private static void CheckTrack(string track, MagneticTrackKind trackKind, bool containsChecksum = false)
{
int length = track.Length;
if (containsChecksum)
{
length--;
}
char sentineStart;
char sentineEnd;
switch (trackKind)
{
case MagneticTrackKind.Track1:
sentineStart = MagneticStripeParser.Track1StartSentinel;
sentineEnd = MagneticStripeParser.Track1EndSentinel;
break;
case MagneticTrackKind.Track2:
sentineStart = MagneticStripeParser.Track2StartSentinel;
sentineEnd = MagneticStripeParser.Track2EndSentinel;
break;
default:
throw new NotSupportedException(string.Format("Retrieval of track '{0}' not supported.", trackKind));
}
// Checking for track sentines
if (length < 2 || track[0] != sentineStart || track[length - 1] != sentineEnd)
{
throw new FormatException("The track doesn't have start and end sentines.");
}
}
/// <summary>
/// Extracts card number from a given track 1.
/// </summary>
/// <param name="track">The track of a payment card.</param>
/// <param name="trackKind">The kind of the track.</param>
/// <returns>The extracted card number.</returns>
/// <remarks>
/// Only format B for track 1 is supported.
/// </remarks>
public static string ExtractCardNumber(string track, MagneticTrackKind trackKind)
{
if (track == null)
{
throw new ArgumentNullException("track");
}
CheckTrack(track, trackKind);
switch (trackKind)
{
case MagneticTrackKind.Track1:
return(ExtractTrack1BCardNumber(track));
case MagneticTrackKind.Track2:
return(ExtractTrack2CardNumber(track));
default:
throw new NotSupportedException(string.Format("Retrieval of card number from track '{0}' not supported.", trackKind));
}
}
/// <summary>
/// Extracts payment card track of given kind from a given raw magnetic stipe track.
/// </summary>
/// <param name="rawTrack">The raw magnetic stripe track.</param>
/// <param name="offset">The offset in the raw track.</param>
/// <param name="length">The length of the track.</param>
/// <param name="trackKind">The kind of the track.</param>
/// <param name="excludeChecksum">True to exclude trailing checksum from the extracted track; otherwise - false.</param>
/// <returns>The extracted track.</returns>
public static string ExtractTrack(byte[] rawTrack, int offset, int length, MagneticTrackKind trackKind, bool excludeChecksum = true)
{
if (rawTrack == null)
{
throw new ArgumentNullException("rawTrack");
}
if (length == 0)
{
return(null);
}
var track = AsciiStringConverter.Ascii8BitToString(rawTrack, offset, length);
CheckTrack(track, trackKind, !excludeChecksum);
return(track);
}
