#include <sys/types.h>
#include <string.h>
#include <strings.h>
#include <stdio.h>
#include <stdlib.h>
#include <pcsclite.h>
#include <winscard.h>
#include <reader.h>

#define	MAX_ATR_BYTES	33

SCARDCONTEXT hContext;
SCARDHANDLE hCard;
char *reader_name_buf;

setup_pcsc_context()
{
	LONG rv;

	rv = SCardEstablishContext(SCARD_SCOPE_SYSTEM, NULL, NULL, &hContext);
	if (rv != SCARD_S_SUCCESS) {
		fprintf(stderr, "SCardEstablishContext: %s\n",
			pcsc_stringify_error(rv));
		exit(1);
	}
	return(0);
}

get_reader_name()
{
	LONG rv;
	DWORD dwReaders;

	rv = SCardListReaders(hContext, NULL, NULL, &dwReaders);
	if (rv != SCARD_S_SUCCESS) {
		fprintf(stderr, "SCardListReaders 1st call: %s\n",
			pcsc_stringify_error(rv));
		SCardReleaseContext(hContext);
		exit(1);
	}
	if (dwReaders < 1) {
		fprintf(stderr,
	"error: dwReaders returned by SCardListReaders() is less than 1\n");
		SCardReleaseContext(hContext);
		exit(1);
	}
	reader_name_buf = malloc(dwReaders);
	if (!reader_name_buf) {
		perror("malloc for readers list");
		SCardReleaseContext(hContext);
		exit(1);
	}
	reader_name_buf[0] = '\0';
	rv = SCardListReaders(hContext, NULL, reader_name_buf, &dwReaders);
	if (rv != SCARD_S_SUCCESS) {
		fprintf(stderr, "SCardListReaders 2nd call: %s\n",
			pcsc_stringify_error(rv));
		SCardReleaseContext(hContext);
		exit(1);
	}
	if (reader_name_buf[0] == '\0') {
		fprintf(stderr,
	"error: list returned by SCardListReaders() begins with a NUL byte\n");
		SCardReleaseContext(hContext);
		exit(1);
	}
	if (!memchr(reader_name_buf, 0, dwReaders)) {
		fprintf(stderr,
"error: list returned by SCardListReaders() does not contain a NUL byte\n");
		SCardReleaseContext(hContext);
		exit(1);
	}
	return(0);
}

connect_to_card()
{
	LONG rv;
	DWORD dwActiveProtocol;

	rv = SCardConnect(hContext, reader_name_buf, SCARD_SHARE_EXCLUSIVE,
			  SCARD_PROTOCOL_T0, &hCard, &dwActiveProtocol);
	if (rv != SCARD_S_SUCCESS) {
		fprintf(stderr, "SCardConnect: %s\n", pcsc_stringify_error(rv));
		SCardReleaseContext(hContext);
		exit(1);
	}
	return(0);
}

retrieve_atr()
{
	u_char atrbuf[MAX_ATR_BYTES];
	LONG rv;
	DWORD dwAttrLen;
	unsigned n;

	dwAttrLen = MAX_ATR_BYTES;
	rv = SCardGetAttrib(hCard, SCARD_ATTR_ATR_STRING, atrbuf, &dwAttrLen);
	if (rv != SCARD_S_SUCCESS) {
		fprintf(stderr, "SCardGetAttrib for ATR: %s\n",
			pcsc_stringify_error(rv));
		return(-1);
	}
	printf("ATR:");
	for (n = 0; n < dwAttrLen; n++)
		printf(" %02X", atrbuf[n]);
	putchar('\n');
	return(0);
}

main(argc, argv)
	char **argv;
{
	setup_pcsc_context();
	get_reader_name();
	printf("Card reader name: %s\n", reader_name_buf);
	connect_to_card();
	retrieve_atr();
	SCardDisconnect(hCard, SCARD_UNPOWER_CARD);
	SCardReleaseContext(hContext);
	exit(0);
}