PWS_BASE64_DECODE(3) BSD Library Functions Manual PWS_BASE64_DECODE(3)NAME
pws_base64_encode, pws_base64_decode — Encode and decode strings to and
from Base64
LIBRARY-lpwstor
SYNOPSIS
#include <pwstor.h>
unsigned char *
pws_base64_encode(unsigned char *src, unsigned char *dst, size_t len);
unsigned char *
pws_base64_decode(unsigned char *src, unsigned char *dst);
DESCRIPTION
The function pws_base64_encode() will encode len bytes of data from the
memory referenced by pointer src and store that data in the memory refer‐
enced by pointer dst. The pointer dst must be at least large enough to
hold (( len * 2) +1) bytes of data just to be on the safe side. (While
this isn't technically correct, the actual expansion is a fraction, which
multiplying by floating point integers may confuse some inexperienced
programmers who may then fall victim to buffer overflows. Experienced
developers should know how much memory is necessary and be able to calcu‐
late it more appropriately to save a few bytes, but *2 will always work
safely.) The +1 is to allow for the storage of a null-terminating byte,
since pws_base64_decode expects its Base64-encoded argument to be null-
terminated. Adding the null-terminating byte is up to the application,
however the safest thing to do is generally to use memset() or calloc()
so that the memory buffer will be initialized to 0s regardless, and it
can simply be propagated by the pws_base64_encode() function. A pointer
to the memory buffer referenced by dst is returned.
The function pws_base64_decode() can be used to decode data stored in
memory pointed to by src from Base64 back to its true value. The true
value will be stored in the memory pointed to by dst. Since src is
Base64 encoded, it is expected to be a null-terminated string. The dst
argument is expected to be a pointer to a memory buffer large enough to
store the results of decoding in. A pointer to the memory buffer refer‐
enced by dst is returned.
SEE ALSOpwstor(3)BSD October 23, 2008 BSD
