base16.c File Reference

Base16 encoding. More...

#include <stdint.h>
#include <stdio.h>
#include <errno.h>
#include <assert.h>
#include <ipxe/string.h>
#include <ipxe/vsprintf.h>
#include <ipxe/base16.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
size_t	hex_encode (char separator, const void *raw, size_t raw_len, char *data, size_t len)
	Encode hexadecimal string (with optional byte separator character) More...
int	hex_decode (char separator, const char *encoded, void *data, size_t len)
	Decode hexadecimal string (with optional byte separator character) More...

Detailed Description

Base16 encoding.

Definition in file base16.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

hex_encode()

size_t hex_encode	(	char	separator,
		const void *	raw,
		size_t	raw_len,
		char *	data,
		size_t	len
	)

Encode hexadecimal string (with optional byte separator character)

Parameters

separator	Byte separator character, or 0 for no separator
raw	Raw data
raw_len	Length of raw data
data	Buffer
len	Length of buffer

Return values

len	Encoded length

Definition at line 50 of file base16.c.

                                             {
        const uint8_t *bytes = raw;
        const char delimiter[2] = { separator, '\0' };
        size_t used = 0;
        unsigned int i;

        if ( len )
                data[0] = 0; /* Ensure that a terminating NUL exists */
        for ( i = 0 ; i < raw_len ; i++ ) {
                used += ssnprintf ( ( data + used ), ( len - used ),
                                    "%s%02x", ( used ? delimiter : "" ),
                                    bytes[i] );
        }
        return used;
}

References bytes, data, len, raw, raw_len, and ssnprintf().

Referenced by format_hex_colon_setting(), format_hex_hyphen_setting(), and format_hex_raw_setting().

hex_decode()

int hex_decode	(	char	separator,
		const char *	encoded,
		void *	data,
		size_t	len
	)

Decode hexadecimal string (with optional byte separator character)

Parameters

separator	Byte separator character, or 0 for no separator
encoded	Encoded string
data	Buffer
len	Length of buffer

Return values

len	Length of data, or negative error

Definition at line 76 of file base16.c.

                                                                               {
        uint8_t *out = data;
        unsigned int count = 0;
        unsigned int sixteens;
        unsigned int units;
        int optional;

        /* Strip out optionality flag from separator character */
        optional = ( separator & HEX_DECODE_OPTIONAL );
        separator &= ~HEX_DECODE_OPTIONAL;

        /* Decode string */
        while ( *encoded ) {

                /* Check separator, if applicable */
                if ( count && separator ) {
                        if ( *encoded == separator ) {
                                encoded++;
                        } else if ( ! optional ) {
                                return -EINVAL;
                        }
                }

                /* Extract digits.  Note that either digit may be NUL,
                 * which would be interpreted as an invalid value by
                 * digit_value(); there is therefore no need for an
                 * explicit end-of-string check.
                 */
                sixteens = digit_value ( *(encoded++) );
                if ( sixteens >= 16 )
                        return -EINVAL;
                units = digit_value ( *(encoded++) );
                if ( units >= 16 )
                        return -EINVAL;

                /* Store result */
                if ( count < len )
                        out[count] = ( ( sixteens << 4 ) | units );
                count++;

        }
        return count;
}

References count, data, digit_value(), EINVAL, HEX_DECODE_OPTIONAL, len, and out.

Referenced by netfront_read_mac(), parse_hex_hyphen_setting(), parse_hex_raw_setting(), parse_hex_setting(), and uuid_aton().