Convert string to binary base64 - xslt

Question

Is there any way on how to convert a string to binary base64? I've seen many references but it didn't work in my end. For example I have this input file:
<RootElement xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<Data>
<Binary>
<RawData>This element should convert string to binary base64.</RawData>
</Binary>
</Data>
</RootElement>
I need to generate:
<RootElement xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<Data>
<Binary>
<RawData>VGhpcyBlbGVtZW50IHNob3VsZCBjb252ZXJ0IHN0cmluZyB0byBiaW5hcnkgYmFzZTY0Lg==</RawData>
</Binary>
</Data>
I created an xslt and used the namespace I've seen online:
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dp="http://www.datapower.com/extensions">
<xsl:output method="xml" version="1.0" indent="yes"/>
<xsl:strip-space elements="*"/>
<xsl:template match="#*|node()">
<xsl:copy>
<xsl:apply-templates select="#*|node()"/>
</xsl:copy>
</xsl:template>
<xsl:template match="RawData">
<xsl:element name="RawData">
<xsl:value-of select="dp:encode(., 'base-64')"/>
</xsl:element>
</xsl:template>
</xsl:stylesheet>
Thank you.

Answer 1

There is a pure XSLT 1.0 solution that works for any XSLT processor: JAXP, Saxon, Xalan, Xsltproc, Microsoft:
Download base64.xsl
Download base64_binarydatamap.xml
Use XSLT 1.0:
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:b64="https://github.com/ilyakharlamov/xslt_base64">
<xsl:output method="xml"/>
<xsl:include href="base64.xsl"/>
<xsl:template match="#*|node()">
<xsl:copy>
<xsl:apply-templates select="#*|node()" />
</xsl:copy>
</xsl:template>
<xsl:template match="/RootElement/Data/Binary/RawData">
<xsl:call-template name="b64:encode">
<xsl:with-param name="asciiString" select="text()"/>
</xsl:call-template>
</xsl:template>
</xsl:stylesheet>