-
Notifications
You must be signed in to change notification settings - Fork 20.1k
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
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
- Loading branch information
Gustav Simonsson
committed
Feb 10, 2015
1 parent
e40c1c6
commit 8c056ae
Showing
4 changed files
with
92 additions
and
18 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -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 | ||
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters