Crate base64

Configs

There isn’t just one type of Base64; that would be too simple. You need to choose a character set (standard, URL-safe, etc) and padding suffix (yes/no). The Config struct encapsulates this info. There are some common configs included: STANDARD, URL_SAFE, etc. You can also make your own Config if needed.

The functions that don’t have config in the name (e.g. encode() and decode()) use the STANDARD config .

The functions that write to a slice (the ones that end in _slice) are generally the fastest because they don’t need to resize anything. If it fits in your workflow and you care about performance, keep using the same buffer (growing as need be) and use the _slice methods for the best performance.

Encoding

Several different encoding functions are available to you depending on your desire for convenience vs performance.

Function	Output	Allocates
encode	Returns a new String	Always
encode_config	Returns a new String	Always
encode_config_buf	Appends to provided String	Only if String needs to grow
encode_config_slice	Writes to provided &[u8]	Never

All of the encoding functions that take a Config will pad as per the config.

Decoding

Just as for encoding, there are different decoding functions available.

Function	Output	Allocates
decode	Returns a new Vec<u8>	Always
decode_config	Returns a new Vec<u8>	Always
decode_config_buf	Appends to provided Vec<u8>	Only if Vec needs to grow
decode_config_slice	Writes to provided &[u8]	Never

Unlike encoding, where all possible input is valid, decoding can fail (see DecodeError).

Input can be invalid because it has invalid characters or invalid padding. (No padding at all is valid, but excess padding is not.) Whitespace in the input is invalid.

Panics

If length calculations result in overflowing usize, a panic will result.

The _slice flavors of encode or decode will panic if the provided output slice is too small,

Modules

• display
  Enables base64’d output anywhere you might use a Display implementation, like a format string.
• write
  Implementations of io::Write to transparently handle base64.

Structs

• Config
  Contains configuration parameters for base64 encoding

Enums

• CharacterSet
  Available encoding character sets
• DecodeError
  Errors that can occur while decoding.

Constants

• CRYPT
  As per crypt(3) requirements
• STANDARD
  Standard character set with padding.
• STANDARD_NO_PAD
  Standard character set without padding.
• URL_SAFE
  URL-safe character set with padding
• URL_SAFE_NO_PAD
  URL-safe character set without padding

Functions

• decode
  Decode from string reference as octets. Returns a Result containing a Vec. Convenience decode_config(input, base64::STANDARD);.
• decode_config
  Decode from string reference as octets. Returns a Result containing a Vec.
• decode_config_buf
  Decode from string reference as octets. Writes into the supplied buffer to avoid allocation. Returns a Result containing an empty tuple, aka ().
• decode_config_slice
  Decode the input into the provided output slice.
• encode
  Encode arbitrary octets as base64. Returns a String. Convenience for encode_config(input, base64::STANDARD);.
• encode_config
  Encode arbitrary octets as base64. Returns a String.
• encode_config_buf
  Encode arbitrary octets as base64. Writes into the supplied output buffer, which will grow the buffer if needed.
• encode_config_slice
  Encode arbitrary octets as base64. Writes into the supplied output buffer.