Internal.Cryptography.Pal.DirectoryBasedStoreProvider.FindOpenSlot C# (CSharp) Method

        private string FindOpenSlot(string thumbprint)
        {
            // We already know that {thumbprint}.pfx is taken, so start with {thumbprint}.1.pfx

            // We need space for {thumbprint} (thumbprint.Length)
            // And ".0.pfx" (6)
            // If MaxSaveAttempts is big enough to use more than one digit, we need that space, too (MaxSaveAttempts / 10)
            StringBuilder pathBuilder = new StringBuilder(thumbprint.Length + PfxOrdinalWildcard.Length + (MaxSaveAttempts / 10));

            pathBuilder.Append(thumbprint);
            pathBuilder.Append('.');
            int prefixLength = pathBuilder.Length;

            for (int i = 1; i <= MaxSaveAttempts; i++)
            {
                pathBuilder.Length = prefixLength;

                pathBuilder.Append(i);
                pathBuilder.Append(PfxExtension);

                string builtPath = Path.Combine(_storePath, pathBuilder.ToString());

                if (!File.Exists(builtPath))
                {
                    return builtPath;
                }
            }

            throw new CryptographicException(SR.Cryptography_X509_StoreNoFileAvailable);
        }