imgsrv/hash/hash.go

43 lines
777 B
Go

package hash
import (
"crypto/md5"
"crypto/sha256"
"fmt"
"io"
"math/rand"
"strings"
"time"
)
func init() {
rand.Seed(time.Now().UnixNano())
}
func Rand64() int64 {
return rand.Int63()
}
/* Convinience method for getting md5 sum of a string */
func GetMd5FromString(blob string) (sum []byte) {
h := md5.New()
defer h.Reset()
io.WriteString(h, blob)
return h.Sum(nil)
}
/* Convinience method for getting md5 sum of some bytes */
func GetMd5FromBytes(blob []byte) (sum []byte) {
h := md5.New()
defer h.Reset()
h.Write(blob)
return h.Sum(nil)
}
/* get a small, decently unique hash */
func GetSmallHash() (small_hash string) {
h := sha256.New()
io.WriteString(h, fmt.Sprintf("%d%d", Rand64()))
return strings.ToLower(fmt.Sprintf("%X", h.Sum(nil)[0:4]))
}