//
// This method reads a standard quoted string. Departing from the RFC, Unicode is permitted for display-name.
//
// Preconditions:
// - Index must be within the bounds of the data string.
// - The char at the given index is the initial quote. (data[index] == Quote)
//
// Return value: The next index past the terminating-quote (data[index + 1] == Quote).
// e.g. In (bob "user name"@domain), starting at index=14 (") returns index=3 (space).
//
// A FormatException will be thrown if:
// - A non-escaped character is encountered that is not valid in a quoted string.
// - A Unicode character is encountered and Unicode has not been allowed.
// - The final double quote is not found.
//
internal static int ReadReverseQuoted(string data, int index, bool permitUnicode)
{
Debug.Assert(0 <= index && index < data.Length, "Index out of range: " + index + ", " + data.Length);
// Check for the first bounding quote
Debug.Assert(data[index] == MailBnfHelper.Quote, "Initial char at index " + index + " was not a quote.");
// Skip the bounding quote
index--;
do
{
// Check for valid whitespace
index = WhitespaceReader.ReadFwsReverse(data, index);
if (index < 0)
{
break;
}
// Check for escaped characters
int quotedCharCount = QuotedPairReader.CountQuotedChars(data, index, permitUnicode);
if (quotedCharCount > 0)
{
// Skip quoted pairs
index = index - quotedCharCount;
}
// Check for the terminating quote
else if (data[index] == MailBnfHelper.Quote)
{
// Skip the final bounding quote
return(index - 1);
}
// Check invalid characters
else if (!IsValidQtext(permitUnicode, data[index]))
{
throw new FormatException(string.Format(Strings.MailHeaderFieldInvalidCharacter, data[index]));
}
// Valid char
else
{
index--;
}
}while (index >= 0);
// We started with a quote, but did not end with one
throw new FormatException(string.Format(Strings.MailHeaderFieldInvalidCharacter, MailBnfHelper.Quote));
}
//
// Reads a domain literal in reverse
//
// Preconditions:
// - Index must be within the bounds of the data string.
// - The char at the given index is the initial bracket. (data[index] == EndSquareBracket)
//
// Return value:
// - The next index past the terminating bracket (data[index + 1] == StartSquareBracket).
// e.g. In (user@[domain]), starting at index=12 (]) returns index=4 (@).
//
// A FormatException will be thrown if:
// - A non-escaped character is encountered that is not valid in a domain literal, including Unicode.
// - The final bracket is not found.
//
internal static int ReadReverse(string data, int index)
{
Debug.Assert(0 <= index && index < data.Length, "index was outside the bounds of the string: " + index);
Debug.Assert(data[index] == MailBnfHelper.EndSquareBracket, "data did not end with a square bracket");
// Skip the end bracket
index--;
do
{
// Check for valid whitespace
index = WhitespaceReader.ReadFwsReverse(data, index);
if (index < 0)
{
break;
}
// Check for escaped characters
int quotedCharCount = QuotedPairReader.CountQuotedChars(data, index, false);
if (quotedCharCount > 0)
{
// Skip quoted pairs
index = index - quotedCharCount;
}
// Check for the terminating bracket
else if (data[index] == MailBnfHelper.StartSquareBracket)
{
// We're done parsing
return(index - 1);
}
// Check for invalid characters
else if (data[index] > MailBnfHelper.Ascii7bitMaxValue || !MailBnfHelper.Dtext[data[index]])
{
throw new FormatException(string.Format(Strings.MailHeaderFieldInvalidCharacter, data[index]));
}
// Valid char
else
{
index--;
}
}while (index >= 0);
// We didn't find a matching '[', throw.
throw new FormatException(string.Format(Strings.MailHeaderFieldInvalidCharacter,
MailBnfHelper.EndSquareBracket));
}
//
// This method attempts reading quoted-string formatted data when the bounding quotes were omitted.
// This is common for e-mail display-names.
//
// Precondition: The index must be within the bounds of the data string.
//
// Return value:
// - The index of the special delimiter provided.
// e.g. In ([email protected], billy box [email protected]), starting at index=19 (x) returns index=9 (,).
// - -1 if the terminating character was not found.
// e.g. In (my name username@domain), starting at index=5 (e) returns index=-1.
//
// A FormatException will be thrown if:
// - A non-escaped character is encountered that is not valid in a quoted string. This includes double quotes.
// - A Unicode character is encountered and Unicode has not been allowed.
//
internal static int ReadReverseUnQuoted(string data, int index, bool permitUnicode, bool expectCommaDelimiter)
{
Debug.Assert(0 <= index && index < data.Length, "Index out of range: " + index + ", " + data.Length);
do
{
// Check for valid whitespace
index = WhitespaceReader.ReadFwsReverse(data, index);
if (index < 0)
{
break;
}
// Check for escaped characters
int quotedCharCount = QuotedPairReader.CountQuotedChars(data, index, permitUnicode);
if (quotedCharCount > 0)
{
index = index - quotedCharCount;
}
// Check for the terminating char
else if (expectCommaDelimiter && data[index] == MailBnfHelper.Comma)
{
break;
}
// Check invalid characters
else if (!IsValidQtext(permitUnicode, data[index]))
{
throw new FormatException(string.Format(Strings.MailHeaderFieldInvalidCharacter, data[index]));
}
// Valid char
else
{
index--;
}
}while (index >= 0);
return(index);
}
