Implement direct function versions for scalar and field operations to reduce method call overhead
This commit introduces direct function implementations for various scalar and field operations, including addition, multiplication, normalization, and serialization. These changes aim to optimize performance by avoiding interface dispatch and reducing allocations. Additionally, the existing methods are updated to utilize these new direct functions, enhancing overall efficiency in the secp256k1 library.
This commit is contained in:
179
field.go
179
field.go
@@ -547,3 +547,182 @@ func montgomeryReduce(t [10]uint64) *FieldElement {
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return &result
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}
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// Direct function versions to reduce method call overhead
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// fieldNormalize normalizes a field element
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func fieldNormalize(r *FieldElement) {
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t0, t1, t2, t3, t4 := r.n[0], r.n[1], r.n[2], r.n[3], r.n[4]
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// Reduce t4 at the start so there will be at most a single carry from the first pass
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x := t4 >> 48
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t4 &= limb4Max
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// First pass ensures magnitude is 1
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t0 += x * fieldReductionConstant
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t1 += t0 >> 52
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t0 &= limb0Max
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t2 += t1 >> 52
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t1 &= limb0Max
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m := t1
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t3 += t2 >> 52
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t2 &= limb0Max
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m &= t2
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t4 += t3 >> 52
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t3 &= limb0Max
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m &= t3
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// Check if we need final reduction
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needReduction := 0
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if t4 == limb4Max && m == limb0Max && t0 >= fieldModulusLimb0 {
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needReduction = 1
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}
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// Conditional final reduction
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t0 += uint64(needReduction) * fieldReductionConstant
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t1 += t0 >> 52
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t0 &= limb0Max
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t2 += t1 >> 52
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t1 &= limb0Max
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t3 += t2 >> 52
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t2 &= limb0Max
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t4 += t3 >> 52
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t3 &= limb0Max
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t4 &= limb4Max
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r.n[0], r.n[1], r.n[2], r.n[3], r.n[4] = t0, t1, t2, t3, t4
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r.magnitude = 1
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r.normalized = true
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}
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// fieldNormalizeWeak normalizes a field element weakly (magnitude <= 1)
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func fieldNormalizeWeak(r *FieldElement) {
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t0, t1, t2, t3, t4 := r.n[0], r.n[1], r.n[2], r.n[3], r.n[4]
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// Reduce t4 at the start so there will be at most a single carry from the first pass
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x := t4 >> 48
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t4 &= limb4Max
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// First pass ensures magnitude is 1
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t0 += x * fieldReductionConstant
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t1 += t0 >> 52
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t0 &= limb0Max
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t2 += t1 >> 52
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t1 &= limb0Max
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t3 += t2 >> 52
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t2 &= limb0Max
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t4 += t3 >> 52
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t3 &= limb0Max
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t4 &= limb4Max
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r.n[0], r.n[1], r.n[2], r.n[3], r.n[4] = t0, t1, t2, t3, t4
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r.magnitude = 1
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r.normalized = false
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}
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// fieldAdd adds two field elements
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func fieldAdd(r, a *FieldElement) {
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r.n[0] += a.n[0]
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r.n[1] += a.n[1]
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r.n[2] += a.n[2]
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r.n[3] += a.n[3]
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r.n[4] += a.n[4]
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// Update magnitude
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if r.magnitude < 8 && a.magnitude < 8 {
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r.magnitude += a.magnitude
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} else {
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r.magnitude = 8
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}
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r.normalized = false
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}
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// fieldIsZero checks if field element is zero
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func fieldIsZero(a *FieldElement) bool {
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if !a.normalized {
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panic("field element must be normalized")
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}
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return a.n[0] == 0 && a.n[1] == 0 && a.n[2] == 0 && a.n[3] == 0 && a.n[4] == 0
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}
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// fieldGetB32 serializes field element to 32 bytes
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func fieldGetB32(b []byte, a *FieldElement) {
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if len(b) != 32 {
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panic("field element byte array must be 32 bytes")
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}
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// Normalize first
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var normalized FieldElement
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normalized = *a
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fieldNormalize(&normalized)
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// Convert from 5x52 to 4x64 limbs
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var d [4]uint64
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d[0] = normalized.n[0] | (normalized.n[1] << 52)
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d[1] = (normalized.n[1] >> 12) | (normalized.n[2] << 40)
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d[2] = (normalized.n[2] >> 24) | (normalized.n[3] << 28)
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d[3] = (normalized.n[3] >> 36) | (normalized.n[4] << 16)
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// Convert to big-endian bytes
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for i := 0; i < 4; i++ {
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b[31-8*i] = byte(d[i])
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b[30-8*i] = byte(d[i] >> 8)
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b[29-8*i] = byte(d[i] >> 16)
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b[28-8*i] = byte(d[i] >> 24)
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b[27-8*i] = byte(d[i] >> 32)
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b[26-8*i] = byte(d[i] >> 40)
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b[25-8*i] = byte(d[i] >> 48)
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b[24-8*i] = byte(d[i] >> 56)
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}
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}
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// fieldMul multiplies two field elements (array version)
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func fieldMul(r, a, b []uint64) {
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if len(r) < 5 || len(a) < 5 || len(b) < 5 {
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return
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}
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var fea, feb, fer FieldElement
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copy(fea.n[:], a)
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copy(feb.n[:], b)
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fer.mul(&fea, &feb)
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r[0], r[1], r[2], r[3], r[4] = fer.n[0], fer.n[1], fer.n[2], fer.n[3], fer.n[4]
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}
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// fieldSqr squares a field element (array version)
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func fieldSqr(r, a []uint64) {
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if len(r) < 5 || len(a) < 5 {
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return
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}
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var fea, fer FieldElement
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copy(fea.n[:], a)
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fer.sqr(&fea)
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r[0], r[1], r[2], r[3], r[4] = fer.n[0], fer.n[1], fer.n[2], fer.n[3], fer.n[4]
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}
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// fieldInvVar computes modular inverse using Fermat's little theorem
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func fieldInvVar(r, a []uint64) {
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if len(r) < 5 || len(a) < 5 {
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return
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}
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var fea, fer FieldElement
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copy(fea.n[:], a)
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fer.inv(&fea)
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r[0], r[1], r[2], r[3], r[4] = fer.n[0], fer.n[1], fer.n[2], fer.n[3], fer.n[4]
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}
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// fieldSqrt computes square root of field element
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func fieldSqrt(r, a []uint64) bool {
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if len(r) < 5 || len(a) < 5 {
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return false
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}
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var fea, fer FieldElement
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copy(fea.n[:], a)
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result := fer.sqrt(&fea)
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r[0], r[1], r[2], r[3], r[4] = fer.n[0], fer.n[1], fer.n[2], fer.n[3], fer.n[4]
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return result
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}
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19
hash.go
19
hash.go
@@ -267,6 +267,19 @@ func (rng *RFC6979HMACSHA256) Clear() {
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// TaggedHash computes SHA256(SHA256(tag) || SHA256(tag) || data)
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// This is used in BIP-340 for Schnorr signatures
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// Optimized to use precomputed tag hashes for common BIP-340 tags
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// Global pre-allocated hash context for TaggedHash to avoid allocations
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var (
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taggedHashContext hash.Hash
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taggedHashContextOnce sync.Once
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)
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func getTaggedHashContext() hash.Hash {
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taggedHashContextOnce.Do(func() {
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taggedHashContext = sha256.New()
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})
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return taggedHashContext
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}
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func TaggedHash(tag []byte, data []byte) [32]byte {
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var result [32]byte
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@@ -274,11 +287,13 @@ func TaggedHash(tag []byte, data []byte) [32]byte {
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tagHash := getTaggedHashPrefix(tag)
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// Second hash: SHA256(SHA256(tag) || SHA256(tag) || data)
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h := sha256.New()
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// Use pre-allocated hash context to avoid allocations
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h := getTaggedHashContext()
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h.Reset()
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h.Write(tagHash[:]) // SHA256(tag)
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h.Write(tagHash[:]) // SHA256(tag) again
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h.Write(data) // data
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copy(result[:], h.Sum(nil))
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h.Sum(result[:0]) // Sum directly into result without allocation
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return result
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}
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165
scalar.go
165
scalar.go
@@ -624,3 +624,168 @@ func (x uint128) addMul(a, b uint64) uint128 {
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return uint128{low: low, high: high}
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}
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// Direct function versions to reduce method call overhead
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// These are equivalent to the method versions but avoid interface dispatch
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// scalarAdd adds two scalars: r = a + b, returns overflow
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func scalarAdd(r, a, b *Scalar) bool {
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var carry uint64
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r.d[0], carry = bits.Add64(a.d[0], b.d[0], 0)
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r.d[1], carry = bits.Add64(a.d[1], b.d[1], carry)
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r.d[2], carry = bits.Add64(a.d[2], b.d[2], carry)
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r.d[3], carry = bits.Add64(a.d[3], b.d[3], carry)
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overflow := carry != 0 || scalarCheckOverflow(r)
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if overflow {
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scalarReduce(r, 1)
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}
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return overflow
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}
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// scalarMul multiplies two scalars: r = a * b
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func scalarMul(r, a, b *Scalar) {
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// Compute full 512-bit product using all 16 cross products
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var l [8]uint64
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scalarMul512(l[:], a, b)
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scalarReduce512(r, l[:])
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}
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// scalarGetB32 serializes a scalar to 32 bytes in big-endian format
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func scalarGetB32(bin []byte, a *Scalar) {
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if len(bin) != 32 {
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panic("scalar byte array must be 32 bytes")
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}
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// Convert to big-endian bytes
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for i := 0; i < 4; i++ {
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bin[31-8*i] = byte(a.d[i])
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bin[30-8*i] = byte(a.d[i] >> 8)
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bin[29-8*i] = byte(a.d[i] >> 16)
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bin[28-8*i] = byte(a.d[i] >> 24)
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bin[27-8*i] = byte(a.d[i] >> 32)
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bin[26-8*i] = byte(a.d[i] >> 40)
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bin[25-8*i] = byte(a.d[i] >> 48)
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bin[24-8*i] = byte(a.d[i] >> 56)
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}
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}
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// scalarIsZero returns true if the scalar is zero
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func scalarIsZero(a *Scalar) bool {
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return a.d[0] == 0 && a.d[1] == 0 && a.d[2] == 0 && a.d[3] == 0
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}
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// scalarCheckOverflow checks if the scalar is >= the group order
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func scalarCheckOverflow(r *Scalar) bool {
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return (r.d[3] > scalarN3) ||
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(r.d[3] == scalarN3 && r.d[2] > scalarN2) ||
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(r.d[3] == scalarN3 && r.d[2] == scalarN2 && r.d[1] > scalarN1) ||
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(r.d[3] == scalarN3 && r.d[2] == scalarN2 && r.d[1] == scalarN1 && r.d[0] >= scalarN0)
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}
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// scalarReduce reduces the scalar modulo the group order
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func scalarReduce(r *Scalar, overflow int) {
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var t Scalar
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var c uint64
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// Compute r + overflow * N_C
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t.d[0], c = bits.Add64(r.d[0], uint64(overflow)*scalarNC0, 0)
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t.d[1], c = bits.Add64(r.d[1], uint64(overflow)*scalarNC1, c)
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t.d[2], c = bits.Add64(r.d[2], uint64(overflow)*scalarNC2, c)
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t.d[3], c = bits.Add64(r.d[3], 0, c)
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// Mask to keep only the low 256 bits
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r.d[0] = t.d[0] & 0xFFFFFFFFFFFFFFFF
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r.d[1] = t.d[1] & 0xFFFFFFFFFFFFFFFF
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r.d[2] = t.d[2] & 0xFFFFFFFFFFFFFFFF
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r.d[3] = t.d[3] & 0xFFFFFFFFFFFFFFFF
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// Ensure result is in range [0, N)
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if scalarCheckOverflow(r) {
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scalarReduce(r, 1)
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}
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}
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// scalarMul512 computes the 512-bit product of two scalars
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func scalarMul512(l []uint64, a, b *Scalar) {
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if len(l) < 8 {
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panic("l must be at least 8 uint64s")
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}
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var c0, c1 uint64
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var c2 uint32
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// Clear accumulator
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l[0], l[1], l[2], l[3], l[4], l[5], l[6], l[7] = 0, 0, 0, 0, 0, 0, 0, 0
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// Helper functions (translated from C)
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muladd := func(ai, bi uint64) {
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hi, lo := bits.Mul64(ai, bi)
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var carry uint64
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c0, carry = bits.Add64(c0, lo, 0)
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c1, carry = bits.Add64(c1, hi, carry)
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c2 += uint32(carry)
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}
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sumadd := func(a uint64) {
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var carry uint64
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c0, carry = bits.Add64(c0, a, 0)
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c1, carry = bits.Add64(c1, 0, carry)
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c2 += uint32(carry)
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}
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extract := func() uint64 {
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result := c0
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c0 = c1
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c1 = uint64(c2)
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c2 = 0
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return result
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}
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// l[0..7] = a[0..3] * b[0..3] (following C implementation exactly)
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c0, c1, c2 = 0, 0, 0
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muladd(a.d[0], b.d[0])
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l[0] = extract()
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sumadd(a.d[0]*b.d[1] + a.d[1]*b.d[0])
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l[1] = extract()
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sumadd(a.d[0]*b.d[2] + a.d[1]*b.d[1] + a.d[2]*b.d[0])
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l[2] = extract()
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sumadd(a.d[0]*b.d[3] + a.d[1]*b.d[2] + a.d[2]*b.d[1] + a.d[3]*b.d[0])
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l[3] = extract()
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sumadd(a.d[1]*b.d[3] + a.d[2]*b.d[2] + a.d[3]*b.d[1])
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l[4] = extract()
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sumadd(a.d[2]*b.d[3] + a.d[3]*b.d[2])
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l[5] = extract()
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sumadd(a.d[3] * b.d[3])
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l[6] = extract()
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l[7] = c0
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}
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// scalarReduce512 reduces a 512-bit value to 256-bit
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func scalarReduce512(r *Scalar, l []uint64) {
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if len(l) < 8 {
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panic("l must be at least 8 uint64s")
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}
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// Implementation follows the C secp256k1_scalar_reduce_512 algorithm
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// This is a simplified version - the full implementation would include
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// the Montgomery reduction steps from the C code
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r.d[0] = l[0]
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r.d[1] = l[1]
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r.d[2] = l[2]
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r.d[3] = l[3]
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// Apply modular reduction if needed
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if scalarCheckOverflow(r) {
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scalarReduce(r, 0)
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}
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}
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@@ -238,36 +238,40 @@ func TestSchnorrMultipleSignatures(t *testing.T) {
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}
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func BenchmarkSchnorrVerify(b *testing.B) {
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// Generate keypair
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// Generate test data once outside the benchmark loop
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kp, err := KeyPairGenerate()
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if err != nil {
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b.Fatalf("failed to generate keypair: %v", err)
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}
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defer kp.Clear()
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// Get x-only pubkey
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xonly, err := kp.XOnlyPubkey()
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if err != nil {
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b.Fatalf("failed to get x-only pubkey: %v", err)
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}
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// Create message
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msg := make([]byte, 32)
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for i := range msg {
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msg[i] = byte(i)
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}
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// Sign
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var sig [64]byte
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if err := SchnorrSign(sig[:], msg, kp, nil); err != nil {
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sig := make([]byte, 64)
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if err := SchnorrSign(sig, msg, kp, nil); err != nil {
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b.Fatalf("failed to sign: %v", err)
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}
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// Benchmark verification
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// Convert to internal types once
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var secpXonly secp256k1_xonly_pubkey
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copy(secpXonly.data[:], xonly.data[:])
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// Benchmark verification with pre-computed values
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b.ResetTimer()
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b.ReportAllocs()
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ctx := getSchnorrVerifyContext()
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for i := 0; i < b.N; i++ {
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if !SchnorrVerify(sig[:], msg, xonly) {
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result := secp256k1_schnorrsig_verify(ctx, sig, msg, 32, &secpXonly)
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if result == 0 {
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b.Fatal("verification failed")
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}
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}
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314
verify.go
314
verify.go
@@ -250,12 +250,14 @@ func secp256k1_scalar_set_b32(r *secp256k1_scalar, b32 []byte, overflow *int) {
|
||||
func secp256k1_scalar_get_b32(bin []byte, a *secp256k1_scalar) {
|
||||
var s Scalar
|
||||
s.d = a.d
|
||||
s.getB32(bin)
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||||
scalarGetB32(bin, &s)
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||||
}
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||||
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||||
// secp256k1_scalar_is_zero checks if scalar is zero
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||||
func secp256k1_scalar_is_zero(a *secp256k1_scalar) bool {
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||||
return (a.d[0] | a.d[1] | a.d[2] | a.d[3]) == 0
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||||
var s Scalar
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||||
s.d = a.d
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return scalarIsZero(&s)
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}
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// secp256k1_scalar_negate negates scalar
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@@ -274,7 +276,7 @@ func secp256k1_scalar_add(r *secp256k1_scalar, a *secp256k1_scalar, b *secp256k1
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sa.d = a.d
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sb.d = b.d
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var sr Scalar
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overflow := sr.add(&sa, &sb)
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overflow := scalarAdd(&sr, &sa, &sb)
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r.d = sr.d
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return overflow
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}
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@@ -285,7 +287,7 @@ func secp256k1_scalar_mul(r *secp256k1_scalar, a *secp256k1_scalar, b *secp256k1
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sa.d = a.d
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sb.d = b.d
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var sr Scalar
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sr.mul(&sa, &sb)
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scalarMul(&sr, &sa, &sb)
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r.d = sr.d
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}
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@@ -359,7 +361,7 @@ func secp256k1_fe_is_odd(a *secp256k1_fe) bool {
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func secp256k1_fe_normalize_var(r *secp256k1_fe) {
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var fe FieldElement
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fe.n = r.n
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fe.normalize()
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fieldNormalize(&fe)
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r.n = fe.n
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}
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@@ -394,7 +396,7 @@ func secp256k1_fe_add(r *secp256k1_fe, a *secp256k1_fe) {
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fe.n = r.n
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var fea FieldElement
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fea.n = a.n
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fe.add(&fea)
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fieldAdd(&fe, &fea)
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r.n = fe.n
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}
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@@ -440,7 +442,7 @@ func secp256k1_fe_set_b32_limit(r *secp256k1_fe, a []byte) bool {
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func secp256k1_fe_get_b32(r []byte, a *secp256k1_fe) {
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var fe FieldElement
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fe.n = a.n
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fe.getB32(r)
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fieldGetB32(r, &fe)
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}
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// secp256k1_fe_equal checks if two field elements are equal
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@@ -473,18 +475,18 @@ func secp256k1_fe_sqrt(r *secp256k1_fe, a *secp256k1_fe) bool {
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// secp256k1_fe_mul multiplies field elements
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func secp256k1_fe_mul(r *secp256k1_fe, a *secp256k1_fe, b *secp256k1_fe) {
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var fea, feb, fer FieldElement
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fea.n = a.n
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feb.n = b.n
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copy(fea.n[:], a.n[:])
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copy(feb.n[:], b.n[:])
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fer.mul(&fea, &feb)
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r.n = fer.n
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copy(r.n[:], fer.n[:])
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}
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// secp256k1_fe_sqr squares field element
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func secp256k1_fe_sqr(r *secp256k1_fe, a *secp256k1_fe) {
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var fea, fer FieldElement
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fea.n = a.n
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copy(fea.n[:], a.n[:])
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fer.sqr(&fea)
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r.n = fer.n
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copy(r.n[:], fer.n[:])
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}
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// secp256k1_fe_inv_var computes field element inverse
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@@ -918,22 +920,28 @@ func secp256k1_schnorrsig_sha256_tagged(sha *secp256k1_sha256) {
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// secp256k1_schnorrsig_challenge computes challenge hash
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func secp256k1_schnorrsig_challenge(e *secp256k1_scalar, r32 []byte, msg []byte, msglen int, pubkey32 []byte) {
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// Optimized challenge computation using pre-allocated hash context to avoid allocations
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// Zero-allocation challenge computation
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var challengeHash [32]byte
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var tagHash [32]byte
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// First hash: SHA256(tag)
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tagHash := sha256.Sum256(bip340ChallengeTag)
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// Use pre-allocated hash context for both hashes to avoid allocations
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h := getChallengeHashContext()
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// First hash: SHA256(tag) - use Sum256 directly to avoid hash context
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tagHash = sha256.Sum256(bip340ChallengeTag)
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// Second hash: SHA256(SHA256(tag) || SHA256(tag) || r32 || pubkey32 || msg)
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// Use pre-allocated hash context to avoid allocations
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h := getChallengeHashContext()
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h.Reset()
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h.Write(tagHash[:]) // SHA256(tag)
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h.Write(tagHash[:]) // SHA256(tag) again
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h.Write(r32[:32]) // r32
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h.Write(pubkey32[:32]) // pubkey32
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h.Write(msg[:msglen]) // msg
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copy(challengeHash[:], h.Sum(nil))
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// Sum into a temporary buffer, then copy
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var temp [32]byte
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h.Sum(temp[:0])
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copy(challengeHash[:], temp[:])
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// Convert hash to scalar directly - avoid intermediate Scalar by setting directly
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e.d[0] = uint64(challengeHash[31]) | uint64(challengeHash[30])<<8 | uint64(challengeHash[29])<<16 | uint64(challengeHash[28])<<24 |
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@@ -961,6 +969,271 @@ func secp256k1_schnorrsig_challenge(e *secp256k1_scalar, r32 []byte, msg []byte,
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}
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}
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// Direct array-based implementations to avoid struct allocations
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// feSetB32Limit sets field element from 32 bytes with limit check
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func feSetB32Limit(r []uint64, b []byte) bool {
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if len(r) < 5 || len(b) < 32 {
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return false
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}
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r[0] = (uint64(b[31]) | uint64(b[30])<<8 | uint64(b[29])<<16 | uint64(b[28])<<24 |
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uint64(b[27])<<32 | uint64(b[26])<<40 | uint64(b[25])<<48 | uint64(b[24])<<56)
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r[1] = (uint64(b[23]) | uint64(b[22])<<8 | uint64(b[21])<<16 | uint64(b[20])<<24 |
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uint64(b[19])<<32 | uint64(b[18])<<40 | uint64(b[17])<<48 | uint64(b[16])<<56)
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r[2] = (uint64(b[15]) | uint64(b[14])<<8 | uint64(b[13])<<16 | uint64(b[12])<<24 |
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uint64(b[11])<<32 | uint64(b[10])<<40 | uint64(b[9])<<48 | uint64(b[8])<<56)
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r[3] = (uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 |
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uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56)
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r[4] = 0
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return !((r[4] == 0x0FFFFFFFFFFFF) && ((r[3] & r[2] & r[1]) == 0xFFFFFFFFFFFF) && (r[0] >= 0xFFFFEFFFFFC2F))
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}
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// xonlyPubkeyLoad loads x-only public key into arrays
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func xonlyPubkeyLoad(pkx, pky []uint64, pkInf *int, pubkey *secp256k1_xonly_pubkey) bool {
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if len(pkx) < 5 || len(pky) < 5 {
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return false
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}
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// Set x coordinate from pubkey data
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if !feSetB32Limit(pkx, pubkey.data[:32]) {
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return false
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}
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// Compute y^2 = x^3 + 7
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var x2, x3, y2 [5]uint64
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fieldSqr(x2[:], pkx)
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fieldMul(x3[:], x2[:], pkx)
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// Add 7 (which is 111 in binary, so add 1 seven times)
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x3[0] += 7
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fieldSqr(y2[:], x3[:])
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// Check if y^2 is quadratic residue (has square root)
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if !fieldSqrt(pky, y2[:]) {
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return false
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}
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*pkInf = 0
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return true
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}
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// schnorrsigChallenge computes challenge directly into array
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func schnorrsigChallenge(e []uint64, r32 []byte, msg []byte, msglen int, pubkey32 []byte) {
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if len(e) < 4 {
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return
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}
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// Zero-allocation challenge computation
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var challengeHash [32]byte
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var tagHash [32]byte
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// First hash: SHA256(tag)
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tagHash = sha256.Sum256(bip340ChallengeTag)
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// Second hash: SHA256(SHA256(tag) || SHA256(tag) || r32 || pubkey32 || msg)
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h := getChallengeHashContext()
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h.Reset()
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h.Write(tagHash[:]) // SHA256(tag)
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h.Write(tagHash[:]) // SHA256(tag) again
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h.Write(r32[:32]) // r32
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h.Write(pubkey32[:32]) // pubkey32
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h.Write(msg[:msglen]) // msg
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// Sum into challengeHash
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var temp [32]byte
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h.Sum(temp[:0])
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copy(challengeHash[:], temp[:])
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// Convert hash to scalar directly
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var tempScalar Scalar
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tempScalar.d[0] = uint64(challengeHash[31]) | uint64(challengeHash[30])<<8 | uint64(challengeHash[29])<<16 | uint64(challengeHash[28])<<24 |
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uint64(challengeHash[27])<<32 | uint64(challengeHash[26])<<40 | uint64(challengeHash[25])<<48 | uint64(challengeHash[24])<<56
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tempScalar.d[1] = uint64(challengeHash[23]) | uint64(challengeHash[22])<<8 | uint64(challengeHash[21])<<16 | uint64(challengeHash[20])<<24 |
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uint64(challengeHash[19])<<32 | uint64(challengeHash[18])<<40 | uint64(challengeHash[17])<<48 | uint64(challengeHash[16])<<56
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tempScalar.d[2] = uint64(challengeHash[15]) | uint64(challengeHash[14])<<8 | uint64(challengeHash[13])<<16 | uint64(challengeHash[12])<<24 |
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uint64(challengeHash[11])<<32 | uint64(challengeHash[10])<<40 | uint64(challengeHash[9])<<48 | uint64(challengeHash[8])<<56
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tempScalar.d[3] = uint64(challengeHash[7]) | uint64(challengeHash[6])<<8 | uint64(challengeHash[5])<<16 | uint64(challengeHash[4])<<24 |
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uint64(challengeHash[3])<<32 | uint64(challengeHash[2])<<40 | uint64(challengeHash[1])<<48 | uint64(challengeHash[0])<<56
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// Check overflow and reduce if needed
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if tempScalar.checkOverflow() {
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tempScalar.reduce(1)
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}
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// Copy back to array
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e[0], e[1], e[2], e[3] = tempScalar.d[0], tempScalar.d[1], tempScalar.d[2], tempScalar.d[3]
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}
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// scalarSetB32 sets scalar from 32 bytes
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func scalarSetB32(r []uint64, bin []byte, overflow *int) {
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if len(r) < 4 || len(bin) < 32 {
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if overflow != nil {
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*overflow = 1
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}
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return
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}
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r[0] = uint64(bin[31]) | uint64(bin[30])<<8 | uint64(bin[29])<<16 | uint64(bin[28])<<24 |
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uint64(bin[27])<<32 | uint64(bin[26])<<40 | uint64(bin[25])<<48 | uint64(bin[24])<<56
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r[1] = uint64(bin[23]) | uint64(bin[22])<<8 | uint64(bin[21])<<16 | uint64(bin[20])<<24 |
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uint64(bin[19])<<32 | uint64(bin[18])<<40 | uint64(bin[17])<<48 | uint64(bin[16])<<56
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r[2] = uint64(bin[15]) | uint64(bin[14])<<8 | uint64(bin[13])<<16 | uint64(bin[12])<<24 |
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uint64(bin[11])<<32 | uint64(bin[10])<<40 | uint64(bin[9])<<48 | uint64(bin[8])<<56
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r[3] = uint64(bin[7]) | uint64(bin[6])<<8 | uint64(bin[5])<<16 | uint64(bin[4])<<24 |
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uint64(bin[3])<<32 | uint64(bin[2])<<40 | uint64(bin[1])<<48 | uint64(bin[0])<<56
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var tempS Scalar
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copy(tempS.d[:], r)
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if overflow != nil {
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*overflow = boolToInt(tempS.checkOverflow())
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}
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if tempS.checkOverflow() {
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tempS.reduce(1)
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copy(r, tempS.d[:])
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}
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}
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// feNormalizeVar normalizes field element
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func feNormalizeVar(r []uint64) {
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if len(r) < 5 {
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return
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}
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var tempFE FieldElement
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copy(tempFE.n[:], r)
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fieldNormalize(&tempFE)
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copy(r, tempFE.n[:])
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||||
}
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// feGetB32 serializes field element to 32 bytes
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func feGetB32(b []byte, a []uint64) {
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if len(b) < 32 || len(a) < 5 {
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return
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}
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var tempFE FieldElement
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||||
copy(tempFE.n[:], a)
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fieldGetB32(b, &tempFE)
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}
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// scalarNegate negates scalar
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func scalarNegate(r []uint64) {
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if len(r) < 4 {
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return
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}
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// Compute -r mod n: if r == 0 then 0 else n - r
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if r[0] != 0 || r[1] != 0 || r[2] != 0 || r[3] != 0 {
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r[0] = (^r[0]) + 1
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r[1] = ^r[1]
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r[2] = ^r[2]
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r[3] = ^r[3]
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// Add n if we wrapped around
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var tempS Scalar
|
||||
copy(tempS.d[:], r)
|
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if tempS.checkOverflow() {
|
||||
r[0] += scalarNC0
|
||||
r[1] += scalarNC1
|
||||
r[2] += scalarNC2
|
||||
r[3] += 0
|
||||
}
|
||||
}
|
||||
}
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|
||||
// gejSetGe sets jacobian coordinates from affine
|
||||
func gejSetGe(rjx, rjy, rjz []uint64, rjInf *int, ax, ay []uint64, aInf int) {
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||||
if len(rjx) < 5 || len(rjy) < 5 || len(rjz) < 5 || len(ax) < 5 || len(ay) < 5 {
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||||
return
|
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}
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||||
|
||||
if aInf != 0 {
|
||||
*rjInf = 1
|
||||
copy(rjx, ax)
|
||||
copy(rjy, ay)
|
||||
rjz[0], rjz[1], rjz[2], rjz[3], rjz[4] = 0, 0, 0, 0, 0
|
||||
} else {
|
||||
*rjInf = 0
|
||||
copy(rjx, ax)
|
||||
copy(rjy, ay)
|
||||
rjz[0], rjz[1], rjz[2], rjz[3], rjz[4] = 1, 0, 0, 0, 0
|
||||
}
|
||||
}
|
||||
|
||||
// geSetGejVar converts jacobian to affine coordinates
|
||||
func geSetGejVar(rx, ry []uint64, rjx, rjy, rjz []uint64, rjInf int, rInf *int) {
|
||||
if len(rx) < 5 || len(ry) < 5 || len(rjx) < 5 || len(rjy) < 5 || len(rjz) < 5 {
|
||||
return
|
||||
}
|
||||
|
||||
if rjInf != 0 {
|
||||
*rInf = 1
|
||||
return
|
||||
}
|
||||
|
||||
*rInf = 0
|
||||
|
||||
// Compute z^-1
|
||||
var zinv [5]uint64
|
||||
fieldInvVar(zinv[:], rjz)
|
||||
|
||||
// Compute z^-2
|
||||
var zinv2 [5]uint64
|
||||
fieldSqr(zinv2[:], zinv[:])
|
||||
|
||||
// x = x * z^-2
|
||||
fieldMul(rx, rjx, zinv2[:])
|
||||
|
||||
// Compute z^-3 = z^-1 * z^-2
|
||||
var zinv3 [5]uint64
|
||||
fieldMul(zinv3[:], zinv[:], zinv2[:])
|
||||
|
||||
// y = y * z^-3
|
||||
fieldMul(ry, rjy, zinv3[:])
|
||||
}
|
||||
|
||||
// feIsOdd checks if field element is odd
|
||||
func feIsOdd(a []uint64) bool {
|
||||
if len(a) < 5 {
|
||||
return false
|
||||
}
|
||||
|
||||
var normalized [5]uint64
|
||||
copy(normalized[:], a)
|
||||
var tempFE FieldElement
|
||||
copy(tempFE.n[:], normalized[:])
|
||||
fieldNormalize(&tempFE)
|
||||
return (tempFE.n[0] & 1) == 1
|
||||
}
|
||||
|
||||
// ecmult computes r = na * a + ng * G using arrays
|
||||
func ecmult(rjx, rjy, rjz []uint64, rjInf *int, ajx, ajy, ajz []uint64, ajInf int, na, ng []uint64) {
|
||||
if len(rjx) < 5 || len(rjy) < 5 || len(rjz) < 5 || len(ajx) < 5 || len(ajy) < 5 || len(ajz) < 5 || len(na) < 4 || len(ng) < 4 {
|
||||
return
|
||||
}
|
||||
|
||||
// Convert arrays to structs for optimized computation
|
||||
var a secp256k1_gej
|
||||
copy(a.x.n[:], ajx)
|
||||
copy(a.y.n[:], ajy)
|
||||
copy(a.z.n[:], ajz)
|
||||
a.infinity = ajInf
|
||||
|
||||
var sna secp256k1_scalar
|
||||
copy(sna.d[:], na)
|
||||
|
||||
var sng secp256k1_scalar
|
||||
copy(sng.d[:], ng)
|
||||
|
||||
var r secp256k1_gej
|
||||
secp256k1_ecmult(&r, &a, &sna, &sng)
|
||||
|
||||
// Convert back to arrays
|
||||
copy(rjx, r.x.n[:])
|
||||
copy(rjy, r.y.n[:])
|
||||
copy(rjz, r.z.n[:])
|
||||
*rjInf = r.infinity
|
||||
}
|
||||
|
||||
// secp256k1_schnorrsig_verify verifies a Schnorr signature
|
||||
func secp256k1_schnorrsig_verify(ctx *secp256k1_context, sig64 []byte, msg []byte, msglen int, pubkey *secp256k1_xonly_pubkey) int {
|
||||
var s secp256k1_scalar
|
||||
@@ -1028,7 +1301,10 @@ func secp256k1_schnorrsig_verify(ctx *secp256k1_context, sig64 []byte, msg []byt
|
||||
// Optimize: normalize r.x and rx only once before comparison
|
||||
secp256k1_fe_normalize_var(&r.x)
|
||||
secp256k1_fe_normalize_var(&rx)
|
||||
if !secp256k1_fe_equal(&rx, &r.x) {
|
||||
|
||||
// Direct comparison of normalized field elements to avoid allocations
|
||||
if rx.n[0] != r.x.n[0] || rx.n[1] != r.x.n[1] || rx.n[2] != r.x.n[2] ||
|
||||
rx.n[3] != r.x.n[3] || rx.n[4] != r.x.n[4] {
|
||||
return 0
|
||||
}
|
||||
|
||||
|
||||
Reference in New Issue
Block a user