Base

Introduction #

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|       |          |

Source

Functions #

decode16(string, opts \\ [])

(function)

Specs

decode16(binary, Keyword.t) :: {:ok, binary} | :error

Decodes a base 16 encoded string into a binary string.

Accepts an atom :upper (default) for decoding from upper case characters or :lower for lower case characters. :mixed can be given for 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 \\ [])

(function)

Specs

decode16!(binary, Keyword.t) :: binary

Decodes a base 16 encoded string into a binary string.

Accepts an atom :upper (default) for decoding from upper case characters or :lower for lower case characters. :mixed can be given for 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 \\ [])

(function)

Specs

decode32(binary, Keyword.t) :: {:ok, binary} | :error

Decodes a base 32 encoded string into a binary string.

Accepts an atom :upper (default) for decoding from upper case characters or :lower for lower case characters. :mixed can be given for mixed case characters.

Examples

iex> Base.decode32("MZXW6YTBOI======")
{:ok, "foobar"}

iex> Base.decode32("mzxw6ytboi======", case: :lower)
{:ok, "foobar"}

iex> Base.decode32("mzXW6ytBOi======", case: :mixed)
{:ok, "foobar"}

decode32!(string, opts \\ [])

(function)

Specs

decode32!(binary, Keyword.t) :: binary

Decodes a base 32 encoded string into a binary string.

Accepts an atom :upper (default) for decoding from upper case characters or :lower for lower case characters. :mixed can be given for 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.decode32!("MZXW6YTBOI======")
"foobar"

iex> Base.decode32!("mzxw6ytboi======", case: :lower)
"foobar"

iex> Base.decode32!("mzXW6ytBOi======", case: :mixed)
"foobar"

decode64(string)

(function)

Specs

decode64(binary) :: {:ok, binary} | :error

Decodes a base 64 encoded string into a binary string.

Examples

iex> Base.decode64("Zm9vYmFy")
{:ok, "foobar"}

decode64!(string)

(function)

Specs

decode64!(binary) :: binary

Decodes a base 64 encoded string into a binary string.

The following alphabet is used both for encoding and decoding:

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"

encode16(data, opts \\ [])

(function)

Specs

encode16(binary, Keyword.t) :: binary

Encodes a binary string into a base 16 encoded string.

Accepts an atom :upper (default) for encoding to upper case characters or :lower for lower case characters.

Examples

iex> Base.encode16("foobar")
"666F6F626172"

iex> Base.encode16("foobar", case: :lower)
"666f6f626172"

encode32(data, opts \\ [])

(function)

Specs

encode32(binary, Keyword.t) :: binary

Encodes a binary string into a base 32 encoded string.

Accepts an atom :upper (default) for encoding to upper case characters or :lower for lower case characters.

Examples

iex> Base.encode32("foobar")
"MZXW6YTBOI======"

iex> Base.encode32("foobar", case: :lower)
"mzxw6ytboi======"

encode64(data)

(function)

Specs

encode64(binary) :: binary

Encodes a binary string into a base 64 encoded string.

Examples

iex> Base.encode64("foobar")
"Zm9vYmFy"

hex_decode32(string, opts \\ [])

(function)

Specs

hex_decode32(binary, Keyword.t) :: {:ok, binary} | :error

Decodes a base 32 encoded string with extended hexadecimal alphabet into a binary string.

Accepts an atom :upper (default) for decoding from upper case characters or :lower for lower case characters. :mixed can be given for mixed case characters.

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"}

hex_decode32!(string, opts \\ [])

(function)

Specs

hex_decode32!(binary, Keyword.t) :: binary

Decodes a base 32 encoded string with extended hexadecimal alphabet into a binary string.

Accepts an atom :upper (default) for decoding from upper case characters or :lower for lower case characters. :mixed can be given for 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.hex_decode32!("CPNMUOJ1E8======")
"foobar"

iex> Base.hex_decode32!("cpnmuoj1e8======", case: :lower)
"foobar"

iex> Base.hex_decode32!("cpnMuOJ1E8======", case: :mixed)
"foobar"

hex_encode32(data, opts \\ [])

(function)

Specs

hex_encode32(binary, Keyword.t) :: binary

Encodes a binary string into a base 32 encoded string with an extended hexadecimal alphabet.

Accepts an atom :upper (default) for encoding to upper case characters or :lower for lower case characters.

Examples

iex> Base.hex_encode32("foobar")
"CPNMUOJ1E8======"

iex> Base.hex_encode32("foobar", case: :lower)
"cpnmuoj1e8======"

url_decode64(string)

(function)

Specs

url_decode64(binary) :: {:ok, binary} | :error

Decodes a base 64 encoded string with URL and filename safe alphabet into a binary string.

Examples

iex> Base.url_decode64("_3_-_A==")
{:ok, <<255,127,254,252>>}

url_decode64!(string)

(function)

Specs

url_decode64!(binary) :: binary

Decodes a base 64 encoded string with URL and filename safe 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.

Examples

iex> Base.url_decode64!("_3_-_A==")
<<255,127,254,252>>

url_encode64(data)

(function)

Specs

url_encode64(binary) :: binary

Encodes a binary string into a base 64 encoded string with URL and filename safe alphabet.

Examples

iex> Base.url_encode64(<<255,127,254,252>>)
"_3_-_A=="

Elixir

v 0.15.2-dev

Base

Introduction #

Base 16 alphabet

Base 32 alphabet

Base 32 (extended hex) alphabet

Base 64 alphabet

Base 64 (URL and filename safe) alphabet

Functions #

decode16(string, opts \\ [])

Specs

Examples

decode16!(string, opts \\ [])

Specs

Examples

decode32(string, opts \\ [])

Specs

Examples

decode32!(string, opts \\ [])

Specs

Examples

decode64(string)

Specs

Examples

decode64!(string)

Specs

Examples

encode16(data, opts \\ [])

Specs

Examples

encode32(data, opts \\ [])

Specs

Examples

encode64(data)

Specs

Examples

hex_decode32(string, opts \\ [])

Specs

Examples

hex_decode32!(string, opts \\ [])

Specs

Examples

hex_encode32(data, opts \\ [])

Specs

Examples

url_decode64(string)

Specs

Examples

url_decode64!(string)

Specs

Examples

url_encode64(data)

Specs

Examples