
 // Returns -1 if x<0; otherwise return 0
-func Int16_negative_mask(x int16) int {
-	var u uint16 = uint16(x)
+func Int16NegativeMask(x int16) int {
+	u := uint16(x)
 	u >>= 15
 	return -(int)(u)
 }

kem/ntruprime/internal/Encode.go

@@ -1,5 +1,6 @@
 package internal
 
+// TO DO: Optimize the Encode function
 /* 0 <= R[i] < M[i] < 16384 */
 func Encode(out []uint8, R []uint16, M []uint16, len int) {
 	if len == 1 {
@@ -15,7 +16,7 @@ func Encode(out []uint8, R []uint16, M []uint16, len int) {
 	if len > 1 {
 		R2 := make([]uint16, (len+1)/2)
 		M2 := make([]uint16, (len+1)/2)
-		var i int = 0
+		var i int
 
 		for i = 0; i < len-1; i += 2 {
 			m0 := uint32(M[i])

kem/ntruprime/kat_test.go

@@ -158,7 +158,6 @@ func testPQCgenStreamlinedKATKem(t *testing.T, name, expected string, p int) {
 		fmt.Fprintf(f, "sk = %X\n", psk)
 		fmt.Fprintf(f, "ct = %X\n", ct)
 		fmt.Fprintf(f, "ss = %X\n\n", ss1)
-
 	}
 	if fmt.Sprintf("%x", f.Sum(nil)) != expected {
 		t.Fatal()