Module: Base64

Defined in:
lib/base64.rb

Overview

The Base64 module provides for the encoding (#encode64, #strict_encode64, #urlsafe_encode64) and decoding (#decode64, #strict_decode64, #urlsafe_decode64) of binary data using a Base64 representation.

Example

A simple encoding and decoding.

require "base64"

enc   = Base64.encode64('Send reinforcements')
                    # -> "U2VuZCByZWluZm9yY2VtZW50cw==\n"
plain = Base64.decode64(enc)
                    # -> "Send reinforcements"

The purpose of using base64 to encode data is that it translates any binary data into purely printable characters.

Class Method Summary collapse

Class Method Details

.decode64(str) ⇒ Object

Returns the Base64-decoded version of str. This method complies with RFC 2045. Characters outside the base alphabet are ignored.

require 'base64'
str = 'VGhpcyBpcyBsaW5lIG9uZQpUaGlzIG' +
      'lzIGxpbmUgdHdvClRoaXMgaXMgbGlu' +
      'ZSB0aHJlZQpBbmQgc28gb24uLi4K'
puts Base64.decode64(str)

Generates:

This is line one
This is line two
This is line three
And so on...


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# File 'lib/base64.rb', line 57

def decode64(str)
  str.unpack("m").first
end

.encode64(bin) ⇒ Object

Returns the Base64-encoded version of bin. This method complies with RFC 2045. Line feeds are added to every 60 encoded characters.

require 'base64'
Base64.encode64("Now is the time for all good coders\nto learn Ruby")

Generates:

Tm93IGlzIHRoZSB0aW1lIGZvciBhbGwgZ29vZCBjb2RlcnMKdG8gbGVhcm4g
UnVieQ==


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# File 'lib/base64.rb', line 37

def encode64(bin)
  [bin].pack("m")
end

.strict_decode64(str) ⇒ Object

Returns the Base64-decoded version of str. This method complies with RFC 4648. ArgumentError is raised if str is incorrectly padded or contains non-alphabet characters. Note that CR or LF are also rejected.



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# File 'lib/base64.rb', line 72

def strict_decode64(str)
  str.unpack("m0").first
end

.strict_encode64(bin) ⇒ Object

Returns the Base64-encoded version of bin. This method complies with RFC 4648. No line feeds are added.



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# File 'lib/base64.rb', line 64

def strict_encode64(bin)
  [bin].pack("m0")
end

.urlsafe_decode64(str) ⇒ Object

Returns the Base64-decoded version of str. This method complies with “Base 64 Encoding with URL and Filename Safe Alphabet'' in RFC 4648. The alphabet uses '-' instead of '+' and '_' instead of '/'.



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# File 'lib/base64.rb', line 88

def urlsafe_decode64(str)
  strict_decode64(str.tr("-_", "+/"))
end

.urlsafe_encode64(bin) ⇒ Object

Returns the Base64-encoded version of bin. This method complies with “Base 64 Encoding with URL and Filename Safe Alphabet'' in RFC 4648. The alphabet uses '-' instead of '+' and '_' instead of '/'.



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# File 'lib/base64.rb', line 80

def urlsafe_encode64(bin)
  strict_encode64(bin).tr("+/", "-_")
end