3 files changed, 235 insertions, 0 deletions

diff --git a/Android.mk b/Android.mk
index 98ea68d9b..d96e53f99 100644
--- a/Android.mk
+++ b/Android.mk
@@ -356,6 +356,7 @@ ifeq ($(TW_INCLUDE_JB_CRYPTO), true)
     include $(commands_recovery_local_path)/crypto/fs_mgr/Android.mk
     include $(commands_recovery_local_path)/crypto/logwrapper/Android.mk
     include $(commands_recovery_local_path)/crypto/scrypt/Android.mk
+    include $(commands_recovery_local_path)/crypto/crypttools/Android.mk
 endif
 ifeq ($(HAVE_SELINUX), true)
     include $(commands_recovery_local_path)/minzip/Android.mk
diff --git a/crypto/crypttools/Android.mk b/crypto/crypttools/Android.mk
new file mode 100644
index 000000000..a2f8dfed5
--- /dev/null
+++ b/crypto/crypttools/Android.mk
@@ -0,0 +1,15 @@
+LOCAL_PATH:= $(call my-dir)
+include $(CLEAR_VARS)
+ifeq ($(TW_INCLUDE_JB_CRYPTO), true)
+LOCAL_SRC_FILES:= \
+	getfooter.c
+LOCAL_CFLAGS:= -g -c -W
+LOCAL_MODULE:=getfooter
+LOCAL_MODULE_TAGS:= eng
+LOCAL_STATIC_LIBRARIES += libfs_mgrtwrp libc libcutils
+LOCAL_MODULE_CLASS := UTILITY_EXECUTABLES
+LOCAL_MODULE_PATH := $(PRODUCT_OUT)/utilities
+LOCAL_FORCE_STATIC_EXECUTABLE := true
+LOCAL_C_INCLUDES := bootable/recovery/crypto/jb/
+include $(BUILD_EXECUTABLE)
+endif
\ No newline at end of file
diff --git a/crypto/crypttools/getfooter.c b/crypto/crypttools/getfooter.c
new file mode 100644
index 000000000..aa7f88e84
--- /dev/null
+++ b/crypto/crypttools/getfooter.c
@@ -0,0 +1,219 @@
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <linux/dm-ioctl.h>
+#include <sys/mount.h>
+#include "../fs_mgr/include/fs_mgr.h"
+#include "cryptfs.h"
+
+#include "cutils/properties.h"
+
+#ifndef PROPERTY_VALUE_MAX
+#define PROPERTY_VALUE_MAX 255
+#endif
+#ifndef FSTAB_PREFIX
+#define FSTAB_PREFIX "/fstab."
+#endif
+#ifndef KEY_IN_FOOTER
+#define KEY_IN_FOOTER "footer"
+#endif
+
+struct fstab *fstab;
+
+static unsigned int get_blkdev_size(int fd)
+{
+  unsigned int nr_sec;
+
+  if ( (ioctl(fd, BLKGETSIZE, &nr_sec)) == -1) {
+    nr_sec = 0;
+  }
+
+  return nr_sec;
+}
+
+int get_crypt_ftr_info(char **metadata_fname, off64_t *off)
+{
+  static int cached_data = 0;
+  static off64_t cached_off = 0;
+  static char cached_metadata_fname[PROPERTY_VALUE_MAX] = "";
+  int fd;
+  char key_loc[PROPERTY_VALUE_MAX];
+  char real_blkdev[PROPERTY_VALUE_MAX];
+  unsigned int nr_sec;
+  int rc = -1;
+
+    fs_mgr_get_crypt_info(fstab, key_loc, real_blkdev, sizeof(key_loc));
+
+    if (!strcmp(key_loc, KEY_IN_FOOTER)) {
+      if ( (fd = open(real_blkdev, O_RDWR)) < 0) {
+        printf("Cannot open real block device %s\n", real_blkdev);
+        return -1;
+      }
+
+      if ((nr_sec = get_blkdev_size(fd))) {
+        /* If it's an encrypted Android partition, the last 16 Kbytes contain the
+         * encryption info footer and key, and plenty of bytes to spare for future
+         * growth.
+         */
+        strlcpy(cached_metadata_fname, real_blkdev, sizeof(cached_metadata_fname));
+        cached_off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET;
+        cached_data = 1;
+      } else {
+        printf("Cannot get size of block device %s\n", real_blkdev);
+      }
+      close(fd);
+    } else {
+      strlcpy(cached_metadata_fname, key_loc, sizeof(cached_metadata_fname));
+      cached_off = 0;
+      cached_data = 1;
+    }
+
+  if (cached_data) {
+    if (metadata_fname) {
+        *metadata_fname = cached_metadata_fname;
+    }
+    if (off) {
+        *off = cached_off;
+    }
+    rc = 0;
+  }
+
+  return rc;
+}
+
+int get_crypt_ftr_and_key(struct crypt_mnt_ftr *crypt_ftr)
+{
+  int fd;
+  unsigned int nr_sec, cnt;
+  off64_t starting_off;
+  int rc = -1;
+  char *fname = NULL;
+  struct stat statbuf;
+
+  if (get_crypt_ftr_info(&fname, &starting_off)) {
+    printf("Unable to get crypt_ftr_info\n");
+    return -1;
+  }
+  if (fname[0] != '/') {
+    printf("Unexpected value for crypto key location '%s'\n", fname);
+    //return -1;
+  }
+  if ( (fd = open(fname, O_RDWR)) < 0) {
+    printf("Cannot open footer file %s for get\n", fname);
+    return -1;
+  }
+
+  /* Make sure it's 16 Kbytes in length */
+  fstat(fd, &statbuf);
+  if (S_ISREG(statbuf.st_mode) && (statbuf.st_size != 0x4000)) {
+    printf("footer file %s is not the expected size!\n", fname);
+	close(fd);
+    return -1;
+  }
+
+  /* Seek to the start of the crypt footer */
+  if (lseek64(fd, starting_off, SEEK_SET) == -1) {
+    printf("Cannot seek to real block device footer\n");
+	close(fd);
+    return -1;
+  }
+
+  if ( (cnt = read(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) {
+    printf("Cannot read real block device footer\n");
+	close(fd);
+    return -1;
+  }
+  close(fd);
+  return 0;
+}
+
+int main(void)
+{
+	char key_loc[PROPERTY_VALUE_MAX];
+	char blk_dev[PROPERTY_VALUE_MAX];
+	char fstab_filename[PROPERTY_VALUE_MAX + sizeof(FSTAB_PREFIX)];
+	struct stat st;
+	struct crypt_mnt_ftr crypt_ftr;
+	int fdout;
+
+	printf("This tool comes with no warranties whatsoever.\n");
+	printf("http://teamw.in\n\n");
+	strcpy(fstab_filename, FSTAB_PREFIX);
+	property_get("ro.hardware", fstab_filename + sizeof(FSTAB_PREFIX) - 1, "");
+
+	if (stat(fstab_filename, &st) != 0) {
+		printf("Cannot locate fstab file '%s'\n", fstab_filename);
+		return -1;
+	}
+
+	fstab = fs_mgr_read_fstab(fstab_filename);
+	if (!fstab) {
+		printf("failed to open %s\n", fstab_filename);
+		return -1;
+	}
+
+	fs_mgr_get_crypt_info(fstab, key_loc, blk_dev, sizeof(blk_dev));
+
+	if (get_crypt_ftr_and_key(&crypt_ftr)) {
+		printf("Error getting crypt footer and key\n");
+		return -1;
+	}
+
+	if ( (fdout = open("/footerfile", O_WRONLY | O_CREAT, 0644)) < 0) {
+		printf("Cannot open output file /footerfile\n");
+		return -1;
+	}
+	if (write(fdout, (void*) &crypt_ftr, sizeof(struct crypt_mnt_ftr)) != sizeof(struct crypt_mnt_ftr)) {
+		printf("Failed to write footer.\n");
+	}
+	close(fdout);
+
+	if (!strcmp(key_loc, KEY_IN_FOOTER)) {
+		unsigned int nr_sec, cnt;
+		off64_t off = 0;
+		char buffer[CRYPT_FOOTER_OFFSET];
+		int fd;
+
+		printf("\n\nDumping footer from '%s'...\n", blk_dev);
+		if ( (fd = open(blk_dev, O_RDONLY)) < 0) {
+			printf("Cannot open real block device %s\n", blk_dev);
+			return -1;
+		}
+
+		if ((nr_sec = get_blkdev_size(fd))) {
+			off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET;
+		} else {
+			printf("Cannot get size of block device %s\n", blk_dev);
+			close(fd);
+			return -1;
+		}
+		printf("Size is %llu, offset is %llu\n", ((off64_t)nr_sec * 512), off);
+		if (lseek64(fd, off, SEEK_SET) == -1) {
+			printf("Cannot seek to real block device footer\n");
+			close(fd);
+			return -1;
+		}
+
+		if ( (cnt = read(fd, buffer, sizeof(buffer))) != sizeof(buffer)) {
+			printf("Cannot read real block device footer\n");
+			close(fd);
+			return -1;
+		}
+		close(fd);
+		if ( (fdout = open("/footerdump", O_WRONLY | O_CREAT, 0644)) < 0) {
+			printf("Cannot open output file /footerdump\n");
+			return -1;
+		}
+		if (write(fdout, buffer, sizeof(buffer)) != sizeof(buffer)) {
+			printf("Failed to write footer.\n");
+		}
+		close(fdout);
+	}
+
+	return 0;
+}