From a1bc148c7c81f886426c253f2ea7beb0f301f6b0 Mon Sep 17 00:00:00 2001
From: Doug Zongker <dougz@android.com>
Date: Thu, 13 Feb 2014 15:18:19 -0800
Subject: remove 'retouch' ASLR support

Older versions of android supported an ASLR system where binaries were
randomly twiddled at OTA install time.  Remove support for this; we
now use the ASLR support in the linux kernel.

Change-Id: I8348eb0d6424692668dc1a00e2416fbef6c158a2
---
 applypatch/applypatch.c | 35 ++++++++---------------------------
 1 file changed, 8 insertions(+), 27 deletions(-)

(limited to 'applypatch/applypatch.c')

diff --git a/applypatch/applypatch.c b/applypatch/applypatch.c
index cb9bc2349..c9c40c98f 100644
--- a/applypatch/applypatch.c
+++ b/applypatch/applypatch.c
@@ -24,6 +24,7 @@
 #include <sys/types.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <stdbool.h>
 
 #include "mincrypt/sha.h"
 #include "applypatch.h"
@@ -44,14 +45,11 @@ static int GenerateTarget(FileContents* source_file,
 
 static int mtd_partitions_scanned = 0;
 
-// Read a file into memory; optionally (retouch_flag == RETOUCH_DO_MASK) mask
-// the retouched entries back to their original value (such that SHA-1 checks
-// don't fail due to randomization); store the file contents and associated
+// Read a file into memory; store the file contents and associated
 // metadata in *file.
 //
 // Return 0 on success.
-int LoadFileContents(const char* filename, FileContents* file,
-                     int retouch_flag) {
+int LoadFileContents(const char* filename, FileContents* file) {
     file->data = NULL;
 
     // A special 'filename' beginning with "MTD:" or "EMMC:" means to
@@ -87,20 +85,6 @@ int LoadFileContents(const char* filename, FileContents* file,
     }
     fclose(f);
 
-    // apply_patch[_check] functions are blind to randomization. Randomization
-    // is taken care of in [Undo]RetouchBinariesFn. If there is a mismatch
-    // within a file, this means the file is assumed "corrupt" for simplicity.
-    if (retouch_flag) {
-        int32_t desired_offset = 0;
-        if (retouch_mask_data(file->data, file->size,
-                              &desired_offset, NULL) != RETOUCH_DATA_MATCHED) {
-            printf("error trying to mask retouch entries\n");
-            free(file->data);
-            file->data = NULL;
-            return -1;
-        }
-    }
-
     SHA_hash(file->data, file->size, file->sha1);
     return 0;
 }
@@ -579,7 +563,7 @@ int applypatch_check(const char* filename,
     // LoadFileContents is successful.  (Useful for reading
     // partitions, where the filename encodes the sha1s; no need to
     // check them twice.)
-    if (LoadFileContents(filename, &file, RETOUCH_DO_MASK) != 0 ||
+    if (LoadFileContents(filename, &file) != 0 ||
         (num_patches > 0 &&
          FindMatchingPatch(file.sha1, patch_sha1_str, num_patches) < 0)) {
         printf("file \"%s\" doesn't have any of expected "
@@ -594,7 +578,7 @@ int applypatch_check(const char* filename,
         // exists and matches the sha1 we're looking for, the check still
         // passes.
 
-        if (LoadFileContents(CACHE_TEMP_SOURCE, &file, RETOUCH_DO_MASK) != 0) {
+        if (LoadFileContents(CACHE_TEMP_SOURCE, &file) != 0) {
             printf("failed to load cache file\n");
             return 1;
         }
@@ -730,8 +714,7 @@ int applypatch(const char* source_filename,
     const Value* copy_patch_value = NULL;
 
     // We try to load the target file into the source_file object.
-    if (LoadFileContents(target_filename, &source_file,
-                         RETOUCH_DO_MASK) == 0) {
+    if (LoadFileContents(target_filename, &source_file) == 0) {
         if (memcmp(source_file.sha1, target_sha1, SHA_DIGEST_SIZE) == 0) {
             // The early-exit case:  the patch was already applied, this file
             // has the desired hash, nothing for us to do.
@@ -750,8 +733,7 @@ int applypatch(const char* source_filename,
         // target file, or we did but it's different from the source file.
         free(source_file.data);
         source_file.data = NULL;
-        LoadFileContents(source_filename, &source_file,
-                         RETOUCH_DO_MASK);
+        LoadFileContents(source_filename, &source_file);
     }
 
     if (source_file.data != NULL) {
@@ -767,8 +749,7 @@ int applypatch(const char* source_filename,
         source_file.data = NULL;
         printf("source file is bad; trying copy\n");
 
-        if (LoadFileContents(CACHE_TEMP_SOURCE, &copy_file,
-                             RETOUCH_DO_MASK) < 0) {
+        if (LoadFileContents(CACHE_TEMP_SOURCE, &copy_file) < 0) {
             // fail.
             printf("failed to read copy file\n");
             return 1;
-- 
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