Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add compatibility for totp codes with different intervals #7

Open
wants to merge 5 commits into
base: master
Choose a base branch
from
Open

Add compatibility for totp codes with different intervals #7

Changes from 4 commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
2694554
First commit
gergesh Feb 9, 2018
02a1be2
Features are complete, codes don't generate properly.
gergesh Feb 9, 2018
dbaf46b
Fixed small mistake, done
gergesh Feb 9, 2018
36d9698
Remove debug print
gergesh Feb 9, 2018
a1bd091
gofmt'ed
gergesh Feb 10, 2018
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
38 changes: 28 additions & 10 deletions main.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -90,11 +90,13 @@ var (
flag7 = flag.Bool("7", false, "generate 7-digit code")
flag8 = flag.Bool("8", false, "generate 8-digit code")
flagClip = flag.Bool("clip", false, "copy code to the clipboard")
flag10 = flag.Bool("10", false, "use a 10-second interval")
flag20 = flag.Bool("20", false, "use a 20-second interval")
)

func usage() {
fmt.Fprintf(os.Stderr, "usage:\n")
fmt.Fprintf(os.Stderr, "\t2fa -add [-7] [-8] [-hotp] keyname\n")
fmt.Fprintf(os.Stderr, "\t2fa -add [-7] [-8] [-10] [-20] [-hotp] keyname\n")
fmt.Fprintf(os.Stderr, "\t2fa -list\n")
fmt.Fprintf(os.Stderr, "\t2fa [-clip] keyname\n")
os.Exit(2)
Expand Down Expand Up @@ -149,6 +151,7 @@ type Key struct {
raw []byte
digits int
offset int // offset of counter
interval int // interval of generation
Copy link

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This isn't gofmted.

Copy link
Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Done.

}

const counterLen = 20
Expand Down Expand Up @@ -176,19 +179,23 @@ func readKeychain(file string) *Keychain {
if len(f) == 1 && len(f[0]) == 0 {
continue
}
if len(f) >= 3 && len(f[1]) == 1 && '6' <= f[1][0] && f[1][0] <= '8' {
if len(f) >= 4 && len(f[1]) == 1 && '6' <= f[1][0] && f[1][0] <= '8' && len(f[2]) == 2 {
var k Key
name := string(f[0])
k.digits = int(f[1][0] - '0')
raw, err := decodeKey(string(f[2]))
k.interval, err = strconv.Atoi(string(f[2]))
if err != nil {
log.Fatal(err)
}
raw, err := decodeKey(string(f[3]))
if err == nil {
k.raw = raw
if len(f) == 3 {
if len(f) == 4 {
c.keys[name] = k
continue
}
if len(f) == 4 && len(f[3]) == counterLen {
_, err := strconv.ParseUint(string(f[3]), 10, 64)
if len(f) == 5 && len(f[4]) == counterLen {
_, err := strconv.ParseUint(string(f[4]), 10, 64)
if err == nil {
// Valid counter.
k.offset = offset - counterLen
Expand Down Expand Up @@ -235,6 +242,16 @@ func (c *Keychain) add(name string) {
size = 8
}

latency := 30
if *flag10 {
latency = 10
if *flag20 {
log.Fatalf("cannot use -10 and -20 together")
}
} else if *flag20 {
latency = 20
}

fmt.Fprintf(os.Stderr, "2fa key for %s: ", name)
text, err := bufio.NewReader(os.Stdin).ReadString('\n')
if err != nil {
Expand All @@ -246,10 +263,11 @@ func (c *Keychain) add(name string) {
log.Fatalf("invalid key: %v", err)
}

line := fmt.Sprintf("%s %d %s", name, size, text)
line := fmt.Sprintf("%s %d %d %s", name, size, latency, text)
if *flagHotp {
line += " " + strings.Repeat("0", 20)
}

line += "\n"

f, err := os.OpenFile(c.file, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0600)
Expand Down Expand Up @@ -291,7 +309,7 @@ func (c *Keychain) code(name string) string {
}
} else {
// Time-based key.
code = totp(k.raw, time.Now(), k.digits)
code = totp(k.raw, time.Now(), k.digits, k.interval)
}
return fmt.Sprintf("%0*d", k.digits, code)
}
Expand Down Expand Up @@ -340,6 +358,6 @@ func hotp(key []byte, counter uint64, digits int) int {
return int(v % d)
}

func totp(key []byte, t time.Time, digits int) int {
return hotp(key, uint64(t.UnixNano())/30e9, digits)
func totp(key []byte, t time.Time, digits int, latency int) int {
return hotp(key, uint64(t.UnixNano())/(uint64(latency)*10e8), digits)
}