Split constant time functions into crypto/subtle.
R=rsc
CC=go-dev
http://go/go-review/1018020
diff --git a/src/pkg/Make.deps b/src/pkg/Make.deps
index 5ef36f5..614f48b 100644
--- a/src/pkg/Make.deps
+++ b/src/pkg/Make.deps
@@ -17,6 +17,7 @@
crypto/md5.install: hash.install os.install
crypto/rc4.install: os.install strconv.install
crypto/sha1.install: hash.install os.install
+crypto/subtle.install:
debug/dwarf.install: encoding/binary.install os.install strconv.install
debug/macho.install: bytes.install debug/dwarf.install encoding/binary.install fmt.install io.install os.install strconv.install
debug/elf.install: debug/dwarf.install encoding/binary.install fmt.install io.install os.install strconv.install
diff --git a/src/pkg/Makefile b/src/pkg/Makefile
index 61bd325..baf2122 100644
--- a/src/pkg/Makefile
+++ b/src/pkg/Makefile
@@ -31,6 +31,7 @@
crypto/md5\
crypto/rc4\
crypto/sha1\
+ crypto/subtle\
debug/dwarf\
debug/macho\
debug/elf\
diff --git a/src/pkg/crypto/rsa/pkcs1v15.go b/src/pkg/crypto/rsa/pkcs1v15.go
index 9fb4584..2583f19 100644
--- a/src/pkg/crypto/rsa/pkcs1v15.go
+++ b/src/pkg/crypto/rsa/pkcs1v15.go
@@ -6,6 +6,7 @@
import (
"bytes";
+ "crypto/subtle";
big "gmp";
"io";
"os";
@@ -27,7 +28,7 @@
// EM = 0x02 || PS || 0x00 || M
em := make([]byte, k-1);
em[0] = 2;
- ps, mm := em[1:len(em)-len(msg)-1], em[len(em)-len(msg):len(em)];
+ ps, mm := em[1 : len(em)-len(msg)-1], em[len(em)-len(msg) : len(em)];
err = nonZeroRandomBytes(ps, rand);
if err != nil {
return;
@@ -77,8 +78,8 @@
return;
}
- valid &= constantTimeEq(int32(len(msg)), int32(len(key)));
- constantTimeCopy(valid, key, msg);
+ valid &= subtle.ConstantTimeEq(int32(len(msg)), int32(len(key)));
+ subtle.ConstantTimeCopy(valid, key, msg);
return;
}
@@ -96,8 +97,8 @@
}
em := leftPad(m.Bytes(), k);
- firstByteIsZero := constantTimeByteEq(em[0], 0);
- secondByteIsTwo := constantTimeByteEq(em[1], 2);
+ firstByteIsZero := subtle.ConstantTimeByteEq(em[0], 0);
+ secondByteIsTwo := subtle.ConstantTimeByteEq(em[1], 2);
// The remainder of the plaintext must be a string of non-zero random
// octets, followed by a 0, followed by the message.
@@ -107,9 +108,9 @@
lookingForIndex = 1;
for i := 2; i < len(em); i++ {
- equals0 := constantTimeByteEq(em[i], 0);
- index = constantTimeSelect(lookingForIndex & equals0, i, index);
- lookingForIndex = constantTimeSelect(equals0, 0, lookingForIndex);
+ equals0 := subtle.ConstantTimeByteEq(em[i], 0);
+ index = subtle.ConstantTimeSelect(lookingForIndex & equals0, i, index);
+ lookingForIndex = subtle.ConstantTimeSelect(equals0, 0, lookingForIndex);
}
valid = firstByteIsZero & secondByteIsTwo & (^lookingForIndex & 1);
@@ -126,7 +127,7 @@
for i := 0; i < len(s); i++ {
for s[i] == 0 {
- _, err = rand.Read(s[i:i+1]);
+ _, err = rand.Read(s[i : i+1]);
if err != nil {
return;
}
diff --git a/src/pkg/crypto/rsa/rsa.go b/src/pkg/crypto/rsa/rsa.go
index adc9c8f..8ca8748 100644
--- a/src/pkg/crypto/rsa/rsa.go
+++ b/src/pkg/crypto/rsa/rsa.go
@@ -8,11 +8,12 @@
// TODO(agl): Add support for PSS padding.
import (
- "bytes";
- big "gmp";
- "hash";
- "io";
- "os";
+ "bytes";
+ "crypto/subtle";
+ big "gmp";
+ "hash";
+ "io";
+ "os";
)
var bigOne = big.NewInt(1)
@@ -92,7 +93,7 @@
// A PrivateKey represents an RSA key
type PrivateKey struct {
- PublicKey; // public part.
+ PublicKey; // public part.
D *big.Int; // private exponent
P, Q *big.Int; // prime factors of N
}
@@ -300,58 +301,6 @@
return x;
}
-// constantTimeCompare returns 1 iff the two equal length slices, x
-// and y, have equal contents. The time taken is a function of the length of
-// the slices and is independent of the contents.
-func constantTimeCompare(x, y []byte) int {
- var v byte;
-
- for i := 0; i < len(x); i++ {
- v |= x[i]^y[i];
- }
-
- return constantTimeByteEq(v, 0);
-}
-
-// constantTimeSelect returns a if v is 1 and b if v is 0.
-// Its behaviour is undefined if v takes any other value.
-func constantTimeSelect(v, a, b int) int {
- return ^(v-1)&a | (v-1)&b;
-}
-
-// constantTimeByteEq returns 1 if a == b and 0 otherwise.
-func constantTimeByteEq(a, b uint8) int {
- x := ^(a^b);
- x &= x>>4;
- x &= x>>2;
- x &= x>>1;
-
- return int(x);
-}
-
-// constantTimeEq returns 1 if a == b and 0 otherwise.
-func constantTimeEq(a, b int32) int {
- x := ^(a^b);
- x &= x>>16;
- x &= x>>8;
- x &= x>>4;
- x &= x>>2;
- x &= x>>1;
-
- return int(x&1);
-}
-
-// constantTimeCopy copies the contents of y into x iff v == 1. If v == 0, x is left unchanged.
-// Its behaviour is undefined if v takes any other value.
-func constantTimeCopy(v int, x, y []byte) {
- xmask := byte(v - 1);
- ymask := byte(^(v - 1));
- for i := 0; i < len(x); i++ {
- x[i] = x[i] & xmask | y[i] & ymask;
- }
- return;
-}
-
// decrypt performs an RSA decryption, resulting in a plaintext integer. If a
// random source is given, RSA blinding is used.
func decrypt(rand io.Reader, priv *PrivateKey, c *big.Int) (m *big.Int, err os.Error) {
@@ -419,7 +368,7 @@
// anything about this.)
em := leftPad(m.Bytes(), k);
- firstByteIsZero := constantTimeByteEq(em[0], 0);
+ firstByteIsZero := subtle.ConstantTimeByteEq(em[0], 0);
seed := em[1 : hash.Size() + 1];
db := em[hash.Size() + 1 : len(em)];
@@ -433,7 +382,7 @@
// attacks like: J. Manger. A Chosen Ciphertext Attack on RSA Optimal
// Asymmetric Encryption Padding (OAEP) as Standardized in PKCS #1
// v2.0. In J. Kilian, editor, Advances in Cryptology.
- lHash2Good := constantTimeCompare(lHash, lHash2);
+ lHash2Good := subtle.ConstantTimeCompare(lHash, lHash2);
// The remainder of the plaintext must be zero or more 0x00, followed
// by 0x01, followed by the message.
@@ -445,11 +394,11 @@
rest := db[hash.Size() : len(db)];
for i := 0; i < len(rest); i++ {
- equals0 := constantTimeByteEq(rest[i], 0);
- equals1 := constantTimeByteEq(rest[i], 1);
- index = constantTimeSelect(lookingForIndex & equals1, i, index);
- lookingForIndex = constantTimeSelect(equals1, 0, lookingForIndex);
- invalid = constantTimeSelect(lookingForIndex & ^equals0, 1, invalid);
+ equals0 := subtle.ConstantTimeByteEq(rest[i], 0);
+ equals1 := subtle.ConstantTimeByteEq(rest[i], 1);
+ index = subtle.ConstantTimeSelect(lookingForIndex & equals1, i, index);
+ lookingForIndex = subtle.ConstantTimeSelect(equals1, 0, lookingForIndex);
+ invalid = subtle.ConstantTimeSelect(lookingForIndex & ^equals0, 1, invalid);
}
if firstByteIsZero & lHash2Good & ^invalid & ^lookingForIndex != 1 {
diff --git a/src/pkg/crypto/rsa/rsa_test.go b/src/pkg/crypto/rsa/rsa_test.go
index df0d160..3bdfc66 100644
--- a/src/pkg/crypto/rsa/rsa_test.go
+++ b/src/pkg/crypto/rsa/rsa_test.go
@@ -5,12 +5,11 @@
package rsa
import (
- "bytes";
- "crypto/sha1";
- big "gmp";
- "os";
- "testing";
- "testing/quick";
+ "bytes";
+ "crypto/sha1";
+ big "gmp";
+ "os";
+ "testing";
)
func TestKeyGeneration(t *testing.T) {
@@ -109,101 +108,6 @@
}
}
-type TestConstantTimeCompareStruct struct {
- a, b []byte;
- out int;
-}
-
-var testConstandTimeCompareData = []TestConstantTimeCompareStruct{
- TestConstantTimeCompareStruct{[]byte{}, []byte{}, 1},
- TestConstantTimeCompareStruct{[]byte{0x11}, []byte{0x11}, 1},
- TestConstantTimeCompareStruct{[]byte{0x12}, []byte{0x11}, 0},
-}
-
-func TestConstantTimeCompare(t *testing.T) {
- for i, test := range testConstandTimeCompareData {
- if r := constantTimeCompare(test.a, test.b); r != test.out {
- t.Errorf("#%d bad result (got %x, want %x)", i, r, test.out);
- }
- }
-}
-
-type TestConstantTimeByteEqStruct struct {
- a, b uint8;
- out int;
-}
-
-var testConstandTimeByteEqData = []TestConstantTimeByteEqStruct{
- TestConstantTimeByteEqStruct{0, 0, 1},
- TestConstantTimeByteEqStruct{0, 1, 0},
- TestConstantTimeByteEqStruct{1, 0, 0},
- TestConstantTimeByteEqStruct{0xff, 0xff, 1},
- TestConstantTimeByteEqStruct{0xff, 0xfe, 0},
-}
-
-func ByteEq(a, b uint8) int {
- if a == b {
- return 1;
- }
- return 0;
-}
-
-func TestConstantTimeByteEq(t *testing.T) {
- for i, test := range testConstandTimeByteEqData {
- if r := constantTimeByteEq(test.a, test.b); r != test.out {
- t.Errorf("#%d bad result (got %x, want %x)", i, r, test.out);
- }
- }
- err := quick.CheckEqual(constantTimeByteEq, ByteEq, nil);
- if err != nil {
- t.Error(err);
- }
-}
-
-func Eq(a, b int32) int {
- if a == b {
- return 1;
- }
- return 0;
-}
-
-func TestConstantTimeEq(t *testing.T) {
- err := quick.CheckEqual(constantTimeEq, Eq, nil);
- if err != nil {
- t.Error(err);
- }
-}
-
-func Copy(v int, x, y []byte) []byte {
- if len(x) > len(y) {
- x = x[0:len(y)];
- } else {
- y = y[0:len(x)];
- }
- if v == 1 {
- bytes.Copy(x, y);
- }
- return x;
-}
-
-func constantTimeCopyWrapper(v int, x, y []byte) []byte {
- if len(x) > len(y) {
- x = x[0:len(y)];
- } else {
- y = y[0:len(x)];
- }
- v &= 1;
- constantTimeCopy(v, x, y);
- return x;
-}
-
-func TestConstantTimeCopy(t *testing.T) {
- err := quick.CheckEqual(constantTimeCopyWrapper, Copy, nil);
- if err != nil {
- t.Error(err);
- }
-}
-
// testEncryptOAEPData contains a subset of the vectors from RSA's "Test vectors for RSA-OAEP".
var testEncryptOAEPData = []testEncryptOAEPStruct{
// Key 1
@@ -305,47 +209,48 @@
65537,
"056b04216fe5f354ac77250a4b6b0c8525a85c59b0bd80c56450a22d5f438e596a333aa875e291dd43f48cb88b9d5fc0d499f9fcd1c397f9afc070cd9e398c8d19e61db7c7410a6b2675dfbf5d345b804d201add502d5ce2dfcb091ce9997bbebe57306f383e4d588103f036f7e85d1934d152a323e4a8db451d6f4a5b1b0f102cc150e02feee2b88dea4ad4c1baccb24d84072d14e1d24a6771f7408ee30564fb86d4393a34bcf0b788501d193303f13a2284b001f0f649eaf79328d4ac5c430ab4414920a9460ed1b7bc40ec653e876d09abc509ae45b525190116a0c26101848298509c1c3bf3a483e7274054e15e97075036e989f60932807b5257751e79",
[]testEncryptOAEPMessage{
- // Example 10.1
- testEncryptOAEPMessage{
- []byte{0x8b, 0xba, 0x6b, 0xf8, 0x2a, 0x6c, 0x0f, 0x86,
- 0xd5, 0xf1, 0x75, 0x6e, 0x97, 0x95, 0x68, 0x70, 0xb0,
- 0x89, 0x53, 0xb0, 0x6b, 0x4e, 0xb2, 0x05, 0xbc, 0x16,
- 0x94, 0xee,
+ // Example 10.1
+ testEncryptOAEPMessage{
+ []byte{0x8b, 0xba, 0x6b, 0xf8, 0x2a, 0x6c, 0x0f, 0x86,
+ 0xd5, 0xf1, 0x75, 0x6e, 0x97, 0x95, 0x68, 0x70, 0xb0,
+ 0x89, 0x53, 0xb0, 0x6b, 0x4e, 0xb2, 0x05, 0xbc, 0x16,
+ 0x94, 0xee,
+ },
+ []byte{0x47, 0xe1, 0xab, 0x71, 0x19, 0xfe, 0xe5, 0x6c,
+ 0x95, 0xee, 0x5e, 0xaa, 0xd8, 0x6f, 0x40, 0xd0, 0xaa,
+ 0x63, 0xbd, 0x33,
+ },
+ []byte{0x53, 0xea, 0x5d, 0xc0, 0x8c, 0xd2, 0x60, 0xfb,
+ 0x3b, 0x85, 0x85, 0x67, 0x28, 0x7f, 0xa9, 0x15, 0x52,
+ 0xc3, 0x0b, 0x2f, 0xeb, 0xfb, 0xa2, 0x13, 0xf0, 0xae,
+ 0x87, 0x70, 0x2d, 0x06, 0x8d, 0x19, 0xba, 0xb0, 0x7f,
+ 0xe5, 0x74, 0x52, 0x3d, 0xfb, 0x42, 0x13, 0x9d, 0x68,
+ 0xc3, 0xc5, 0xaf, 0xee, 0xe0, 0xbf, 0xe4, 0xcb, 0x79,
+ 0x69, 0xcb, 0xf3, 0x82, 0xb8, 0x04, 0xd6, 0xe6, 0x13,
+ 0x96, 0x14, 0x4e, 0x2d, 0x0e, 0x60, 0x74, 0x1f, 0x89,
+ 0x93, 0xc3, 0x01, 0x4b, 0x58, 0xb9, 0xb1, 0x95, 0x7a,
+ 0x8b, 0xab, 0xcd, 0x23, 0xaf, 0x85, 0x4f, 0x4c, 0x35,
+ 0x6f, 0xb1, 0x66, 0x2a, 0xa7, 0x2b, 0xfc, 0xc7, 0xe5,
+ 0x86, 0x55, 0x9d, 0xc4, 0x28, 0x0d, 0x16, 0x0c, 0x12,
+ 0x67, 0x85, 0xa7, 0x23, 0xeb, 0xee, 0xbe, 0xff, 0x71,
+ 0xf1, 0x15, 0x94, 0x44, 0x0a, 0xae, 0xf8, 0x7d, 0x10,
+ 0x79, 0x3a, 0x87, 0x74, 0xa2, 0x39, 0xd4, 0xa0, 0x4c,
+ 0x87, 0xfe, 0x14, 0x67, 0xb9, 0xda, 0xf8, 0x52, 0x08,
+ 0xec, 0x6c, 0x72, 0x55, 0x79, 0x4a, 0x96, 0xcc, 0x29,
+ 0x14, 0x2f, 0x9a, 0x8b, 0xd4, 0x18, 0xe3, 0xc1, 0xfd,
+ 0x67, 0x34, 0x4b, 0x0c, 0xd0, 0x82, 0x9d, 0xf3, 0xb2,
+ 0xbe, 0xc6, 0x02, 0x53, 0x19, 0x62, 0x93, 0xc6, 0xb3,
+ 0x4d, 0x3f, 0x75, 0xd3, 0x2f, 0x21, 0x3d, 0xd4, 0x5c,
+ 0x62, 0x73, 0xd5, 0x05, 0xad, 0xf4, 0xcc, 0xed, 0x10,
+ 0x57, 0xcb, 0x75, 0x8f, 0xc2, 0x6a, 0xee, 0xfa, 0x44,
+ 0x12, 0x55, 0xed, 0x4e, 0x64, 0xc1, 0x99, 0xee, 0x07,
+ 0x5e, 0x7f, 0x16, 0x64, 0x61, 0x82, 0xfd, 0xb4, 0x64,
+ 0x73, 0x9b, 0x68, 0xab, 0x5d, 0xaf, 0xf0, 0xe6, 0x3e,
+ 0x95, 0x52, 0x01, 0x68, 0x24, 0xf0, 0x54, 0xbf, 0x4d,
+ 0x3c, 0x8c, 0x90, 0xa9, 0x7b, 0xb6, 0xb6, 0x55, 0x32,
+ 0x84, 0xeb, 0x42, 0x9f, 0xcc,
+ },
},
- []byte{0x47, 0xe1, 0xab, 0x71, 0x19, 0xfe, 0xe5, 0x6c,
- 0x95, 0xee, 0x5e, 0xaa, 0xd8, 0x6f, 0x40, 0xd0, 0xaa,
- 0x63, 0xbd, 0x33,
- },
- []byte{0x53, 0xea, 0x5d, 0xc0, 0x8c, 0xd2, 0x60, 0xfb,
- 0x3b, 0x85, 0x85, 0x67, 0x28, 0x7f, 0xa9, 0x15, 0x52,
- 0xc3, 0x0b, 0x2f, 0xeb, 0xfb, 0xa2, 0x13, 0xf0, 0xae,
- 0x87, 0x70, 0x2d, 0x06, 0x8d, 0x19, 0xba, 0xb0, 0x7f,
- 0xe5, 0x74, 0x52, 0x3d, 0xfb, 0x42, 0x13, 0x9d, 0x68,
- 0xc3, 0xc5, 0xaf, 0xee, 0xe0, 0xbf, 0xe4, 0xcb, 0x79,
- 0x69, 0xcb, 0xf3, 0x82, 0xb8, 0x04, 0xd6, 0xe6, 0x13,
- 0x96, 0x14, 0x4e, 0x2d, 0x0e, 0x60, 0x74, 0x1f, 0x89,
- 0x93, 0xc3, 0x01, 0x4b, 0x58, 0xb9, 0xb1, 0x95, 0x7a,
- 0x8b, 0xab, 0xcd, 0x23, 0xaf, 0x85, 0x4f, 0x4c, 0x35,
- 0x6f, 0xb1, 0x66, 0x2a, 0xa7, 0x2b, 0xfc, 0xc7, 0xe5,
- 0x86, 0x55, 0x9d, 0xc4, 0x28, 0x0d, 0x16, 0x0c, 0x12,
- 0x67, 0x85, 0xa7, 0x23, 0xeb, 0xee, 0xbe, 0xff, 0x71,
- 0xf1, 0x15, 0x94, 0x44, 0x0a, 0xae, 0xf8, 0x7d, 0x10,
- 0x79, 0x3a, 0x87, 0x74, 0xa2, 0x39, 0xd4, 0xa0, 0x4c,
- 0x87, 0xfe, 0x14, 0x67, 0xb9, 0xda, 0xf8, 0x52, 0x08,
- 0xec, 0x6c, 0x72, 0x55, 0x79, 0x4a, 0x96, 0xcc, 0x29,
- 0x14, 0x2f, 0x9a, 0x8b, 0xd4, 0x18, 0xe3, 0xc1, 0xfd,
- 0x67, 0x34, 0x4b, 0x0c, 0xd0, 0x82, 0x9d, 0xf3, 0xb2,
- 0xbe, 0xc6, 0x02, 0x53, 0x19, 0x62, 0x93, 0xc6, 0xb3,
- 0x4d, 0x3f, 0x75, 0xd3, 0x2f, 0x21, 0x3d, 0xd4, 0x5c,
- 0x62, 0x73, 0xd5, 0x05, 0xad, 0xf4, 0xcc, 0xed, 0x10,
- 0x57, 0xcb, 0x75, 0x8f, 0xc2, 0x6a, 0xee, 0xfa, 0x44,
- 0x12, 0x55, 0xed, 0x4e, 0x64, 0xc1, 0x99, 0xee, 0x07,
- 0x5e, 0x7f, 0x16, 0x64, 0x61, 0x82, 0xfd, 0xb4, 0x64,
- 0x73, 0x9b, 0x68, 0xab, 0x5d, 0xaf, 0xf0, 0xe6, 0x3e,
- 0x95, 0x52, 0x01, 0x68, 0x24, 0xf0, 0x54, 0xbf, 0x4d,
- 0x3c, 0x8c, 0x90, 0xa9, 0x7b, 0xb6, 0xb6, 0x55, 0x32,
- 0x84, 0xeb, 0x42, 0x9f, 0xcc,
- },
- }},
+ },
},
}
diff --git a/src/pkg/crypto/subtle/Makefile b/src/pkg/crypto/subtle/Makefile
new file mode 100644
index 0000000..4d245c6
--- /dev/null
+++ b/src/pkg/crypto/subtle/Makefile
@@ -0,0 +1,11 @@
+# Copyright 2009 The Go Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+include $(GOROOT)/src/Make.$(GOARCH)
+
+TARG=crypto/subtle
+GOFILES=\
+ constant_time.go\
+
+include $(GOROOT)/src/Make.pkg
diff --git a/src/pkg/crypto/subtle/constant_time.go b/src/pkg/crypto/subtle/constant_time.go
new file mode 100644
index 0000000..a1d2eaf
--- /dev/null
+++ b/src/pkg/crypto/subtle/constant_time.go
@@ -0,0 +1,59 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This package implements functions that are often useful in cryptographic
+// code but require careful thought to use correctly.
+package subtle
+
+// ConstantTimeCompare returns 1 iff the two equal length slices, x
+// and y, have equal contents. The time taken is a function of the length of
+// the slices and is independent of the contents.
+func ConstantTimeCompare(x, y []byte) int {
+ var v byte;
+
+ for i := 0; i < len(x); i++ {
+ v |= x[i]^y[i];
+ }
+
+ return ConstantTimeByteEq(v, 0);
+}
+
+// ConstantTimeSelect returns x if v is 1 and y if v is 0.
+// Its behavior is undefined if v takes any other value.
+func ConstantTimeSelect(v, x, y int) int {
+ return ^(v-1) & x | (v-1)&y;
+}
+
+// ConstantTimeByteEq returns 1 if x == x and 0 otherwise.
+func ConstantTimeByteEq(x, y uint8) int {
+ z := ^(x^y);
+ z &= z>>4;
+ z &= z>>2;
+ z &= z>>1;
+
+ return int(z);
+}
+
+// ConstantTimeEq returns 1 if x == y and 0 otherwise.
+func ConstantTimeEq(x, y int32) int {
+ z := ^(x^y);
+ z &= z>>16;
+ z &= z>>8;
+ z &= z>>4;
+ z &= z>>2;
+ z &= z>>1;
+
+ return int(z&1);
+}
+
+// ConstantTimeCopy copies the contents of y into x iff v == 1. If v == 0, x is left unchanged.
+// Its behavior is undefined if v takes any other value.
+func ConstantTimeCopy(v int, x, y []byte) {
+ xmask := byte(v-1);
+ ymask := byte(^(v-1));
+ for i := 0; i < len(x); i++ {
+ x[i] = x[i]&xmask | y[i]&ymask;
+ }
+ return;
+}
diff --git a/src/pkg/crypto/subtle/constant_time_test.go b/src/pkg/crypto/subtle/constant_time_test.go
new file mode 100644
index 0000000..78aa677
--- /dev/null
+++ b/src/pkg/crypto/subtle/constant_time_test.go
@@ -0,0 +1,106 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package subtle
+
+import (
+ "bytes";
+ "testing";
+ "testing/quick";
+)
+
+type TestConstantTimeCompareStruct struct {
+ a, b []byte;
+ out int;
+}
+
+var testConstandTimeCompareData = []TestConstantTimeCompareStruct{
+ TestConstantTimeCompareStruct{[]byte{}, []byte{}, 1},
+ TestConstantTimeCompareStruct{[]byte{0x11}, []byte{0x11}, 1},
+ TestConstantTimeCompareStruct{[]byte{0x12}, []byte{0x11}, 0},
+}
+
+func TestConstantTimeCompare(t *testing.T) {
+ for i, test := range testConstandTimeCompareData {
+ if r := ConstantTimeCompare(test.a, test.b); r != test.out {
+ t.Errorf("#%d bad result (got %x, want %x)", i, r, test.out);
+ }
+ }
+}
+
+type TestConstantTimeByteEqStruct struct {
+ a, b uint8;
+ out int;
+}
+
+var testConstandTimeByteEqData = []TestConstantTimeByteEqStruct{
+ TestConstantTimeByteEqStruct{0, 0, 1},
+ TestConstantTimeByteEqStruct{0, 1, 0},
+ TestConstantTimeByteEqStruct{1, 0, 0},
+ TestConstantTimeByteEqStruct{0xff, 0xff, 1},
+ TestConstantTimeByteEqStruct{0xff, 0xfe, 0},
+}
+
+func byteEq(a, b uint8) int {
+ if a == b {
+ return 1;
+ }
+ return 0;
+}
+
+func TestConstantTimeByteEq(t *testing.T) {
+ for i, test := range testConstandTimeByteEqData {
+ if r := ConstantTimeByteEq(test.a, test.b); r != test.out {
+ t.Errorf("#%d bad result (got %x, want %x)", i, r, test.out);
+ }
+ }
+ err := quick.CheckEqual(ConstantTimeByteEq, byteEq, nil);
+ if err != nil {
+ t.Error(err);
+ }
+}
+
+func eq(a, b int32) int {
+ if a == b {
+ return 1;
+ }
+ return 0;
+}
+
+func TestConstantTimeEq(t *testing.T) {
+ err := quick.CheckEqual(ConstantTimeEq, eq, nil);
+ if err != nil {
+ t.Error(err);
+ }
+}
+
+func copy(v int, x, y []byte) []byte {
+ if len(x) > len(y) {
+ x = x[0:len(y)];
+ } else {
+ y = y[0:len(x)];
+ }
+ if v == 1 {
+ bytes.Copy(x, y);
+ }
+ return x;
+}
+
+func constantTimeCopyWrapper(v int, x, y []byte) []byte {
+ if len(x) > len(y) {
+ x = x[0:len(y)];
+ } else {
+ y = y[0:len(x)];
+ }
+ v &= 1;
+ ConstantTimeCopy(v, x, y);
+ return x;
+}
+
+func TestConstantTimeCopy(t *testing.T) {
+ err := quick.CheckEqual(constantTimeCopyWrapper, copy, nil);
+ if err != nil {
+ t.Error(err);
+ }
+}
