From 8c056aebe10c8c56f7c25889780b04e00f9ca00b Mon Sep 17 00:00:00 2001 From: Gustav Simonsson Date: Wed, 4 Feb 2015 17:06:06 +0100 Subject: [PATCH 1/3] Set both key generation and ECDSA nonce to use mixed entropy * Move random entropy functions to new package randentropy * Add function to get n bytes entropy where up to first 32 bytes are mixed with OS entropy sources --- crypto/key_store_passphrase.go | 15 ++---- crypto/key_store_test.go | 8 +-- crypto/randentropy/rand_entropy.go | 82 ++++++++++++++++++++++++++++++ crypto/secp256k1/secp256.go | 5 +- 4 files changed, 92 insertions(+), 18 deletions(-) create mode 100644 crypto/randentropy/rand_entropy.go diff --git a/crypto/key_store_passphrase.go b/crypto/key_store_passphrase.go index 0862b7886..74408f874 100644 --- a/crypto/key_store_passphrase.go +++ b/crypto/key_store_passphrase.go @@ -68,10 +68,10 @@ import ( "code.google.com/p/go.crypto/scrypt" "crypto/aes" "crypto/cipher" - crand "crypto/rand" "encoding/hex" "encoding/json" "errors" + "github.com/ethereum/go-ethereum/crypto/randentropy" "io" "os" "path" @@ -116,7 +116,7 @@ func (ks keyStorePassphrase) GetKeyAddresses() (addresses [][]byte, err error) { func (ks keyStorePassphrase) StoreKey(key *Key, auth string) (err error) { authArray := []byte(auth) - salt := GetEntropyCSPRNG(32) + salt := randentropy.GetEntropyMixed(32) derivedKey, err := scrypt.Key(authArray, salt, scryptN, scryptr, scryptp, scryptdkLen) if err != nil { return err @@ -131,7 +131,7 @@ func (ks keyStorePassphrase) StoreKey(key *Key, auth string) (err error) { return err } - iv := GetEntropyCSPRNG(aes.BlockSize) // 16 + iv := randentropy.GetEntropyMixed(aes.BlockSize) // 16 AES256CBCEncrypter := cipher.NewCBCEncrypter(AES256Block, iv) cipherText := make([]byte, len(toEncrypt)) AES256CBCEncrypter.CryptBlocks(cipherText, toEncrypt) @@ -196,12 +196,3 @@ func DecryptKey(ks keyStorePassphrase, keyAddr []byte, auth string) (keyBytes [] } return keyBytes, keyId, err } - -func GetEntropyCSPRNG(n int) []byte { - mainBuff := make([]byte, n) - _, err := io.ReadFull(crand.Reader, mainBuff) - if err != nil { - panic("key generation: reading from crypto/rand failed: " + err.Error()) - } - return mainBuff -} diff --git a/crypto/key_store_test.go b/crypto/key_store_test.go index 0d229ab65..a136ba992 100644 --- a/crypto/key_store_test.go +++ b/crypto/key_store_test.go @@ -1,7 +1,7 @@ package crypto import ( - crand "crypto/rand" + "github.com/ethereum/go-ethereum/crypto/randentropy" "reflect" "testing" ) @@ -9,7 +9,7 @@ import ( func TestKeyStorePlain(t *testing.T) { ks := NewKeyStorePlain(DefaultDataDir()) pass := "" // not used but required by API - k1, err := ks.GenerateNewKey(crand.Reader, pass) + k1, err := ks.GenerateNewKey(new(randentropy.RandEntropy), pass) if err != nil { t.Fatal(err) } @@ -37,7 +37,7 @@ func TestKeyStorePlain(t *testing.T) { func TestKeyStorePassphrase(t *testing.T) { ks := NewKeyStorePassphrase(DefaultDataDir()) pass := "foo" - k1, err := ks.GenerateNewKey(crand.Reader, pass) + k1, err := ks.GenerateNewKey(new(randentropy.RandEntropy), pass) if err != nil { t.Fatal(err) } @@ -63,7 +63,7 @@ func TestKeyStorePassphrase(t *testing.T) { func TestKeyStorePassphraseDecryptionFail(t *testing.T) { ks := NewKeyStorePassphrase(DefaultDataDir()) pass := "foo" - k1, err := ks.GenerateNewKey(crand.Reader, pass) + k1, err := ks.GenerateNewKey(new(randentropy.RandEntropy), pass) if err != nil { t.Fatal(err) } diff --git a/crypto/randentropy/rand_entropy.go b/crypto/randentropy/rand_entropy.go new file mode 100644 index 000000000..28181030c --- /dev/null +++ b/crypto/randentropy/rand_entropy.go @@ -0,0 +1,82 @@ +package randentropy + +import ( + crand "crypto/rand" + "encoding/binary" + "github.com/ethereum/go-ethereum/crypto/sha3" + "io" + "os" + "strings" + "time" +) + +type RandEntropy struct { +} + +func (*RandEntropy) Read(bytes []byte) (n int, err error) { + readBytes := GetEntropyMixed(len(bytes)) + copy(bytes, readBytes) + return len(bytes), nil +} + +// TODO: copied from crypto.go , move to sha3 package? +func Sha3(data []byte) []byte { + d := sha3.NewKeccak256() + d.Write(data) + + return d.Sum(nil) +} + +// TODO: verify. this needs to be audited +// we start with crypt/rand, then XOR in additional entropy from OS +func GetEntropyMixed(n int) []byte { + startTime := time.Now().UnixNano() + // for each source, we take SHA3 of the source and use it as seed to math/rand + // then read bytes from it and XOR them onto the bytes read from crypto/rand + mainBuff := GetEntropyCSPRNG(n) + // 1. OS entropy sources + startTimeBytes := make([]byte, 32) + binary.PutVarint(startTimeBytes, startTime) + startTimeHash := Sha3(startTimeBytes) + mixBytes(mainBuff, startTimeHash) + + pid := os.Getpid() + pidBytes := make([]byte, 32) + binary.PutUvarint(pidBytes, uint64(pid)) + pidHash := Sha3(pidBytes) + mixBytes(mainBuff, pidHash) + + osEnv := os.Environ() + osEnvBytes := []byte(strings.Join(osEnv, "")) + osEnvHash := Sha3(osEnvBytes) + mixBytes(mainBuff, osEnvHash) + + // not all OS have hostname in env variables + osHostName, err := os.Hostname() + if err != nil { + osHostNameBytes := []byte(osHostName) + osHostNameHash := Sha3(osHostNameBytes) + mixBytes(mainBuff, osHostNameHash) + } + return mainBuff +} + +func GetEntropyCSPRNG(n int) []byte { + mainBuff := make([]byte, n) + _, err := io.ReadFull(crand.Reader, mainBuff) + if err != nil { + panic("reading from crypto/rand failed: " + err.Error()) + } + return mainBuff +} + +func mixBytes(buff []byte, mixBuff []byte) []byte { + bytesToMix := len(buff) + if bytesToMix > 32 { + bytesToMix = 32 + } + for i := 0; i < bytesToMix; i++ { + buff[i] ^= mixBuff[i] + } + return buff +} diff --git a/crypto/secp256k1/secp256.go b/crypto/secp256k1/secp256.go index c01598b84..c1e37629e 100644 --- a/crypto/secp256k1/secp256.go +++ b/crypto/secp256k1/secp256.go @@ -15,6 +15,7 @@ import "C" import ( "bytes" "errors" + "github.com/ethereum/go-ethereum/crypto/randentropy" "unsafe" ) @@ -68,7 +69,7 @@ func GenerateKeyPair() ([]byte, []byte) { const seckey_len = 32 var pubkey []byte = make([]byte, pubkey_len) - var seckey []byte = RandByte(seckey_len) + var seckey []byte = randentropy.GetEntropyMixed(seckey_len) var pubkey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&pubkey[0])) var seckey_ptr *C.uchar = (*C.uchar)(unsafe.Pointer(&seckey[0])) @@ -124,7 +125,7 @@ int secp256k1_ecdsa_sign_compact(const unsigned char *msg, int msglen, */ func Sign(msg []byte, seckey []byte) ([]byte, error) { - nonce := RandByte(32) + nonce := randentropy.GetEntropyMixed(32) var sig []byte = make([]byte, 65) var recid C.int From 39434e383b9e6fee30371afd5a9841de75671f56 Mon Sep 17 00:00:00 2001 From: Gustav Simonsson Date: Fri, 13 Feb 2015 15:38:18 +0100 Subject: [PATCH 2/3] Unexport randEntropy type and use exported Reader instead --- crypto/key_store_test.go | 6 +++--- crypto/randentropy/rand_entropy.go | 6 ++++-- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/crypto/key_store_test.go b/crypto/key_store_test.go index a136ba992..485d8f536 100644 --- a/crypto/key_store_test.go +++ b/crypto/key_store_test.go @@ -9,7 +9,7 @@ import ( func TestKeyStorePlain(t *testing.T) { ks := NewKeyStorePlain(DefaultDataDir()) pass := "" // not used but required by API - k1, err := ks.GenerateNewKey(new(randentropy.RandEntropy), pass) + k1, err := ks.GenerateNewKey(randentropy.Reader, pass) if err != nil { t.Fatal(err) } @@ -37,7 +37,7 @@ func TestKeyStorePlain(t *testing.T) { func TestKeyStorePassphrase(t *testing.T) { ks := NewKeyStorePassphrase(DefaultDataDir()) pass := "foo" - k1, err := ks.GenerateNewKey(new(randentropy.RandEntropy), pass) + k1, err := ks.GenerateNewKey(randentropy.Reader, pass) if err != nil { t.Fatal(err) } @@ -63,7 +63,7 @@ func TestKeyStorePassphrase(t *testing.T) { func TestKeyStorePassphraseDecryptionFail(t *testing.T) { ks := NewKeyStorePassphrase(DefaultDataDir()) pass := "foo" - k1, err := ks.GenerateNewKey(new(randentropy.RandEntropy), pass) + k1, err := ks.GenerateNewKey(randentropy.Reader, pass) if err != nil { t.Fatal(err) } diff --git a/crypto/randentropy/rand_entropy.go b/crypto/randentropy/rand_entropy.go index 28181030c..b87fa564e 100644 --- a/crypto/randentropy/rand_entropy.go +++ b/crypto/randentropy/rand_entropy.go @@ -10,10 +10,12 @@ import ( "time" ) -type RandEntropy struct { +var Reader io.Reader = &randEntropy{} + +type randEntropy struct { } -func (*RandEntropy) Read(bytes []byte) (n int, err error) { +func (*randEntropy) Read(bytes []byte) (n int, err error) { readBytes := GetEntropyMixed(len(bytes)) copy(bytes, readBytes) return len(bytes), nil From f35d62b75977231bb45d2e298c3f39744c875e67 Mon Sep 17 00:00:00 2001 From: Gustav Simonsson Date: Fri, 13 Feb 2015 18:22:36 +0100 Subject: [PATCH 3/3] Remove secp256_rand.go and update tests --- crypto/secp256k1/secp256_rand.go | 97 -------------------------------- crypto/secp256k1/secp256_test.go | 21 +++---- 2 files changed, 11 insertions(+), 107 deletions(-) delete mode 100644 crypto/secp256k1/secp256_rand.go diff --git a/crypto/secp256k1/secp256_rand.go b/crypto/secp256k1/secp256_rand.go deleted file mode 100644 index bb10025fc..000000000 --- a/crypto/secp256k1/secp256_rand.go +++ /dev/null @@ -1,97 +0,0 @@ -package secp256k1 - -import ( - crand "crypto/rand" - "io" - mrand "math/rand" - "os" - "strings" - "time" -) - -/* -Note: - -- On windows cryto/rand uses CrytoGenRandom which uses RC4 which is insecure -- Android random number generator is known to be insecure. -- Linux uses /dev/urandom , which is thought to be secure and uses entropy pool - -Therefore the output is salted. -*/ - -//finalizer from MurmerHash3 -func mmh3f(key uint64) uint64 { - key ^= key >> 33 - key *= 0xff51afd7ed558ccd - key ^= key >> 33 - key *= 0xc4ceb9fe1a85ec53 - key ^= key >> 33 - return key -} - -//knuth hash -func knuth_hash(in []byte) uint64 { - var acc uint64 = 3074457345618258791 - for i := 0; i < len(in); i++ { - acc += uint64(in[i]) - acc *= 3074457345618258799 - } - return acc -} - -var _rand *mrand.Rand - -func init() { - var seed1 uint64 = mmh3f(uint64(time.Now().UnixNano())) - var seed2 uint64 = knuth_hash([]byte(strings.Join(os.Environ(), ""))) - var seed3 uint64 = mmh3f(uint64(os.Getpid())) - - _rand = mrand.New(mrand.NewSource(int64(seed1 ^ seed2 ^ seed3))) -} - -func saltByte(n int) []byte { - buff := make([]byte, n) - for i := 0; i < len(buff); i++ { - var v uint64 = uint64(_rand.Int63()) - var b byte - for j := 0; j < 8; j++ { - b ^= byte(v & 0xff) - v = v >> 8 - } - buff[i] = b - } - return buff -} - -//On Unix-like systems, Reader reads from /dev/urandom. -//On Windows systems, Reader uses the CryptGenRandom API. - -//use entropy pool etc and cryptographic random number generator -//mix in time -//mix in mix in cpu cycle count -func RandByte(n int) []byte { - buff := make([]byte, n) - ret, err := io.ReadFull(crand.Reader, buff) - if len(buff) != ret || err != nil { - return nil - } - - buff2 := saltByte(n) - for i := 0; i < n; i++ { - buff[i] ^= buff2[2] - } - return buff -} - -/* - On Unix-like systems, Reader reads from /dev/urandom. - On Windows systems, Reader uses the CryptGenRandom API. -*/ -func RandByteWeakCrypto(n int) []byte { - buff := make([]byte, n) - ret, err := io.ReadFull(crand.Reader, buff) - if len(buff) != ret || err != nil { - return nil - } - return buff -} diff --git a/crypto/secp256k1/secp256_test.go b/crypto/secp256k1/secp256_test.go index 468c50db9..5e657cd72 100644 --- a/crypto/secp256k1/secp256_test.go +++ b/crypto/secp256k1/secp256_test.go @@ -3,6 +3,7 @@ package secp256k1 import ( "bytes" "fmt" + "github.com/ethereum/go-ethereum/crypto/randentropy" "log" "testing" ) @@ -12,7 +13,7 @@ const SigSize = 65 //64+1 func Test_Secp256_00(t *testing.T) { - var nonce []byte = RandByte(32) //going to get bitcoins stolen! + var nonce []byte = randentropy.GetEntropyMixed(32) //going to get bitcoins stolen! if len(nonce) != 32 { t.Fatal() @@ -50,7 +51,7 @@ func Test_Secp256_01(t *testing.T) { //test size of messages func Test_Secp256_02s(t *testing.T) { pubkey, seckey := GenerateKeyPair() - msg := RandByte(32) + msg := randentropy.GetEntropyMixed(32) sig, _ := Sign(msg, seckey) CompactSigTest(sig) if sig == nil { @@ -73,7 +74,7 @@ func Test_Secp256_02s(t *testing.T) { //test signing message func Test_Secp256_02(t *testing.T) { pubkey1, seckey := GenerateKeyPair() - msg := RandByte(32) + msg := randentropy.GetEntropyMixed(32) sig, _ := Sign(msg, seckey) if sig == nil { t.Fatal("Signature nil") @@ -96,7 +97,7 @@ func Test_Secp256_02(t *testing.T) { //test pubkey recovery func Test_Secp256_02a(t *testing.T) { pubkey1, seckey1 := GenerateKeyPair() - msg := RandByte(32) + msg := randentropy.GetEntropyMixed(32) sig, _ := Sign(msg, seckey1) if sig == nil { @@ -125,7 +126,7 @@ func Test_Secp256_02a(t *testing.T) { func Test_Secp256_03(t *testing.T) { _, seckey := GenerateKeyPair() for i := 0; i < TESTS; i++ { - msg := RandByte(32) + msg := randentropy.GetEntropyMixed(32) sig, _ := Sign(msg, seckey) CompactSigTest(sig) @@ -141,7 +142,7 @@ func Test_Secp256_03(t *testing.T) { func Test_Secp256_04(t *testing.T) { for i := 0; i < TESTS; i++ { pubkey1, seckey := GenerateKeyPair() - msg := RandByte(32) + msg := randentropy.GetEntropyMixed(32) sig, _ := Sign(msg, seckey) CompactSigTest(sig) @@ -164,7 +165,7 @@ func Test_Secp256_04(t *testing.T) { // -SIPA look at this func randSig() []byte { - sig := RandByte(65) + sig := randentropy.GetEntropyMixed(65) sig[32] &= 0x70 sig[64] %= 4 return sig @@ -172,7 +173,7 @@ func randSig() []byte { func Test_Secp256_06a_alt0(t *testing.T) { pubkey1, seckey := GenerateKeyPair() - msg := RandByte(32) + msg := randentropy.GetEntropyMixed(32) sig, _ := Sign(msg, seckey) if sig == nil { @@ -203,12 +204,12 @@ func Test_Secp256_06a_alt0(t *testing.T) { func Test_Secp256_06b(t *testing.T) { pubkey1, seckey := GenerateKeyPair() - msg := RandByte(32) + msg := randentropy.GetEntropyMixed(32) sig, _ := Sign(msg, seckey) fail_count := 0 for i := 0; i < TESTS; i++ { - msg = RandByte(32) + msg = randentropy.GetEntropyMixed(32) pubkey2, _ := RecoverPubkey(msg, sig) if bytes.Equal(pubkey1, pubkey2) == true { t.Fail()