init

Tests/ELF/elf.c

@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+int main()
+{
+    return puts("Unix\n");
+}

Tests/ELF/makefile

@@ -0,0 +1,2 @@
+all:
+	gcc elf.c -o elf.exe

Tests/PE/makefile

@@ -0,0 +1,2 @@
+all:
+	x86_64-w64-mingw32-gcc-posix pe.c -o pe.exe

Tests/PE/pe.c

@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+int main()
+{
+    return puts("Windows\n");
+}

compile_flags.txt

@@ -0,0 +1,14 @@
+-std=c99
+--target=x86_64-pc-windows-msvc
+-isystem/usr/x86_64-w64-mingw32/include
+-isystem/usr/lib/gcc/x86_64-w64-mingw32/9.3-win32/include
+-isystem/usr/lib/gcc/x86_64-w64-mingw32/9.3-win32/include-fixed
+-Iinclude
+-Wall
+-Wextra
+-Werror
+-Wshadow
+-Wpedantic
+-Wconversion
+-fms-compatibility
+-fms-extensions

makefile

@@ -0,0 +1,42 @@
+TARGET    = vpr-extract
+
+CC        = gcc
+CFLAGS    = -O3 -Wall -Wextra -Werror -Wshadow -Wpedantic -Wconversion
+
+LD        = gcc
+LDFLAGS   = -s
+
+BIN       = bin
+BUILD     = build
+
+SOURCE    = src
+OBJECT    = $(BUILD)
+SOURCES   = $(wildcard $(SOURCE)/*.c)
+OBJECTS   = $(patsubst $(SOURCE)/%.c,$(OBJECT)/%.o,$(SOURCES))
+
+INCLUDE   = include
+INCLUDES  = $(addprefix -I,$(INCLUDE))
+
+all: $(TARGET)
+
+$(TARGET): $(BIN) $(BUILD) $(OBJECTS)
+	$(LD) $(LDFLAGS) $(OBJECTS) -o $(BIN)/$(TARGET)
+
+$(OBJECTS): $(OBJECT)/%.o : $(SOURCE)/%.c
+	$(CC) $(CFLAGS) $(INCLUDES) -c $< -o $@
+
+$(BIN):
+	mkdir -p $@
+
+$(BUILD):
+	mkdir -p $@
+
+.PHONY: clean
+clean:
+	rm -fr $(BIN)/*
+	rm -fr $(BUILD)/*
+
+.PHONY: extra-clean
+extra-clean:
+	rm -fr $(BIN)
+	rm -fr $(BUILD)

src/main.c

@@ -0,0 +1,186 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+static FILE* out_stream;
+static char* program;
+static char* target;
+static int format;
+
+static inline void __attribute((noreturn)) __usage_error(int error_code, char* restrict message)
+{
+    fprintf(stderr,
+        "Error %d: %s.\n" // error_code, message
+        "\n"
+        "Usage:\n"
+        "  %s <path/to/executable> [ optional switches ]\n" // program
+        "\n"
+        "positional arguments:\n"
+        "  path/to/executable\n"
+        "\n"
+        "optional switches:\n"
+        "  -c,-C\t\toutput as c-style char array\n"
+        "  -s,-S\t\toutput as double quoted string\n"
+        "example :\n"
+        "  %s path/to/executable\n" // program
+        ,error_code, message, program, program
+    );
+
+    exit(error_code);
+}
+
+static inline void verify_requirements(void)
+{
+    if (system("type objdump > /dev/null"))
+    {
+        __usage_error(-1, "'objdump' not found");
+    }
+    if (system("type grep > /dev/null"))
+    {
+        __usage_error(-1, "'grep' not found");
+    }
+    if (system("type cut > /dev/null"))
+    {
+        __usage_error(-1, "'cut' not found");
+    }
+}
+
+static void handle_command_line(int argc, char** argv)
+{
+    if (argc < 2)
+    {
+        __usage_error(1, "Missing positional arguments");
+    }
+
+    for (int i = 2; i < argc; i++)
+    {
+        switch (argv[i][0])
+        {
+            case '-':
+            {
+                switch (argv[i][1])
+                {
+                    case 'C':
+                    case 'c':
+                    {
+                        format = 'c';
+                        break;
+                    }
+                    case 'S':
+                    case 's':
+                    {
+                        format = 's';
+                        break;
+                    }
+                    case 'O':
+                    case 'o':
+                    {
+                        if (i+1 >= argc)
+                        {
+                            __usage_error(2, "No file specified");
+                        }
+                        if (!(out_stream = fopen(argv[i+1], "w")))
+                        {
+                            char buffer[256] = { 0 };
+                            snprintf(buffer, sizeof(buffer), "Failed to open: %s", argv[i+1]);
+                            __usage_error(4, "Failed to open file");
+                        }
+                        break;
+                    }
+                    default:
+                    {
+                        __usage_error(3, "Unknown option supplied");
+                    }
+                }
+            }
+        }
+    }
+
+    if (!format)
+    {
+        format = 'c';
+    }
+
+    if (!out_stream)
+    {
+        out_stream = stdout;
+    }
+}
+
+static inline void verify_target_exists(void)
+{
+    FILE* fp;
+    if (!(fp = fopen(target, "rb")))
+    {
+        char buffer[256] = { 0 };
+        snprintf(buffer, sizeof(buffer), "Failed to find executable '%s'", target);
+        __usage_error(6, buffer);
+    }
+    fclose(fp);
+}
+
+int main(int argc, char** argv)
+{
+    FILE*   fp = NULL;
+    char    disassembler[256] = { 0 };
+
+    program = argv[0];
+    handle_command_line(argc, argv);
+
+    target = argv[1];
+    verify_requirements();
+    verify_target_exists();
+
+    snprintf(disassembler, sizeof(disassembler), "objdump -d --section=.text %s | grep '^ ' | cut -f2", target);
+    if (!(fp = popen(disassembler, "r")))
+    {
+        fprintf(stderr, "Failed to disassemble %s\n", target);
+        return 5;
+    }
+
+    if (format == 'c')
+    {
+        unsigned size = 0;
+        for (int c; (c = fgetc(fp)) != EOF;)
+        {
+            if (c != ' ' && c != '\n' && c != '\t')
+            {
+                ++size;
+            }
+        }
+        pclose(fp);
+
+        if (!(fp = popen(disassembler, "r")))
+        {
+            fprintf(stderr, "Failed to disassemble %s\n", target);
+            return 5;
+        }
+
+        fprintf(out_stream, "unsigned char shellcode[%u] = {\n    ", size);
+        unsigned position = 0;
+        for (int c = 0; (c = fgetc(fp)) != EOF;)
+        {
+            if (c != ' ' && c != '\n' && c != '\t')
+            {
+                ++position;
+                fprintf(out_stream, "0x%2X%c%s", c, (position < size ? ',' : '\0'), (position % 10 == 0  && position != 0 ? "\n    " : " "));
+            }
+        }
+        fprintf(out_stream, "\n}\n");
+    }
+    else if (format == 's')
+    {
+        fputc('"', out_stream);
+        for (int c = 0; (c = fgetc(fp)) != EOF;)
+        {
+            if (c != ' ' && c != '\n' && c != '\t')
+            {
+                fprintf(out_stream, "\\x%2X", c);
+            }
+        }
+        fputc('"', out_stream);
+        pclose(fp);
+    }
+
+    fclose(out_stream);
+    return 0;
+}