-
Notifications
You must be signed in to change notification settings - Fork 0
/
hasher.go
113 lines (95 loc) · 2.51 KB
/
hasher.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
package crypto
import (
"crypto/rand"
"crypto/subtle"
"encoding/base64"
"fmt"
"strings"
"golang.org/x/crypto/argon2"
)
type Argon2Hasher struct {
config Argon2Config
}
func NewDefaultArgon2PassHasher() Argon2Hasher {
return Argon2Hasher{config: NewDefaultArgon2Config()}
}
func (a Argon2Hasher) Hash(password string) (string, error) {
salt, err := generateRandomSalt(a.config.saltLength)
if err != nil {
return "", err
}
hash := argon2.IDKey(
[]byte(password),
salt,
a.config.iterations,
a.config.memory,
a.config.threads,
a.config.keyLength,
)
// Base64 encode the salt and hashed password.
b64Salt := base64.RawStdEncoding.EncodeToString(salt)
b64Hash := base64.RawStdEncoding.EncodeToString(hash)
// Return a string using the standard encoded hash representation.
encodedHash := fmt.Sprintf(
"$argon2id$v=%d$m=%d,t=%d,p=%d$%s$%s",
argon2.Version,
a.config.memory,
a.config.iterations,
a.config.threads,
b64Salt,
b64Hash,
)
return encodedHash, nil
}
// Verify checks a candidate password against a known hash using the argon2 hashing algorithm
func (a Argon2Hasher) Verify(password, hash string) (bool, error) {
// hash is our known argon2 hash in the standard encoded representation
knownEncodedHashParts := strings.Split(hash, "$")
// Extract metadata from the known encoded argon2 hash
var knownHashMemory uint32
var knownHashIterations uint32
var knownHashThreads uint8
_, err := fmt.Sscanf(
knownEncodedHashParts[3],
"m=%d,t=%d,p=%d",
&knownHashMemory,
&knownHashIterations,
&knownHashThreads,
)
if err != nil {
return false, err
}
// Base64 decode the salt from the known encoded argon2 hash
knownB64Salt := knownEncodedHashParts[4]
knownSalt, err := base64.RawStdEncoding.DecodeString(knownB64Salt)
if err != nil {
return false, err
}
// Base64 decode the password section from the known encoded argon2 hash
knownB64HashedPassword := knownEncodedHashParts[5]
knownHashedPassword, err := base64.RawStdEncoding.DecodeString(knownB64HashedPassword)
if err != nil {
return false, err
}
keyLength := uint32(len(knownHashedPassword))
candidateHashedPassword := argon2.IDKey(
[]byte(password),
knownSalt,
knownHashIterations,
knownHashMemory,
knownHashThreads,
keyLength,
)
if subtle.ConstantTimeCompare(knownHashedPassword, candidateHashedPassword) == 1 {
return true, nil
}
return false, nil
}
func generateRandomSalt(n uint32) ([]byte, error) {
b := make([]byte, n)
_, err := rand.Read(b)
if err != nil {
return nil, err
}
return b, nil
}