Base64 encoder and decoder. More...

Detailed Description

Base64 encoder and decoder.

Encoding and decoding functions for base64

Author: Martin Landsmann Marti.nosp@m.n.La.nosp@m.ndsma.nosp@m.nn@H.nosp@m.AW-Ha.nosp@m.mbur.nosp@m.g.de

Macros
#define	BASE64_SUCCESS (0)
	return value for success

#define	BASE64_ERROR_BUFFER_OUT (-1)
	error value for invalid output buffer pointer

#define	BASE64_ERROR_BUFFER_OUT_SIZE (-2)
	error value for invalid output buffer size

#define	BASE64_ERROR_DATA_IN (-3)
	error value for invalid input buffer

#define	BASE64_ERROR_DATA_IN_SIZE (-4)
	error value for invalid input buffer size

#define	BASE64_ERROR_OVERFLOW (-5)
	error value for buffer overflow

Functions
static size_t	base64_estimate_decode_size (size_t base64_in_size)
	Estimates the amount of bytes needed for decoding `base64_in_size` characters from base64.

static size_t	base64_estimate_encode_size (size_t data_in_size)
	Estimates the length of the resulting string after encoding `data_in_size` bytes into base64.

static bool	base64_can_estimate_encode_size (size_t data_in_size)
	Checks if the given size of data can return a valid estimate for the size without an integer overflow.

int	base64_encode (const void data_in, size_t data_in_size, void base64_out, size_t *base64_out_size)
	Encodes a given datum to base64 and save the result to the given destination.

int	base64url_encode (const void data_in, size_t data_in_size, void base64_out, size_t *base64_out_size)
	Encodes a given datum to base64 with URL and Filename Safe Alphabet and save the result to the given destination.

int	base64_decode (const void base64_in, size_t base64_in_size, void data_out, size_t *data_out_size)
	Decodes a given base64 string and save the result to the given destination.

Macro Definition Documentation

◆ BASE64_ERROR_BUFFER_OUT

#define BASE64_ERROR_BUFFER_OUT (-1)

error value for invalid output buffer pointer

Definition at line 27 of file base64.h.

◆ BASE64_ERROR_BUFFER_OUT_SIZE

#define BASE64_ERROR_BUFFER_OUT_SIZE (-2)

error value for invalid output buffer size

Definition at line 28 of file base64.h.

◆ BASE64_ERROR_DATA_IN

#define BASE64_ERROR_DATA_IN (-3)

error value for invalid input buffer

Definition at line 29 of file base64.h.

◆ BASE64_ERROR_DATA_IN_SIZE

#define BASE64_ERROR_DATA_IN_SIZE (-4)

error value for invalid input buffer size

Definition at line 30 of file base64.h.

◆ BASE64_ERROR_OVERFLOW

#define BASE64_ERROR_OVERFLOW (-5)

error value for buffer overflow

Definition at line 31 of file base64.h.

◆ BASE64_SUCCESS

#define BASE64_SUCCESS (0)

return value for success

Definition at line 26 of file base64.h.

Function Documentation

◆ base64_can_estimate_encode_size()

static bool base64_can_estimate_encode_size ( size_t data_in_size )

inlinestatic

Checks if the given size of data can return a valid estimate for the size without an integer overflow.

Parameters

[in] data_in_size Amount of bytes to be encoded

Return values

true	if the given size can be encoded to base64
false	if the given size would overflow

Definition at line 71 of file base64.h.

◆ base64_decode()

int base64_decode	(	const void *	base64_in,
		size_t	base64_in_size,
		void *	data_out,
		size_t *	data_out_size )

Decodes a given base64 string and save the result to the given destination.

Parameters

[in]	base64_in	Pointer to the datum to decode
[in]	base64_in_size	The size of `base64_in`
[out]	data_out	Pointer to store the decoded base64 string (may be tainted on error)
[in,out]	data_out_size	The size of `data_out`. This value is overwritten with the estimated size used for the decoded string on BASE64_ERROR_BUFFER_OUT_SIZE. This value is overwritten with the actual used size for the decoded string on BASE64_SUCCESS.

Return values

BASE64_SUCCESS	on success
BASE64_ERROR_BUFFER_OUT_SIZE	on insufficient size for decoding to `data_out`
BASE64_ERROR_BUFFER_OUT	if `data_out` equals NULL but the size for `data_out_size` is sufficient
BASE64_ERROR_DATA_IN	if `base64_in` equals NULL
BASE64_ERROR_DATA_IN_SIZE	if `base64_in_size` has remainder 1 (mod 4)

◆ base64_encode()

int base64_encode	(	const void *	data_in,
		size_t	data_in_size,
		void *	base64_out,
		size_t *	base64_out_size )

Encodes a given datum to base64 and save the result to the given destination.

Parameters

[in]	data_in	Pointer to the datum to encode
[in]	data_in_size	The size of `data_in`
[out]	base64_out	Pointer to store the encoded base64 string (may be tainted on error)
[in,out]	base64_out_size	Pointer to the variable containing the size of `base64_out.` This value is overwritten with the estimated size used for the encoded base64 string on BASE64_ERROR_BUFFER_OUT_SIZE. This value is overwritten with the actual used size for the encoded base64 string on BASE64_SUCCESS.

Return values

BASE64_SUCCESS	on success
BASE64_ERROR_BUFFER_OUT_SIZE	on insufficient size for encoding to `base64_out`
BASE64_ERROR_BUFFER_OUT	if `base64_out` equals NULL but the `base64_out_size` is sufficient
BASE64_ERROR_DATA_IN	if `data_in` equals NULL
BASE64_ERROR_OVERFLOW	if `data_in_size` is too large to be encoded to base64

◆ base64_estimate_decode_size()

static size_t base64_estimate_decode_size ( size_t base64_in_size )

inlinestatic

Estimates the amount of bytes needed for decoding base64_in_size characters from base64.

Parameters

[in] base64_in_size Size of the string to be decoded

Returns: Amount of bytes estimated to be used after decoding

Definition at line 41 of file base64.h.

◆ base64_estimate_encode_size()

static size_t base64_estimate_encode_size ( size_t data_in_size )

inlinestatic

Estimates the length of the resulting string after encoding data_in_size bytes into base64.

Precondition: data_in_size must be smaller than ~75% of the SIZE_MAX to prevent integer overflow in the calculation of the return value.

Parameters

[in] data_in_size Amount of bytes to be encoded

Returns: Amount of characters the output string is estimated to have

Definition at line 57 of file base64.h.

◆ base64url_encode()

int base64url_encode	(	const void *	data_in,
		size_t	data_in_size,
		void *	base64_out,
		size_t *	base64_out_size )

Encodes a given datum to base64 with URL and Filename Safe Alphabet and save the result to the given destination.

See also: RFC 4648, section 5

Note: Requires the use of the base64url module.

Parameters

[in]	data_in	Pointer to the datum to encode
[in]	data_in_size	The size of `data_in`
[out]	base64_out	Pointer to store the encoded base64 string (may be tainted on error)
[in,out]	base64_out_size	Pointer to the variable containing the size of `base64_out.` This value is overwritten with the estimated size used for the encoded base64 string on BASE64_ERROR_BUFFER_OUT_SIZE. This value is overwritten with the actual used size for the encoded base64 string on BASE64_SUCCESS.

Return values

BASE64_SUCCESS	on success
BASE64_ERROR_BUFFER_OUT_SIZE	on insufficient size for encoding to `base64_out`
BASE64_ERROR_BUFFER_OUT	if `base64_out` equals NULL but the `base64_out_size` is sufficient
BASE64_ERROR_DATA_IN	if `data_in` equals NULL
BASE64_ERROR_OVERFLOW	if `data_in_size` is too large to be encoded to base64

Detailed Description

Macros

Functions

Macro Definition Documentation

◆ BASE64_ERROR_BUFFER_OUT

◆ BASE64_ERROR_BUFFER_OUT_SIZE

◆ BASE64_ERROR_DATA_IN

◆ BASE64_ERROR_DATA_IN_SIZE

◆ BASE64_ERROR_OVERFLOW

◆ BASE64_SUCCESS

Function Documentation

◆ base64_can_estimate_encode_size()

◆ base64_decode()

◆ base64_encode()

◆ base64_estimate_decode_size()

◆ base64_estimate_encode_size()

◆ base64url_encode()