import (
"bytes"
- "crypto/sha512"
+ "encoding/base64"
+ "errors"
+ "fmt"
"io/ioutil"
"log"
"strings"
"github.com/agl/ed25519"
- "golang.org/x/crypto/pbkdf2"
+ "github.com/magical/argon2"
)
const (
- PBKDF2Iters = 1 << 16
+ DefaultM = 1 << 12
+ DefaultT = 1 << 7
+ DefaultP = 1
)
-// Create verifier from supplied password for given PeerId.
-func NewVerifier(id *PeerId, password string) (*[ed25519.PublicKeySize]byte, *[ed25519.PrivateKeySize]byte) {
- r := pbkdf2.Key(
- []byte(password),
- id[:],
- PBKDF2Iters,
- ed25519.PrivateKeySize,
- sha512.New,
- )
+type Verifier struct {
+ M int
+ T int
+ P int
+ Id *PeerId
+ Pub *[ed25519.PublicKeySize]byte
+}
+
+// Generate new verifier for given peer, with specified password and
+// hashing parameters.
+func VerifierNew(m, t, p int, id *PeerId) *Verifier {
+ return &Verifier{M: m, T: t, P: p, Id: id}
+}
+
+// Apply the password: create Ed25519 keypair based on it, save public
+// key in verifier.
+func (v *Verifier) PasswordApply(password string) *[ed25519.PrivateKeySize]byte {
+ r, err := argon2.Key([]byte(password), v.Id[:], v.T, v.P, int64(v.M), 32)
+ if err != nil {
+ log.Fatalln("Unable to apply Argon2d", err)
+ }
defer sliceZero(r)
src := bytes.NewBuffer(r)
- pub, priv, err := ed25519.GenerateKey(src)
+ pub, prv, err := ed25519.GenerateKey(src)
if err != nil {
log.Fatalln("Unable to generate Ed25519 keypair", err)
}
- return pub, priv
+ v.Pub = pub
+ return prv
+}
+
+// Parse either short or long verifier form.
+func VerifierFromString(input string) (*Verifier, error) {
+ s := strings.Split(input, "$")
+ if !(len(s) != 4 || len(s) != 5) || s[1] != "argon2d" {
+ return nil, errors.New("Invalid verifier structure")
+ }
+ var m, t, p int
+ n, err := fmt.Sscanf(s[2], "m=%d,t=%d,p=%d", &m, &t, &p)
+ if n != 3 || err != nil {
+ return nil, errors.New("Invalid verifier parameters")
+ }
+ salt, err := base64.RawStdEncoding.DecodeString(s[3])
+ if err != nil {
+ return nil, err
+ }
+ v := Verifier{M: m, T: t, P: p}
+ id := new([IDSize]byte)
+ copy(id[:], salt)
+ pid := PeerId(*id)
+ v.Id = &pid
+ if len(s) == 5 {
+ pub, err := base64.RawStdEncoding.DecodeString(s[4])
+ if err != nil {
+ return nil, err
+ }
+ v.Pub = new([ed25519.PublicKeySize]byte)
+ copy(v.Pub[:], pub)
+ }
+ return &v, nil
+}
+
+// Short verifier string form -- it is useful for the client.
+// Does not include public key.
+func (v *Verifier) ShortForm() string {
+ return fmt.Sprintf(
+ "$argon2d$m=%d,t=%d,p=%d$%s",
+ v.M, v.T, v.P, base64.RawStdEncoding.EncodeToString(v.Id[:]),
+ )
+}
+
+// Long verifier string form -- it is useful for the server.
+// Includes public key.
+func (v *Verifier) LongForm() string {
+ return fmt.Sprintf(
+ "%s$%s", v.ShortForm(),
+ base64.RawStdEncoding.EncodeToString(v.Pub[:]),
+ )
}
// Read string from the file, trimming newline.