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@DJm00n
Created December 29, 2023 14:04
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Search UAPKI public key on CMP server.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Threading.Tasks;
namespace CA_Client.Helpers
{
internal static class SearchByCmp
{
private static int GetHexVal(char hex)
{
int val = (int)hex;
//For uppercase A-F letters:
//return val - (val < 58 ? 48 : 55);
//For lowercase a-f letters:
//return val - (val < 58 ? 48 : 87);
//Or the two combined, but a bit slower:
return val - (val < 58 ? 48 : (val < 97 ? 55 : 87));
}
private static byte[] HexToBytes(string hex)
{
if (hex.Length % 2 == 1)
throw new ArgumentException("The hexadecimal key must have an even number of digits");
byte[] arr = new byte[hex.Length >> 1];
for (int i = 0; i < hex.Length >> 1; ++i)
{
arr[i] = (byte)((GetHexVal(hex[i << 1]) << 4) + (GetHexVal(hex[(i << 1) + 1])));
}
return arr;
}
public static byte[] GetCertBundle(string url, string keyId1, string keyId2)
{
string pre = "30818706092a864886f70d010701a07a04780d0000000000000002000000";
string post = "0000000000000000000000000000000000000000000000000000000000000000010000000100000000000000";
if (keyId1.Length == 40)
keyId1 += "000000000000000000000000";
if (keyId2.Length == 40)
keyId2 += "000000000000000000000000";
if ((keyId1.Length != 64) || (keyId2.Length != 64))
throw new ArgumentException("CMP supports only DSTU keys");
var req = HexToBytes(pre + keyId1 + keyId2 + post);
var byteContent = new ByteArrayContent(req);
var client = new HttpClient();
var result = client.PostAsync(url, byteContent).Result.Content.ReadAsByteArrayAsync().Result;
if (result.Length < 280)
throw new Exception("Certificates not found");
if (result.Length > 65536)
throw new Exception("Response too long");
int offset = 31;
var bundle = new byte[result.Length - offset];
Array.Copy(result, offset, bundle, 0, result.Length - offset);
return bundle;
}
}
}
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