ref: 1852584ca32bba1d1bae0041972c00c08ae4b43e
dir: /sys/src/libsec/port/readcert.c/
#include "os.h"
#include <libsec.h>
static char*
readfile(char *name)
{
	int fd;
	char *s;
	Dir *d;
	fd = open(name, OREAD|OCEXEC);
	if(fd < 0)
		return nil;
	if((d = dirfstat(fd)) == nil) {
		close(fd);
		return nil;
	}
	s = malloc(d->length + 1);
	if(s == nil || readn(fd, s, d->length) != d->length){
		free(s);
		free(d);
		close(fd);
		return nil;
	}
	close(fd);
	s[d->length] = '\0';
	free(d);
	return s;
}
uchar*
readcert(char *filename, int *pcertlen)
{
	char *pem;
	uchar *binary;
	pem = readfile(filename);
	if(pem == nil){
		werrstr("can't read %s: %r", filename);
		return nil;
	}
	binary = decodePEM(pem, "CERTIFICATE", pcertlen, nil);
	free(pem);
	if(binary == nil){
		werrstr("can't parse %s", filename);
		return nil;
	}
	return binary;
}
PEMChain *
readcertchain(char *filename)
{
	char *chfile;
	chfile = readfile(filename);
	if (chfile == nil) {
		werrstr("can't read %s: %r", filename);
		return nil;
	}
	return decodepemchain(chfile, "CERTIFICATE");
}