mirror of
https://github.com/kopia/kopia.git
synced 2026-05-11 16:25:13 -04:00
02463ab118
Reverts to using the `PasswordHashVersion` in the user profile. Adds a simple mechanism for translating between password hash version and the corresponding password hashing algorithm (key derivation algorithm).
62 lines
1.7 KiB
Go
62 lines
1.7 KiB
Go
//go:build !testing
|
|
// +build !testing
|
|
|
|
package crypto
|
|
|
|
import (
|
|
"github.com/pkg/errors"
|
|
"golang.org/x/crypto/scrypt"
|
|
)
|
|
|
|
// The recommended minimum size for a salt to be used for scrypt.
|
|
// Currently set to 16 bytes (128 bits).
|
|
//
|
|
// TBD: A good rule of thumb is to use a salt that is the same size
|
|
// as the output of the hash function. For example, the output of SHA256
|
|
// is 256 bits (32 bytes), so the salt should be at least 32 random bytes.
|
|
// Scrypt uses a SHA256 hash function.
|
|
// https://crackstation.net/hashing-security.htm
|
|
const (
|
|
minScryptSha256SaltSize = 16 // size in bytes == 128 bits
|
|
|
|
// ScryptAlgorithm is the key for the scrypt algorithm.
|
|
ScryptAlgorithm = "scrypt-65536-8-1"
|
|
|
|
// Legacy hash version salt length.
|
|
V1SaltLength = 32
|
|
)
|
|
|
|
func init() {
|
|
RegisterKeyDerivers(ScryptAlgorithm, &scryptKeyDeriver{
|
|
n: 65536, //nolint:gomnd
|
|
r: 8, //nolint:gomnd
|
|
p: 1,
|
|
recommendedSaltLength: V1SaltLength,
|
|
minSaltLength: minScryptSha256SaltSize,
|
|
})
|
|
}
|
|
|
|
type scryptKeyDeriver struct {
|
|
// n scryptCostParameterN is scrypt's CPU/memory cost parameter.
|
|
n int
|
|
// r scryptCostParameterR is scrypt's work factor.
|
|
r int
|
|
// p scryptCostParameterP is scrypt's parallelization parameter.
|
|
p int
|
|
|
|
recommendedSaltLength int
|
|
minSaltLength int
|
|
}
|
|
|
|
func (s *scryptKeyDeriver) DeriveKeyFromPassword(password string, salt []byte) ([]byte, error) {
|
|
if len(salt) < s.minSaltLength {
|
|
return nil, errors.Errorf("required salt size is atleast %d bytes", s.minSaltLength)
|
|
}
|
|
//nolint:wrapcheck
|
|
return scrypt.Key([]byte(password), salt, s.n, s.r, s.p, MasterKeyLength)
|
|
}
|
|
|
|
func (s *scryptKeyDeriver) RecommendedSaltLength() int {
|
|
return s.recommendedSaltLength
|
|
}
|