base64.h File Reference

Base64 encoder/decoder. More...

#include <stddef.h>
#include <stdint.h>

Go to the source code of this file.

Functions
void	base64_encode (const uint8_t *src, size_t src_len, char *dst)
	Encode src_len bytes of src as Base64.
size_t	base64_decode (const char *src, uint8_t *dst)
	Decode a null-terminated Base64 string.

Detailed Description

Base64 encoder/decoder.

On Arduino (ESP32) targets, delegates to mbedtls_base64_encode/decode() from the ESP-IDF mbedTLS bundle — same SDK path as SHA-1.

On native (x86) test targets, uses a portable software implementation so unit tests run without mbedTLS installed.

Used to encode the SHA-1 digest in the WebSocket handshake response (RFC 6455 §4.2.2) and to decode Basic Auth credentials (RFC 7617).

Author

Douglas Quigg (dstroy0)

Date

2026

Definition in file base64.h.

Function Documentation

base64_encode()

void base64_encode	(	const uint8_t *	src,
		size_t	src_len,
		char *	dst
	)

Encode src_len bytes of src as Base64.

Writes a null-terminated string into dst. dst must be at least ((src_len + 2) / 3) * 4 + 1 bytes.

Parameters

src	Input bytes.
src_len	Number of input bytes.
dst	Output buffer (null-terminated Base64 string).

Definition at line 23 of file base64.cpp.

base64_decode()

size_t base64_decode	(	const char *	src,
		uint8_t *	dst
	)

Decode a null-terminated Base64 string.

Writes decoded bytes into dst. dst must be at least (strlen(src) / 4) * 3 bytes. Returns the number of decoded bytes. Returns 0 on invalid input.

Parameters

src	Null-terminated Base64 input string.
dst	Output byte buffer.

Returns

Number of bytes written to dst, or 0 on error.

Definition at line 31 of file base64.cpp.