monorepo fixes

crypto/auth_digest.go

@@ -0,0 +1,40 @@
+package crypto
+
+import (
+	"crypto/sha1"
+	"encoding/hex"
+	"strings"
+)
+
+func twosComplement(p []byte) []byte {
+	carry := true
+	for i := len(p) - 1; i >= 0; i-- {
+		p[i] = byte(^p[i])
+		if carry {
+			carry = p[i] == 0xff
+			p[i]++
+		}
+	}
+	return p
+}
+
+// AuthDigest stolen from https://gist.github.com/toqueteos/5372776
+func AuthDigest(elems ...[]byte) string {
+	h := sha1.New()
+	for _, elem := range elems {
+		h.Write(elem)
+	}
+	hash := h.Sum(nil)
+
+	negative := (hash[0] & 0x80) == 0x80
+	if negative {
+		hash = twosComplement(hash)
+	}
+
+	res := strings.TrimLeft(hex.EncodeToString(hash), "0")
+	if negative {
+		res = "-" + res
+	}
+
+	return res
+}