argon2/crypto.go
2022-12-04 02:18:05 +01:00

84 lines
2.1 KiB
Go

package argon2_utils
import (
"crypto/rand"
"crypto/subtle"
"encoding/base64"
"fmt"
"golang.org/x/crypto/argon2"
"strings"
)
func generateRandomBytes(n uint32) ([]byte, error) {
b := make([]byte, n)
_, err := rand.Read(b)
if err != nil {
return nil, err
}
return b, nil
}
func decodeHash(encodedHash string) (p *params, salt, hash []byte, err error) {
vals := strings.Split(encodedHash, "$")
if len(vals) != 6 {
return nil, nil, nil, ErrInvalidHash
}
var version int
_, err = fmt.Sscanf(vals[2], "v=%d", &version)
if err != nil {
return nil, nil, nil, err
}
if version != argon2.Version {
return nil, nil, nil, ErrIncompatibleVersion
}
p = &params{}
_, err = fmt.Sscanf(vals[3], "m=%d,t=%d,p=%d", &p.memory, &p.iterations, &p.parallelism)
if err != nil {
return nil, nil, nil, err
}
salt, err = base64.RawStdEncoding.DecodeString(vals[4])
if err != nil {
return nil, nil, nil, err
}
p.saltLength = uint32(len(salt))
hash, err = base64.RawStdEncoding.DecodeString(vals[5])
if err != nil {
return nil, nil, nil, err
}
p.keyLength = uint32(len(hash))
return p, salt, hash, nil
}
func CompareStringToArgon2Hash(password string, hashedPassword string) (match bool, err error) {
p, salt, hash, err := decodeHash(hashedPassword)
if err != nil {
return false, err
}
otherHash := argon2.IDKey([]byte(password), salt, p.iterations, p.memory, p.parallelism, p.keyLength)
if subtle.ConstantTimeCompare(hash, otherHash) == 1 {
return true, nil
}
return false, nil
}
func HashStringArgon2(password string) (encodedHash string, err error) {
salt, err := generateRandomBytes(p.saltLength)
if err != nil {
return "", err
}
hash := argon2.IDKey([]byte(password), salt, p.iterations, p.memory, p.parallelism, p.keyLength)
b64Salt := base64.RawStdEncoding.EncodeToString(salt)
b64Hash := base64.RawStdEncoding.EncodeToString(hash)
encodedHash = fmt.Sprintf("$argon2id$v=%d$m=%d,t=%d,p=%d$%s$%s", argon2.Version, p.memory, p.iterations, p.parallelism, b64Salt, b64Hash)
return encodedHash, nil
}
func RandomString(s int) (string, error) {
b, err := generateRandomBytes(uint32(s))
return base64.URLEncoding.EncodeToString(b), err
}