MD5 Hash a String

SQL Server example to Digest-MD5 hash an XML document.

Download Chilkat Crypt ActiveX

CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @crypt int
    EXEC @hr = sp_OACreate 'Chilkat.Crypt2', @crypt OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    --  Any string argument automatically begins the 30-day trial.
    DECLARE @success int

    EXEC sp_OAMethod @crypt, 'UnlockComponent', @success OUT, '30-day trial'
    IF @success <> 1
      BEGIN
        PRINT 'Crypt component unlock failed'
        RETURN
      END

    DECLARE @xmlDoc nvarchar(4000)

    SELECT @xmlDoc = '<test><a>123</a><b>456</b><c>789</c></test>'

    --  This example was created in response to a request to
    --  do this:
    --  XML-->byte[]-->MD5(byte[])-->Base64(string)

    --  The output will be Base64, so set the EncodingMode:
    EXEC sp_OASetProperty @crypt, 'EncodingMode', 'base64'

    --  It is desired to hash bytes.  Depending on the programming
    --  language, strings may be Unicode (2 bytes/char).  We don't
    --  want to hash Unicode.  By setting the Charset property,
    --  we're telling the encryption component to first convert
    --  a string to the multibyte charset indicated.
    EXEC sp_OASetProperty @crypt, 'Charset', 'windows-1252'

    --  Set the hash algorithm:
    --  Choices are: md5, sha1, sha256, sha384, sha512, md2, haval
    EXEC sp_OASetProperty @crypt, 'HashAlgorithm', 'md5'

    DECLARE @hashStr nvarchar(4000)

    --  Hash the string:
    --  Internally, this converts the string to bytes, hashes the bytes,
    --  and converts the hash bytes to a Base64 encoded string:

    --  Note: Any method in Chilkat Crypt that ends with "ENC" returns the
    --  output bytes (i.e. hashed or encrypted) as an encoded string
    --  according to the EncodingMode property, which can be "base64",
    --  "hex", "url", "quoted-printable", or "html" (for HTML entities).
    EXEC sp_OAMethod @crypt, 'HashStringENC', @hashStr OUT, @xmlDoc


    PRINT @hashStr
END
GO