admin: new route to generate htpasswd corresponding to certificate in use by team

libfic/utils.go

@@ -1,6 +1,8 @@
 package fic
 
 import (
+	"bytes"
+	"crypto/md5"
 	"regexp"
 	"strings"
 )
@@ -10,3 +12,81 @@ func ToURLid(str string) string {
 	re := regexp.MustCompile("[^a-zA-Z0-9]+")
 	return strings.TrimSuffix(re.ReplaceAllLiteralString(str, "-"), "-")
 }
+
+// Apr1Md5 computes a usable hash for basic auth in Apache and nginx.
+// Function copied from https://github.com/jimstudt/http-authentication/blob/master/basic/md5.go
+// as it was not exported in package and comes with other unwanted functions.
+// Original source code under MIT.
+func Apr1Md5(password string, salt string) string {
+	initBin := md5.Sum([]byte(password + salt + password))
+
+	initText := bytes.NewBufferString(password + "$apr1$" + salt)
+
+	for i := len(password); i > 0; i -= 16 {
+		lim := i
+		if lim > 16 {
+			lim = 16
+		}
+		initText.Write(initBin[0:lim])
+	}
+
+	for i := len(password); i > 0; i >>= 1 {
+		if (i & 1) == 1 {
+			initText.WriteByte(byte(0))
+		} else {
+			initText.WriteByte(password[0])
+		}
+	}
+
+	bin := md5.Sum(initText.Bytes())
+
+	n := bytes.NewBuffer([]byte{})
+
+	for i := 0; i < 1000; i++ {
+		n.Reset()
+
+		if (i & 1) == 1 {
+			n.WriteString(password)
+		} else {
+			n.Write(bin[:])
+		}
+
+		if i%3 != 0 {
+			n.WriteString(salt)
+		}
+
+		if i%7 != 0 {
+			n.WriteString(password)
+		}
+
+		if (i & 1) == 1 {
+			n.Write(bin[:])
+		} else {
+			n.WriteString(password)
+		}
+
+		bin = md5.Sum(n.Bytes())
+	}
+
+	result := bytes.NewBuffer([]byte{})
+
+	fill := func(a byte, b byte, c byte) {
+		v := (uint(a) << 16) + (uint(b) << 8) + uint(c)
+
+		for i := 0; i < 4; i++ {
+			result.WriteByte("./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"[v&0x3f])
+			v >>= 6
+		}
+	}
+
+	fill(bin[0], bin[6], bin[12])
+	fill(bin[1], bin[7], bin[13])
+	fill(bin[2], bin[8], bin[14])
+	fill(bin[3], bin[9], bin[15])
+	fill(bin[4], bin[10], bin[5])
+	fill(0, 0, bin[11])
+
+	resultString := string(result.Bytes()[0:22])
+
+	return resultString
+}