The OpenD Programming Language

std.base64

Support for Base64 encoding and decoding.

This module provides two default implementations of Base64 encoding, Base64 with a standard encoding alphabet, and a variant Base64URL that has a modified encoding alphabet designed to be safe for embedding in URLs and filenames.

Both variants are implemented as instantiations of the template Base64Impl. Most users will not need to use this template directly; however, it can be used to create customized Base64 encodings, such as one that omits padding characters, or one that is safe to embed inside a regular expression.

Members

Aliases

Base64
alias Base64 = Base64Impl!('+', '/')

Implementation of standard Base64 encoding.

Base64URL
alias Base64URL = Base64Impl!('-', '_')

Variation of Base64 encoding that is safe for use in URLs and filenames.

Base64URLNoPadding
alias Base64URLNoPadding = Base64Impl!('-', '_', Base64.NoPadding)

Unpadded variation of Base64 encoding that is safe for use in URLs and filenames, as used in RFCs 4648 and 7515 (JWS/JWT/JWE).

Classes

Base64Exception
class Base64Exception

Exception thrown upon encountering Base64 encoding or decoding errors.

Templates

Base64Impl
template Base64Impl(char Map62th, char Map63th, char Padding = '=')

Template for implementing Base64 encoding and decoding.

Examples

ubyte[] data = [0x14, 0xfb, 0x9c, 0x03, 0xd9, 0x7e];

const(char)[] encoded = Base64.encode(data);
assert(encoded == "FPucA9l+");

ubyte[] decoded = Base64.decode("FPucA9l+");
assert(decoded == [0x14, 0xfb, 0x9c, 0x03, 0xd9, 0x7e]);

The range API is supported for both encoding and decoding:

// Create MIME Base64 with CRLF, per line 76.
File f = File("./text.txt", "r");
scope(exit) f.close();

Appender!string mime64 = appender!string;

foreach (encoded; Base64.encoder(f.byChunk(57)))
{
    mime64.put(encoded);
    mime64.put("\r\n");
}

writeln(mime64.data);

References: RFC 4648 - The Base16

Meta

Authors

Masahiro Nakagawa, Daniel Murphy (Single value Encoder and Decoder)