Here is a MIME64 encoder function written entirely in T-SQL
© 2006 Peter Larsson, Developer Workshop, all rights reserved
As long as the copyright notice is visible within the function declaration
and you include a note in the documentation of your system that these
functions are written by me, you may use these functions for free of charge.
If you intend to use these functions in a commercial application,
you are required to email me about your system and provide an email address
to the application manager.
If you like the code and use it just for fun, send an e-mail to me
and tell me about your experience with these functions.
I hope you enjoy these functions. I spent about two hours
writing them because I could not find them on the Internet.CREATE FUNCTION dbo.fnMIME64Encode
(
@RFC3548 BIT = 1,
@PlainText VARCHAR(6000)
)
RETURNS VARCHAR(8000)
AS
BEGIN
-- © 2006 Peter Larsson, Developer Workshop, all rights reserved
DECLARE @Characters VARCHAR(64), @Index SMALLINT,
@m1 TINYINT, @m2 TINYINT, @m3 TINYINT, @m4 TINYINT,
@MimeText VARCHAR(8000), @FinalBlock TINYINT
SELECT @Characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/',
@FinalBlock = DATALENGTH(@PlainText) % 3,
@PlainText = @PlainText + REPLICATE(CHAR(0), (3 - DATALENGTH(@PlainText) % 3) % 3),
@Index = DATALENGTH(@PlainText) - 2,
@MimeText = ''
WHILE @Index > 0
BEGIN
SELECT @m1 = (ASCII(SUBSTRING(@PlainText, @Index, 1)) & 252) / 4,
@m2 = (ASCII(SUBSTRING(@PlainText, @Index, 1)) & 3) * 16 + (ASCII(SUBSTRING(@PlainText, @Index + 1, 1)) & 240) / 16,
@m3 = (ASCII(SUBSTRING(@PlainText, @Index + 1, 1)) & 15) * 4 + (ASCII(SUBSTRING(@PlainText, @Index + 2, 1)) & 192) / 64,
@m4 = ASCII(SUBSTRING(@PlainText, @Index + 2, 1)) & 63
SELECT @MimeText = CASE
WHEN @FinalBlock = 1 THEN SUBSTRING(@Characters, @m1 + 1, 1) + SUBSTRING(@Characters, @m2 + 1, 1) + '=='
WHEN @FinalBlock = 2 THEN SUBSTRING(@Characters, @m1 + 1, 1) + SUBSTRING(@Characters, @m2 + 1, 1) + SUBSTRING(@Characters, @m3 + 1, 1) + '='
ELSE SUBSTRING(@Characters, @m1 + 1, 1) + SUBSTRING(@Characters, @m2 + 1, 1) + SUBSTRING(@Characters, @m3 + 1, 1) + SUBSTRING(@Characters, @m4 + 1, 1)
END + @MimeText,
@Index = @Index - 3,
@FinalBlock = 0
END
IF @RFC3548 = 1
BEGIN
SELECT @Index = 1 + DATALENGTH(@MimeText) - DATALENGTH(@MimeText) % 76
IF @Index > DATALENGTH(@MimeText)
SELECT @Index = @Index - 76
WHILE @Index > 1
SELECT @MimeText = STUFF(@MimeText, @Index, 0, CHAR(13) + CHAR(10)),
@Index = @Index - 76
END
RETURN @MimeText
END
and of course the MIME64 decoder functionCREATE FUNCTION dbo.fnMIME64Decode
(
@MimeText VARCHAR(8000)
)
RETURNS VARCHAR(6000)
AS
BEGIN
-- © 2006 Peter Larsson, Developer Workshop, all rights reserved
DECLARE @Characters VARCHAR(64), @Index SMALLINT,
@m1 TINYINT, @m2 TINYINT, @m3 SMALLINT, @m4 SMALLINT,
@p1 TINYINT, @p2 TINYINT, @p3 TINYINT,
@PlainText VARCHAR(6000), @Paddings TINYINT
SELECT @Characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/',
@MimeText = REPLACE(REPLACE(@MimeText, CHAR(13), ''), CHAR(10), ''),
@Index = DATALENGTH(@MimeText) - 3,
@Paddings = DATALENGTH(@MimeText) - DATALENGTH(REPLACE(@MimeText, '=', '')),
@PlainText = ''
WHILE @Index > 0
SELECT @m1 = CHARINDEX(CAST(SUBSTRING(@MimeText, @Index, 1) AS BINARY(1)), CAST(@Characters AS BINARY(64))) - 1,
@m2 = CHARINDEX(CAST(SUBSTRING(@MimeText, @Index + 1, 1) AS BINARY(1)), CAST(@Characters AS BINARY(64))) - 1,
@m3 = CHARINDEX(CAST(SUBSTRING(@MimeText, @Index + 2, 1) AS BINARY(1)), CAST(@Characters AS BINARY(64))) - 1,
@m4 = CHARINDEX(CAST(SUBSTRING(@MimeText, @Index + 3, 1) AS BINARY(1)), CAST(@Characters AS BINARY(64))) - 1,
@p1 = (@m1 & 63) * 4 + (@m2 & 48) / 16,
@p2 = (@m2 & 15) * 16 + (@m3 & 60) / 4,
@p3 = (@m3 & 3) * 64 + (@m4 & 63),
@PlainText = CHAR(@p1) + CHAR(@p2) + CHAR(@p3) + @PlainText,
@Index = @Index - 4
RETURN LEFT(@PlainText, DATALENGTH(@PlainText) - @Paddings)
END
Peter Larsson
Helsingborg, Sweden
MIME64 Encoder and Decoder
Posted - 06/15/2006 : 02:39:52
