Remove TLSConfig fields

tofu.go

@@ -0,0 +1,70 @@
+package gemini
+
+import (
+	"bufio"
+	"bytes"
+	"crypto/sha512"
+	"crypto/x509"
+	"errors"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+)
+
+var (
+	ErrInvalidKnownHosts = errors.New("gemini: invalid known hosts")
+)
+
+// KnownHost represents a known host.
+type KnownHost struct {
+	Hostname    string // e.g. gemini.circumlunar.space
+	Algorithm   string // fingerprint algorithm
+	Fingerprint string // fingerprint in hexadecimal, with ':' between each octet
+	NotAfter    int64  // unix time of certificate notAfter date
+}
+
+// ParseKnownHosts parses and returns a list of known hosts from the provided io.Reader.
+func ParseKnownHosts(r io.Reader) ([]KnownHost, error) {
+	hosts := []KnownHost{}
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		text := scanner.Text()
+
+		parts := strings.Split(text, " ")
+		if len(parts) < 4 {
+			return nil, ErrInvalidKnownHosts
+		}
+
+		hostname := parts[0]
+		algorithm := parts[1]
+		fingerprint := parts[2]
+		notAfter, err := strconv.ParseInt(parts[3], 10, 0)
+		if err != nil {
+			return nil, ErrInvalidKnownHosts
+		}
+
+		hosts = append(hosts, KnownHost{
+			Hostname:    hostname,
+			Algorithm:   algorithm,
+			Fingerprint: fingerprint,
+			NotAfter:    notAfter,
+		})
+	}
+
+	return hosts, nil
+}
+
+// Fingerprint returns the SHA-512 fingerprint of the provided certificate.
+func Fingerprint(cert *x509.Certificate) string {
+	sum512 := sha512.Sum512(cert.Raw)
+	var buf bytes.Buffer
+	for i, f := range sum512 {
+		if i > 0 {
+			fmt.Fprintf(&buf, ":")
+		}
+		fmt.Fprintf(&buf, "%02X", f)
+	}
+	return buf.String()
+}