55using System ;
66using System . Diagnostics ;
77using System . Security . Cryptography ;
8+ using System . Security . Cryptography . X509Certificates ;
89
910namespace Microsoft . Data . SqlClient
1011{
11- // Contains methods to convert cryptography keys between different formats.
12- internal sealed class KeyConverter
13- {
12+ internal sealed partial class KeyConverter
13+ {
14+ // Magic numbers identifying blob types
15+ // https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-wcce/cba27df5-4880-4f95-a879-783f8657e53b
16+ private readonly struct KeyBlobMagicNumber
17+ {
18+ internal static readonly byte [ ] ECDHPublicP384 = new byte [ ] { 0x45 , 0x43 , 0x4b , 0x33 } ;
19+ }
20+
21+ // The ECC public key blob is structured as follows:
22+ // BCRYPT_ECCKEY_BLOB header
23+ // byte[KeySize] X
24+ // byte[KeySize] Y
25+ private readonly struct ECCPublicKeyBlob
26+ {
27+ // Size of an ECC public key blob
28+ internal const int Size = 104 ;
29+ // Size of the BCRYPT_ECCKEY_BLOB header
30+ internal const int HeaderSize = 8 ;
31+ // Size of each coordinate
32+ internal const int KeySize = ( Size - HeaderSize ) / 2 ;
33+ }
34+
35+ // Serializes an ECDiffieHellmanPublicKey to an ECC public key blob
36+ // "ECDiffieHellmanPublicKey.ToByteArray() doesn't have a (standards-)defined export
37+ // format. The version used by ECDiffieHellmanPublicKeyCng is Windows-specific"
38+ // from https://github.com/dotnet/runtime/issues/27276
39+ // => ECDiffieHellmanPublicKey.ToByteArray() is not supported in Unix
40+ internal static byte [ ] GetECDiffieHellmanPublicKeyBlob ( ECDiffieHellman ecDiffieHellman )
41+ {
42+ byte [ ] keyBlob = new byte [ ECCPublicKeyBlob . Size ] ;
43+
44+ // Set magic number
45+ Buffer . BlockCopy ( KeyBlobMagicNumber . ECDHPublicP384 , 0 , keyBlob , 0 , 4 ) ;
46+ // Set key size
47+ keyBlob [ 4 ] = ( byte ) ECCPublicKeyBlob . KeySize ;
48+
49+ ECPoint ecPoint = ecDiffieHellman . PublicKey . ExportParameters ( ) . Q ;
50+ Debug . Assert ( ecPoint . X . Length == ECCPublicKeyBlob . KeySize && ecPoint . Y . Length == ECCPublicKeyBlob . KeySize ,
51+ $ "ECDH public key was not the expected length. Actual (X): { ecPoint . X . Length } . Actual (Y): { ecPoint . Y . Length } Expected: { ECCPublicKeyBlob . Size } ") ;
52+ // Copy x and y coordinates to key blob
53+ Buffer . BlockCopy ( ecPoint . X , 0 , keyBlob , ECCPublicKeyBlob . HeaderSize , ECCPublicKeyBlob . KeySize ) ;
54+ Buffer . BlockCopy ( ecPoint . Y , 0 , keyBlob , ECCPublicKeyBlob . HeaderSize + ECCPublicKeyBlob . KeySize , ECCPublicKeyBlob . KeySize ) ;
55+ return keyBlob ;
56+ }
57+
1458 // The RSA public key blob is structured as follows:
1559 // BCRYPT_RSAKEY_BLOB header
1660 // byte[ExponentSize] publicExponent
@@ -29,59 +73,32 @@ private readonly struct RSAPublicKeyBlob
2973 internal const int ModulusOffset = HeaderSize ;
3074 }
3175
32- // Extracts the public key's modulus and exponent from an RSA public key blob
33- // and returns an RSAParameters object
34- internal static RSAParameters RSAPublicKeyBlobToParams ( byte [ ] keyBlob )
76+ internal static RSA CreateRSAFromPublicKeyBlob ( byte [ ] keyBlob )
3577 {
36- Debug . Assert ( keyBlob . Length == RSAPublicKeyBlob . Size ,
37- $ "RSA public key blob was not the expected length. Actual: { keyBlob . Length } . Expected: { RSAPublicKeyBlob . Size } ") ;
78+ Debug . Assert ( keyBlob . Length == RSAPublicKeyBlob . Size , $ "RSA public key blob was not the expected length. Actual: { keyBlob . Length } . Expected: { RSAPublicKeyBlob . Size } ") ;
3879
3980 byte [ ] exponent = new byte [ RSAPublicKeyBlob . ExponentSize ] ;
4081 byte [ ] modulus = new byte [ RSAPublicKeyBlob . ModulusSize ] ;
4182 Buffer . BlockCopy ( keyBlob , RSAPublicKeyBlob . ExponentOffset , exponent , 0 , RSAPublicKeyBlob . ExponentSize ) ;
4283 Buffer . BlockCopy ( keyBlob , RSAPublicKeyBlob . ModulusOffset , modulus , 0 , RSAPublicKeyBlob . ModulusSize ) ;
43-
44- return new RSAParameters ( )
84+ var rsaParameters = new RSAParameters ( )
4585 {
4686 Exponent = exponent ,
4787 Modulus = modulus
4888 } ;
89+ return RSA . Create ( rsaParameters ) ;
4990 }
5091
51- // The ECC public key blob is structured as follows:
52- // BCRYPT_ECCKEY_BLOB header
53- // byte[KeySize] X
54- // byte[KeySize] Y
55- private readonly struct ECCPublicKeyBlob
56- {
57- // Size of an ECC public key blob
58- internal const int Size = 104 ;
59- // Size of the BCRYPT_ECCKEY_BLOB header
60- internal const int HeaderSize = 8 ;
61- // Size of each coordinate
62- internal const int KeySize = ( Size - HeaderSize ) / 2 ;
63- }
64-
65- // Magic numbers identifying blob types
66- // https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-wcce/cba27df5-4880-4f95-a879-783f8657e53b
67- private readonly struct KeyBlobMagicNumber
68- {
69- internal static readonly byte [ ] ECDHPublicP384 = new byte [ ] { 0x45 , 0x43 , 0x4b , 0x33 } ;
70- }
71-
72- // Extracts the public key's X and Y coordinates from an ECC public key blob
73- // and returns an ECParameters object
74- internal static ECParameters ECCPublicKeyBlobToParams ( byte [ ] keyBlob )
92+ internal static ECDiffieHellman CreateECDiffieHellmanFromPublicKeyBlob ( byte [ ] keyBlob )
7593 {
76- Debug . Assert ( keyBlob . Length == ECCPublicKeyBlob . Size ,
77- $ "ECC public key blob was not the expected length. Actual: { keyBlob . Length } . Expected: { ECCPublicKeyBlob . Size } ") ;
94+ Debug . Assert ( keyBlob . Length == ECCPublicKeyBlob . Size , $ "ECC public key blob was not the expected length. Actual: { keyBlob . Length } . Expected: { ECCPublicKeyBlob . Size } ") ;
7895
7996 byte [ ] x = new byte [ ECCPublicKeyBlob . KeySize ] ;
8097 byte [ ] y = new byte [ ECCPublicKeyBlob . KeySize ] ;
8198 Buffer . BlockCopy ( keyBlob , ECCPublicKeyBlob . HeaderSize , x , 0 , ECCPublicKeyBlob . KeySize ) ;
8299 Buffer . BlockCopy ( keyBlob , ECCPublicKeyBlob . HeaderSize + ECCPublicKeyBlob . KeySize , y , 0 , ECCPublicKeyBlob . KeySize ) ;
83100
84- return new ECParameters
101+ var parameters = new ECParameters
85102 {
86103 Curve = ECCurve . NamedCurves . nistP384 ,
87104 Q = new ECPoint
@@ -90,29 +107,29 @@ internal static ECParameters ECCPublicKeyBlobToParams(byte[] keyBlob)
90107 Y = y
91108 } ,
92109 } ;
110+
111+ return ECDiffieHellman . Create ( parameters ) ;
93112 }
94113
95- // Serializes an ECDiffieHellmanPublicKey to an ECC public key blob
96- // "ECDiffieHellmanPublicKey.ToByteArray() doesn't have a (standards-)defined export
97- // format. The version used by ECDiffieHellmanPublicKeyCng is Windows-specific"
98- // from https://github.com/dotnet/runtime/issues/27276
99- // => ECDiffieHellmanPublicKey.ToByteArray() is not supported in Unix
100- internal static byte [ ] ECDHPublicKeyToECCKeyBlob ( ECDiffieHellmanPublicKey publicKey )
114+ internal static ECDiffieHellman CreateECDiffieHellman ( int keySize )
101115 {
102- byte [ ] keyBlob = new byte [ ECCPublicKeyBlob . Size ] ;
116+ // platform agnostic creates a key of the correct size but does not
117+ // set the key derivation type or algorithm, these must be set by calling
118+ // DeriveKeyFromHash later in DeriveKey
119+ ECDiffieHellman clientDHKey = ECDiffieHellman . Create ( ) ;
120+ clientDHKey . KeySize = keySize ;
121+ return clientDHKey ;
122+ }
103123
104- // Set magic number
105- Buffer . BlockCopy ( KeyBlobMagicNumber . ECDHPublicP384 , 0 , keyBlob , 0 , 4 ) ;
106- // Set key size
107- keyBlob [ 4 ] = ( byte ) ECCPublicKeyBlob . KeySize ;
124+ internal static byte [ ] DeriveKey ( ECDiffieHellman ecd , ECDiffieHellmanPublicKey publicKey )
125+ {
126+ // see notes in CreateECDDiffieHellman
127+ return ecd . DeriveKeyFromHash ( publicKey , HashAlgorithmName . SHA256 ) ;
128+ }
108129
109- ECPoint ecPoint = publicKey . ExportParameters ( ) . Q ;
110- Debug . Assert ( ecPoint . X . Length == ECCPublicKeyBlob . KeySize && ecPoint . Y . Length == ECCPublicKeyBlob . KeySize ,
111- $ "ECDH public key was not the expected length. Actual (X): { ecPoint . X . Length } . Actual (Y): { ecPoint . Y . Length } Expected: { ECCPublicKeyBlob . Size } ") ;
112- // Copy x and y coordinates to key blob
113- Buffer . BlockCopy ( ecPoint . X , 0 , keyBlob , ECCPublicKeyBlob . HeaderSize , ECCPublicKeyBlob . KeySize ) ;
114- Buffer . BlockCopy ( ecPoint . Y , 0 , keyBlob , ECCPublicKeyBlob . HeaderSize + ECCPublicKeyBlob . KeySize , ECCPublicKeyBlob . KeySize ) ;
115- return keyBlob ;
130+ internal static RSA GetRSAFromCertificate ( X509Certificate2 certificate )
131+ {
132+ return certificate . GetRSAPublicKey ( ) ;
116133 }
117134 }
118135}
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