grafana/pkg/util/encoding.go

105 lines
2.5 KiB
Go

package util
import (
"crypto/hmac"
"crypto/md5"
"crypto/rand"
"crypto/sha256"
"encoding/base64"
"encoding/hex"
"errors"
"fmt"
"hash"
"strings"
)
// source: https://github.com/gogits/gogs/blob/9ee80e3e5426821f03a4e99fad34418f5c736413/modules/base/tool.go#L58
func GetRandomString(n int, alphabets ...byte) string {
const alphanum = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
var bytes = make([]byte, n)
rand.Read(bytes)
for i, b := range bytes {
if len(alphabets) == 0 {
bytes[i] = alphanum[b%byte(len(alphanum))]
} else {
bytes[i] = alphabets[b%byte(len(alphabets))]
}
}
return string(bytes)
}
func EncodePassword(password string, salt string) string {
newPasswd := PBKDF2([]byte(password), []byte(salt), 10000, 50, sha256.New)
return fmt.Sprintf("%x", newPasswd)
}
// Encode string to md5 hex value.
func EncodeMd5(str string) string {
m := md5.New()
m.Write([]byte(str))
return hex.EncodeToString(m.Sum(nil))
}
// http://code.google.com/p/go/source/browse/pbkdf2/pbkdf2.go?repo=crypto
func PBKDF2(password, salt []byte, iter, keyLen int, h func() hash.Hash) []byte {
prf := hmac.New(h, password)
hashLen := prf.Size()
numBlocks := (keyLen + hashLen - 1) / hashLen
var buf [4]byte
dk := make([]byte, 0, numBlocks*hashLen)
U := make([]byte, hashLen)
for block := 1; block <= numBlocks; block++ {
// N.B.: || means concatenation, ^ means XOR
// for each block T_i = U_1 ^ U_2 ^ ... ^ U_iter
// U_1 = PRF(password, salt || uint(i))
prf.Reset()
prf.Write(salt)
buf[0] = byte(block >> 24)
buf[1] = byte(block >> 16)
buf[2] = byte(block >> 8)
buf[3] = byte(block)
prf.Write(buf[:4])
dk = prf.Sum(dk)
T := dk[len(dk)-hashLen:]
copy(U, T)
// U_n = PRF(password, U_(n-1))
for n := 2; n <= iter; n++ {
prf.Reset()
prf.Write(U)
U = U[:0]
U = prf.Sum(U)
for x := range U {
T[x] ^= U[x]
}
}
}
return dk[:keyLen]
}
func GetBasicAuthHeader(user string, password string) string {
var userAndPass = user + ":" + password
return "Basic " + base64.StdEncoding.EncodeToString([]byte(userAndPass))
}
func DecodeBasicAuthHeader(header string) (string, string, error) {
var code string
parts := strings.SplitN(header, " ", 2)
if len(parts) == 2 && parts[0] == "Basic" {
code = parts[1]
}
decoded, err := base64.StdEncoding.DecodeString(code)
if err != nil {
return "", "", err
}
userAndPass := strings.SplitN(string(decoded), ":", 2)
if len(userAndPass) != 2 {
return "", "", errors.New("Invalid basic auth header")
}
return userAndPass[0], userAndPass[1], nil
}