From db314d69f023d2a6c8956073aa9d283e20b280ef Mon Sep 17 00:00:00 2001 From: Hristo Bojinov Date: Mon, 2 Aug 2010 10:29:49 -0700 Subject: [PATCH] Working ASLR implementation Separate files for retouch functionality are in minelf/* ASLR for shared libraries is controlled by "-a" in ota_from_target_files. Binary files are self-contained. Retouch logic can recover from crashes. Signed-off-by: Hristo Bojinov Change-Id: I76c596abf4febd68c14f9d807ac62e8751e0b1bd --- Android.mk | 1 + applypatch/Android.mk | 4 +- applypatch/applypatch.c | 42 ++++- applypatch/applypatch.h | 9 +- applypatch/main.c | 2 +- minelf/Android.mk | 27 +++ minelf/Retouch.c | 406 ++++++++++++++++++++++++++++++++++++++++ minelf/Retouch.h | 51 +++++ updater/Android.mk | 1 + updater/install.c | 124 +++++++++++- 10 files changed, 649 insertions(+), 18 deletions(-) create mode 100644 minelf/Android.mk create mode 100644 minelf/Retouch.c create mode 100644 minelf/Retouch.h diff --git a/Android.mk b/Android.mk index 4a3d285..e8e7a79 100644 --- a/Android.mk +++ b/Android.mk @@ -67,6 +67,7 @@ include $(BUILD_EXECUTABLE) include $(commands_recovery_local_path)/minui/Android.mk +include $(commands_recovery_local_path)/minelf/Android.mk include $(commands_recovery_local_path)/minzip/Android.mk include $(commands_recovery_local_path)/mtdutils/Android.mk include $(commands_recovery_local_path)/tools/Android.mk diff --git a/applypatch/Android.mk b/applypatch/Android.mk index e91e4bf..eff1d77 100644 --- a/applypatch/Android.mk +++ b/applypatch/Android.mk @@ -31,7 +31,7 @@ include $(CLEAR_VARS) LOCAL_SRC_FILES := main.c LOCAL_MODULE := applypatch LOCAL_C_INCLUDES += bootable/recovery -LOCAL_STATIC_LIBRARIES += libapplypatch libmtdutils libmincrypt libbz +LOCAL_STATIC_LIBRARIES += libapplypatch libmtdutils libmincrypt libbz libminelf LOCAL_SHARED_LIBRARIES += libz libcutils libstdc++ libc include $(BUILD_EXECUTABLE) @@ -43,7 +43,7 @@ LOCAL_MODULE := applypatch_static LOCAL_FORCE_STATIC_EXECUTABLE := true LOCAL_MODULE_TAGS := eng LOCAL_C_INCLUDES += bootable/recovery -LOCAL_STATIC_LIBRARIES += libapplypatch libmtdutils libmincrypt libbz +LOCAL_STATIC_LIBRARIES += libapplypatch libmtdutils libmincrypt libbz libminelf LOCAL_STATIC_LIBRARIES += libz libcutils libstdc++ libc include $(BUILD_EXECUTABLE) diff --git a/applypatch/applypatch.c b/applypatch/applypatch.c index d182821..1d9ef6e 100644 --- a/applypatch/applypatch.c +++ b/applypatch/applypatch.c @@ -30,16 +30,21 @@ #include "mtdutils/mtdutils.h" #include "edify/expr.h" -static int SaveFileContents(const char* filename, FileContents file); +int SaveFileContents(const char* filename, FileContents file); static int LoadPartitionContents(const char* filename, FileContents* file); int ParseSha1(const char* str, uint8_t* digest); static ssize_t FileSink(unsigned char* data, ssize_t len, void* token); static int mtd_partitions_scanned = 0; -// Read a file into memory; store it and its associated metadata in -// *file. Return 0 on success. -int LoadFileContents(const char* filename, FileContents* file) { +// 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 +// metadata in *file. +// +// Return 0 on success. +int LoadFileContents(const char* filename, FileContents* file, + int retouch_flag) { file->data = NULL; // A special 'filename' beginning with "MTD:" or "EMMC:" means to @@ -75,6 +80,20 @@ 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(file->data, file->size, file->sha1); return 0; } @@ -303,7 +322,7 @@ static int LoadPartitionContents(const char* filename, FileContents* file) { // Save the contents of the given FileContents object under the given // filename. Return 0 on success. -static int SaveFileContents(const char* filename, FileContents file) { +int SaveFileContents(const char* filename, FileContents file) { int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC); if (fd < 0) { printf("failed to open \"%s\" for write: %s\n", @@ -477,7 +496,7 @@ 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) != 0 || + if (LoadFileContents(filename, &file, RETOUCH_DO_MASK) != 0 || (num_patches > 0 && FindMatchingPatch(file.sha1, patch_sha1_str, num_patches) < 0)) { printf("file \"%s\" doesn't have any of expected " @@ -491,7 +510,7 @@ 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) != 0) { + if (LoadFileContents(CACHE_TEMP_SOURCE, &file, RETOUCH_DO_MASK) != 0) { printf("failed to load cache file\n"); return 1; } @@ -617,7 +636,8 @@ int applypatch(const char* source_filename, int made_copy = 0; // We try to load the target file into the source_file object. - if (LoadFileContents(target_filename, &source_file) == 0) { + if (LoadFileContents(target_filename, &source_file, + RETOUCH_DO_MASK) == 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. @@ -633,7 +653,8 @@ int applypatch(const char* source_filename, // Need to load the source file: either we failed to load the // target file, or we did but it's different from the source file. free(source_file.data); - LoadFileContents(source_filename, &source_file); + LoadFileContents(source_filename, &source_file, + RETOUCH_DO_MASK); } if (source_file.data != NULL) { @@ -648,7 +669,8 @@ int applypatch(const char* source_filename, free(source_file.data); printf("source file is bad; trying copy\n"); - if (LoadFileContents(CACHE_TEMP_SOURCE, ©_file) < 0) { + if (LoadFileContents(CACHE_TEMP_SOURCE, ©_file, + RETOUCH_DO_MASK) < 0) { // fail. printf("failed to read copy file\n"); return 1; diff --git a/applypatch/applypatch.h b/applypatch/applypatch.h index 10c0125..a78c89b 100644 --- a/applypatch/applypatch.h +++ b/applypatch/applypatch.h @@ -19,6 +19,7 @@ #include #include "mincrypt/sha.h" +#include "minelf/Retouch.h" #include "edify/expr.h" typedef struct _Patch { @@ -59,10 +60,12 @@ int applypatch_check(const char* filename, int num_patches, char** const patch_sha1_str); -// Read a file into memory; store it and its associated metadata in -// *file. Return 0 on success. -int LoadFileContents(const char* filename, FileContents* file); +int LoadFileContents(const char* filename, FileContents* file, + int retouch_flag); +int SaveFileContents(const char* filename, FileContents file); void FreeFileContents(FileContents* file); +int FindMatchingPatch(uint8_t* sha1, char** const patch_sha1_str, + int num_patches); // bsdiff.c void ShowBSDiffLicense(); diff --git a/applypatch/main.c b/applypatch/main.c index 3917f86..7025a2e 100644 --- a/applypatch/main.c +++ b/applypatch/main.c @@ -74,7 +74,7 @@ static int ParsePatchArgs(int argc, char** argv, (*patches)[i] = NULL; } else { FileContents fc; - if (LoadFileContents(colon, &fc) != 0) { + if (LoadFileContents(colon, &fc, RETOUCH_DONT_MASK) != 0) { goto abort; } (*patches)[i] = malloc(sizeof(Value)); diff --git a/minelf/Android.mk b/minelf/Android.mk new file mode 100644 index 0000000..0f41ff5 --- /dev/null +++ b/minelf/Android.mk @@ -0,0 +1,27 @@ +# Copyright (C) 2009 The Android Open Source Project +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +LOCAL_PATH := $(call my-dir) +include $(CLEAR_VARS) + +LOCAL_SRC_FILES := \ + Retouch.c + +LOCAL_C_INCLUDES += bootable/recovery + +LOCAL_MODULE := libminelf + +LOCAL_CFLAGS += -Wall + +include $(BUILD_STATIC_LIBRARY) diff --git a/minelf/Retouch.c b/minelf/Retouch.c new file mode 100644 index 0000000..33809cd --- /dev/null +++ b/minelf/Retouch.c @@ -0,0 +1,406 @@ +/* + * Copyright (C) 2009 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include +#include +#include +#include +#include +#include +#include +#include "Retouch.h" +#include "applypatch/applypatch.h" + +typedef struct { + int32_t mmap_addr; + char tag[4]; /* 'P', 'R', 'E', ' ' */ +} prelink_info_t __attribute__((packed)); + +#define false 0 +#define true 1 + +static int32_t offs_prev; +static uint32_t cont_prev; + +static void init_compression_state(void) { + offs_prev = 0; + cont_prev = 0; +} + +// For details on the encoding used for relocation lists, please +// refer to build/tools/retouch/retouch-prepare.c. The intent is to +// save space by removing most of the inherent redundancy. + +static void decode_bytes(uint8_t *encoded_bytes, int encoded_size, + int32_t *dst_offset, uint32_t *dst_contents) { + if (encoded_size == 2) { + *dst_offset = offs_prev + (((encoded_bytes[0]&0x60)>>5)+1)*4; + + // if the original was negative, we need to 1-pad before applying delta + int32_t tmp = (((encoded_bytes[0] & 0x0000001f) << 8) | + encoded_bytes[1]); + if (tmp & 0x1000) tmp = 0xffffe000 | tmp; + *dst_contents = cont_prev + tmp; + } else if (encoded_size == 3) { + *dst_offset = offs_prev + (((encoded_bytes[0]&0x30)>>4)+1)*4; + + // if the original was negative, we need to 1-pad before applying delta + int32_t tmp = (((encoded_bytes[0] & 0x0000000f) << 16) | + (encoded_bytes[1] << 8) | + encoded_bytes[2]); + if (tmp & 0x80000) tmp = 0xfff00000 | tmp; + *dst_contents = cont_prev + tmp; + } else { + *dst_offset = + (encoded_bytes[0]<<24) | + (encoded_bytes[1]<<16) | + (encoded_bytes[2]<<8) | + encoded_bytes[3]; + if (*dst_offset == 0x3fffffff) *dst_offset = -1; + *dst_contents = + (encoded_bytes[4]<<24) | + (encoded_bytes[5]<<16) | + (encoded_bytes[6]<<8) | + encoded_bytes[7]; + } +} + +static uint8_t *decode_in_memory(uint8_t *encoded_bytes, + int32_t *offset, uint32_t *contents) { + int input_size, charIx; + uint8_t input[8]; + + input[0] = *(encoded_bytes++); + if (input[0] & 0x80) + input_size = 2; + else if (input[0] & 0x40) + input_size = 3; + else + input_size = 8; + + // we already read one byte.. + charIx = 1; + while (charIx < input_size) { + input[charIx++] = *(encoded_bytes++); + } + + // depends on the decoder state! + decode_bytes(input, input_size, offset, contents); + + offs_prev = *offset; + cont_prev = *contents; + + return encoded_bytes; +} + +int retouch_mask_data(uint8_t *binary_object, + int32_t binary_size, + int32_t *desired_offset, + int32_t *retouch_offset) { + retouch_info_t *r_info; + prelink_info_t *p_info; + + int32_t target_offset = 0; + if (desired_offset) target_offset = *desired_offset; + + int32_t p_offs = binary_size-sizeof(prelink_info_t); // prelink_info_t + int32_t r_offs = p_offs-sizeof(retouch_info_t); // retouch_info_t + int32_t b_offs; // retouch data blob + + // If not retouched, we say it was a match. This might get invoked on + // non-retouched binaries, so that's why we need to do this. + if (retouch_offset != NULL) *retouch_offset = target_offset; + if (r_offs < 0) return (desired_offset == NULL) ? + RETOUCH_DATA_NOTAPPLICABLE : RETOUCH_DATA_MATCHED; + p_info = (prelink_info_t *)(binary_object+p_offs); + r_info = (retouch_info_t *)(binary_object+r_offs); + if (strncmp(p_info->tag, "PRE ", 4) || + strncmp(r_info->tag, "RETOUCH ", 8)) + return (desired_offset == NULL) ? + RETOUCH_DATA_NOTAPPLICABLE : RETOUCH_DATA_MATCHED; + + b_offs = r_offs-r_info->blob_size; + if (b_offs < 0) { + printf("negative binary offset: %d = %d - %d\n", + b_offs, r_offs, r_info->blob_size); + return RETOUCH_DATA_ERROR; + } + uint8_t *b_ptr = binary_object+b_offs; + + // Retouched: let's go through the work then. + int32_t offset_candidate = target_offset; + bool offset_set = false, offset_mismatch = false; + init_compression_state(); + while (b_ptr < (uint8_t *)r_info) { + int32_t retouch_entry_offset; + uint32_t *retouch_entry; + uint32_t retouch_original_value; + + b_ptr = decode_in_memory(b_ptr, + &retouch_entry_offset, + &retouch_original_value); + if (retouch_entry_offset < (-1) || + retouch_entry_offset >= b_offs) { + printf("bad retouch_entry_offset: %d", retouch_entry_offset); + return RETOUCH_DATA_ERROR; + } + + // "-1" means this is the value in prelink_info_t, which also gets + // randomized. + if (retouch_entry_offset == -1) + retouch_entry = (uint32_t *)&(p_info->mmap_addr); + else + retouch_entry = (uint32_t *)(binary_object+retouch_entry_offset); + + if (desired_offset) + *retouch_entry = retouch_original_value + target_offset; + + // Infer the randomization shift, compare to previously inferred. + int32_t offset_of_this_entry = (int32_t)(*retouch_entry- + retouch_original_value); + if (!offset_set) { + offset_candidate = offset_of_this_entry; + offset_set = true; + } else { + if (offset_candidate != offset_of_this_entry) { + offset_mismatch = true; + printf("offset is mismatched: %d, this entry is %d," + " original 0x%x @ 0x%x", + offset_candidate, offset_of_this_entry, + retouch_original_value, retouch_entry_offset); + } + } + } + if (b_ptr > (uint8_t *)r_info) { + printf("b_ptr went too far: %p, while r_info is %p", + b_ptr, r_info); + return RETOUCH_DATA_ERROR; + } + + if (offset_mismatch) return RETOUCH_DATA_MISMATCHED; + if (retouch_offset != NULL) *retouch_offset = offset_candidate; + return RETOUCH_DATA_MATCHED; +} + +// On success, _override is set to the offset that was actually applied. +// This implies that once we randomize to an offset we stick with it. +// This in turn is necessary in order to guarantee recovery after crash. +bool retouch_one_library(const char *binary_name, + const char *binary_sha1, + int32_t retouch_offset, + int32_t *retouch_offset_override) { + bool success = true; + int result; + + FileContents file; + file.data = NULL; + + char binary_name_atomic[strlen(binary_name)+10]; + strcpy(binary_name_atomic, binary_name); + strcat(binary_name_atomic, ".atomic"); + + // We need a path that exists for calling statfs() later. + // + // Assume that binary_name (eg "/system/app/Foo.apk") is located + // on the same filesystem as its top-level directory ("/system"). + char target_fs[strlen(binary_name)+1]; + char* slash = strchr(binary_name+1, '/'); + if (slash != NULL) { + int count = slash - binary_name; + strncpy(target_fs, binary_name, count); + target_fs[count] = '\0'; + } else { + strcpy(target_fs, binary_name); + } + + result = LoadFileContents(binary_name, &file, RETOUCH_DONT_MASK); + + if (result == 0) { + // Figure out the *apparent* offset to which this file has been + // retouched. If it looks good, we will skip processing (we might + // have crashed and during this recovery pass we don't want to + // overwrite a valuable saved file in /cache---which would happen + // if we blindly retouch everything again). NOTE: This implies + // that we might have to override the supplied retouch offset. We + // can do the override only once though: everything should match + // afterward. + + int32_t inferred_offset; + int retouch_probe_result = retouch_mask_data(file.data, + file.size, + NULL, + &inferred_offset); + + if (retouch_probe_result == RETOUCH_DATA_MATCHED) { + if ((retouch_offset == inferred_offset) || + ((retouch_offset != 0 && inferred_offset != 0) && + (retouch_offset_override != NULL))) { + // This file is OK already and we are allowed to override. + // Let's just return the offset override value. It is critical + // to skip regardless of override: a broken file might need + // recovery down the list and we should not mess up the saved + // copy by doing unnecessary retouching. + // + // NOTE: If retouching was already started with a different + // value, we will not be allowed to override. This happens + // if on the retouch list there is a patched binary (which is + // masked in apply_patch()) before there is a non-patched + // binary. + if (retouch_offset_override != NULL) + *retouch_offset_override = inferred_offset; + success = true; + goto out; + } else { + // Retouch to zero (mask the retouching), to make sure that + // the SHA-1 check will pass below. + int32_t zero = 0; + retouch_mask_data(file.data, file.size, &zero, NULL); + SHA(file.data, file.size, file.sha1); + } + } + + if (retouch_probe_result == RETOUCH_DATA_NOTAPPLICABLE) { + // In the case of not retouchable, fake it. We do not want + // to do the normal processing and overwrite the backup file: + // we might be recovering! + // + // We return a zero override, which tells the caller that we + // simply skipped the file. + if (retouch_offset_override != NULL) + *retouch_offset_override = 0; + success = true; + goto out; + } + + // If we get here, either there was a mismatch in the offset, or + // the file has not been processed yet. Continue with normal + // processing. + } + + if (result != 0 || FindMatchingPatch(file.sha1, &binary_sha1, 1) < 0) { + free(file.data); + printf("Attempting to recover source from '%s' ...\n", + CACHE_TEMP_SOURCE); + result = LoadFileContents(CACHE_TEMP_SOURCE, &file, RETOUCH_DO_MASK); + if (result != 0 || FindMatchingPatch(file.sha1, &binary_sha1, 1) < 0) { + printf(" failed.\n"); + success = false; + goto out; + } + printf(" succeeded.\n"); + } + + // Retouch in-memory before worrying about backing up the original. + // + // Recovery steps will be oblivious to the actual retouch offset used, + // so might as well write out the already-retouched copy. Then, in the + // usual case, we will just swap the file locally, with no more writes + // needed. In the no-free-space case, we will then write the same to the + // original location. + + result = retouch_mask_data(file.data, file.size, &retouch_offset, NULL); + if (result != RETOUCH_DATA_MATCHED) { + success = false; + goto out; + } + if (retouch_offset_override != NULL) + *retouch_offset_override = retouch_offset; + + // How much free space do we need? + bool enough_space = false; + size_t free_space = FreeSpaceForFile(target_fs); + // 50% margin when estimating the space needed. + enough_space = (free_space > (file.size * 3 / 2)); + + // The experts say we have to allow for a retry of the + // whole process to avoid filesystem weirdness. + int retry = 1; + bool made_copy = false; + do { + // First figure out where to store a copy of the original. + // Ideally leave the original itself intact until the + // atomic swap. If no room on the same partition, fall back + // to the cache partition and remove the original. + + if (!enough_space) { + printf("Target is %ldB; free space is %ldB: not enough.\n", + (long)file.size, (long)free_space); + + retry = 0; + if (MakeFreeSpaceOnCache(file.size) < 0) { + printf("Not enough free space on '/cache'.\n"); + success = false; + goto out; + } + if (SaveFileContents(CACHE_TEMP_SOURCE, file) < 0) { + printf("Failed to back up source file.\n"); + success = false; + goto out; + } + made_copy = true; + unlink(binary_name); + + size_t free_space = FreeSpaceForFile(target_fs); + printf("(now %ld bytes free for target)\n", (long)free_space); + } + + result = SaveFileContents(binary_name_atomic, file); + if (result != 0) { + // Maybe the filesystem was optimistic: retry. + enough_space = false; + unlink(binary_name_atomic); + printf("Saving the retouched contents failed; retrying.\n"); + continue; + } + + // Succeeded; no need to retry. + break; + } while (retry-- > 0); + + // Give the .atomic file the same owner, group, and mode of the + // original source file. + if (chmod(binary_name_atomic, file.st.st_mode) != 0) { + printf("chmod of \"%s\" failed: %s\n", + binary_name_atomic, strerror(errno)); + success = false; + goto out; + } + if (chown(binary_name_atomic, file.st.st_uid, file.st.st_gid) != 0) { + printf("chown of \"%s\" failed: %s\n", + binary_name_atomic, + strerror(errno)); + success = false; + goto out; + } + + // Finally, rename the .atomic file to replace the target file. + if (rename(binary_name_atomic, binary_name) != 0) { + printf("rename of .atomic to \"%s\" failed: %s\n", + binary_name, strerror(errno)); + success = false; + goto out; + } + + // If this run created a copy, and we're here, we can delete it. + if (made_copy) unlink(CACHE_TEMP_SOURCE); + + out: + // clean up + free(file.data); + unlink(binary_name_atomic); + + return success; +} diff --git a/minelf/Retouch.h b/minelf/Retouch.h new file mode 100644 index 0000000..048d78e --- /dev/null +++ b/minelf/Retouch.h @@ -0,0 +1,51 @@ +/* + * Copyright (C) 2009 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef _MINELF_RETOUCH +#define _MINELF_RETOUCH + +#include +#include + +typedef struct { + char tag[8]; /* "RETOUCH ", not zero-terminated */ + uint32_t blob_size; /* in bytes, located right before this struct */ +} retouch_info_t __attribute__((packed)); + +// Retouch a file. Use CACHED_SOURCE_TEMP to store a copy. +bool retouch_one_library(const char *binary_name, + const char *binary_sha1, + int32_t retouch_offset, + int32_t *retouch_offset_override); + +#define RETOUCH_DONT_MASK 0 +#define RETOUCH_DO_MASK 1 + +#define RETOUCH_DATA_ERROR 0 // This is bad. Should not happen. +#define RETOUCH_DATA_MATCHED 1 // Up to an uniform random offset. +#define RETOUCH_DATA_MISMATCHED 2 // Partially randomized, or total mess. +#define RETOUCH_DATA_NOTAPPLICABLE 3 // Not retouched. Only when inferring. + +// Mask retouching in-memory. Used before apply_patch[_check]. +// Also used to determine status of retouching after a crash. +// +// If desired_offset is not NULL, then apply retouching instead, +// and return that in retouch_offset. +int retouch_mask_data(uint8_t *binary_object, + int32_t binary_size, + int32_t *desired_offset, + int32_t *retouch_offset); +#endif diff --git a/updater/Android.mk b/updater/Android.mk index c8f61f4..e3d62bc 100644 --- a/updater/Android.mk +++ b/updater/Android.mk @@ -27,6 +27,7 @@ endif LOCAL_STATIC_LIBRARIES += $(TARGET_RECOVERY_UPDATER_LIBS) $(TARGET_RECOVERY_UPDATER_EXTRA_LIBS) LOCAL_STATIC_LIBRARIES += libapplypatch libedify libmtdutils libminzip libz LOCAL_STATIC_LIBRARIES += libmincrypt libbz +LOCAL_STATIC_LIBRARIES += libminelf LOCAL_STATIC_LIBRARIES += libcutils libstdc++ libc LOCAL_C_INCLUDES += $(LOCAL_PATH)/.. diff --git a/updater/install.c b/updater/install.c index 167b402..6a8c5d4 100644 --- a/updater/install.c +++ b/updater/install.c @@ -25,12 +25,15 @@ #include #include #include +#include +#include #include "cutils/misc.h" #include "cutils/properties.h" #include "edify/expr.h" #include "mincrypt/sha.h" #include "minzip/DirUtil.h" +#include "minelf/Retouch.h" #include "mtdutils/mounts.h" #include "mtdutils/mtdutils.h" #include "updater.h" @@ -429,6 +432,121 @@ Value* PackageExtractFileFn(const char* name, State* state, } +// retouch_binaries(lib1, lib2, ...) +Value* RetouchBinariesFn(const char* name, State* state, + int argc, Expr* argv[]) { + UpdaterInfo* ui = (UpdaterInfo*)(state->cookie); + + char **retouch_entries = ReadVarArgs(state, argc, argv); + if (retouch_entries == NULL) { + return StringValue(strdup("t")); + } + + // some randomness from the clock + int32_t override_base; + bool override_set = false; + int32_t random_base = time(NULL) % 1024; + // some more randomness from /dev/random + FILE *f_random = fopen("/dev/random", "rb"); + uint16_t random_bits = 0; + if (f_random != NULL) { + fread(&random_bits, 2, 1, f_random); + random_bits = random_bits % 1024; + fclose(f_random); + } + random_base = (random_base + random_bits) % 1024; + fprintf(ui->cmd_pipe, "ui_print Random offset: 0x%x\n", random_base); + fprintf(ui->cmd_pipe, "ui_print\n"); + + // make sure we never randomize to zero; this let's us look at a file + // and know for sure whether it has been processed; important in the + // crash recovery process + if (random_base == 0) random_base = 1; + // make sure our randomization is page-aligned + random_base *= -0x1000; + override_base = random_base; + + int i = 0; + bool success = true; + while (i < (argc - 1)) { + success = success && retouch_one_library(retouch_entries[i], + retouch_entries[i+1], + random_base, + override_set ? + NULL : + &override_base); + if (!success) + ErrorAbort(state, "Failed to retouch '%s'.", retouch_entries[i]); + + free(retouch_entries[i]); + free(retouch_entries[i+1]); + i += 2; + + if (success && override_base != 0) { + random_base = override_base; + override_set = true; + } + } + if (i < argc) { + free(retouch_entries[i]); + success = false; + } + free(retouch_entries); + + if (!success) { + Value* v = malloc(sizeof(Value)); + v->type = VAL_STRING; + v->data = NULL; + v->size = -1; + return v; + } + return StringValue(strdup("t")); +} + + +// undo_retouch_binaries(lib1, lib2, ...) +Value* UndoRetouchBinariesFn(const char* name, State* state, + int argc, Expr* argv[]) { + UpdaterInfo* ui = (UpdaterInfo*)(state->cookie); + + char **retouch_entries = ReadVarArgs(state, argc, argv); + if (retouch_entries == NULL) { + return StringValue(strdup("t")); + } + + int i = 0; + bool success = true; + int32_t override_base; + while (i < (argc-1)) { + success = success && retouch_one_library(retouch_entries[i], + retouch_entries[i+1], + 0 /* undo => offset==0 */, + NULL); + if (!success) + ErrorAbort(state, "Failed to unretouch '%s'.", + retouch_entries[i]); + + free(retouch_entries[i]); + free(retouch_entries[i+1]); + i += 2; + } + if (i < argc) { + free(retouch_entries[i]); + success = false; + } + free(retouch_entries); + + if (!success) { + Value* v = malloc(sizeof(Value)); + v->type = VAL_STRING; + v->data = NULL; + v->size = -1; + return v; + } + return StringValue(strdup("t")); +} + + // symlink target src1 src2 ... // unlinks any previously existing src1, src2, etc before creating symlinks. Value* SymlinkFn(const char* name, State* state, int argc, Expr* argv[]) { @@ -1007,7 +1125,7 @@ Value* Sha1CheckFn(const char* name, State* state, int argc, Expr* argv[]) { return args[i]; } -// Read a local file and return its contents (the char* returned +// Read a local file and return its contents (the Value* returned // is actually a FileContents*). Value* ReadFileFn(const char* name, State* state, int argc, Expr* argv[]) { if (argc != 1) { @@ -1020,7 +1138,7 @@ Value* ReadFileFn(const char* name, State* state, int argc, Expr* argv[]) { v->type = VAL_BLOB; FileContents fc; - if (LoadFileContents(filename, &fc) != 0) { + if (LoadFileContents(filename, &fc, RETOUCH_DONT_MASK) != 0) { ErrorAbort(state, "%s() loading \"%s\" failed: %s", name, filename, strerror(errno)); free(filename); @@ -1047,6 +1165,8 @@ void RegisterInstallFunctions() { RegisterFunction("delete_recursive", DeleteFn); RegisterFunction("package_extract_dir", PackageExtractDirFn); RegisterFunction("package_extract_file", PackageExtractFileFn); + RegisterFunction("retouch_binaries", RetouchBinariesFn); + RegisterFunction("undo_retouch_binaries", UndoRetouchBinariesFn); RegisterFunction("symlink", SymlinkFn); RegisterFunction("set_perm", SetPermFn); RegisterFunction("set_perm_recursive", SetPermFn);