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authorWorksButNotTested <62701594+WorksButNotTested@users.noreply.github.com>2021-04-28 09:25:26 +0100
committerGitHub <noreply@github.com>2021-04-28 10:25:26 +0200
commit39ad3b89467d6de12cbb9d08ccd77d331c0d1f9e (patch)
tree18bdf509d47e0d971bd9d7faf56d27758b23b09c /frida_mode/src/lib.c
parent8da5cba4012080afca5e7f7da9aaa6aa6e263f3e (diff)
downloadafl++-39ad3b89467d6de12cbb9d08ccd77d331c0d1f9e.tar.gz
Frida persistent (#880)
* Added x64 support for persistent mode (function call only), in-memory teest cases and complog

* Review changes, fix NeverZero and code to parse the .text section of the main executable. Excluded ranges TBC

* Various minor fixes and finished support for AFL_INST_LIBS

* Review changes

Co-authored-by: Your Name <you@example.com>
Diffstat (limited to 'frida_mode/src/lib.c')
-rw-r--r--frida_mode/src/lib.c167
1 files changed, 167 insertions, 0 deletions
diff --git a/frida_mode/src/lib.c b/frida_mode/src/lib.c
new file mode 100644
index 00000000..326d4819
--- /dev/null
+++ b/frida_mode/src/lib.c
@@ -0,0 +1,167 @@
+#include <elf.h>
+#include <fcntl.h>
+#include <linux/limits.h>
+#include <stdio.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include "frida-gum.h"
+
+#include "debug.h"
+
+#include "lib.h"
+
+#if defined(__arm__) || defined(__i386__)
+  #define ELFCLASS ELFCLASS32
+typedef Elf32_Ehdr Elf_Ehdr;
+typedef Elf32_Phdr Elf_Phdr;
+typedef Elf32_Shdr Elf_Shdr;
+#elif defined(__aarch64__) || defined(__x86_64__)
+  #define ELFCLASS ELFCLASS64
+typedef Elf64_Ehdr Elf_Ehdr;
+typedef Elf64_Phdr Elf_Phdr;
+typedef Elf64_Shdr Elf_Shdr;
+#else
+  #error "Unsupported platform"
+#endif
+
+typedef struct {
+
+  gchar      name[PATH_MAX + 1];
+  gchar      path[PATH_MAX + 1];
+  GumAddress base_address;
+  gsize      size;
+
+} lib_details_t;
+
+static guint64 text_base = 0;
+static guint64 text_limit = 0;
+
+static gboolean lib_find_exe(const GumModuleDetails *details,
+                             gpointer                user_data) {
+
+  lib_details_t *lib_details = (lib_details_t *)user_data;
+
+  memcpy(lib_details->name, details->name, PATH_MAX);
+  memcpy(lib_details->path, details->path, PATH_MAX);
+  lib_details->base_address = details->range->base_address;
+  lib_details->size = details->range->size;
+  return FALSE;
+
+}
+
+static gboolean lib_is_little_endian(void) {
+
+  int probe = 1;
+  return *(char *)&probe;
+
+}
+
+static void lib_validate_hdr(Elf_Ehdr *hdr) {
+
+  if (hdr->e_ident[0] != ELFMAG0) FATAL("Invalid e_ident[0]");
+  if (hdr->e_ident[1] != ELFMAG1) FATAL("Invalid e_ident[1]");
+  if (hdr->e_ident[2] != ELFMAG2) FATAL("Invalid e_ident[2]");
+  if (hdr->e_ident[3] != ELFMAG3) FATAL("Invalid e_ident[3]");
+  if (hdr->e_ident[4] != ELFCLASS) FATAL("Invalid class");
+  if (hdr->e_ident[5] != (lib_is_little_endian() ? ELFDATA2LSB : ELFDATA2MSB))
+    FATAL("Invalid endian");
+  if (hdr->e_ident[6] != EV_CURRENT) FATAL("Invalid version");
+  if (hdr->e_type != ET_DYN) FATAL("Invalid type");
+  if (hdr->e_version != EV_CURRENT) FATAL("Invalid e_version");
+  if (hdr->e_phoff != sizeof(Elf_Ehdr)) FATAL("Invalid e_phoff");
+  if (hdr->e_ehsize != sizeof(Elf_Ehdr)) FATAL("Invalid e_ehsize");
+  if (hdr->e_phentsize != sizeof(Elf_Phdr)) FATAL("Invalid e_phentsize");
+  if (hdr->e_shentsize != sizeof(Elf_Shdr)) FATAL("Invalid e_shentsize");
+
+}
+
+static void lib_read_text_section(lib_details_t *lib_details, Elf_Ehdr *hdr) {
+
+  Elf_Shdr *shdr;
+  Elf_Shdr *shstrtab;
+  char *    shstr;
+  char *    section_name;
+  Elf_Shdr *curr;
+  char      text_name[] = ".text";
+
+  shdr = (Elf_Shdr *)((char *)hdr + hdr->e_shoff);
+  shstrtab = &shdr[hdr->e_shstrndx];
+  shstr = (char *)hdr + shstrtab->sh_offset;
+
+  OKF("shdr: %p", shdr);
+  OKF("shstrtab: %p", shstrtab);
+  OKF("shstr: %p", shstr);
+
+  for (size_t i = 0; i < hdr->e_shnum; i++) {
+
+    curr = &shdr[i];
+
+    if (curr->sh_name == 0) continue;
+
+    section_name = &shstr[curr->sh_name];
+    OKF("Section: %2lu - base: 0x%016lX size: 0x%016lX %s", i, curr->sh_addr,
+        curr->sh_size, section_name);
+    if (memcmp(section_name, text_name, sizeof(text_name)) == 0 &&
+        text_base == 0) {
+
+      text_base = lib_details->base_address + curr->sh_addr;
+      text_limit = lib_details->base_address + curr->sh_addr + curr->sh_size;
+      OKF("> text_addr: 0x%016lX", text_base);
+      OKF("> text_limit: 0x%016lX", text_limit);
+
+    }
+
+  }
+
+}
+
+static void lib_get_text_section(lib_details_t *details) {
+
+  int       fd = -1;
+  off_t     len;
+  Elf_Ehdr *hdr;
+
+  fd = open(details->path, O_RDONLY);
+  if (fd < 0) { FATAL("Failed to open %s", details->path); }
+
+  len = lseek(fd, 0, SEEK_END);
+
+  if (len == (off_t)-1) { FATAL("Failed to lseek %s", details->path); }
+
+  OKF("len: %ld\n", len);
+
+  hdr = (Elf_Ehdr *)mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
+  if (hdr == MAP_FAILED) { FATAL("Failed to map %s", details->path); }
+
+  lib_validate_hdr(hdr);
+  lib_read_text_section(details, hdr);
+
+  munmap(hdr, len);
+  close(fd);
+
+}
+
+void lib_init(void) {
+
+  lib_details_t lib_details;
+  gum_process_enumerate_modules(lib_find_exe, &lib_details);
+  OKF("Executable: 0x%016lx - %s", lib_details.base_address, lib_details.path);
+  lib_get_text_section(&lib_details);
+
+}
+
+guint64 lib_get_text_base(void) {
+
+  if (text_base == 0) FATAL("Lib not initialized");
+  return text_base;
+
+}
+
+guint64 lib_get_text_limit(void) {
+
+  if (text_limit == 0) FATAL("Lib not initialized");
+  return text_limit;
+
+}
+