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//
// CryptoConfig.cs: Handles cryptographic implementations and OIDs mappings.
//
// Author:
// Sebastien Pouliot (sebastien@ximian.com)
// Tim Coleman (tim@timcoleman.com)
//
// (C) 2002, 2003 Motus Technologies Inc. (http://www.motus.com)
// Copyright (C) Tim Coleman, 2004
// Copyright (C) 2004-2007, 2009 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
namespace System.Security.Cryptography {
public partial class CryptoConfig {
public static byte[] EncodeOID (string str)
{
if (str == null)
throw new ArgumentNullException ("str");
char[] delim = { '.' };
string[] parts = str.Split (delim);
// according to X.208 n is always at least 2
if (parts.Length < 2) {
throw new CryptographicUnexpectedOperationException (
Locale.GetText ("OID must have at least two parts"));
}
// we're sure that the encoded OID is shorter than its string representation
byte[] oid = new byte [str.Length];
// now encoding value
try {
byte part0 = Convert.ToByte (parts [0]);
// OID[0] > 2 is invalid but "supported" in MS BCL
// uncomment next line to trap this error
// if (part0 > 2) throw new CryptographicUnexpectedOperationException ();
byte part1 = Convert.ToByte (parts [1]);
// OID[1] >= 40 is illegal for OID[0] < 2 because of the % 40
// however the syntax is "supported" in MS BCL
// uncomment next 2 lines to trap this error
//if ((part0 < 2) && (part1 >= 40))
// throw new CryptographicUnexpectedOperationException ();
oid[2] = Convert.ToByte (part0 * 40 + part1);
}
catch {
throw new CryptographicUnexpectedOperationException (
Locale.GetText ("Invalid OID"));
}
int j = 3;
for (int i = 2; i < parts.Length; i++) {
long x = Convert.ToInt64 (parts [i]);
if (x > 0x7F) {
byte[] num = EncodeLongNumber (x);
Buffer.BlockCopy (num, 0, oid, j, num.Length);
j += num.Length;
}
else
oid[j++] = Convert.ToByte (x);
}
int k = 2;
// copy the exact number of byte required
byte[] oid2 = new byte [j];
oid2[0] = 0x06; // always - this tag means OID
// Length (of value)
if (j > 0x7F) {
// for compatibility with MS BCL
throw new CryptographicUnexpectedOperationException (
Locale.GetText ("OID > 127 bytes"));
// comment exception and uncomment next 3 lines to remove restriction
//byte[] num = EncodeLongNumber (j);
//Buffer.BlockCopy (num, 0, oid, j, num.Length);
//k = num.Length + 1;
}
else
oid2 [1] = Convert.ToByte (j - 2);
Buffer.BlockCopy (oid, k, oid2, k, j - k);
return oid2;
}
// encode (7bits array) number greater than 127
private static byte[] EncodeLongNumber (long x)
{
// for MS BCL compatibility
// comment next two lines to remove restriction
if ((x > Int32.MaxValue) || (x < Int32.MinValue))
throw new OverflowException (Locale.GetText ("Part of OID doesn't fit in Int32"));
long y = x;
// number of bytes required to encode this number
int n = 1;
while (y > 0x7F) {
y = y >> 7;
n++;
}
byte[] num = new byte [n];
// encode all bytes
for (int i = 0; i < n; i++) {
y = x >> (7 * i);
y = y & 0x7F;
if (i != 0)
y += 0x80;
num[n-i-1] = Convert.ToByte (y);
}
return num;
}
}
}
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