Z85

Z85 Encoding functions. More...

Functions
unsigned char *	pcp_padfour (unsigned char *src, size_t srclen, size_t *dstlen)
	Zero-pad some input data.
size_t	pcp_unpadfour (unsigned char *src, size_t srclen)
	Unpad padded input data.
unsigned char *	pcp_z85_decode (char *z85block, size_t *dstlen)
	Decode data from Z85 encoding.
char *	pcp_z85_encode (unsigned char *raw, size_t srclen, size_t *dstlen)
	Encode data to Z85 encoding.
char *	pcp_readz85file (FILE *infile)
	Read a Z85 encoded file.
char *	pcp_readz85string (unsigned char *input, size_t bufsize)
	Read a Z85 encoded string.

Detailed Description

Z85 Encoding functions.

The Z85 encoding format is described here: ZeroMQ Spec.32. It's part of ZeroMQ. Z85 is based on ASCII85 with a couple of modifications (portability, readability etc).

To fulfil the requirements of the ZeroMQ Z85 functions, PCP does some additional preparations of raw input before actually doing the encoding, since the input for zmq_z85_encode() must be divisible by 4. Therefore we pad the input with zeroes and remove them after decoding.

Function Documentation

unsigned char* pcp_padfour	(	unsigned char *	src,
		size_t	srclen,
		size_t *	dstlen
	)

Zero-pad some input data.

This function allocates new memory for the returned data. It puts the original pointer into it and adds a number of zeros so that the result has a size divisable by 4.

Parameters

[in]	src	Unpadded data.
[in]	srclen	Size of unpadded data.
[in]	dstlen	Returned size of padded data (pointer to int).

Returns

Returns a pointer to the padded data.

char* pcp_readz85file

(

FILE *

infile

)

Read a Z85 encoded file.

Reads a file and returns the raw Z85 encoded string. It ignores newlines, comments and Headerstrings.

Parameters

[in]

infile

FILE stream to read from.

Returns

Raw Z85 encoded string with comments, headers and newlines removed.

char* pcp_readz85string	(	unsigned char *	input,
		size_t	bufsize
	)

Read a Z85 encoded string.

Parses the given input string and returns the raw Z85 encoded string. It ignores newlines, comments and Headerstrings.

Parameters

[in]	input	Z85 encoded string.
[in]	bufsize	Size of the string.

Returns

Raw Z85 encoded string with comments, headers and newlines removed.

size_t pcp_unpadfour	(	unsigned char *	src,
		size_t	srclen
	)

Unpad padded input data.

It just calculates the size of the unpadded result (size - all trailing zeroes). Doesn't allocate any memory or modify anything.

Parameters

[in]	src	Padded data.
[in]	srclen	Size of padded data.

Returns

Returns the unpadded size of the data.

unsigned char* pcp_z85_decode	(	char *	z85block,
		size_t *	dstlen
	)

Decode data from Z85 encoding.

The input z85block may contain newlines which will be removed.

Parameters

[in]	z85block	The Z85 encoded string.
[in]	dstlen	Returned size of decoded data (pointer to int).

Returns

Returns a newly allocated pointer to the decoded data. If decoding failed, returns NULL. Check fatals_if_any().

char* pcp_z85_encode	(	unsigned char *	raw,
		size_t	srclen,
		size_t *	dstlen
	)

Encode data to Z85 encoding.

Beside Z85 encoding it also adds a newline everiy 72 characters.

Parameters

[in]	raw	Pointer to raw data.
[in]	srclen	Size of the data.
[in]	dstlen	Returned size of encoded data (pointer to int).

Returns

Returns a string (char array) containing the Z85 encoded data.