Poseidon BN128 (#20)

* initial commit of poseidon bn128

* got challenger working

* deserialize is working

* cleaned up deserialization function a bit

* fixed challenger

* add in the hack to the challenges

* fixed some bugs in poseidon_bn128

* fri verification is working

* some changes for benchmarking

* added decode_block plonky2 data

* initial commit for poseidon_mds_gate

* updated gate test cases

* working poseidon mds gate

* full verifier test case working

verifier/internal/gates/gate.go

@@ -23,6 +23,7 @@ var gateRegexHandlers = map[*regexp.Regexp]func(parameters map[string]string) Ga
 	mulExtensionGateRegex:       deserializeMulExtensionGate,
 	noopGateRegex:               deserializeNoopGate,
 	poseidonGateRegex:           deserializePoseidonGate,
+	poseidonMdsGateRegex:        deserializePoseidonMdsGate,
 	publicInputGateRegex:        deserializePublicInputGate,
 	randomAccessGateRegex:       deserializeRandomAccessGate,
 	reducingExtensionGateRegex:  deserializeReducingExtensionGate,

verifier/internal/gates/poseidon_mds_gate.go

@@ -0,0 +1,86 @@
+package gates
+
+import (
+	"regexp"
+
+	"github.com/consensys/gnark/frontend"
+	"github.com/succinctlabs/gnark-plonky2-verifier/field"
+	"github.com/succinctlabs/gnark-plonky2-verifier/poseidon"
+)
+
+var poseidonMdsGateRegex = regexp.MustCompile("PoseidonMdsGate.*")
+
+func deserializePoseidonMdsGate(parameters map[string]string) Gate {
+	// Has the format "PoseidonMdsGate(PhantomData<plonky2_field::goldilocks_field::GoldilocksField>)<WIDTH=12>"
+	return NewPoseidonMdsGate()
+}
+
+type PoseidonMdsGate struct {
+}
+
+func NewPoseidonMdsGate() *PoseidonMdsGate {
+	return &PoseidonMdsGate{}
+}
+
+func (g *PoseidonMdsGate) Id() string {
+	return "PoseidonMdsGate"
+}
+
+func (g *PoseidonMdsGate) WireInput(i uint64) Range {
+	if i >= poseidon.SPONGE_WIDTH {
+		panic("Input less than sponge width")
+	}
+	return Range{i * field.D, (i + 1) * field.D}
+}
+
+func (g *PoseidonMdsGate) WireOutput(i uint64) Range {
+	if i >= poseidon.SPONGE_WIDTH {
+		panic("Input less than sponge width")
+	}
+	return Range{(poseidon.SPONGE_WIDTH + i) * field.D, (poseidon.SPONGE_WIDTH + i + 1) * field.D}
+}
+
+func (g *PoseidonMdsGate) mdsRowShfAlgebra(r uint64, v [poseidon.SPONGE_WIDTH]field.QEAlgebra, qeAPI *field.QuadraticExtensionAPI) field.QEAlgebra {
+	if r >= poseidon.SPONGE_WIDTH {
+		panic("MDS row index out of range")
+	}
+
+	res := qeAPI.ZERO_QE_ALGEBRA
+	for i := uint64(0); i < poseidon.SPONGE_WIDTH; i++ {
+		coeff := qeAPI.FieldToQE(poseidon.MDS_MATRIX_CIRC[i])
+		res = qeAPI.AddExtensionAlgebra(res, qeAPI.ScalarMulExtensionAlgebra(coeff, v[(i+r)%poseidon.SPONGE_WIDTH]))
+	}
+
+	coeff := qeAPI.FieldToQE(poseidon.MDS_MATRIX_DIAG[r])
+	res = qeAPI.AddExtensionAlgebra(res, qeAPI.ScalarMulExtensionAlgebra(coeff, v[r]))
+
+	return res
+}
+
+func (g *PoseidonMdsGate) mdsLayerAlgebra(state [poseidon.SPONGE_WIDTH]field.QEAlgebra, qeAPI *field.QuadraticExtensionAPI) [poseidon.SPONGE_WIDTH]field.QEAlgebra {
+	var result [poseidon.SPONGE_WIDTH]field.QEAlgebra
+	for r := uint64(0); r < poseidon.SPONGE_WIDTH; r++ {
+		result[r] = g.mdsRowShfAlgebra(r, state, qeAPI)
+	}
+
+	return result
+}
+
+func (g *PoseidonMdsGate) EvalUnfiltered(api frontend.API, qeAPI *field.QuadraticExtensionAPI, vars EvaluationVars) []field.QuadraticExtension {
+	constraints := []field.QuadraticExtension{}
+
+	var inputs [poseidon.SPONGE_WIDTH]field.QEAlgebra
+	for i := uint64(0); i < poseidon.SPONGE_WIDTH; i++ {
+		inputs[i] = vars.GetLocalExtAlgebra(g.WireInput(i))
+	}
+
+	computed_outputs := g.mdsLayerAlgebra(inputs, qeAPI)
+
+	for i := uint64(0); i < poseidon.SPONGE_WIDTH; i++ {
+		output := vars.GetLocalExtAlgebra(g.WireOutput(i))
+		diff := qeAPI.SubExtensionAlgebra(output, computed_outputs[i])
+		constraints = append(constraints, diff[0], diff[1])
+	}
+
+	return constraints
+}

verifier/internal/gates/vars.go

@@ -8,13 +8,13 @@ import (
 type EvaluationVars struct {
 	localConstants   []field.QuadraticExtension
 	localWires       []field.QuadraticExtension
-	publicInputsHash poseidon.Hash
+	publicInputsHash poseidon.PoseidonHashOut
 }
 
 func NewEvaluationVars(
 	localConstants []field.QuadraticExtension,
 	localWires []field.QuadraticExtension,
-	publicInputsHash poseidon.Hash,
+	publicInputsHash poseidon.PoseidonHashOut,
 ) *EvaluationVars {
 	return &EvaluationVars{
 		localConstants:   localConstants,