From 47d3b3dd58172c2e7c1f72fb072bd9385aff8205 Mon Sep 17 00:00:00 2001 From: Gustav Simonsson Date: Thu, 15 Jan 2015 17:45:45 +0100 Subject: Address pull request comments * Remove flags field from key struct * Change JSON struct fields from string to []byte * Change GenerateNewKey API to take io.Reader for random source * Remove mixing entropy source function * Use testing Fatal in tests --- crypto/key.go | 150 +++++++++++----------------------------------------------- 1 file changed, 28 insertions(+), 122 deletions(-) (limited to 'crypto/key.go') diff --git a/crypto/key.go b/crypto/key.go index 1a8b770e0..0e7c04275 100644 --- a/crypto/key.go +++ b/crypto/key.go @@ -28,43 +28,31 @@ import ( "code.google.com/p/go-uuid/uuid" "crypto/ecdsa" "crypto/elliptic" - crand "crypto/rand" - "encoding/binary" - "encoding/hex" "encoding/json" - "errors" - "fmt" "io" - "os" - "runtime" - "strings" - "time" ) type Key struct { - Id *uuid.UUID // Version 4 "random" for unique id not derived from key data - Flags [4]byte // RFU + Id *uuid.UUID // Version 4 "random" for unique id not derived from key data // we only store privkey as pubkey/address can be derived from it // privkey in this struct is always in plaintext PrivateKey *ecdsa.PrivateKey } -type PlainKeyJSON struct { - Id string - Flags string - PrivateKey string +type plainKeyJSON struct { + Id []byte + PrivateKey []byte } -type CipherJSON struct { - Salt string - IV string - CipherText string +type cipherJSON struct { + Salt []byte + IV []byte + CipherText []byte } -type EncryptedKeyJSON struct { - Id string - Flags string - Crypto CipherJSON +type encryptedKeyJSON struct { + Id []byte + Crypto cipherJSON } func (k *Key) Address() []byte { @@ -73,48 +61,40 @@ func (k *Key) Address() []byte { } func (k *Key) MarshalJSON() (j []byte, err error) { - stringStruct := PlainKeyJSON{ - k.Id.String(), - hex.EncodeToString(k.Flags[:]), - hex.EncodeToString(FromECDSA(k.PrivateKey)), + jStruct := plainKeyJSON{ + *k.Id, + FromECDSA(k.PrivateKey), } - j, err = json.Marshal(stringStruct) + j, err = json.Marshal(jStruct) return j, err } func (k *Key) UnmarshalJSON(j []byte) (err error) { - keyJSON := new(PlainKeyJSON) + keyJSON := new(plainKeyJSON) err = json.Unmarshal(j, &keyJSON) if err != nil { return err } u := new(uuid.UUID) - *u = uuid.Parse(keyJSON.Id) - if *u == nil { - err = errors.New("UUID parsing failed") - return err - } + *u = keyJSON.Id k.Id = u - flagsBytes, err := hex.DecodeString(keyJSON.Flags) - if err != nil { - return err - } - - PrivateKeyBytes, err := hex.DecodeString(keyJSON.PrivateKey) - if err != nil { - return err - } - - copy(k.Flags[:], flagsBytes[0:4]) - k.PrivateKey = ToECDSA(PrivateKeyBytes) + k.PrivateKey = ToECDSA(keyJSON.PrivateKey) return err } -func NewKey() *Key { - randBytes := GetEntropyCSPRNG(32) +func NewKey(rand io.Reader) *Key { + randBytes := make([]byte, 32) + n, err := rand.Read(randBytes) + if err != nil { + panic("key generation: could not read from random source: " + err.Error()) + } else { + if n != 32 { + panic("key generation: read less than required bytes from random source: " + err.Error()) + } + } reader := bytes.NewReader(randBytes) _, x, y, err := elliptic.GenerateKey(S256(), reader) if err != nil { @@ -126,80 +106,6 @@ func NewKey() *Key { key := new(Key) id := uuid.NewRandom() key.Id = &id - // flags := new([4]byte) - // key.Flags = flags key.PrivateKey = privateKeyECDSA return key } - -// plain crypto/rand. this is /dev/urandom on Unix-like systems. -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 -} - -// TODO: verify. Do not use until properly discussed. -// we start with crypt/rand, then mix in additional sources of entropy. -// These sources are from three types: OS, go runtime and ethereum client state. -func GetEntropyTinFoilHat() []byte { - startTime := time.Now().UnixNano() - // for each source, we XOR in it's SHA3 hash. - mainBuff := GetEntropyCSPRNG(32) - // 1. OS entropy sources - startTimeBytes := make([]byte, 32) - binary.PutVarint(startTimeBytes, startTime) - startTimeHash := Sha3(startTimeBytes) - mix32Byte(mainBuff, startTimeHash) - - pid := os.Getpid() - pidBytes := make([]byte, 32) - binary.PutUvarint(pidBytes, uint64(pid)) - pidHash := Sha3(pidBytes) - mix32Byte(mainBuff, pidHash) - - osEnv := os.Environ() - osEnvBytes := []byte(strings.Join(osEnv, "")) - osEnvHash := Sha3(osEnvBytes) - mix32Byte(mainBuff, osEnvHash) - - // not all OS have hostname in env variables - osHostName, err := os.Hostname() - if err != nil { - osHostNameBytes := []byte(osHostName) - osHostNameHash := Sha3(osHostNameBytes) - mix32Byte(mainBuff, osHostNameHash) - } - - // 2. go runtime entropy sources - memStats := new(runtime.MemStats) - runtime.ReadMemStats(memStats) - memStatsBytes := []byte(fmt.Sprintf("%v", memStats)) - memStatsHash := Sha3(memStatsBytes) - mix32Byte(mainBuff, memStatsHash) - - // 3. Mix in ethereum / client state - // TODO: list of network peers structs (IP, port, etc) - // TODO: merkle patricia tree root hash for world state and tx list - - // 4. Yo dawg we heard you like entropy so we'll grab some entropy from how - // long it took to grab the above entropy. And a yield, for good measure. - runtime.Gosched() - diffTime := time.Now().UnixNano() - startTime - diffTimeBytes := make([]byte, 32) - binary.PutVarint(diffTimeBytes, diffTime) - diffTimeHash := Sha3(diffTimeBytes) - mix32Byte(mainBuff, diffTimeHash) - - return mainBuff -} - -func mix32Byte(buff []byte, mixBuff []byte) []byte { - for i := 0; i < 32; i++ { - buff[i] ^= mixBuff[i] - } - return buff -} -- cgit v1.2.3