internal static string Sanitize()

in src/Microsoft.Azure.WebJobs.Shared/Sanitizer.cs [29:78]
37 lines of code
10 McCabe index (conditional complexity)

        internal static string Sanitize(string input)
        {
            if (string.IsNullOrEmpty(input))
            {
                return string.Empty;
            }

            // Everything we *might* replace contains an equal, so if we don't have that short circuit out.
            // This can be likely be more efficient with a Regex, but that's best done with a large test suite and this is
            // a quick/simple win for the high traffic case.
            if (!MayContainCredentials(input))
            {
                return input;
            }

            string t = input;
            string inputWithAllowedTokensHidden = input;

            // Remove any known safe strings from the input before looking for Credentials
            foreach (string allowedToken in AllowedTokens)
            {
                if (inputWithAllowedTokensHidden.Contains(allowedToken))
                {
                    string hiddenString = new string('#', allowedToken.Length);
                    inputWithAllowedTokensHidden = inputWithAllowedTokensHidden.Replace(allowedToken, hiddenString);
                }
            }

            foreach (var token in CredentialTokens)
            {
                int startIndex = 0;
                while (true)
                {
                    // search for the next token instance
                    startIndex = inputWithAllowedTokensHidden.IndexOf(token, startIndex, StringComparison.OrdinalIgnoreCase);
                    if (startIndex == -1)
                    {
                        break;
                    }

                    // Find the end of the secret. It most likely ends with either a double quota " or tag opening <
                    int credentialEnd = t.IndexOfAny(ValueTerminators, startIndex);

                    t = t.Substring(0, startIndex) + SecretReplacement + (credentialEnd != -1 ? t.Substring(credentialEnd) : string.Empty);
                    inputWithAllowedTokensHidden = inputWithAllowedTokensHidden.Substring(0, startIndex) + SecretReplacement + (credentialEnd != -1 ? inputWithAllowedTokensHidden.Substring(credentialEnd) : string.Empty);
                }
            }

            return t;
        }