module Base64

Overview

The Base64 module provides for the encoding (#encode, #strict_encode, #urlsafe_encode) and decoding (#decode) of binary data using a Base64 representation.

Example

A simple encoding and decoding.

require "base64"
enc   = Base64.encode("Send reinforcements")
                    # => "U2VuZCByZWluZm9yY2VtZW50cw==\n"
plain = Base64.decode(enc)
                    # => "Send reinforcements"

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

Extended Modules

Defined in:

base64.cr

Instance Method Summary

Instance Method Detail

def decode(data, io : IO) #

Write the Base64-decoded version of data to io. This will decode either the normal or urlsafe alphabets.


[View source]
def decode(data) : Bytes #

Returns the Base64-decoded version of data as a Slice(UInt8). This will decode either the normal or urlsafe alphabets.


[View source]
def decode_string(data) : String #

Returns the Base64-decoded version of data as a string. If the data doesn't decode to a valid UTF8 string, InvalidByteSequenceError will be raised. This will decode either the normal or urlsafe alphabets.


[View source]
def encode(data, io : IO) #

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

require "base64"
Base64.encode("Now is the time for all good coders\nto learn Crystal", io)

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def encode(data) : String #

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

require "base64"
puts Base64.encode("Now is the time for all good coders\nto learn Crystal")

Generates:

Tm93IGlzIHRoZSB0aW1lIGZvciBhbGwgZ29vZCBjb2RlcnMKdG8gbGVhcm4g

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def strict_encode(data, io : IO) #

Write the Base64-encoded version of data with no newlines to io. This method complies with RFC 4648.

require "base64"
Base64.strict_encode("Now is the time for all good coders\nto learn Crystal", io)

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def strict_encode(data) : String #

Returns the Base64-encoded version of data with no newlines. This method complies with RFC 4648.

require "base64"
puts Base64.strict_encode("Now is the time for all good coders\nto learn Crystal")

Generates:

Tm93IGlzIHRoZSB0aW1lIGZvciBhbGwgZ29vZCBjb2RlcnMKdG8gbGVhcm4gQ3J5c3RhbA==

[View source]
def urlsafe_encode(data, io : IO) #

Write the Base64-encoded version of data using a urlsafe alphabet to io. 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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def urlsafe_encode(data, padding = true) : String #

Returns the Base64-encoded version of data using a urlsafe alphabet. This method complies with "Base 64 Encoding with URL and Filename Safe Alphabet" in RFC 4648.

The alphabet uses '-' instead of '+' and '_' instead of '/'.

The padding parameter defaults to true. When false, enough = characters are not added to make the output divisible by 4.


[View source]