//
// CryptoConvert.cs - Crypto Convertion Routines
//
// Author:
// Sebastien Pouliot <sebastien@ximian.com>
//
// (C) 2003 Motus Technologies Inc. (http://www.motus.com)
// (C) 2004 Novell (http://www.novell.com)
//
using System;
using System.Globalization;
using System.Security.Cryptography;
using System.Text;
namespace Mono.Security.Cryptography{
#if INSIDE_CORLIB
internal
#else
public
#endif
sealed class CryptoConvert {
private CryptoConvert ()
{
}
static private int ToInt32LE (byte [] bytes, int offset)
{
return (bytes [offset+3] << 24) | (bytes [offset+2] << 16) | (bytes [offset+1] << 8) | bytes [offset];
}
static private uint ToUInt32LE (byte [] bytes, int offset)
{
return (uint)((bytes [offset+3] << 24) | (bytes [offset+2] << 16) | (bytes [offset+1] << 8) | bytes [offset]);
}
static private byte [] GetBytesLE (int val)
{
return new byte [] {
(byte) (val & 0xff),
(byte) ((val >> 8) & 0xff),
(byte) ((val >> 16) & 0xff),
(byte) ((val >> 24) & 0xff)
};
}
static private byte[] Trim (byte[] array)
{
for (int i=0; i < array.Length; i++) {
if (array [i] != 0x00) {
byte[] result = new byte [array.Length - i];
Buffer.BlockCopy (array, i, result, 0, result.Length);
return result;
}
}
return null;
}
// convert the key from PRIVATEKEYBLOB to RSA
// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/security/Security/private_key_blobs.asp
// e.g. SNK files, PVK files
static public RSA FromCapiPrivateKeyBlob (byte[] blob)
{
return FromCapiPrivateKeyBlob (blob, 0);
}
static public RSA FromCapiPrivateKeyBlob (byte[] blob, int offset)
{
if (blob == null)
throw new ArgumentNullException ("blob");
if (offset >= blob.Length)
throw new ArgumentException ("blob is too small.");
try {
if ((blob [offset] != 0x07) || // PRIVATEKEYBLOB (0x07)
(blob [offset+1] != 0x02) || // Version (0x02)
(blob [offset+2] != 0x00) || // Reserved (word)
(blob [offset+3] != 0x00) ||
(ToUInt32LE (blob, offset+8) != 0x32415352)) // DWORD magic = RSA2
throw new CryptographicException ("Invalid blob header");
// ALGID (CALG_RSA_SIGN, CALG_RSA_KEYX, ...)
int algId = ToInt32LE (blob, offset+4);
// DWORD bitlen
int bitLen = ToInt32LE (blob, offset+12);
// DWORD public exponent
RSAParameters rsap = new RSAParameters ();
byte[] exp = new byte [4];
Buffer.BlockCopy (blob, offset+16, exp, 0, 4);
Array.Reverse (exp);
rsap.Exponent = Trim (exp);
int pos = offset+20;
// BYTE modulus[rsapubkey.bitlen/8];
int byteLen = (bitLen >> 3);
rsap.Modulus = new byte [byteLen];
Buffer.BlockCopy (blob, pos, rsap.Modulus, 0, byteLen);
Array.Reverse (rsap.Modulus);
pos += byteLen;
// BYTE prime1[rsapubkey.bitlen/16];
int byteHalfLen = (byteLen >> 1);
rsap.P = new byte [byteHalfLen];
Buffer.BlockCopy (blob, pos, rsap.P, 0, byteHalfLen);
Array.Reverse (rsap.P);
pos += byteHalfLen;
// BYTE prime2[rsapubkey.bitlen/16];
rsap.Q = new byte [byteHalfLen];
Buffer.BlockCopy (blob, pos, rsap.Q, 0, byteHalfLen);
Array.Reverse (rsap.Q);
pos += byteHalfLen;
// BYTE exponent1[rsapubkey.bitlen/16];
rsap.DP = new byte [byteHalfLen];
Buffer.BlockCopy (blob, pos, rsap.DP, 0, byteHalfLen);
Array.Reverse (rsap.DP);
pos += byteHalfLen;
// BYTE exponent2[rsapubkey.bitlen/16];
rsap.DQ = new byte [byteHalfLen];
Buffer.BlockCopy (blob, pos, rsap.DQ, 0, byteHalfLen);
Array.Reverse (rsap.DQ);
pos += byteHalfLen;
// BYTE coefficient[rsapubkey.bitlen/16];
rsap.InverseQ = new byte [byteHalfLen];
Buffer.BlockCopy (blob, pos, rsap.InverseQ, 0, byteHalfLen);
Array.Reverse (rsap.InverseQ);
pos += byteHalfLen;
// ok, this is hackish but CryptoAPI support it so...
// note: only works because CRT is used by default
// http://bugzilla.ximian.com/show_bug.cgi?id=57941
rsap.D = new byte [byteLen]; // must be allocated
if (pos + byteLen + offset <= blob.Length) {
// BYTE privateExponent[rsapubkey.bitlen/8];
Buffer.BlockCopy (blob, pos, rsap.D, 0, byteLen);
Array.Reverse (rsap.D);
}
RSA rsa = (RSA)RSA.Create ();
rsa.ImportParameters (rsap);
return rsa;
}
catch (Exception e) {
throw new CryptographicException ("Invalid blob.", e);
}
}
static public byte[] ToCapiPrivateKeyBlob (RSA rsa)
{
RSAParameters p = rsa.ExportParameters (true);
int keyLength = p.Modulus.Length; // in bytes
byte[] blob = new byte [20 + (keyLength << 2) + (keyLength >> 1)];
blob [0] = 0x07; // Type - PRIVATEKEYBLOB (0x07)
blob [1] = 0x02; // Version - Always CUR_BLOB_VERSION (0x02)
// [2], [3] // RESERVED - Always 0
blob [5] = 0x24; // ALGID - Always 00 24 00 00 (for CALG_RSA_SIGN)
blob [8] = 0x52; // Magic - RSA2 (ASCII in hex)
blob [9] = 0x53;
blob [10] = 0x41;
blob [11] = 0x32;
byte[] bitlen = GetBytesLE (keyLength << 3);
blob [12] = bitlen [0]; // bitlen
blob [13] = bitlen [1];
blob [14] = bitlen [2];
blob [15] = bitlen [3];
// public exponent (DWORD)
int pos = 16;
int n = p.Exponent.Length;
while (n > 0)
blob [pos++] = p.Exponent [--n];
// modulus
pos = 20;
byte[] part = p.Modulus;
int len = part.Length;
Array.Reverse (part, 0, len);
Buffer.BlockCopy (part, 0, blob, pos, len);
pos += len;
// private key
part = p.P;
len = part.Length;
Array.Reverse (part, 0, len);
Buffer.BlockCopy (part, 0, blob, pos, len);
pos += len;
part = p.Q;
len = part.Length;
Array.Reverse (part, 0, len);
Buffer.BlockCopy (part, 0, blob, pos, len);
pos += len;
part = p.DP;
len = part.Length;
Array.Reverse (part, 0, len);
Buffer.BlockCopy (part, 0, blob, pos, len);
pos += len;
part = p.DQ;
len = part.Length;
Array.Reverse (part, 0, len);
Buffer.BlockCopy (part, 0, blob, pos, len);
pos += len;
part = p.InverseQ;
len = part.Length;
Array.Reverse (part, 0, len);
Buffer.BlockCopy (part, 0, blob, pos, len);
pos += len;
part = p.D;
len = part.Length;
Array.Reverse (part, 0, len);
Buffer.BlockCopy (part, 0, blob, pos, len);
return blob;
}
static public RSA FromCapiPublicKeyBlob (byte[] blob)
{
return FromCapiPublicKeyBlob (blob, 0);
}
static public RSA FromCapiPublicKeyBlob (byte[] blob, int offset)
{
if (blob == null)
throw new ArgumentNullException ("blob");
if (offset >= blob.Length)
throw new ArgumentException ("blob is too small.");
try {
if ((blob [offset] != 0x06) || // PUBLICKEYBLOB (0x06)
(blob [offset+1] != 0x02) || // Version (0x02)
(blob [offset+2] != 0x00) || // Reserved (word)
(blob [offset+3] != 0x00) ||
(ToUInt32LE (blob, offset+8) != 0x31415352)) // DWORD magic = RSA1
throw new CryptographicException ("Invalid blob header");
// ALGID (CALG_RSA_SIGN, CALG_RSA_KEYX, ...)
int algId = ToInt32LE (blob, offset+4);
// DWORD bitlen
int bitLen = ToInt32LE (blob, offset+12);
// DWORD public exponent
RSAParameters rsap = new RSAParameters ();
rsap.Exponent = new byte [3];
rsap.Exponent [0] = blob [offset+18];
rsap.Exponent [1] = blob [offset+17];
rsap.Exponent [2] = blob [offset+16];
int pos = offset+20;
// BYTE modulus[rsapubkey.bitlen/8];
int byteLen = (bitLen >> 3);
rsap.Modulus = new byte [byteLen];
Buffer.BlockCopy (blob, pos, rsap.Modulus, 0, byteLen);
Array.Reverse (rsap.Modulus);
RSA rsa = (RSA)RSA.Create ();
rsa.ImportParameters (rsap);
return rsa;
}
catch (Exception e) {
throw new CryptographicException ("Invalid blob.", e);
}
}
static public byte[] ToCapiPublicKeyBlob (RSA rsa)
{
RSAParameters p = rsa.ExportParameters (false);
int keyLength = p.Modulus.Length; // in bytes
byte[] blob = new byte [20 + keyLength];
blob [0] = 0x06; // Type - PUBLICKEYBLOB (0x06)
blob [1] = 0x02; // Version - Always CUR_BLOB_VERSION (0x02)
// [2], [3] // RESERVED - Always 0
blob [5] = 0x24; // ALGID - Always 00 24 00 00 (for CALG_RSA_SIGN)
blob [8] = 0x52; // Magic - RSA1 (ASCII in hex)
blob [9] = 0x53;
blob [10] = 0x41;
blob [11] = 0x31;
byte[] bitlen = GetBytesLE (keyLength << 3);
blob [12] = bitlen [0]; // bitlen
blob [13] = bitlen [1];
blob [14] = bitlen [2];
blob [15] = bitlen [3];
// public exponent (DWORD)
int pos = 16;
int n = p.Exponent.Length;
while (n > 0)
blob [pos++] = p.Exponent [--n];
// modulus
pos = 20;
byte[] part = p.Modulus;
int len = part.Length;
Array.Reverse (part, 0, len);
Buffer.BlockCopy (part, 0, blob, pos, len);
pos += len;
return blob;
}
// PRIVATEKEYBLOB
// PUBLICKEYBLOB
static public RSA FromCapiKeyBlob (byte[] blob)
{
return FromCapiKeyBlob (blob, 0);
}
static public RSA FromCapiKeyBlob (byte[] blob, int offset)
{
if (blob == null)
throw new ArgumentNullException ("blob");
if (offset >= blob.Length)
throw new ArgumentException ("blob is too small.");
switch (blob [offset]) {
case 0x00:
// this could be a public key inside an header
// like "sn -e" would produce
if (blob [offset + 12] == 0x06) {
return FromCapiPublicKeyBlob (blob, offset + 12);
}
break;
case 0x06:
return FromCapiPublicKeyBlob (blob, offset);
case 0x07:
return FromCapiPrivateKeyBlob (blob, offset);
}
throw new CryptographicException ("Unknown blob format.");
}
static public byte[] ToCapiKeyBlob (AsymmetricAlgorithm keypair, bool includePrivateKey)
{
if (keypair == null)
throw new ArgumentNullException ("keypair");
// check between RSA and DSA (and potentially others like DH)
if (keypair is RSA)
return ToCapiKeyBlob ((RSA)keypair, includePrivateKey);
else
return null; // TODO
}
static public byte[] ToCapiKeyBlob (RSA rsa, bool includePrivateKey)
{
if (rsa == null)
throw new ArgumentNullException ("rsa");
RSAParameters p = rsa.ExportParameters (includePrivateKey);
if (includePrivateKey)
return ToCapiPrivateKeyBlob (rsa);
else
return ToCapiPublicKeyBlob (rsa);
}
static public string ToHex (byte[] input)
{
if (input == null)
return null;
StringBuilder sb = new StringBuilder (input.Length * 2);
foreach (byte b in input) {
sb.Append (b.ToString ("X2", CultureInfo.InvariantCulture));
}
return sb.ToString ();
}
static private byte FromHexChar (char c)
{
if ((c >= 'a') && (c <= 'f'))
return (byte) (c - 'a' + 10);
if ((c >= 'A') && (c <= 'F'))
return (byte) (c - 'A' + 10);
if ((c >= '0') && (c <= '9'))
return (byte) (c - '0');
throw new ArgumentException ("invalid hex char");
}
static public byte[] FromHex (string hex)
{
if (hex == null)
return null;
if ((hex.Length & 0x1) == 0x1)
throw new ArgumentException ("Length must be a multiple of 2");
byte[] result = new byte [hex.Length >> 1];
int n = 0;
int i = 0;
while (n < result.Length) {
result [n] = (byte) (FromHexChar (hex [i++]) << 4);
result [n++] += FromHexChar (hex [i++]);
}
return result;
}
}
}
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