forked from volatiletech/authboss
/
creds_generator.go
52 lines (41 loc) · 1.47 KB
/
creds_generator.go
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package defaults
import (
"crypto/rand"
"crypto/sha512"
"encoding/base64"
"io"
)
const (
tokenSize = 64
tokenSplit = tokenSize / 2
)
type Sha512CredsGenerator struct{}
func NewSha512CredsGenerator() *Sha512CredsGenerator {
return &Sha512CredsGenerator{}
}
// GenerateCreds generates pieces needed as credentials
// selector: hash of the first half of an N byte value
// (to be stored in the database and used in SELECT query)
// verifier: hash of the second half of an N byte value
// (to be stored in database but never used in SELECT query)
// token: the user-facing base64 encoded selector+verifier
func (cg *Sha512CredsGenerator) GenerateCreds() (selector, verifier, token string, err error) {
rawToken := make([]byte, tokenSize)
if _, err = io.ReadFull(rand.Reader, rawToken); err != nil {
return "", "", "", err
}
selectorBytes := sha512.Sum512(rawToken[:tokenSplit])
verifierBytes := sha512.Sum512(rawToken[tokenSplit:])
return base64.StdEncoding.EncodeToString(selectorBytes[:]),
base64.StdEncoding.EncodeToString(verifierBytes[:]),
base64.URLEncoding.EncodeToString(rawToken),
nil
}
func (cg *Sha512CredsGenerator) ParseToken(rawToken string) (selectorBytes, verifierBytes []byte) {
selectorBytes64 := sha512.Sum512([]byte(rawToken)[:tokenSplit])
selectorBytes = selectorBytes64[:]
verifierBytes64 := sha512.Sum512([]byte(rawToken)[tokenSplit:])
verifierBytes = verifierBytes64[:]
return
}
func (cg *Sha512CredsGenerator) TokenSize() int { return tokenSize }