Org.BouncyCastle.Asn1.DerApplicationSpecific.ReplaceTagNumber C# (CSharp) Méthode

		private byte[] ReplaceTagNumber(
			int		newTag,
			byte[]	input)
		{
			int tagNo = input[0] & 0x1f;
			int index = 1;
			//
			// with tagged object tag number is bottom 5 bits, or stored at the start of the content
			//
			if (tagNo == 0x1f)
			{
				tagNo = 0;

				int b = input[index++] & 0xff;

				// X.690-0207 8.1.2.4.2
				// "c) bits 7 to 1 of the first subsequent octet shall not all be zero."
				if ((b & 0x7f) == 0) // Note: -1 will pass
				{
					throw new InvalidOperationException("corrupted stream - invalid high tag number found");
				}

				while ((b >= 0) && ((b & 0x80) != 0))
				{
					tagNo |= (b & 0x7f);
					tagNo <<= 7;
					b = input[index++] & 0xff;
				}

				tagNo |= (b & 0x7f);
			}

			byte[] tmp = new byte[input.Length - index + 1];

			Array.Copy(input, index, tmp, 1, tmp.Length - 1);

			tmp[0] = (byte)newTag;

			return tmp;
		}
    }