PasswordHasher 算法

 1         public override PasswordVerificationResult VerifyHashedPassword(string hashedPassword, string providedPassword)
 2         {
 3             string[] passwordProperties = hashedPassword.Split(‘|‘);
 4             if (passwordProperties.Length != 3)
 5             {
 6                 return base.VerifyHashedPassword(hashedPassword, providedPassword);
 7             }
 8             else
 9             {
10                 string passwordHash = passwordProperties[0];
11                 int passwordformat = 1;
12                 string salt = passwordProperties[2];
13                 if (String.Equals(EncryptPassword(providedPassword, passwordformat, salt), passwordHash, StringComparison.CurrentCultureIgnoreCase))
14                 {
15                     return PasswordVerificationResult.SuccessRehashNeeded;
16                 }
17                 else
18                 {
19                     return PasswordVerificationResult.Failed;
20                 }
21             }
22         }
23 
24         
25         private string EncryptPassword(string pass, int passwordFormat, string salt)
26         {
27             if (passwordFormat == 0) 
28                 return pass;
29 
30             byte[] bIn = Encoding.Unicode.GetBytes(pass);
31             byte[] bSalt = Convert.FromBase64String(salt);
32             byte[] bRet = null;
33 
34             if (passwordFormat == 1)
35             { // MembershipPasswordFormat.Hashed 
36                 HashAlgorithm hm = HashAlgorithm.Create("SHA1");
37                 if (hm is KeyedHashAlgorithm)
38                 {
39                     KeyedHashAlgorithm kha = (KeyedHashAlgorithm)hm;
40                     if (kha.Key.Length == bSalt.Length)
41                     {
42                         kha.Key = bSalt;
43                     }
44                     else if (kha.Key.Length < bSalt.Length)
45                     {
46                         byte[] bKey = new byte[kha.Key.Length];
47                         Buffer.BlockCopy(bSalt, 0, bKey, 0, bKey.Length);
48                         kha.Key = bKey;
49                     }
50                     else
51                     {
52                         byte[] bKey = new byte[kha.Key.Length];
53                         for (int iter = 0; iter < bKey.Length; )
54                         {
55                             int len = Math.Min(bSalt.Length, bKey.Length - iter);
56                             Buffer.BlockCopy(bSalt, 0, bKey, iter, len);
57                             iter += len;
58                         }
59                         kha.Key = bKey;
60                     }
61                     bRet = kha.ComputeHash(bIn);
62                 }
63                 else
64                 {
65                     byte[] bAll = new byte[bSalt.Length + bIn.Length];
66                     Buffer.BlockCopy(bSalt, 0, bAll, 0, bSalt.Length);
67                     Buffer.BlockCopy(bIn, 0, bAll, bSalt.Length, bIn.Length);
68                     bRet = hm.ComputeHash(bAll);
69                 }
70             }
71 
72             return Convert.ToBase64String(bRet);
73         }