View Source Base (Elixir v1.13.1)
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 |
Link to this section Summary
Functions
Decodes a base 16 encoded string into a binary string.
Decodes a base 16 encoded string into a binary string.
Decodes a base 32 encoded string into a binary string.
Decodes a base 32 encoded string into a binary string.
Decodes a base 64 encoded string into a binary string.
Decodes a base 64 encoded string into a binary string.
Encodes a binary string into a base 16 encoded string.
Encodes a binary string into a base 32 encoded string.
Encodes a binary string into a base 64 encoded string.
Decodes a base 32 encoded string with extended hexadecimal alphabet into a binary string.
Decodes a base 32 encoded string with extended hexadecimal alphabet into a binary string.
Encodes a binary string into a base 32 encoded string with an extended hexadecimal alphabet.
Decodes a base 64 encoded string with URL and filename safe alphabet into a binary string.
Decodes a base 64 encoded string with URL and filename safe alphabet into a binary string.
Encodes a binary string into a base 64 encoded string with URL and filename safe alphabet.
Link to this section Types
@type decode_case() :: :upper | :lower | :mixed
@type encode_case() :: :upper | :lower
Link to this section Functions
@spec decode16(binary(), [{:case, decode_case()}]) :: {: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 allows upper case characters (default):lower- only allows lower case characters:mixed- allows 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"}@spec decode16!(binary(), [{:case, encode_case()}]) :: 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 allows upper case characters (default):lower- only allows lower case characters:mixed- allows 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"@spec decode32(binary(), case: decode_case(), padding: boolean()) :: {: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 allows upper case characters (default):lower- only allows lower case characters:mixed- allows mixed case characters
The values for :padding can be:
true- requires the input string to be padded to the nearest multiple of 8 (default)false- ignores 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"}@spec decode32!(binary(), case: decode_case(), padding: boolean()) :: 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 allows upper case characters (default):lower- only allows lower case characters:mixed- allows mixed case characters
The values for :padding can be:
true- requires the input string to be padded to the nearest multiple of 8 (default)false- ignores 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"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"}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"@spec encode16(binary(), [{:case, encode_case()}]) :: 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- uses upper case characters (default):lower- uses lower case characters
Examples
iex> Base.encode16("foobar")
"666F6F626172"
iex> Base.encode16("foobar", case: :lower)
"666f6f626172"@spec encode32(binary(), case: encode_case(), padding: boolean()) :: 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- uses upper case characters (default):lower- uses 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"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"@spec hex_decode32(binary(), case: decode_case(), padding: boolean()) :: {: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 allows upper case characters (default):lower- only allows lower case characters:mixed- allows mixed case characters
The values for :padding can be:
true- requires the input string to be padded to the nearest multiple of 8 (default)false- ignores 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"}@spec hex_decode32!(binary(), case: decode_case(), padding: boolean()) :: 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 allows upper case characters (default):lower- only allows lower case characters:mixed- allows mixed case characters
The values for :padding can be:
true- requires the input string to be padded to the nearest multiple of 8 (default)false- ignores 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"@spec hex_encode32(binary(), case: encode_case(), padding: boolean()) :: 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- uses upper case characters (default):lower- uses 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"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>>}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>>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"