sidh: updates

Makefile

@@ -32,12 +32,6 @@ endif
 test:
 	$(OPTS_ENV) $(GO) test $(OPTS) $(TEST_PATH)
 
-test_csidh: clean make_dirs $(addprefix prep-,$(TARGETS))
-	cd $(GOPATH_LOCAL); $(OPTS_ENV) GOPATH=$(GOPATH_LOCAL) go test $(OPTS) github.com/henrydcase/nobs/dh/csidh
-
-test_csidh_bin: clean make_dirs $(addprefix prep-,$(TARGETS))
-	cd $(GOPATH_LOCAL); $(OPTS_ENV) GOPATH=$(GOPATH_LOCAL) go test -c $(OPTS) github.com/henrydcase/nobs/dh/csidh
-
 cover:
 	$(GO) test \
 		-coverprofile=coverage.txt -covermode=atomic $(OPTS) $(TEST_PATH)
@@ -45,10 +39,6 @@ cover:
 bench:
 	$(GO) test $(BENCH_OPTS) $(TEST_PATH)
 
-bench_csidh: clean $(addprefix prep-,$(TARGETS))
-	cd $(GOPATH_LOCAL); GOCACHE=$(GOCACHE) GOPATH=$(GOPATH_LOCAL) $(GO) test \
-		$(BENCH_OPTS) github.com/henrydcase/nobs/dh/csidh
-		
 clean:
 	rm -rf $(VENDOR_DIR)
 	rm -rf coverage.txt
@@ -58,6 +48,10 @@ vendor-sidh-for-tls: clean
 	rsync -a . $(VENDOR_DIR)/github_com/henrydcase/nobs/ --exclude=$(VENDOR_DIR) --exclude=.git --exclude=.travis.yml --exclude=README.md
 	find $(VENDOR_DIR) -type f -print0 -name "*.go" | xargs -0 sed -i 's/github\.com/github_com/g'
 
+gen: clean
+	$(GO) generate -v ./...
+	$(GO) mod tidy
+
 pprof-cpu:
 	$(GO) tool pprof cpu.out
 

dh/sidh/internal/doc.go

@@ -0,0 +1 @@
+package sidh

dh/sidh/internal/p434/arith_amd64_test.go

@@ -10,7 +10,7 @@ import (
 	"testing"
 	"testing/quick"
 
-	"github.com/henrydcase/nobs/sidh/internal/common"
+	"github.com/henrydcase/nobs/dh/sidh/internal/common"
 	"golang.org/x/sys/cpu"
 )
 

dh/sidh/internal/p434/doc.go

@@ -0,0 +1 @@
+package p434

dh/sidh/sidh_test.go

@@ -9,7 +9,6 @@ import (
 	"testing"
 
 	"github.com/henrydcase/nobs/dh/sidh/internal/common"
-	. "github.com/henrydcase/nobs/internal/test"
 )
 
 /* -------------------------------------------------------------------------
@@ -24,6 +23,13 @@ type sidhVec struct {
 	PrB  string
 }
 
+func checkErr(t testing.TB, err error, msg string) {
+	t.Helper()
+	if err != nil {
+		t.Error(msg)
+	}
+}
+
 var tdataSidh = map[uint8]sidhVec{
 	Fp434: {
 		id:   Fp434,
@@ -203,9 +209,9 @@ func testRoundtrip(t *testing.T, v sidhVec) {
 
 	// Generate private keys
 	err = prvA.Generate(rand.Reader)
-	CheckNoErr(t, err, "key generation failed")
+	checkErr(t, err, "key generation failed")
 	err = prvB.Generate(rand.Reader)
-	CheckNoErr(t, err, "key generation failed")
+	checkErr(t, err, "key generation failed")
 
 	// Generate public keys
 	prvA.GeneratePublicKey(pubA)
@@ -241,11 +247,11 @@ func testKeyAgreement(t *testing.T, v sidhVec) {
 
 	// Negative case
 	dec, err := hex.DecodeString(v.PkA)
-	CheckNoErr(t, err, "decoding failed")
+	checkErr(t, err, "decoding failed")
 
 	dec[0] = ^dec[0]
 	err = alicePublic.Import(dec)
-	CheckNoErr(t, err, "import failed")
+	checkErr(t, err, "import failed")
 
 	bobPrivate.DeriveSecret(s1, alicePublic)
 	alicePrivate.DeriveSecret(s2, bobPublic)
@@ -261,16 +267,16 @@ func testImportExport(t *testing.T, v sidhVec) {
 
 	// Import keys
 	aHex, err := hex.DecodeString(v.PkA)
-	CheckNoErr(t, err, "invalid hex-number provided")
+	checkErr(t, err, "invalid hex-number provided")
 
 	err = a.Import(aHex)
-	CheckNoErr(t, err, "import failed")
+	checkErr(t, err, "import failed")
 
 	bHex, err := hex.DecodeString(v.PkB)
-	CheckNoErr(t, err, "invalid hex-number provided")
+	checkErr(t, err, "invalid hex-number provided")
 
 	err = b.Import(bHex)
-	CheckNoErr(t, err, "import failed")
+	checkErr(t, err, "import failed")
 
 	aBytes := make([]byte, a.Size())
 	bBytes := make([]byte, b.Size())
@@ -313,7 +319,7 @@ func testPrivateKeyBelowMax(t *testing.T, vec sidhVec) {
 			// Do same test 1000 times
 			for i := 0; i < 1000; i++ {
 				err := prv.Generate(rand.Reader)
-				CheckNoErr(t, err, "Private key generation")
+				checkErr(t, err, "Private key generation")
 
 				// Convert to big-endian, as that's what expected by (*Int)SetBytes()
 				prv.Export(secretBytes)

dh/sidh/sike.go

@@ -6,7 +6,7 @@ import (
 	"io"
 
 	"github.com/henrydcase/nobs/dh/sidh/internal/common"
-	"github.com/henrydcase/nobs/internal/shake"
+	"github.com/henrydcase/nobs/hash/sha3"
 )
 
 // SIKE KEM interface.
@@ -16,7 +16,7 @@ type KEM struct {
 	msg         []byte
 	secretBytes []byte
 	params      *common.SidhParams
-	shake       shake.Shake
+	shake       sha3.ShakeHash
 }
 
 // NewSike434 instantiates SIKE/p434 KEM.
@@ -47,7 +47,7 @@ func (c *KEM) Allocate(id uint8, rng io.Reader) {
 	c.params = common.Params(id)
 	c.msg = make([]byte, c.params.MsgLen)
 	c.secretBytes = make([]byte, c.params.A.SecretByteLen)
-	c.shake = shake.NewShake256()
+	c.shake = sha3.NewShake256()
 	c.allocated = true
 }
 

dh/sidh/sike_test.go

@@ -5,6 +5,7 @@ import (
 	"bytes"
 	"crypto/rand"
 	"encoding/hex"
+	"errors"
 	"fmt"
 	"io"
 	"os"
@@ -12,7 +13,6 @@ import (
 	"testing"
 
 	"github.com/henrydcase/nobs/dh/sidh/internal/common"
-	. "github.com/henrydcase/nobs/internal/test"
 )
 
 type sikeVec struct {
@@ -24,6 +24,25 @@ type sikeVec struct {
 	PrB     string
 }
 
+func Ok(t testing.TB, err error, msg string) {
+	t.Helper()
+	if err != nil {
+		t.Error(msg)
+	}
+}
+
+// testPanic returns true if call to function 'f' caused panic.
+func testPanic(f func()) error {
+	var hasPanicked = errors.New("no panic detected")
+	defer func() {
+		if r := recover(); r != nil {
+			hasPanicked = nil
+		}
+	}()
+	f()
+	return hasPanicked
+}
+
 var tdataSike = map[uint8]sikeVec{
 	Fp434: {
 		Fp434, "P-434", NewSike434(rand.Reader),
@@ -99,17 +118,17 @@ func testPKERoundTrip(t *testing.T, v sikeVec) {
 	pkB := NewPublicKey(params.ID, KeyVariantSike)
 	skB := NewPrivateKey(params.ID, KeyVariantSike)
 	pkHex, err := hex.DecodeString(v.PkB)
-	CheckNoErr(t, err, "Test vector wrong")
+	Ok(t, err, "Test vector wrong")
 	skHex, err := hex.DecodeString(v.PrB)
-	CheckNoErr(t, err, "Test vector wrong")
+	Ok(t, err, "Test vector wrong")
 	err = pkB.Import(pkHex)
-	CheckNoErr(t, err, "Public key import failed")
+	Ok(t, err, "Public key import failed")
 	err = skB.Import(skHex)
-	CheckNoErr(t, err, "Private key import failed")
+	Ok(t, err, "Private key import failed")
 	err = v.kem.encrypt(ct, rand.Reader, pkB, msg[:])
-	CheckNoErr(t, err, "PKE roundtrip - encryption failed")
+	Ok(t, err, "PKE roundtrip - encryption failed")
 	ptLen, err := v.kem.decrypt(pt[:], skB, ct)
-	CheckNoErr(t, err, "PKE roundtrip - decription failed")
+	Ok(t, err, "PKE roundtrip - decription failed")
 
 	if !bytes.Equal(pt[:ptLen], msg[:]) {
 		t.Errorf("Decryption failed \n got : %X\n exp : %X", pt[:ptLen], msg)
@@ -132,13 +151,13 @@ func testPKEKeyGeneration(t *testing.T, v sikeVec) {
 	}
 
 	err = sk.Generate(rand.Reader)
-	CheckNoErr(t, err, "PKE key generation")
+	Ok(t, err, "PKE key generation")
 	sk.GeneratePublicKey(pk)
 
 	err = v.kem.encrypt(ct, rand.Reader, pk, msg[:])
-	CheckNoErr(t, err, "PKE encryption")
+	Ok(t, err, "PKE encryption")
 	ptLen, err := v.kem.decrypt(pt[:], sk, ct)
-	CheckNoErr(t, err, "PKE key decryption")
+	Ok(t, err, "PKE key decryption")
 
 	if !bytes.Equal(pt[:ptLen], msg[:]) {
 		t.Fatalf("Decryption failed \n got : %X\n exp : %X", pt, msg)
@@ -154,12 +173,15 @@ func testNegativePKE(t *testing.T, v sikeVec) {
 
 	// Generate key
 	err = sk.Generate(rand.Reader)
-	CheckNoErr(t, err, "key generation")
+	Ok(t, err, "key generation")
 	sk.GeneratePublicKey(pk)
 
 	// bytelen(msg) - 1
 	err = v.kem.encrypt(ct, rand.Reader, pk, msg[:v.kem.params.KemSize+8-1])
-	CheckIsErr(t, err, "PKE encryption doesn't fail")
+	if err == nil {
+		t.Error(msg)
+	}
+
 	for _, v := range ct {
 		if v != 0 {
 			t.Fatal("Returned ciphertext must be not changed")
@@ -178,16 +200,16 @@ func testKEMRoundTrip(t *testing.T, pkB, skB []byte, v sikeVec) {
 	var ssBsz = v.kem.SharedSecretSize()
 
 	err = pk.Import(pkB)
-	CheckNoErr(t, err, "Public key import failed")
+	Ok(t, err, "Public key import failed")
 	err = sk.Import(skB)
-	CheckNoErr(t, err, "Private key import failed")
+	Ok(t, err, "Private key import failed")
 
 	v.kem.Reset()
 	err = v.kem.Encapsulate(ct, ssE[:], pk)
-	CheckNoErr(t, err, "Encapsulation failed")
+	Ok(t, err, "Encapsulation failed")
 	v.kem.Reset()
 	err = v.kem.Decapsulate(ssD[:ssBsz], sk, pk, ct)
-	CheckNoErr(t, err, "Decapsulation failed")
+	Ok(t, err, "Decapsulation failed")
 
 	if !bytes.Equal(ssE[:v.kem.SharedSecretSize()], ssD[:v.kem.SharedSecretSize()]) {
 		t.Errorf("Shared secrets from decapsulation and encapsulation differ [%s]", v.name)
@@ -201,16 +223,16 @@ func testKEMKeyGeneration(t *testing.T, v sikeVec) {
 
 	sk := NewPrivateKey(v.id, KeyVariantSike)
 	pk := NewPublicKey(v.id, KeyVariantSike)
-	CheckNoErr(t, sk.Generate(rand.Reader), "error: key generation")
+	Ok(t, sk.Generate(rand.Reader), "error: key generation")
 	sk.GeneratePublicKey(pk)
 
 	// calculated shared secret
 	v.kem.Reset()
 	err := v.kem.Encapsulate(ct, ssE[:], pk)
-	CheckNoErr(t, err, "encapsulation failed")
+	Ok(t, err, "encapsulation failed")
 	v.kem.Reset()
 	err = v.kem.Decapsulate(ssD[:v.kem.SharedSecretSize()], sk, pk, ct)
-	CheckNoErr(t, err, "decapsulation failed")
+	Ok(t, err, "decapsulation failed")
 
 	if !bytes.Equal(ssE[:], ssD[:]) {
 		t.Fatalf("KEM failed \n encapsulated: %X\n decapsulated: %X", ssD[:], ssE[:])
@@ -226,33 +248,33 @@ func testNegativeKEM(t *testing.T, v sikeVec) {
 
 	sk := NewPrivateKey(v.id, KeyVariantSike)
 	pk := NewPublicKey(v.id, KeyVariantSike)
-	CheckNoErr(t, sk.Generate(rand.Reader), "error: key generation")
+	Ok(t, sk.Generate(rand.Reader), "error: key generation")
 	sk.GeneratePublicKey(pk)
 
 	v.kem.Reset()
 	err := v.kem.Encapsulate(ct, ssE[:], pk)
-	CheckNoErr(t, err, "pre-requisite for a test failed")
+	Ok(t, err, "pre-requisite for a test failed")
 
 	// Try decapsulate too small ciphertext
 	v.kem.Reset()
-	CheckNoErr(
+	Ok(
 		t,
-		CheckPanic(func() { _ = v.kem.Decapsulate(ssTmp[:ssBsz], sk, pk, ct[:len(ct)-2]) }),
+		testPanic(func() { _ = v.kem.Decapsulate(ssTmp[:ssBsz], sk, pk, ct[:len(ct)-2]) }),
 		"Decapsulation must panic if ciphertext is too small")
 
 	ctTmp := make([]byte, len(ct)+1)
 	// Try decapsulate too big ciphertext
 	v.kem.Reset()
-	CheckNoErr(
+	Ok(
 		t,
-		CheckPanic(func() { _ = v.kem.Decapsulate(ssTmp[:ssBsz], sk, pk, ctTmp) }),
+		testPanic(func() { _ = v.kem.Decapsulate(ssTmp[:ssBsz], sk, pk, ctTmp) }),
 		"Decapsulation must panic if ciphertext is too big")
 
 	// Change ciphertext
 	ct[0] = ct[0] - 1
 	v.kem.Reset()
 	err = v.kem.Decapsulate(ssD[:ssBsz], sk, pk, ct)
-	CheckNoErr(t, err, "decapsulation returns error when invalid ciphertext provided")
+	Ok(t, err, "decapsulation returns error when invalid ciphertext provided")
 
 	if bytes.Equal(ssE[:], ssD[:]) {
 		// no idea how this could ever happen, but it would be very bad
@@ -263,16 +285,16 @@ func testNegativeKEM(t *testing.T, v sikeVec) {
 	pkSidh := NewPublicKey(v.id, KeyVariantSidhB)
 	prSidh := NewPrivateKey(v.id, KeyVariantSidhB)
 	v.kem.Reset()
-	CheckNoErr(
+	Ok(
 		t,
-		CheckPanic(func() { _ = v.kem.Encapsulate(ct, ssE[:], pkSidh) }),
+		testPanic(func() { _ = v.kem.Encapsulate(ct, ssE[:], pkSidh) }),
 		"encapsulation accepts SIDH public key")
 
 	// Try decapsulating with SIDH key
 	v.kem.Reset()
-	CheckNoErr(
+	Ok(
 		t,
-		CheckPanic(func() { _ = v.kem.Decapsulate(ssD[:ssBsz], prSidh, pk, ct) }),
+		testPanic(func() { _ = v.kem.Decapsulate(ssD[:ssBsz], prSidh, pk, ct) }),
 		"encapsulation accepts SIDH public key")
 }
 
@@ -287,18 +309,18 @@ func testNegativeKEMSameWrongResult(t *testing.T, v sikeVec) {
 
 	sk := NewPrivateKey(v.id, KeyVariantSike)
 	pk := NewPublicKey(v.id, KeyVariantSike)
-	CheckNoErr(t, sk.Generate(rand.Reader), "error: key generation")
+	Ok(t, sk.Generate(rand.Reader), "error: key generation")
 	sk.GeneratePublicKey(pk)
 
 	v.kem.Reset()
 	err := v.kem.Encapsulate(ct, ssE[:], pk)
-	CheckNoErr(t, err, "pre-requisite for a test failed")
+	Ok(t, err, "pre-requisite for a test failed")
 
 	// make ciphertext wrong
 	ct[0] = ct[0] - 1
 	v.kem.Reset()
 	err = v.kem.Decapsulate(ssD1[:ssBsz], sk, pk, ct)
-	CheckNoErr(t, err, "pre-requisite for a test failed")
+	Ok(t, err, "pre-requisite for a test failed")
 
 	// change secret keysecond decapsulation must be done with same, but imported private key
 	var expSk [common.MaxSikePrivateKeyBsz]byte
@@ -306,12 +328,12 @@ func testNegativeKEMSameWrongResult(t *testing.T, v sikeVec) {
 
 	// create new private key
 	sk = NewPrivateKey(v.id, KeyVariantSike)
-	CheckNoErr(t, sk.Import(expSk[:sk.Size()]), "import failed")
+	Ok(t, sk.Import(expSk[:sk.Size()]), "import failed")
 
 	// try decapsulating again.
 	v.kem.Reset()
 	err = v.kem.Decapsulate(ssD2[:ssBsz], sk, pk, ct)
-	CheckNoErr(t, err, "pre-requisite for a test failed")
+	Ok(t, err, "pre-requisite for a test failed")
 
 	// ssD1 must be same as ssD2
 	if !bytes.Equal(ssD1[:], ssD2[:]) {
@@ -335,7 +357,7 @@ func testKAT(t *testing.T, v sikeVec) {
 		}
 
 		err := v.kem.Decapsulate(ssGot, prvKey, pubKey, ct)
-		CheckNoErr(t, err, "sike test: can't perform degcapsulation KAT")
+		Ok(t, err, "sike test: can't perform degcapsulation KAT")
 		if !bytes.Equal(ssGot, ssExpected) {
 			t.Fatalf("KAT decapsulation failed\n")
 		}
@@ -365,7 +387,7 @@ func testKAT(t *testing.T, v sikeVec) {
 		var prvKey = NewPrivateKey(v.id, KeyVariantSike)
 		var pubKey = NewPublicKey(v.id, KeyVariantSike)
 		var pubKeyBytes = make([]byte, pubKey.Size())
-		CheckNoErr(t, prvKey.Import(sk), "Can't load KAT")
+		Ok(t, prvKey.Import(sk), "Can't load KAT")
 
 		// Generate public key
 		prvKey.GeneratePublicKey(pubKey)
@@ -439,9 +461,9 @@ func TestKEMRoundTrip(t *testing.T) {
 	for _, val := range tdataSike {
 		//		fmt.Printf("\tTesting: %s\n", val.name)
 		pk, err := hex.DecodeString(val.PkB)
-		CheckNoErr(t, err, "public key B not a number")
+		Ok(t, err, "public key B not a number")
 		sk, err := hex.DecodeString(val.PrB)
-		CheckNoErr(t, err, "private key B not a number")
+		Ok(t, err, "private key B not a number")
 		testKEMRoundTrip(t, pk, sk, val)
 	}
 }

go.mod

@@ -1,7 +1,5 @@
 module github.com/henrydcase/nobs
 
-go 1.14
+go 1.12
 
-require (
+require golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e
-	golang.org/x/sys v0.0.0-20191120155948-bd437916bb0e
-)

kem/sike/sike.go

@@ -1,217 +0,0 @@
-// [SIKE] http://www.sike.org/files/SIDH-spec.pdf
-// [REF] https://github.com/Microsoft/PQCrypto-SIDH
-package sike
-
-import (
-	"crypto/subtle"
-	"errors"
-	"io"
-	// TODO: Use implementation from xcrypto, once PR below merged
-	// https://go-review.googlesource.com/c/crypto/+/111281/
-	. "github.com/henrydcase/nobs/dh/sidh"
-	cshake "github.com/henrydcase/nobs/hash/sha3"
-)
-
-// Constants used for cSHAKE customization
-// Those values are different than in [SIKE] - they are encoded on 16bits. This is
-// done in order for implementation to be compatible with [REF] and test vectors.
-var G = []byte{0x00, 0x00}
-var H = []byte{0x01, 0x00}
-var F = []byte{0x02, 0x00}
-
-// Generates cShake-256 sum
-func cshakeSum(out, in, S []byte) {
-	h := cshake.NewCShake256(nil, S)
-	h.Write(in)
-	h.Read(out)
-}
-
-func encrypt(skA *PrivateKey, pkA, pkB *PublicKey, ptext []byte) ([]byte, error) {
-	var n [40]byte // n can is max 320-bit (see 1.4 of [SIKE])
-	var ptextLen = len(ptext)
-
-	if pkB.Variant() != KeyVariant_SIKE {
-		return nil, errors.New("wrong key type")
-	}
-
-	j, err := DeriveSecret(skA, pkB)
-	if err != nil {
-		return nil, err
-	}
-
-	cshakeSum(n[:ptextLen], j, F)
-	for i, _ := range ptext {
-		n[i] ^= ptext[i]
-	}
-
-	ret := make([]byte, pkA.Size()+ptextLen)
-	copy(ret, pkA.Export())
-	copy(ret[pkA.Size():], n[:ptextLen])
-	return ret, nil
-}
-
-// -----------------------------------------------------------------------------
-// PKE interface
-//
-
-// Uses SIKE public key to encrypt plaintext. Requires cryptographically secure PRNG
-// Returns ciphertext in case encryption succeeds. Returns error in case PRNG fails
-// or wrongly formated input was provided.
-func Encrypt(rng io.Reader, pub *PublicKey, ptext []byte) ([]byte, error) {
-	var params = pub.Params()
-	var ptextLen = uint(len(ptext))
-	// c1 must be security level + 64 bits (see [SIKE] 1.4 and 4.3.3)
-	if ptextLen != (params.KemSize + 8) {
-		return nil, errors.New("Unsupported message length")
-	}
-
-	skA := NewPrivateKey(params.Id, KeyVariant_SIDH_A)
-	err := skA.Generate(rng)
-	if err != nil {
-		return nil, err
-	}
-
-	pkA := skA.GeneratePublicKey()
-	return encrypt(skA, pkA, pub, ptext)
-}
-
-// Uses SIKE private key to decrypt ciphertext. Returns plaintext in case
-// decryption succeeds or error in case unexptected input was provided.
-// Constant time
-func Decrypt(prv *PrivateKey, ctext []byte) ([]byte, error) {
-	var params = prv.Params()
-	var n [40]byte // n can is max 320-bit (see 1.4 of [SIKE])
-	var c1_len int
-	var pk_len = params.PublicKeySize
-
-	if prv.Variant() != KeyVariant_SIKE {
-		return nil, errors.New("wrong key type")
-	}
-
-	// ctext is a concatenation of (pubkey_A || c1=ciphertext)
-	// it must be security level + 64 bits (see [SIKE] 1.4 and 4.3.3)
-	c1_len = len(ctext) - pk_len
-	if c1_len != (int(params.KemSize) + 8) {
-		return nil, errors.New("wrong size of cipher text")
-	}
-
-	c0 := NewPublicKey(params.Id, KeyVariant_SIDH_A)
-	err := c0.Import(ctext[:pk_len])
-	if err != nil {
-		return nil, err
-	}
-	j, err := DeriveSecret(prv, c0)
-	if err != nil {
-		return nil, err
-	}
-
-	cshakeSum(n[:c1_len], j, F)
-	for i, _ := range n[:c1_len] {
-		n[i] ^= ctext[pk_len+i]
-	}
-
-	return n[:c1_len], nil
-}
-
-// -----------------------------------------------------------------------------
-// KEM interface
-//
-
-// Encapsulation receives the public key and generates SIKE ciphertext and shared secret.
-// The generated ciphertext is used for authentication.
-// The rng must be cryptographically secure PRNG.
-// Error is returned in case PRNG fails or wrongly formated input was provided.
-func Encapsulate(rng io.Reader, pub *PublicKey) (ctext []byte, secret []byte, err error) {
-	var params = pub.Params()
-	// Buffer for random, secret message
-	var ptext = make([]byte, params.MsgLen)
-	// r = G(ptext||pub)
-	var r = make([]byte, params.A.SecretByteLen)
-	// Resulting shared secret
-	secret = make([]byte, params.KemSize)
-
-	// Generate ephemeral value
-	_, err = io.ReadFull(rng, ptext)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	h := cshake.NewCShake256(nil, G)
-	h.Write(ptext)
-	h.Write(pub.Export())
-	h.Read(r)
-
-	// cSHAKE256 implementation is byte oriented. Ensure bitlength is not bigger then to 2^e2-1
-	r[len(r)-1] &= (1 << (params.A.SecretBitLen % 8)) - 1
-
-	// (c0 || c1) = Enc(pkA, ptext; r)
-	skA := NewPrivateKey(params.Id, KeyVariant_SIDH_A)
-	err = skA.Import(r)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	pkA := skA.GeneratePublicKey()
-	ctext, err = encrypt(skA, pkA, pub, ptext)
-	if err != nil {
-		return nil, nil, err
-	}
-
-	// K = H(ptext||(c0||c1))
-	h = cshake.NewCShake256(nil, H)
-	h.Write(ptext)
-	h.Write(ctext)
-	h.Read(secret)
-
-	return ctext, secret, nil
-}
-
-// Decapsulate given the keypair and ciphertext as inputs, Decapsulate outputs a shared
-// secret if plaintext verifies correctly, otherwise function outputs random value.
-// Decapsulation may fail in case input is wrongly formated.
-// Constant time for properly initialized input.
-func Decapsulate(prv *PrivateKey, pub *PublicKey, ctext []byte) ([]byte, error) {
-	var params = pub.Params()
-	var r = make([]byte, params.A.SecretByteLen)
-	// Resulting shared secret
-	var secret = make([]byte, params.KemSize)
-	var skA = NewPrivateKey(params.Id, KeyVariant_SIDH_A)
-
-	m, err := Decrypt(prv, ctext)
-	if err != nil {
-		return nil, err
-	}
-
-	// r' = G(m'||pub)
-	h := cshake.NewCShake256(nil, G)
-	h.Write(m)
-	h.Write(pub.Export())
-	h.Read(r)
-
-	// cSHAKE256 implementation is byte oriented: Ensure bitlength is not bigger than 2^e2-1
-	r[len(r)-1] &= (1 << (params.A.SecretBitLen % 8)) - 1
-
-	// Never fails
-	skA.Import(r)
-
-	// Never fails
-	pkA := skA.GeneratePublicKey()
-	c0 := pkA.Export()
-
-	h = cshake.NewCShake256(nil, H)
-	if subtle.ConstantTimeCompare(c0, ctext[:len(c0)]) == 1 {
-		h.Write(m)
-	} else {
-		// S is chosen at random when generating a key and unknown to other party. It
-		// may seem weird, but it's correct. It is important that S is unpredictable
-		// to other party. Without this check, it is possible to recover a secret, by
-		// providing series of invalid ciphertexts. It is also important that in case
-		//
-		// See more details in "On the security of supersingular isogeny cryptosystems"
-		// (S. Galbraith, et al., 2016, ePrint #859).
-		h.Write(prv.S)
-	}
-	h.Write(ctext)
-	h.Read(secret)
-	return secret, nil
-}

kem/sike/sike_test.go

@@ -1,378 +0,0 @@
-package sike
-
-import (
-	"testing"
-
-	"bufio"
-	"bytes"
-	"encoding/hex"
-	"io"
-	"os"
-	"strings"
-
-	"fmt"
-
-	rand "crypto/rand"
-	. "github.com/henrydcase/nobs/dh/sidh"
-)
-
-const (
-	Pk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
-	PrB = "00010203040506070809000102030405060708090001020304050607080901028626ED79D451140800E03B59B956F8210E556067407D13DC90FA9E8B872BFB8FAB0A7289852106E40538D3575C500201"
-)
-
-var params = Params(FP_751)
-
-type MultiIdTestingFunc func(*testing.T, uint8)
-
-func Do(f MultiIdTestingFunc, t *testing.T) {
-	for id, val := range tdata {
-		params = Params(id)
-		fmt.Printf("\tTesting: %s\n", val.name)
-		f(t, id)
-	}
-}
-
-var tdata = map[uint8]struct {
-	name    string
-	KatFile string
-	PkB     string
-	PrB     string
-}{
-	FP_503: {
-		"P-503",
-		"../../etc/PQCkemKAT_434.rsp",
-		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
-		"9BC5315580207C6C16DCF3A30C48DAF278DE12E8C27DF6735A4D0A8A41C4F666854E9B13673071CEB2FD61DEF9A850C211E7C50071B1DD0D"},
-	FP_751: {
-		"P-751",
-		"../../etc/PQCkemKAT_644.rsp",
-		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
-		"00010203040506070809000102030405060708090001020304050607080901028626ED79D451140800E03B59B956F8210E556067407D13DC90FA9E8B872BFB8FAB0A7289852106E40538D3575C500201"},
-}
-
-// Fail if err !=nil. Display msg as an error message
-func checkErr(t testing.TB, err error, msg string) {
-	if err != nil {
-		t.Errorf("%s [%s]", msg, err)
-	}
-}
-
-// Encrypt, Decrypt, check if input/output plaintext is the same
-func testPKERoundTrip(t *testing.T, id uint8) {
-	// Message to be encrypted
-	var params = Params(id)
-	var msg = make([]byte, params.MsgLen)
-	for i, _ := range msg {
-		msg[i] = byte(i)
-	}
-
-	// Import keys
-	pkB := NewPublicKey(params.Id, KeyVariant_SIKE)
-	skB := NewPrivateKey(params.Id, KeyVariant_SIKE)
-	pk_hex, err := hex.DecodeString(tdata[id].PkB)
-	if err != nil {
-		t.Fatal(err)
-	}
-	sk_hex, err := hex.DecodeString(tdata[id].PrB)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if pkB.Import(pk_hex) != nil || skB.Import(sk_hex) != nil {
-		t.Error("Import")
-	}
-
-	ct, err := Encrypt(rand.Reader, pkB, msg[:])
-	if err != nil {
-		t.Fatal(err)
-	}
-	pt, err := Decrypt(skB, ct)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if !bytes.Equal(pt[:], msg[:]) {
-		t.Errorf("Decryption failed \n got : %X\n exp : %X", pt, msg)
-	}
-}
-
-// Generate key and check if can encrypt
-func testPKEKeyGeneration(t *testing.T, id uint8) {
-	// Message to be encrypted
-	var params = Params(id)
-	var msg = make([]byte, params.MsgLen)
-	var err error
-	for i, _ := range msg {
-		msg[i] = byte(i)
-	}
-
-	sk := NewPrivateKey(id, KeyVariant_SIKE)
-	err = sk.Generate(rand.Reader)
-	checkErr(t, err, "PEK key generation")
-	pk := sk.GeneratePublicKey()
-
-	// Try to encrypt
-	ct, err := Encrypt(rand.Reader, pk, msg[:])
-	checkErr(t, err, "PEK encryption")
-	pt, err := Decrypt(sk, ct)
-	checkErr(t, err, "PEK key decryption")
-
-	if !bytes.Equal(pt[:], msg[:]) {
-		t.Fatalf("Decryption failed \n got : %X\n exp : %X", pt, msg)
-	}
-}
-
-func testNegativePKE(t *testing.T, id uint8) {
-	var msg [40]byte
-	var err error
-	var params = Params(id)
-
-	// Generate key
-	sk := NewPrivateKey(params.Id, KeyVariant_SIKE)
-	err = sk.Generate(rand.Reader)
-	checkErr(t, err, "key generation")
-
-	pk := sk.GeneratePublicKey()
-
-	// bytelen(msg) - 1
-	ct, err := Encrypt(rand.Reader, pk, msg[:params.KemSize+8-1])
-	if err == nil {
-		t.Fatal("Error hasn't been returned")
-	}
-	if ct != nil {
-		t.Fatal("Ciphertext must be nil")
-	}
-
-	// KemSize - 1
-	pt, err := Decrypt(sk, msg[:params.KemSize+8-1])
-	if err == nil {
-		t.Fatal("Error hasn't been returned")
-	}
-	if pt != nil {
-		t.Fatal("Ciphertext must be nil")
-	}
-}
-
-func testKEMRoundTrip(t *testing.T, pkB, skB []byte, id uint8) {
-	// Import keys
-	pk := NewPublicKey(id, KeyVariant_SIKE)
-	sk := NewPrivateKey(id, KeyVariant_SIKE)
-	if pk.Import(pkB) != nil || sk.Import(skB) != nil {
-		t.Error("Import failed")
-	}
-
-	ct, ss_e, err := Encapsulate(rand.Reader, pk)
-	if err != nil {
-		t.Error("Encapsulate failed")
-	}
-
-	ss_d, err := Decapsulate(sk, pk, ct)
-	if err != nil {
-		t.Error("Decapsulate failed")
-	}
-	if !bytes.Equal(ss_e, ss_d) {
-		t.Error("Shared secrets from decapsulation and encapsulation differ")
-	}
-}
-
-func TestKEMRoundTrip(t *testing.T) {
-	for id, val := range tdata {
-		fmt.Printf("\tTesting: %s\n", val.name)
-		pk, err := hex.DecodeString(tdata[id].PkB)
-		checkErr(t, err, "public key B not a number")
-		sk, err := hex.DecodeString(tdata[id].PrB)
-		checkErr(t, err, "private key B not a number")
-		testKEMRoundTrip(t, pk, sk, id)
-	}
-}
-
-func testKEMKeyGeneration(t *testing.T, id uint8) {
-	// Generate key
-	sk := NewPrivateKey(id, KeyVariant_SIKE)
-	checkErr(t, sk.Generate(rand.Reader), "error: key generation")
-	pk := sk.GeneratePublicKey()
-
-	// calculated shared secret
-	ct, ss_e, err := Encapsulate(rand.Reader, pk)
-	checkErr(t, err, "encapsulation failed")
-	ss_d, err := Decapsulate(sk, pk, ct)
-	checkErr(t, err, "decapsulation failed")
-
-	if !bytes.Equal(ss_e, ss_d) {
-		t.Fatalf("KEM failed \n encapsulated: %X\n decapsulated: %X", ss_d, ss_e)
-	}
-}
-
-func testNegativeKEM(t *testing.T, id uint8) {
-	sk := NewPrivateKey(id, KeyVariant_SIKE)
-	checkErr(t, sk.Generate(rand.Reader), "error: key generation")
-	pk := sk.GeneratePublicKey()
-
-	ct, ss_e, err := Encapsulate(rand.Reader, pk)
-	checkErr(t, err, "pre-requisite for a test failed")
-
-	ct[0] = ct[0] - 1
-	ss_d, err := Decapsulate(sk, pk, ct)
-	checkErr(t, err, "decapsulation returns error when invalid ciphertext provided")
-
-	if bytes.Equal(ss_e, ss_d) {
-		// no idea how this could ever happen, but it would be very bad
-		t.Error("critical error")
-	}
-
-	// Try encapsulating with SIDH key
-	pkSidh := NewPublicKey(params.Id, KeyVariant_SIDH_B)
-	prSidh := NewPrivateKey(params.Id, KeyVariant_SIDH_B)
-	_, _, err = Encapsulate(rand.Reader, pkSidh)
-	if err == nil {
-		t.Error("encapsulation accepts SIDH public key")
-	}
-	// Try decapsulating with SIDH key
-	_, err = Decapsulate(prSidh, pk, ct)
-	if err == nil {
-		t.Error("decapsulation accepts SIDH private key key")
-	}
-}
-
-// In case invalid ciphertext is provided, SIKE's decapsulation must
-// return same (but unpredictable) result for a given key.
-func testNegativeKEMSameWrongResult(t *testing.T, id uint8) {
-	sk := NewPrivateKey(id, KeyVariant_SIKE)
-	checkErr(t, sk.Generate(rand.Reader), "error: key generation")
-	pk := sk.GeneratePublicKey()
-
-	ct, encSs, err := Encapsulate(rand.Reader, pk)
-	checkErr(t, err, "pre-requisite for a test failed")
-
-	// make ciphertext wrong
-	ct[0] = ct[0] - 1
-	decSs1, err := Decapsulate(sk, pk, ct)
-	checkErr(t, err, "pre-requisite for a test failed")
-
-	// second decapsulation must be done with same, but imported private key
-	expSk := sk.Export()
-
-	// creat new private key
-	sk = NewPrivateKey(params.Id, KeyVariant_SIKE)
-	err = sk.Import(expSk)
-	checkErr(t, err, "import failed")
-
-	// try decapsulating again. ss2 must be same as ss1 and different than
-	// original plaintext
-	decSs2, err := Decapsulate(sk, pk, ct)
-	checkErr(t, err, "pre-requisite for a test failed")
-
-	if !bytes.Equal(decSs1, decSs2) {
-		t.Error("decapsulation is insecure")
-	}
-
-	if bytes.Equal(encSs, decSs1) || bytes.Equal(encSs, decSs2) {
-		// this test requires that decapsulation returns wrong result
-		t.Errorf("test implementation error")
-	}
-}
-
-func readAndCheckLine(r *bufio.Reader) []byte {
-	// Read next line from buffer
-	line, isPrefix, err := r.ReadLine()
-	if err != nil || isPrefix {
-		panic("Wrong format of input file")
-	}
-
-	// Function expects that line is in format "KEY = HEX_VALUE". Get
-	// value, which should be a hex string
-	hexst := strings.Split(string(line), "=")[1]
-	hexst = strings.TrimSpace(hexst)
-	// Convert value to byte string
-	ret, err := hex.DecodeString(hexst)
-	if err != nil {
-		panic("Wrong format of input file")
-	}
-	return ret
-}
-
-func testKeygen(pk, sk []byte) bool {
-	// Import provided private key
-	var prvKey = NewPrivateKey(params.Id, KeyVariant_SIKE)
-	if prvKey.Import(sk) != nil {
-		panic("sike test: can't load KAT")
-	}
-
-	// Generate public key
-	pubKey := prvKey.GeneratePublicKey()
-	return bytes.Equal(pubKey.Export(), pk)
-}
-
-func testDecapsulation(pk, sk, ct, ssExpected []byte) bool {
-	var pubKey = NewPublicKey(params.Id, KeyVariant_SIKE)
-	var prvKey = NewPrivateKey(params.Id, KeyVariant_SIKE)
-	if pubKey.Import(pk) != nil || prvKey.Import(sk) != nil {
-		panic("sike test: can't load KAT")
-	}
-
-	ssGot, err := Decapsulate(prvKey, pubKey, ct)
-	if err != nil {
-		panic("sike test: can't perform decapsulation KAT")
-	}
-
-	if err != nil {
-		return false
-	}
-	return bytes.Equal(ssGot, ssExpected)
-}
-
-func testSIKE_KAT(t *testing.T, id uint8) {
-	f, err := os.Open(tdata[id].KatFile)
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	r := bufio.NewReader(f)
-	for {
-		line, isPrefix, err := r.ReadLine()
-		if err != nil || isPrefix {
-			if err == io.EOF {
-				break
-			} else {
-				t.Fatal(err)
-			}
-		}
-		if len(strings.TrimSpace(string(line))) == 0 || line[0] == '#' {
-			continue
-		}
-
-		// count
-		count := strings.Split(string(line), "=")[1]
-		// seed
-		_ = readAndCheckLine(r)
-		// pk
-		pk := readAndCheckLine(r)
-		// sk (secret key in test vector is concatenation of
-		// MSG + SECRET_BOB_KEY + PUBLIC_BOB_KEY. We use only MSG+SECRET_BOB_KEY
-		sk := readAndCheckLine(r)
-		sk = sk[:params.MsgLen+uint(params.B.SecretByteLen)]
-		// ct
-		ct := readAndCheckLine(r)
-		// ss
-		ss := readAndCheckLine(r)
-
-		if !testKeygen(pk, sk) {
-			t.Fatalf("KAT keygen form private failed at %s\n", count)
-		}
-
-		if !testDecapsulation(pk, sk, ct, ss) {
-			t.Fatalf("KAT decapsulation failed at %s\n", count)
-		}
-
-		// aditionally test roundtrip with a keypair
-		testKEMRoundTrip(t, pk, sk, id)
-	}
-}
-
-// Interface to "testing"
-func TestPKEKeyGeneration(t *testing.T)           { Do(testPKEKeyGeneration, t) }
-func TestPKERoundTrip(t *testing.T)               { Do(testPKERoundTrip, t) }
-func TestNegativePKE(t *testing.T)                { Do(testNegativePKE, t) }
-func TestKEMKeyGeneration(t *testing.T)           { Do(testKEMKeyGeneration, t) }
-func TestNegativeKEM(t *testing.T)                { Do(testNegativeKEM, t) }
-func TestSIKE_KAT(t *testing.T)                   { Do(testSIKE_KAT, t) }
-func TestNegativeKEMSameWrongResult(t *testing.T) { Do(testNegativeKEMSameWrongResult, t) }