little update.

libmxclient/determinant/mxpassfile/mxpassfile.go

@@ -0,0 +1,125 @@
+package mxpassfile
+
+import (
+	"bufio"
+	"io"
+	"os"
+	"strings"
+)
+
+// inspired by https://github.com/jackc/pgpassfile
+
+// Entry represents a line in a MX passfile.
+type Entry struct {
+	Matrixhost string
+	Localpart  string
+	Domain     string
+	Token      string
+}
+
+// Passfile is the in memory data structure representing a MX passfile.
+type Passfile struct {
+	Entries []*Entry
+}
+
+// ReadPassfile reads the file at path and parses it into a Passfile.
+func readPassfile(path string) (*Passfile, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	return ParsePassfile(f)
+}
+
+// ParsePassfile reads r and parses it into a Passfile.
+func ParsePassfile(r io.Reader) (*Passfile, error) {
+	passfile := &Passfile{}
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		entry := parseLine(scanner.Text())
+		if entry != nil {
+			passfile.Entries = append(passfile.Entries, entry)
+		}
+	}
+
+	return passfile, scanner.Err()
+}
+
+// parseLine parses a line into an *Entry. It returns nil on comment lines or any other unparsable
+// line.
+func parseLine(line string) *Entry {
+	const (
+		tmpBackslash = "\r"
+		tmpPipe      = "\n"
+	)
+
+	line = strings.TrimSpace(line)
+
+	if strings.HasPrefix(line, "#") {
+		return nil
+	}
+
+	line = strings.ReplaceAll(line, `\\`, tmpBackslash)
+	line = strings.ReplaceAll(line, `\|`, tmpPipe)
+
+	parts := strings.Split(line, "|")
+	if len(parts) != 4 {
+		return nil
+	}
+
+	// Unescape escaped colons and backslashes
+	for i := range parts {
+		parts[i] = strings.ReplaceAll(parts[i], tmpBackslash, `\`)
+		parts[i] = strings.ReplaceAll(parts[i], tmpPipe, `|`)
+		parts[i] = strings.TrimSpace(parts[i])
+	}
+
+	return &Entry{
+		Matrixhost: parts[0],
+		Localpart:  parts[1],
+		Domain:     parts[2],
+		Token:      parts[3],
+	}
+}
+
+func isWild(s string) bool {
+	if s == "" || s == "*" {
+		return true
+	}
+	return false
+}
+
+func superCMP(s1, s2 string) bool {
+	if isWild(s1) || isWild(s2) {
+		return true
+	}
+	//fmt.Printf("sCMP: '%s' '%s'\n", s1, s2)
+	return s1 == s2
+}
+
+// FindPassword finds the password for the provided synapsehost, localpart, and domain. An empty
+// string will be returned if no match is found.
+func (pf *Passfile) FindPassword(matrixhost, localpart, domain string) string {
+	for _, e := range pf.Entries {
+		if (e.Matrixhost == "*" || e.Matrixhost == matrixhost) &&
+			(e.Localpart == "*" || e.Localpart == localpart) &&
+			(e.Domain == "*" || e.Domain == domain) {
+			return e.Token
+		}
+	}
+	return ""
+}
+
+func (pf *Passfile) FindPasswordFill(matrixhost, localpart, domain string) *Entry {
+	for _, e := range pf.Entries {
+		if superCMP(e.Matrixhost, matrixhost) &&
+			superCMP(e.Localpart, localpart) &&
+			superCMP(e.Domain, domain) {
+			return e
+		}
+	}
+	return nil
+}