Basic Bugs in Demo Application
A demo giftcardreader application was given. here is how I discovered the bugs
2 crashes and 1 infinite loop discovery:
Bug description:
crash1.gft => I discovered a crash by putting data length = -1 in gengift.py. This crashes the code at line at 198 where it tries to allocate memory. Since, program can't allocate negative memory, I fixed it by adding a check for negative number of bytes. Program exits if it detects negative number of bytes.
crash2.gft => type of record 3 in the gengift file crashes code at line 254 and then at line 260 because then it tries to allocate memory that is out of bounds. Non-animated gift card allocates a memory lesser than 256 bytes and animated gift card allocates 256 bytes plus. So, I added a check, if number of bytes are more than 255, it will only then execute the part where animated gift card is processed by pointers. Or else exits.
hang.gft => I discovered an infinite loop in genanim.py -> program data section by refering the lecture and adding \x09\xfd + 254 bytes of B to the data buffer will cause an infinite loop. I fixed it by going to giftcardreader.c in the animate() function and in case of "09" opcode, changed it to unsigned char from original char
Initial giftcardreader.c code:
/*
* Gift Card Reading Application
* Original Author: Shoddycorp's Cut-Rate Contracting
* Comments added by: Justin Cappos (JAC) and Brendan Dolan-Gavitt (BDG)
* Maintainer:
* Date: 8 July 2020
*/
#include "giftcard.h"
#include <stdio.h>
#include <string.h>
#include <unistd.h>
// .,~==== interpreter for THX-1138 assembly ====~,.
//
// This is an emulated version of a microcontroller with
// 16 registers, one flag (the zero flag), and display
// functionality. Programs can operate on the message
// buffer and use opcode 0x07 to update the display, so
// that animated greetings can be created.
void animate(char *msg, unsigned char *program) {
unsigned char regs[16];
char *mptr = msg; // TODO: how big is this buffer?
unsigned char *pc = program;
int i = 0;
int zf = 0;
while (pc < program+256) {
unsigned char op, arg1, arg2;
op = *pc;
arg1 = *(pc+1);
arg2 = *(pc+2);
switch (*pc) {
case 0x00:
break;
case 0x01:
regs[arg1] = *mptr;
break;
case 0x02:
*mptr = regs[arg1];
break;
case 0x03:
mptr += (char)arg1;
break;
case 0x04:
regs[arg2] = arg1;
break;
case 0x05:
regs[arg1] ^= regs[arg2];
zf = !regs[arg1];
break;
case 0x06:
regs[arg1] += regs[arg2];
zf = !regs[arg1];
break;
case 0x07:
puts(msg);
break;
case 0x08:
goto done;
case 0x09:
pc += (char)arg1;
break;
case 0x10:
if (zf) pc += (char)arg1;
break;
}
pc+=3;
#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
// Slow down animation to make it more visible (disabled if fuzzing)
usleep(5000);
#endif
}
done:
return;
}
int get_gift_card_value(struct this_gift_card *thisone) {
struct gift_card_data *gcd_ptr;
struct gift_card_record_data *gcrd_ptr;
struct gift_card_amount_change *gcac_ptr;
int ret_count = 0;
gcd_ptr = thisone->gift_card_data;
for(int i=0;i<gcd_ptr->number_of_gift_card_records; i++) {
gcrd_ptr = (struct gift_card_record_data *) gcd_ptr->gift_card_record_data[i];
if (gcrd_ptr->type_of_record == 1) {
gcac_ptr = gcrd_ptr->actual_record;
ret_count += gcac_ptr->amount_added;
}
}
return ret_count;
}
void print_gift_card_info(struct this_gift_card *thisone) {
struct gift_card_data *gcd_ptr;
struct gift_card_record_data *gcrd_ptr;
struct gift_card_amount_change *gcac_ptr;
struct gift_card_program *gcp_ptr;
gcd_ptr = thisone->gift_card_data;
printf(" Merchant ID: %32.32s\n",gcd_ptr->merchant_id);
printf(" Customer ID: %32.32s\n",gcd_ptr->customer_id);
printf(" Num records: %d\n",gcd_ptr->number_of_gift_card_records);
for(int i=0;i<gcd_ptr->number_of_gift_card_records; i++) {
gcrd_ptr = (struct gift_card_record_data *) gcd_ptr->gift_card_record_data[i];
if (gcrd_ptr->type_of_record == 1) {
printf(" record_type: amount_change\n");
gcac_ptr = gcrd_ptr->actual_record;
printf(" amount_added: %d\n",gcac_ptr->amount_added);
if (gcac_ptr->amount_added>0) {
printf(" signature: %32.32s\n",gcac_ptr->actual_signature);
}
}
else if (gcrd_ptr->type_of_record == 2) {
printf(" record_type: message\n");
printf(" message: %s\n",(char *)gcrd_ptr->actual_record);
}
else if (gcrd_ptr->type_of_record == 3) {
gcp_ptr = gcrd_ptr->actual_record;
printf(" record_type: animated message\n");
// BDG: Hmm... is message guaranteed to be null-terminated?
printf(" message: %s\n", gcp_ptr->message);
printf(" [running embedded program] \n");
animate(gcp_ptr->message, gcp_ptr->program);
}
}
printf(" Total value: %d\n\n",get_gift_card_value(thisone));
}
// Added to support web functionalities
void gift_card_json(struct this_gift_card *thisone) {
struct gift_card_data *gcd_ptr;
struct gift_card_record_data *gcrd_ptr;
struct gift_card_amount_change *gcac_ptr;
gcd_ptr = thisone->gift_card_data;
printf("{\n");
printf(" \"merchant_id\": \"%32.32s\",\n", gcd_ptr->merchant_id);
printf(" \"customer_id\": \"%32.32s\",\n", gcd_ptr->customer_id);
printf(" \"total_value\": %d,\n", get_gift_card_value(thisone));
printf(" \"records\": [\n");
for(int i=0;i<gcd_ptr->number_of_gift_card_records; i++) {
gcrd_ptr = (struct gift_card_record_data *) gcd_ptr->gift_card_record_data[i];
printf(" {\n");
if (gcrd_ptr->type_of_record == 1) {
printf(" \"record_type\": \"amount_change\",\n");
gcac_ptr = gcrd_ptr->actual_record;
printf(" \"amount_added\": %d,\n",gcac_ptr->amount_added);
if (gcac_ptr->amount_added>0) {
printf(" \"signature\": \"%32.32s\"\n",gcac_ptr->actual_signature);
}
}
else if (gcrd_ptr->type_of_record == 2) {
printf(" \"record_type\": \"message\",\n");
printf(" \"message\": \"%s\"\n",(char *)gcrd_ptr->actual_record);
}
else if (gcrd_ptr->type_of_record == 3) {
struct gift_card_program *gcp = gcrd_ptr->actual_record;
printf(" \"record_type\": \"animated message\",\n");
printf(" \"message\": \"%s\",\n",gcp->message);
// programs are binary so we will hex for the json
char *hexchars = "01234567890abcdef";
char program_hex[512+1];
program_hex[512] = '\0';
int i;
for(i = 0; i < 256; i++) {
program_hex[i*2] = hexchars[((gcp->program[i] & 0xf0) >> 4)];
program_hex[i*2+1] = hexchars[(gcp->program[i] & 0x0f)];
}
printf(" \"program\": \"%s\"\n",program_hex);
}
if (i < gcd_ptr->number_of_gift_card_records-1)
printf(" },\n");
else
printf(" }\n");
}
printf(" ]\n");
printf("}\n");
}
struct this_gift_card *gift_card_reader(FILE *input_fd) {
struct this_gift_card *ret_val = malloc(sizeof(struct this_gift_card));
void *optr;
void *ptr;
// Loop to do the whole file
while (!feof(input_fd)) {
struct gift_card_data *gcd_ptr;
/* JAC: Why aren't return types checked? */
fread(&ret_val->num_bytes, 4,1, input_fd);
// Make something the size of the rest and read it in
ptr = malloc(ret_val->num_bytes);
fread(ptr, ret_val->num_bytes, 1, input_fd);
optr = ptr-4;
gcd_ptr = ret_val->gift_card_data = malloc(sizeof(struct gift_card_data));
gcd_ptr->merchant_id = ptr;
ptr += 32;
// printf("VD: %d\n",(int)ptr - (int) gcd_ptr->merchant_id);
gcd_ptr->customer_id = ptr;
ptr += 32;
/* JAC: Something seems off here... */
gcd_ptr->number_of_gift_card_records = *((char *)ptr);
ptr += 4;
gcd_ptr->gift_card_record_data = (void *)malloc(gcd_ptr->number_of_gift_card_records*sizeof(void*));
// Now ptr points at the gift card recrod data
for (int i=0; i < gcd_ptr->number_of_gift_card_records; i++){
//printf("i: %d\n",i);
struct gift_card_record_data *gcrd_ptr;
gcrd_ptr = gcd_ptr->gift_card_record_data[i] = malloc(sizeof(struct gift_card_record_data));
struct gift_card_amount_change *gcac_ptr;
gcac_ptr = gcrd_ptr->actual_record = malloc(sizeof(struct gift_card_record_data));
struct gift_card_program *gcp_ptr;
gcp_ptr = malloc(sizeof(struct gift_card_program));
gcrd_ptr->record_size_in_bytes = *((char *)ptr);
//printf("rec at %x, %d bytes\n", ptr - optr, gcrd_ptr->record_size_in_bytes);
ptr += 4;
//printf("record_data: %d\n",gcrd_ptr->record_size_in_bytes);
gcrd_ptr->type_of_record = *((char *)ptr);
ptr += 4;
//printf("type of rec: %d\n", gcrd_ptr->type_of_record);
// amount change
if (gcrd_ptr->type_of_record == 1) {
gcac_ptr->amount_added = *((int*) ptr);
ptr += 4;
// don't need a sig if negative
/* JAC: something seems off here */
if (gcac_ptr < 0) break;
gcac_ptr->actual_signature = ptr;
ptr+=32;
}
// message
if (gcrd_ptr->type_of_record == 2) {
gcrd_ptr->actual_record = ptr;
// advance by the string size + 1 for nul
// BDG: does not seem right
ptr=ptr+strlen((char *)gcrd_ptr->actual_record)+1;
}
// BDG: gift cards can run code?? Might want to check this one carefully...
// text animatino (BETA)
if (gcrd_ptr->type_of_record == 3) {
gcp_ptr->message = malloc(32);
gcp_ptr->program = malloc(256);
memcpy(gcp_ptr->message, ptr, 32);
ptr+=32;
memcpy(gcp_ptr->program, ptr, 256);
ptr+=256;
gcrd_ptr->actual_record = gcp_ptr;
}
if (gcrd_ptr->type_of_record > 3) {
printf("unknown record type: %d\n", gcrd_ptr->type_of_record);
exit(1);
}
}
}
return ret_val;
}
struct this_gift_card *thisone;
int main(int argc, char **argv) {
if (argc != 3) {
fprintf(stderr, "usage: %s <1|2> file.gft\n", argv[0]);
fprintf(stderr, " - Use 1 for text output, 2 for JSON output\n");
return 1;
}
FILE *input_fd = fopen(argv[2],"r");
if (!input_fd) {
fprintf(stderr, "error opening file\n");
return 1;
}
thisone = gift_card_reader(input_fd);
if (argv[1][0] == '1') print_gift_card_info(thisone);
else if (argv[1][0] == '2') gift_card_json(thisone);
return 0;
}Initial gengift.py code:
To generate a giftcard file: python3 gengift.py name.gft
import struct
import sys
# We build the content of the file in a byte string first
# This lets us calculate the length for the header at the end
data = b''
data += b"GiftCardz.com".ljust(32, b' ') # Merchant ID
data += b"B"*32 # Customer ID
data += struct.pack("<I", 1) # One record
# Record of type message
data += struct.pack("<I", 8 + 32) # Record size: 4 bytes size, 4 bytes type, 32 bytes message
data += struct.pack("<I", 2) # Record type
data += b"x"*31 + b'\0' # Note: 32 byte message
f = open(sys.argv[1], 'wb')
datalen = len(data) + 4 # Plus 4 bytes for the length itself
f.write(struct.pack("<I", datalen))
f.write(data)
f.close()Initial genanim.py code:
To generate animated giftcard file: python3 genanim.py animated_name.gft
import struct
import sys
# We build the content of the file in a byte string first
# This lets us calculate the length for the header at the end
data = b''
data += b"A"*32 # Merchant ID
data += b"B"*32 # Customer ID
data += struct.pack("<I", 1) # One record
# Record of type animation
data += struct.pack("<I", 8 + 32 + 256) # Record size (4 bytes)
data += struct.pack("<I", 3) # Record type (4 bytes)
data += b"A"*31 + b'\x00' # Note: 32 byte message
data += b'\x08' * 256 # Program made entirely of "end program" (256 bytes)
f = open(sys.argv[1], 'wb')
datalen = len(data) + 4 # Plus 4 bytes for the length itself
f.write(struct.pack("<I", datalen))
f.write(data)
f.close()Crash 1 python file:
import struct
import sys
# We build the content of the file in a byte string first
# This lets us calculate the length for the header at the end
data = b''
data += b"GiftCardz.com".ljust(32, b' ') # Merchant ID
data += b"B"*32 # Customer ID
data += struct.pack("<I", 1) # One record
# Record of type message
data += struct.pack("<I", 8 + 32) # Record size: 4 bytes size, 4 bytes type, 32 bytes message
data += struct.pack("<I", 1) # Record type
data += b"x"*31 + b'\0' # Note: 32 byte message
f = open(sys.argv[1], 'wb')
datalen = -1 # crash for -1 data length
f.write(struct.pack("<i", datalen))
f.write(data)
f.close()Crash 2 Python file
import struct
import sys
# We build the content of the file in a byte string first
# This lets us calculate the length for the header at the end
data = b''
data += b"GiftCardz.com".ljust(32, b' ') # Merchant ID
data += b"B"*32 # Customer ID
data += struct.pack("<I", 1) # One record
# Record of type message
data += struct.pack("<I", 8 + 32) # Record size: 4 bytes size, 4 bytes type, 32 bytes message
data += struct.pack("<I", 3) # Record type
data += b"x"*31 + b'\0' # Note: 32 byte message
f = open(sys.argv[1], 'wb')
datalen = len(data) + 4 # Plus 4 bytes for the length itself
f.write(struct.pack("<I", datalen))
f.write(data)
f.close()Hang file python code:
import struct
import sys
# We build the content of the file in a byte string first
# This lets us calculate the length for the header at the end
data = b''
data += b"A"*32 # Merchant ID
data += b"B"*32 # Customer ID
data += struct.pack("<I", 1) # One record
# Record of type animation
data += struct.pack("<I", 8 + 32 + 256) # Record size (4 bytes)
data += struct.pack("<I", 3) # Record type (4 bytes)
data += b"A"*31 + b'\x00' # Note: 32 byte message
data += b'\x09\xfd' +b'\x08'* 254 # Program to make it loop infinitely and then random 254 bytes
f = open(sys.argv[1], 'wb')
datalen = len(data) + 4 # Plus 4 bytes for the length itself
f.write(struct.pack("<I", datalen))
f.write(data)
f.close()Fixed C code:
/*
* Gift Card Reading Application
* Original Author: Shoddycorp's Cut-Rate Contracting
* Comments added by: Justin Cappos (JAC) and Brendan Dolan-Gavitt (BDG)
* Maintainer:
* Date: 8 July 2020
*/
#include "giftcard.h"
#include <stdio.h>
#include <string.h>
#include <unistd.h>
// .,~==== interpreter for THX-1138 assembly ====~,.
//
// This is an emulated version of a microcontroller with
// 16 registers, one flag (the zero flag), and display
// functionality. Programs can operate on the message
// buffer and use opcode 0x07 to update the display, so
// that animated greetings can be created.
void animate(char *msg, unsigned char *program) {
unsigned char regs[16];
char *mptr = msg; // TODO: how big is this buffer?
unsigned char *pc = program;
int i = 0;
int zf = 0;
while (pc < program+256) {
unsigned char op, arg1, arg2;
op = *pc;
arg1 = *(pc+1);
arg2 = *(pc+2);
switch (*pc) {
case 0x00:
break;
case 0x01:
regs[arg1] = *mptr;
break;
case 0x02:
*mptr = regs[arg1];
break;
case 0x03:
mptr += (char)arg1;
break;
case 0x04:
regs[arg2] = arg1;
break;
case 0x05:
regs[arg1] ^= regs[arg2];
zf = !regs[arg1];
break;
case 0x06:
regs[arg1] += regs[arg2];
zf = !regs[arg1];
break;
case 0x07:
puts(msg);
break;
case 0x08:
goto done;
case 0x09:
pc += (unsigned char)arg1; /* fix 3 for hang (infinite loop) */
break;
case 0x10:
if (zf) pc += (char)arg1;
break;
}
pc+=3;
#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
// Slow down animation to make it more visible (disabled if fuzzing)
usleep(5000);
#endif
}
done:
return;
}
int get_gift_card_value(struct this_gift_card *thisone) {
struct gift_card_data *gcd_ptr;
struct gift_card_record_data *gcrd_ptr;
struct gift_card_amount_change *gcac_ptr;
int ret_count = 0;
gcd_ptr = thisone->gift_card_data;
for(int i=0;i<gcd_ptr->number_of_gift_card_records; i++) {
gcrd_ptr = (struct gift_card_record_data *) gcd_ptr->gift_card_record_data[i];
if (gcrd_ptr->type_of_record == 1) {
gcac_ptr = gcrd_ptr->actual_record;
ret_count += gcac_ptr->amount_added;
}
}
return ret_count;
}
void print_gift_card_info(struct this_gift_card *thisone) {
struct gift_card_data *gcd_ptr;
struct gift_card_record_data *gcrd_ptr;
struct gift_card_amount_change *gcac_ptr;
struct gift_card_program *gcp_ptr;
gcd_ptr = thisone->gift_card_data;
printf(" Merchant ID: %32.32s\n",gcd_ptr->merchant_id);
printf(" Customer ID: %32.32s\n",gcd_ptr->customer_id);
printf(" Num records: %d\n",gcd_ptr->number_of_gift_card_records);
for(int i=0;i<gcd_ptr->number_of_gift_card_records; i++) {
gcrd_ptr = (struct gift_card_record_data *) gcd_ptr->gift_card_record_data[i];
if (gcrd_ptr->type_of_record == 1) {
printf(" record_type: amount_change\n");
gcac_ptr = gcrd_ptr->actual_record;
printf(" amount_added: %d\n",gcac_ptr->amount_added);
if (gcac_ptr->amount_added>0) {
printf(" signature: %32.32s\n",gcac_ptr->actual_signature);
}
}
else if (gcrd_ptr->type_of_record == 2) {
printf(" record_type: message\n");
printf(" message: %s\n",(char *)gcrd_ptr->actual_record);
}
else if (gcrd_ptr->type_of_record == 3) {
gcp_ptr = gcrd_ptr->actual_record;
printf(" record_type: animated message\n");
// BDG: Hmm... is message guaranteed to be null-terminated?
printf(" message: %s\n", gcp_ptr->message);
printf(" [running embedded program] \n");
animate(gcp_ptr->message, gcp_ptr->program);
}
}
printf(" Total value: %d\n\n",get_gift_card_value(thisone));
}
// Added to support web functionalities
void gift_card_json(struct this_gift_card *thisone) {
struct gift_card_data *gcd_ptr;
struct gift_card_record_data *gcrd_ptr;
struct gift_card_amount_change *gcac_ptr;
gcd_ptr = thisone->gift_card_data;
printf("{\n");
printf(" \"merchant_id\": \"%32.32s\",\n", gcd_ptr->merchant_id);
printf(" \"customer_id\": \"%32.32s\",\n", gcd_ptr->customer_id);
printf(" \"total_value\": %d,\n", get_gift_card_value(thisone));
printf(" \"records\": [\n");
for(int i=0;i<gcd_ptr->number_of_gift_card_records; i++) {
gcrd_ptr = (struct gift_card_record_data *) gcd_ptr->gift_card_record_data[i];
printf(" {\n");
if (gcrd_ptr->type_of_record == 1) {
printf(" \"record_type\": \"amount_change\",\n");
gcac_ptr = gcrd_ptr->actual_record;
printf(" \"amount_added\": %d,\n",gcac_ptr->amount_added);
if (gcac_ptr->amount_added>0) {
printf(" \"signature\": \"%32.32s\"\n",gcac_ptr->actual_signature);
}
}
else if (gcrd_ptr->type_of_record == 2) {
printf(" \"record_type\": \"message\",\n");
printf(" \"message\": \"%s\"\n",(char *)gcrd_ptr->actual_record);
}
else if (gcrd_ptr->type_of_record == 3) {
struct gift_card_program *gcp = gcrd_ptr->actual_record;
printf(" \"record_type\": \"animated message\",\n");
printf(" \"message\": \"%s\",\n",gcp->message);
// programs are binary so we will hex for the json
char *hexchars = "01234567890abcdef";
char program_hex[512+1];
program_hex[512] = '\0';
int i;
for(i = 0; i < 256; i++) {
program_hex[i*2] = hexchars[((gcp->program[i] & 0xf0) >> 4)];
program_hex[i*2+1] = hexchars[(gcp->program[i] & 0x0f)];
}
printf(" \"program\": \"%s\"\n",program_hex);
}
if (i < gcd_ptr->number_of_gift_card_records-1)
printf(" },\n");
else
printf(" }\n");
}
printf(" ]\n");
printf("}\n");
}
struct this_gift_card *gift_card_reader(FILE *input_fd) {
struct this_gift_card *ret_val = malloc(sizeof(struct this_gift_card));
void *optr;
void *ptr;
// Loop to do the whole file
while (!feof(input_fd)) {
struct gift_card_data *gcd_ptr;
/* JAC: Why aren't return types checked? */
fread(&ret_val->num_bytes, 4,1, input_fd);
/* fix for crash 1 -> number bytes = -1 */
if (ret_val->num_bytes<0){ //if statement to fix the crashes
printf("Invalid byte value! Exiting now...");
printf("\n");
exit(0);
}
// Make something the size of the rest and read it in
ptr = malloc(ret_val->num_bytes);
fread(ptr, ret_val->num_bytes, 1, input_fd);
optr = ptr-4;
gcd_ptr = ret_val->gift_card_data = malloc(sizeof(struct gift_card_data));
gcd_ptr->merchant_id = ptr;
ptr += 32;
// printf("VD: %d\n",(int)ptr - (int) gcd_ptr->merchant_id);
gcd_ptr->customer_id = ptr;
ptr += 32;
/* JAC: Something seems off here... */
gcd_ptr->number_of_gift_card_records = *((int *)ptr);
ptr += 4;
gcd_ptr->gift_card_record_data = (void *)malloc(gcd_ptr->number_of_gift_card_records*sizeof(void*));
// Now ptr points at the gift card recrod data
for (int i=0; i < gcd_ptr->number_of_gift_card_records; i++){
//printf("i: %d\n",i);
struct gift_card_record_data *gcrd_ptr;
gcrd_ptr = gcd_ptr->gift_card_record_data[i] = malloc(sizeof(struct gift_card_record_data));
struct gift_card_amount_change *gcac_ptr;
gcac_ptr = gcrd_ptr->actual_record = malloc(sizeof(struct gift_card_record_data));
struct gift_card_program *gcp_ptr;
gcp_ptr = malloc(sizeof(struct gift_card_program));
gcrd_ptr->record_size_in_bytes = *((char *)ptr);
//printf("rec at %x, %d bytes\n", ptr - optr, gcrd_ptr->record_size_in_bytes);
ptr += 4;
//printf("record_data: %d\n",gcrd_ptr->record_size_in_bytes);
gcrd_ptr->type_of_record = *((char *)ptr);
ptr += 4;
//printf("type of rec: %d\n", gcrd_ptr->type_of_record);
// amount change
if (gcrd_ptr->type_of_record == 1) {
gcac_ptr->amount_added = *((int*) ptr);
ptr += 4;
// don't need a sig if negative
/* JAC: something seems off here */
if (gcac_ptr < 0) break;
gcac_ptr->actual_signature = ptr;
ptr+=32;
}
// message
if (gcrd_ptr->type_of_record == 2) {
gcrd_ptr->actual_record = ptr;
// advance by the string size + 1 for nul
// BDG: does not seem right
ptr=ptr+strlen((char *)gcrd_ptr->actual_record)+1;
}
// BDG: gift cards can run code?? Might want to check this one carefully...
// text animatino (BETA)
/* fix for crash 2 */
if (gcrd_ptr->type_of_record == 3 && ret_val->num_bytes > 255 ) {
gcp_ptr->message = malloc(32);
gcp_ptr->program = malloc(256);
memcpy(gcp_ptr->message, ptr, 32);
ptr+=32;
memcpy(gcp_ptr->program, ptr, 256);
ptr+=256;
gcrd_ptr->actual_record = gcp_ptr;
}
else{
printf("Invalid record type for the specified gift card! Exiting...\n");
exit(1);
}
if (gcrd_ptr->type_of_record > 3) {
printf("unknown record type: %d\n", gcrd_ptr->type_of_record);
exit(1);
}
}
}
return ret_val;
}
struct this_gift_card *thisone;
int main(int argc, char **argv) {
if (argc != 3) {
fprintf(stderr, "usage: %s <1|2> file.gft\n", argv[0]);
fprintf(stderr, " - Use 1 for text output, 2 for JSON output\n");
return 1;
}
FILE *input_fd = fopen(argv[2],"r");
if (!input_fd) {
fprintf(stderr, "error opening file\n");
return 1;
}
thisone = gift_card_reader(input_fd);
if (argv[1][0] == '1') print_gift_card_info(thisone);
else if (argv[1][0] == '2') gift_card_json(thisone);
return 0;
}Last updated