Base
This module provides data encoding and decoding functions according to RFC 4648.
This document defines the commonly used base 16, base 32, and base 64 encoding schemes.
Base 16 alphabet
| Value | Encoding | Value | Encoding | Value | Encoding | Value | Encoding | |------:|---------:|------:|---------:|------:|---------:|------:|---------:| | 0| 0| 4| 4| 8| 8| 12| C| | 1| 1| 5| 5| 9| 9| 13| D| | 2| 2| 6| 6| 10| A| 14| E| | 3| 3| 7| 7| 11| B| 15| F|
Base 32 alphabet
| Value | Encoding | Value | Encoding | Value | Encoding | Value | Encoding | |------:|---------:|------:|---------:|------:|---------:|------:|---------:| | 0| A| 9| J| 18| S| 27| 3| | 1| B| 10| K| 19| T| 28| 4| | 2| C| 11| L| 20| U| 29| 5| | 3| D| 12| M| 21| V| 30| 6| | 4| E| 13| N| 22| W| 31| 7| | 5| F| 14| O| 23| X| | | | 6| G| 15| P| 24| Y| (pad)| =| | 7| H| 16| Q| 25| Z| | | | 8| I| 17| R| 26| 2| | |
Base 32 (extended hex) alphabet
| Value | Encoding | Value | Encoding | Value | Encoding | Value | Encoding | |------:|---------:|------:|---------:|------:|---------:|------:|---------:| | 0| 0| 9| 9| 18| I| 27| R| | 1| 1| 10| A| 19| J| 28| S| | 2| 2| 11| B| 20| K| 29| T| | 3| 3| 12| C| 21| L| 30| U| | 4| 4| 13| D| 22| M| 31| V| | 5| 5| 14| E| 23| N| | | | 6| 6| 15| F| 24| O| (pad)| =| | 7| 7| 16| G| 25| P| | | | 8| 8| 17| H| 26| Q| | |
Base 64 alphabet
| Value | Encoding | Value | Encoding | Value | Encoding | Value | Encoding | |------:|---------:|------:|---------:|------:|---------:|------:|---------:| | 0| A| 17| R| 34| i| 51| z| | 1| B| 18| S| 35| j| 52| 0| | 2| C| 19| T| 36| k| 53| 1| | 3| D| 20| U| 37| l| 54| 2| | 4| E| 21| V| 38| m| 55| 3| | 5| F| 22| W| 39| n| 56| 4| | 6| G| 23| X| 40| o| 57| 5| | 7| H| 24| Y| 41| p| 58| 6| | 8| I| 25| Z| 42| q| 59| 7| | 9| J| 26| a| 43| r| 60| 8| | 10| K| 27| b| 44| s| 61| 9| | 11| L| 28| c| 45| t| 62| +| | 12| M| 29| d| 46| u| 63| /| | 13| N| 30| e| 47| v| | | | 14| O| 31| f| 48| w| (pad)| =| | 15| P| 32| g| 49| x| | | | 16| Q| 33| h| 50| y| | |
Base 64 (URL and filename safe) alphabet
| Value | Encoding | Value | Encoding | Value | Encoding | Value | Encoding | |------:|---------:|------:|---------:|------:|---------:|------:|---------:| | 0| A| 17| R| 34| i| 51| z| | 1| B| 18| S| 35| j| 52| 0| | 2| C| 19| T| 36| k| 53| 1| | 3| D| 20| U| 37| l| 54| 2| | 4| E| 21| V| 38| m| 55| 3| | 5| F| 22| W| 39| n| 56| 4| | 6| G| 23| X| 40| o| 57| 5| | 7| H| 24| Y| 41| p| 58| 6| | 8| I| 25| Z| 42| q| 59| 7| | 9| J| 26| a| 43| r| 60| 8| | 10| K| 27| b| 44| s| 61| 9| | 11| L| 28| c| 45| t| 62| -| | 12| M| 29| d| 46| u| 63| _| | 13| N| 30| e| 47| v| | | | 14| O| 31| f| 48| w| (pad)| =| | 15| P| 32| g| 49| x| | | | 16| Q| 33| h| 50| y| | |
Summary
Functions
- decode16(string, opts \\ [])
-
Decodes a base 16 encoded string into a binary string
- decode16!(string, opts \\ [])
-
Decodes a base 16 encoded string into a binary string
- decode32(string, opts \\ [])
-
Decodes a base 32 encoded string into a binary string
- decode32!(string, opts \\ [])
-
Decodes a base 32 encoded string into a binary string
- decode64(string, opts \\ [])
-
Decodes a base 64 encoded string into a binary string
- decode64!(string, opts \\ [])
-
Decodes a base 64 encoded string into a binary string
- encode16(data, opts \\ [])
-
Encodes a binary string into a base 16 encoded string
- encode32(data, opts \\ [])
-
Encodes a binary string into a base 32 encoded string
- encode64(data, opts \\ [])
-
Encodes a binary string into a base 64 encoded string
- hex_decode32(string, opts \\ [])
-
Decodes a base 32 encoded string with extended hexadecimal alphabet into a binary string
- hex_decode32!(string, opts \\ [])
-
Decodes a base 32 encoded string with extended hexadecimal alphabet into a binary string
- hex_encode32(data, opts \\ [])
-
Encodes a binary string into a base 32 encoded string with an extended hexadecimal alphabet
- url_decode64(string, opts \\ [])
-
Decodes a base 64 encoded string with URL and filename safe alphabet into a binary string
- url_decode64!(string, opts \\ [])
-
Decodes a base 64 encoded string with URL and filename safe alphabet into a binary string
- url_encode64(data, opts \\ [])
-
Encodes a binary string into a base 64 encoded string with URL and filename safe alphabet
Functions
decode16(string, opts \\ [])
decode16(binary, Keyword.t) :: {:ok, binary} | :error Decodes a base 16 encoded string into a binary string.
Options
The accepted options are:
-
:case- specifies the character case to accept when decoding
The values for :case can be:
-
:upper- only allow upper case characters (default) -
:lower- only allow lower case characters -
:mixed- allow mixed case characters
Examples
iex> Base.decode16("666F6F626172")
{:ok, "foobar"}
iex> Base.decode16("666f6f626172", case: :lower)
{:ok, "foobar"}
iex> Base.decode16("666f6F626172", case: :mixed)
{:ok, "foobar"} decode16!(string, opts \\ [])
decode16!(binary, Keyword.t) :: binary
Decodes a base 16 encoded string into a binary string.
Options
The accepted options are:
-
:case- specifies the character case to accept when decoding
The values for :case can be:
-
:upper- only allow upper case characters (default) -
:lower- only allow lower case characters -
:mixed- allow mixed case characters
An ArgumentError exception is raised if the padding is incorrect or a non-alphabet character is present in the string.
Examples
iex> Base.decode16!("666F6F626172")
"foobar"
iex> Base.decode16!("666f6f626172", case: :lower)
"foobar"
iex> Base.decode16!("666f6F626172", case: :mixed)
"foobar" decode32(string, opts \\ [])
decode32(binary, Keyword.t) :: {:ok, binary} | :error Decodes a base 32 encoded string into a binary string.
Options
The accepted options are:
-
:case- specifies the character case to accept when decoding -
:padding- specifies whether to require padding
The values for :case can be:
-
:upper- only allow upper case characters (default) -
:lower- only allow lower case characters -
:mixed- allow mixed case characters
The values for :padding can be:
-
true- require the input string to be padded to the nearest multiple of 8 (default) -
false- ignore padding from the input string
Examples
iex> Base.decode32("MZXW6YTBOI======")
{:ok, "foobar"}
iex> Base.decode32("mzxw6ytboi======", case: :lower)
{:ok, "foobar"}
iex> Base.decode32("mzXW6ytBOi======", case: :mixed)
{:ok, "foobar"}
iex> Base.decode32("MZXW6YTBOI", padding: false)
{:ok, "foobar"} decode32!(string, opts \\ [])
decode32!(binary, Keyword.t) :: binary
Decodes a base 32 encoded string into a binary string.
An ArgumentError exception is raised if the padding is incorrect or a non-alphabet character is present in the string.
Options
The accepted options are:
-
:case- specifies the character case to accept when decoding -
:padding- specifies whether to require padding
The values for :case can be:
-
:upper- only allow upper case characters (default) -
:lower- only allow lower case characters -
:mixed- allow mixed case characters
The values for :padding can be:
-
true- require the input string to be padded to the nearest multiple of 8 (default) -
false- ignore padding from the input string
Examples
iex> Base.decode32!("MZXW6YTBOI======")
"foobar"
iex> Base.decode32!("mzxw6ytboi======", case: :lower)
"foobar"
iex> Base.decode32!("mzXW6ytBOi======", case: :mixed)
"foobar"
iex> Base.decode32!("MZXW6YTBOI", padding: false)
"foobar" decode64(string, opts \\ [])
decode64(binary, Keyword.t) :: {:ok, binary} | :error Decodes a base 64 encoded string into a binary string.
Accepts ignore: :whitespace option which will ignore all the whitespace characters in the input string.
Accepts padding: false option which will ignore padding from the input string.
Examples
iex> Base.decode64("Zm9vYmFy")
{:ok, "foobar"}
iex> Base.decode64("Zm9vYmFy\n", ignore: :whitespace)
{:ok, "foobar"}
iex> Base.decode64("Zm9vYg==")
{:ok, "foob"}
iex> Base.decode64("Zm9vYg", padding: false)
{:ok, "foob"} decode64!(string, opts \\ [])
decode64!(binary, Keyword.t) :: binary
Decodes a base 64 encoded string into a binary string.
Accepts ignore: :whitespace option which will ignore all the whitespace characters in the input string.
Accepts padding: false option which will ignore padding from the input string.
An ArgumentError exception is raised if the padding is incorrect or a non-alphabet character is present in the string.
Examples
iex> Base.decode64!("Zm9vYmFy")
"foobar"
iex> Base.decode64!("Zm9vYmFy\n", ignore: :whitespace)
"foobar"
iex> Base.decode64!("Zm9vYg==")
"foob"
iex> Base.decode64!("Zm9vYg", padding: false)
"foob" encode16(data, opts \\ [])
encode16(binary, Keyword.t) :: binary
Encodes a binary string into a base 16 encoded string.
Options
The accepted options are:
-
:case- specifies the character case to use when encoding
The values for :case can be:
-
:upper- use upper case characters (default) -
:lower- use lower case characters
Examples
iex> Base.encode16("foobar")
"666F6F626172"
iex> Base.encode16("foobar", case: :lower)
"666f6f626172" encode32(data, opts \\ [])
encode32(binary, Keyword.t) :: binary
Encodes a binary string into a base 32 encoded string.
Options
The accepted options are:
-
:case- specifies the character case to use when encoding -
:padding- specifies whether to apply padding
The values for :case can be:
-
:upper- use upper case characters (default) -
:lower- use lower case characters
The values for :padding can be:
-
true- pad the output string to the nearest multiple of 8 (default) -
false- omit padding from the output string
Examples
iex> Base.encode32("foobar")
"MZXW6YTBOI======"
iex> Base.encode32("foobar", case: :lower)
"mzxw6ytboi======"
iex> Base.encode32("foobar", padding: false)
"MZXW6YTBOI" encode64(data, opts \\ [])
encode64(binary, Keyword.t) :: binary
Encodes a binary string into a base 64 encoded string.
Accepts padding: false option which will omit padding from the output string.
Examples
iex> Base.encode64("foobar")
"Zm9vYmFy"
iex> Base.encode64("foob")
"Zm9vYg=="
iex> Base.encode64("foob", padding: false)
"Zm9vYg" hex_decode32(string, opts \\ [])
hex_decode32(binary, Keyword.t) :: {:ok, binary} | :error Decodes a base 32 encoded string with extended hexadecimal alphabet into a binary string.
Options
The accepted options are:
-
:case- specifies the character case to accept when decoding -
:padding- specifies whether to require padding
The values for :case can be:
-
:upper- only allow upper case characters (default) -
:lower- only allow lower case characters -
:mixed- allow mixed case characters
The values for :padding can be:
-
true- require the input string to be padded to the nearest multiple of 8 (default) -
false- ignore padding from the input string
Examples
iex> Base.hex_decode32("CPNMUOJ1E8======")
{:ok, "foobar"}
iex> Base.hex_decode32("cpnmuoj1e8======", case: :lower)
{:ok, "foobar"}
iex> Base.hex_decode32("cpnMuOJ1E8======", case: :mixed)
{:ok, "foobar"}
iex> Base.hex_decode32("CPNMUOJ1E8", padding: false)
{:ok, "foobar"} hex_decode32!(string, opts \\ [])
hex_decode32!(binary, Keyword.t) :: binary
Decodes a base 32 encoded string with extended hexadecimal alphabet into a binary string.
An ArgumentError exception is raised if the padding is incorrect or a non-alphabet character is present in the string.
Options
The accepted options are:
-
:case- specifies the character case to accept when decoding -
:padding- specifies whether to require padding
The values for :case can be:
-
:upper- only allow upper case characters (default) -
:lower- only allow lower case characters -
:mixed- allow mixed case characters
The values for :padding can be:
-
true- require the input string to be padded to the nearest multiple of 8 (default) -
false- ignore padding from the input string
Examples
iex> Base.hex_decode32!("CPNMUOJ1E8======")
"foobar"
iex> Base.hex_decode32!("cpnmuoj1e8======", case: :lower)
"foobar"
iex> Base.hex_decode32!("cpnMuOJ1E8======", case: :mixed)
"foobar"
iex> Base.hex_decode32!("CPNMUOJ1E8", padding: false)
"foobar" hex_encode32(data, opts \\ [])
hex_encode32(binary, Keyword.t) :: binary
Encodes a binary string into a base 32 encoded string with an extended hexadecimal alphabet.
Options
The accepted options are:
-
:case- specifies the character case to use when encoding -
:padding- specifies whether to apply padding
The values for :case can be:
-
:upper- use upper case characters (default) -
:lower- use lower case characters
The values for :padding can be:
-
true- pad the output string to the nearest multiple of 8 (default) -
false- omit padding from the output string
Examples
iex> Base.hex_encode32("foobar")
"CPNMUOJ1E8======"
iex> Base.hex_encode32("foobar", case: :lower)
"cpnmuoj1e8======"
iex> Base.hex_encode32("foobar", padding: false)
"CPNMUOJ1E8" url_decode64(string, opts \\ [])
url_decode64(binary, Keyword.t) :: {:ok, binary} | :error Decodes a base 64 encoded string with URL and filename safe alphabet into a binary string.
Accepts ignore: :whitespace option which will ignore all the whitespace characters in the input string.
Accepts padding: false option which will ignore padding from the input string.
Examples
iex> Base.url_decode64("_3_-_A==")
{:ok, <<255, 127, 254, 252>>}
iex> Base.url_decode64("_3_-_A==\n", ignore: :whitespace)
{:ok, <<255, 127, 254, 252>>}
iex> Base.url_decode64("_3_-_A", padding: false)
{:ok, <<255, 127, 254, 252>>} url_decode64!(string, opts \\ [])
url_decode64!(binary, Keyword.t) :: binary
Decodes a base 64 encoded string with URL and filename safe alphabet into a binary string.
Accepts ignore: :whitespace option which will ignore all the whitespace characters in the input string.
Accepts padding: false option which will ignore padding from the input string.
An ArgumentError exception is raised if the padding is incorrect or a non-alphabet character is present in the string.
Examples
iex> Base.url_decode64!("_3_-_A==")
<<255, 127, 254, 252>>
iex> Base.url_decode64!("_3_-_A==\n", ignore: :whitespace)
<<255, 127, 254, 252>>
iex> Base.url_decode64!("_3_-_A", padding: false)
<<255, 127, 254, 252>> url_encode64(data, opts \\ [])
url_encode64(binary, Keyword.t) :: binary
Encodes a binary string into a base 64 encoded string with URL and filename safe alphabet.
Accepts padding: false option which will omit padding from the output string.
Examples
iex> Base.url_encode64(<<255, 127, 254, 252>>) "_3_-_A==" iex> Base.url_encode64(<<255, 127, 254, 252>>, padding: false) "_3_-_A"
© 2012 Plataformatec
Licensed under the Apache License, Version 2.0.
https://hexdocs.pm/elixir/1.3.4/Base.html