diff --git a/std/blockcipher/aes/aes128.go b/std/blockcipher/aes/aes128.go new file mode 100644 index 0000000000..db84fd31cb --- /dev/null +++ b/std/blockcipher/aes/aes128.go @@ -0,0 +1,320 @@ +/* +Copyright © 2023 Jan Lauinger + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +*/ + +package aes + +import ( + "github.com/consensys/gnark/frontend" +) + +type AES128Wrapper struct { + Key [16]frontend.Variable + Plaintext [16]frontend.Variable + Ciphertext [16]frontend.Variable `gnark:"public"` +} + +func (circuit *AES128Wrapper) Define(api frontend.API) error { + + // init aes gadget + aes := NewAES128(api) + + // encrypt plaintext under key + cipher := aes.Encrypt(circuit.Key, circuit.Plaintext) + + // constraints check + for i := 0; i < 16; i++ { + api.AssertIsEqual(circuit.Ciphertext[i], cipher[i]) + } + + // return error + return nil +} + +type AES128 struct { + api frontend.API +} + +// retuns AES128 instance which can be used inside a circuit +func NewAES128(api frontend.API) AES128 { + return AES128{api: api} +} + +// aes128 encrypt function +func (aes *AES128) Encrypt(key [16]frontend.Variable, pt [16]frontend.Variable) [16]frontend.Variable { + + // FIPS-197 Figure 7. S-box substitution values in hexadecimal format. + sbox0 := [256]frontend.Variable{ + 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, + 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, + 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, + 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, + 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, + 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, + 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, + 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, + 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, + 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, + 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, + 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, + 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, + 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, + 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, + 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16, + } + + RCon := [11]frontend.Variable{0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36} + + // expand key + expandedKey := aes.ExpandKey(key, sbox0, RCon) + + var state [16]frontend.Variable + var i = 0 + for k := 0; k < 4; k++ { + state[0+k] = pt[i] + state[4+k] = pt[i+1] + state[8+k] = pt[i+2] + state[12+k] = pt[i+3] + i += 4 + } + state = aes.AddRoundKey(state, expandedKey, 0) // works + + // iterate rounds + i = 1 + for ; i < 10; i++ { + state = aes.SubBytes(sbox0, state) + state = aes.ShiftRows(state) + state = aes.MixColumns(state) + state = aes.AddRoundKey2(state, expandedKey, i*4*4) // woks + } + + state = aes.SubBytes(sbox0, state) + state = aes.ShiftRows(state) + state = aes.AddRoundKey2(state, expandedKey, 10*4*4) + + var out [16]frontend.Variable + ctr := 0 + for i := 0; i < 4; i++ { + out[ctr] = state[i] + out[ctr+1] = state[4+i] + out[ctr+2] = state[8+i] + out[ctr+3] = state[12+i] + ctr += 4 + } + + return out +} + +func (aes *AES128) SubBytes(sbox [256]frontend.Variable, state [16]frontend.Variable) [16]frontend.Variable { + var newState [16]frontend.Variable + for i := 0; i < 16; i++ { + newState[i] = aes.Subw(sbox, state[i]) + } + return newState +} + +func (aes *AES128) MixColumns(state [16]frontend.Variable) [16]frontend.Variable { + + var a [4]frontend.Variable + var newState [16]frontend.Variable + + for c := 0; c < 4; c++ { + + a[0] = state[c] + a[1] = state[4+c] + a[2] = state[8+c] + a[3] = state[12+c] + + a0Bits := aes.api.ToBinary(a[0], 8) + a0gmc3Bits := aes.api.ToBinary(aes.GaloisMulConst(a[0], 3), 8) + a0gmc2Bits := aes.api.ToBinary(aes.GaloisMulConst(a[0], 2), 8) + a1Bits := aes.api.ToBinary(a[1], 8) + a1gmc3Bits := aes.api.ToBinary(aes.GaloisMulConst(a[1], 3), 8) + a1gmc2Bits := aes.api.ToBinary(aes.GaloisMulConst(a[1], 2), 8) + a2Bits := aes.api.ToBinary(a[2], 8) + a2gmc3Bits := aes.api.ToBinary(aes.GaloisMulConst(a[2], 3), 8) + a2gmc2Bits := aes.api.ToBinary(aes.GaloisMulConst(a[2], 2), 8) + a3Bits := aes.api.ToBinary(a[3], 8) + a3gmc3Bits := aes.api.ToBinary(aes.GaloisMulConst(a[3], 3), 8) + a3gmc2Bits := aes.api.ToBinary(aes.GaloisMulConst(a[3], 2), 8) + + // bitwise xor + tmp1 := make([]frontend.Variable, 8) + tmp2 := make([]frontend.Variable, 8) // api.ToBinary(0, 8) + tmp3 := make([]frontend.Variable, 8) + tmp4 := make([]frontend.Variable, 8) + for g := 0; g < 8; g++ { + tmp1[g] = aes.api.Xor(aes.api.Xor(aes.api.Xor(a0gmc2Bits[g], a1gmc3Bits[g]), a2Bits[g]), a3Bits[g]) + tmp2[g] = aes.api.Xor(aes.api.Xor(aes.api.Xor(a0Bits[g], a1gmc2Bits[g]), a2gmc3Bits[g]), a3Bits[g]) + tmp3[g] = aes.api.Xor(aes.api.Xor(aes.api.Xor(a0Bits[g], a1Bits[g]), a2gmc2Bits[g]), a3gmc3Bits[g]) + tmp4[g] = aes.api.Xor(aes.api.Xor(aes.api.Xor(a0gmc3Bits[g], a1Bits[g]), a2Bits[g]), a3gmc2Bits[g]) + } + + newState[c] = aes.api.FromBinary(tmp1...) + newState[4+c] = aes.api.FromBinary(tmp2...) + newState[8+c] = aes.api.FromBinary(tmp3...) + newState[12+c] = aes.api.FromBinary(tmp4...) + } + + return newState +} + +func (aes *AES128) GaloisMulConst(a frontend.Variable, idx int) frontend.Variable { + p := frontend.Variable(0) + for counter := 0; counter < 8; counter++ { + if (idx & 1) != 0 { + p = aes.VariableXor(p, a, 8) + } + idx = idx >> 1 + if idx == 0 { + counter = 8 + break + } + + hiBitSet := aes.GetBit(a, 8, 1) + a = aes.ShiftLeft(a, 8, 1) + tmp := aes.VariableXor(a, 0x1B, 8) + a = aes.api.Add(a, aes.api.Mul(hiBitSet, aes.api.Sub(tmp, a))) + } + return p +} + +func (aes *AES128) GetBit(a frontend.Variable, size, idx int) frontend.Variable { + bits := aes.api.ToBinary(a, size) + return bits[len(bits)-idx] +} + +func (aes *AES128) ShiftLeft(a frontend.Variable, size, shift int) frontend.Variable { + + bits := aes.api.ToBinary(a, size) + x := make([]frontend.Variable, size) + for i := 0; i < size; i++ { + if i < shift { + x[i] = 0 + } else { + x[i] = bits[i-shift] + } + } + return aes.api.FromBinary(x...) +} + +func (aes *AES128) ShiftRows(state [16]frontend.Variable) [16]frontend.Variable { + var newState [16]frontend.Variable + for i := 0; i < 4; i++ { + newState[i] = state[i] // 0, 1, 2, 3 == t0 + } + for i := 0; i < 4; i++ { + newState[4+i] = state[4+((i+1)%4)] // 1, 2, 3, 0 == t1 + } + for i := 0; i < 4; i++ { + newState[8+i] = state[8+((i+2)%4)] // 2, 3, 0, 1 == t2 + } + for i := 0; i < 4; i++ { + newState[12+i] = state[12+((i+3)%4)] // 3, 0, 1, 2 == t3 + } + return newState +} + +// adds xor and shifts bytes in matrix to match next round representation requirements +func (aes *AES128) AddRoundKey(state [16]frontend.Variable, expandedKey [176]frontend.Variable, from int) [16]frontend.Variable { + var newState [16]frontend.Variable + for i := 0; i < 4; i++ { + newState[i] = aes.VariableXor(state[i], expandedKey[from+(4*i)], 8) + newState[4+i] = aes.VariableXor(state[4+i], expandedKey[from+(4*i)+1], 8) + newState[8+i] = aes.VariableXor(state[8+i], expandedKey[from+(4*i)+2], 8) + newState[12+i] = aes.VariableXor(state[12+i], expandedKey[from+(4*i)+3], 8) + } + return newState +} + +// different re-arrangement of variables +func (aes *AES128) AddRoundKey2(state [16]frontend.Variable, expandedKey [176]frontend.Variable, from int) [16]frontend.Variable { + var newState [16]frontend.Variable + ctr := 0 + for i := 0; i < 4; i++ { + newState[i] = aes.VariableXor(state[i], expandedKey[from+ctr], 8) + newState[4+i] = aes.VariableXor(state[4+i], expandedKey[from+ctr+1], 8) + newState[8+i] = aes.VariableXor(state[8+i], expandedKey[from+ctr+2], 8) + newState[12+i] = aes.VariableXor(state[12+i], expandedKey[from+ctr+3], 8) + ctr += 4 + } + return newState +} + +// xor on bits of two frontend.Variables +func (aes *AES128) VariableXor(a frontend.Variable, b frontend.Variable, size int) frontend.Variable { + bitsA := aes.api.ToBinary(a, size) + bitsB := aes.api.ToBinary(b, size) + x := make([]frontend.Variable, size) + for i := 0; i < size; i++ { + x[i] = aes.api.Xor(bitsA[i], bitsB[i]) + } + return aes.api.FromBinary(x...) +} + +// expands 16 byte key to 176 byte output +func (aes *AES128) ExpandKey(key [16]frontend.Variable, sbox0 [256]frontend.Variable, RCon [11]frontend.Variable) [176]frontend.Variable { + + var expand [176]frontend.Variable + i := 0 + + for i < 16 { + expand[i] = key[i] + expand[i+1] = key[i+1] + expand[i+2] = key[i+2] + expand[i+3] = key[i+3] + + i += 4 + } + + for i < 176 { + t0 := expand[i-4] + t1 := expand[i-3] + t2 := expand[i-2] + t3 := expand[i-1] + + if i%16 == 0 { + // t = subw(rotw(t)) ^ (uint32(powx[i/nb-1]) << 24) + + // rotation + t0, t1, t2, t3 = t1, t2, t3, t0 + + // subwords + t0 = aes.Subw(sbox0, t0) + t1 = aes.Subw(sbox0, t1) + t2 = aes.Subw(sbox0, t2) + t3 = aes.Subw(sbox0, t3) + t0 = aes.VariableXor(t0, RCon[i/16], 8) + } + + expand[i] = aes.VariableXor(expand[i-16], t0, 8) + expand[i+1] = aes.VariableXor(expand[i-16+1], t1, 8) + expand[i+2] = aes.VariableXor(expand[i-16+2], t2, 8) + expand[i+3] = aes.VariableXor(expand[i-16+3], t3, 8) + + i += 4 + } + + return expand +} + +// substitute word with naive lookup of sbox +func (aes *AES128) Subw(sbox [256]frontend.Variable, a frontend.Variable) frontend.Variable { + out := frontend.Variable(0) + for j := 0; j < 256; j++ { + out = aes.api.Add(out, aes.api.Mul(aes.api.IsZero(aes.api.Sub(a, j)), sbox[j])) // api.Cmp instead of api.Sub works but is inefficient + } + return out +} diff --git a/std/blockcipher/aes/aes128_test.go b/std/blockcipher/aes/aes128_test.go new file mode 100644 index 0000000000..9e84222690 --- /dev/null +++ b/std/blockcipher/aes/aes128_test.go @@ -0,0 +1,83 @@ +/* +Copyright © 2023 Jan Lauinger + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +*/ + +package aes + +import ( + "encoding/hex" + "testing" + + "github.com/consensys/gnark/frontend" + "github.com/consensys/gnark/test" +) + +func TestAES128(t *testing.T) { + assert := test.NewAssert(t) + + key := "ab72c77b97cb5fe9a382d9fe81ffdbed" + plaintext := "54cc7dc2c37ec006bcc6d1da00000002" + ciphertext := "0e67807b545e76e666750658b707181a" + + byteSlice, _ := hex.DecodeString(key) + keyByteLen := len(byteSlice) + byteSlice, _ = hex.DecodeString(plaintext) + ptByteLen := len(byteSlice) + byteSlice, _ = hex.DecodeString(ciphertext) + ctByteLen := len(byteSlice) + + keyAssign := StrToIntSlice(key, true) + ptAssign := StrToIntSlice(plaintext, true) + ctAssign := StrToIntSlice(ciphertext, true) + + // witness values preparation + assignment := AES128Wrapper{ + Key: [16]frontend.Variable{}, + Plaintext: [16]frontend.Variable{}, + Ciphertext: [16]frontend.Variable{}, + } + + // assign values here because required to use make in assignment + for i := 0; i < keyByteLen; i++ { + assignment.Key[i] = keyAssign[i] + } + for i := 0; i < ptByteLen; i++ { + assignment.Plaintext[i] = ptAssign[i] + } + for i := 0; i < ctByteLen; i++ { + assignment.Ciphertext[i] = ctAssign[i] + } + + // var circuit SHA256 + var circuit AES128Wrapper + + assert.SolvingSucceeded(&circuit, &assignment) +} + +func StrToIntSlice(inputData string, hexRepresentation bool) []int { + var byteSlice []byte + if hexRepresentation { + hexBytes, _ := hex.DecodeString(inputData) + byteSlice = hexBytes + } else { + byteSlice = []byte(inputData) + } + + var data []int + for i := 0; i < len(byteSlice); i++ { + data = append(data, int(byteSlice[i])) + } + return data +} diff --git a/std/blockcipher/aes/gcm.go b/std/blockcipher/aes/gcm.go new file mode 100644 index 0000000000..66d3982c01 --- /dev/null +++ b/std/blockcipher/aes/gcm.go @@ -0,0 +1,128 @@ +/* +Copyright 2023 Jan Lauinger + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +*/ + +package aes + +import ( + "github.com/consensys/gnark/frontend" +) + +// AES gcm testing +type GCMWrapper struct { + Key [16]frontend.Variable + PlainChunks []frontend.Variable + Iv [12]frontend.Variable `gnark:",public"` + ChunkIndex frontend.Variable `gnark:",public"` + CipherChunks []frontend.Variable `gnark:",public"` +} + +// Define declares the circuit's constraints +func (circuit *GCMWrapper) Define(api frontend.API) error { + + // init aes gadget + aes := NewAES128(api) + + // init gcm gadget + gcm := NewGCM(api, &aes) + + // verify aes gcm of chunks + gcm.Assert(circuit.Key, circuit.Iv, circuit.ChunkIndex, circuit.PlainChunks, circuit.CipherChunks) + + return nil +} + +type AES interface { + Encrypt(key [16]frontend.Variable, pt [16]frontend.Variable) [16]frontend.Variable +} + +func NewGCM(api frontend.API, aes AES) GCM { + return GCM{api: api, aes: aes} +} + +type GCM struct { + api frontend.API + aes AES +} + +// aes gcm encryption +func (gcm *GCM) Assert(key [16]frontend.Variable, iv [12]frontend.Variable, chunkIndex frontend.Variable, plaintext, ciphertext []frontend.Variable) { + + inputSize := len(plaintext) + numberBlocks := int(inputSize / 16) + var epoch int + for epoch = 0; epoch < numberBlocks; epoch++ { + + idx := gcm.api.Add(chunkIndex, frontend.Variable(epoch)) + eIndex := epoch * 16 + + var ptBlock [16]frontend.Variable + var ctBlock [16]frontend.Variable + + for j := 0; j < 16; j++ { + ptBlock[j] = plaintext[eIndex+j] + ctBlock[j] = ciphertext[eIndex+j] + } + + ivCounter := gcm.GetIV(iv, idx) + intermediate := gcm.aes.Encrypt(key, ivCounter) + ct := gcm.Xor16(intermediate, ptBlock) + + // check ciphertext to plaintext constraints + for i := 0; i < 16; i++ { + gcm.api.AssertIsEqual(ctBlock[i], ct[i]) + } + } +} + +// required for aes_gcm +func (gcm *GCM) GetIV(nonce [12]frontend.Variable, ctr frontend.Variable) [16]frontend.Variable { + + var out [16]frontend.Variable + var i int + for i = 0; i < len(nonce); i++ { + out[i] = nonce[i] + } + bits := gcm.api.ToBinary(ctr, 32) + remain := 12 + for j := 3; j >= 0; j-- { + start := 8 * j + // little endian order chunk parsing from back to front + out[remain] = gcm.api.FromBinary(bits[start : start+8]...) + remain += 1 + } + + return out +} + +// required for plaintext xor encrypted counter blocks +func (gcm *GCM) Xor16(a [16]frontend.Variable, b [16]frontend.Variable) [16]frontend.Variable { + + var out [16]frontend.Variable + for i := 0; i < 16; i++ { + out[i] = gcm.VariableXor(a[i], b[i], 8) + } + return out +} + +func (gcm *GCM) VariableXor(a frontend.Variable, b frontend.Variable, size int) frontend.Variable { + bitsA := gcm.api.ToBinary(a, size) + bitsB := gcm.api.ToBinary(b, size) + x := make([]frontend.Variable, size) + for i := 0; i < size; i++ { + x[i] = gcm.api.Xor(bitsA[i], bitsB[i]) + } + return gcm.api.FromBinary(x...) +} diff --git a/std/blockcipher/aes/gcm_test.go b/std/blockcipher/aes/gcm_test.go new file mode 100644 index 0000000000..881a0a8cee --- /dev/null +++ b/std/blockcipher/aes/gcm_test.go @@ -0,0 +1,106 @@ +/* +Copyright © 2023 Jan Lauinger + +Licensed under the Apache License, Version 2.0 (the "License"); +you may not use this file except in compliance with the License. +You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + +Unless required by applicable law or agreed to in writing, software +distributed under the License is distributed on an "AS IS" BASIS, +WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +See the License for the specific language governing permissions and +limitations under the License. +*/ + +package aes + +import ( + "encoding/hex" + "testing" + + "github.com/consensys/gnark/frontend" + "github.com/consensys/gnark/test" +) + +type gcmData struct { + key string + chunkIndex int + iv string + plaintext string + ciphertext string +} + +func TestGCM(t *testing.T) { + assert := test.NewAssert(t) + + // aes gcm test data + gcmDataList := []gcmData{ + { + key: "ab72c77b97cb5fe9a382d9fe81ffdbed", + chunkIndex: 2, + iv: "54cc7dc2c37ec006bcc6d1da", + plaintext: "007c5e5b3e59df24a7c355584fc1518d", + ciphertext: "0e1bde206a07a9c2c1b65300f8c64997", + }, + { + key: "fe47fcce5fc32665d2ae399e4eec72ba", + chunkIndex: 2, + iv: "5adb9609dbaeb58cbd6e7275", + plaintext: "7c0e88c88899a779228465074797cd4c2e1498d259b54390b85e3eef1c02df60e743f1b840382c4bccaf3bafb4ca8429", + ciphertext: "98f4826f05a265e6dd2be82db241c0fbbbf9ffb1c173aa83964b7cf5393043736365253ddbc5db8778371495da76d269", // authtag=f5f6e7d0b3d0418b82296ac7dd951d0e + + }, + } + for _, gcmData := range gcmDataList { + + // convert to bytes + byteSlice, _ := hex.DecodeString(gcmData.key) + keyByteLen := len(byteSlice) + byteSlice, _ = hex.DecodeString(gcmData.iv) + nonceByteLen := len(byteSlice) + byteSlice, _ = hex.DecodeString(gcmData.plaintext) + ptByteLen := len(byteSlice) + byteSlice, _ = hex.DecodeString(gcmData.ciphertext) + ctByteLen := len(byteSlice) + + // witness definition + keyAssign := StrToIntSlice(gcmData.key, true) + nonceAssign := StrToIntSlice(gcmData.iv, true) + ptAssign := StrToIntSlice(gcmData.plaintext, true) + ctAssign := StrToIntSlice(gcmData.ciphertext, true) + + // witness values preparation + assignment := GCMWrapper{ + PlainChunks: make([]frontend.Variable, ptByteLen), + CipherChunks: make([]frontend.Variable, ctByteLen), + ChunkIndex: gcmData.chunkIndex, + Iv: [12]frontend.Variable{}, + Key: [16]frontend.Variable{}, + } + + // assign values here because required to use make in assignment + for i := 0; i < ptByteLen; i++ { + assignment.PlainChunks[i] = ptAssign[i] + } + for i := 0; i < ctByteLen; i++ { + assignment.CipherChunks[i] = ctAssign[i] + } + for i := 0; i < nonceByteLen; i++ { + assignment.Iv[i] = nonceAssign[i] + } + for i := 0; i < keyByteLen; i++ { + assignment.Key[i] = keyAssign[i] + } + + // var circuit GCM + circuit := GCMWrapper{ + PlainChunks: make([]frontend.Variable, ptByteLen), + CipherChunks: make([]frontend.Variable, ctByteLen), + ChunkIndex: gcmData.chunkIndex, + } + + assert.SolvingSucceeded(&circuit, &assignment) + } +}