Agent incorrectly reporting corrective changes when base64 padding is missing from Content-MD5

Puppet Version: 6.11.1
Puppet Server Version: 6
OS Name/Version: Centos 

Reproducing this requires using a file from an https server as the source for a local file. In our case it is things that are secret like /etc/shadow that we don't want committed to our puppet repo. 

Local Reproducing Steps:

• run the command below and copy the md5 resulted

[root@unpaved-song ttt]# printf '%s' "File Data" | md5sum

0ee8336a3589503bcb03c7885950c909

• create a .rb file and copy the following inside to have a server with a get response with "File Data" text and a Content-MD5 header.

# server.rb

require 'socket'

server = TCPServer.new 5678

while session = server.accept

  request = session.gets

  puts request 

  session.print "HTTP/1.1 200\r\n"

  session.print "Content-Type: text/html\r\n"

  session.print "Content-MD5: 0ee8336a3589503bcb03c7885950c909\r\n"

  session.print "\r\n"

  session.print "File Data"

  session.close

end

• run ruby server.rb to start the server
• run puppet apply -e 'file {"/file_from_server": source => "http://localhost:5678"}' to get the data form the local server

[root@unpaved-song ttt]# puppet apply -e 'file {"/file_from_server": source => "http://localhost:5678"}'

Notice: Compiled catalog for unpaved-song.delivery.puppetlabs.net in environment production in 0.01 seconds

Notice: /Stage[main]/Main/File[/file_from_server]/ensure: defined content as '{md5}f5d7fb75fe1beb6f1bedaefa6bddf7df9e7df797b9ef4d9c'

Notice: Applied catalog in 0.07 seconds

• Running the command again you will get

Notice: /Stage[main]/Main/File[/file_from_server]/content: content changed '{md5}0ee8336a3589503bcb03c7885950c909' to '{md5}f5d7fb75fe1beb6f1bedaefa6bddf7df9e7df797b9ef4d9c'

Desired Behavior:

I want the agent to calculate the md5sum correctly when pulling a file from a remote https server. 

Actual Behavior:

Agent reports changing content from an MD5 with 128 bits to an 'MD5' with 196 bits. It doesn't change the file as no changes are needed. The 'changed' file's md5sum is the same before and  after the agent runs.

It seems to be using a 196 bit hash in place of an md5sum and reporting it needs changing as the 128 bit and 196 bit values are not equal.