diff options
Diffstat (limited to 'twinstall.cpp')
| -rw-r--r-- | twinstall.cpp | 580 |
1 files changed, 580 insertions, 0 deletions
diff --git a/twinstall.cpp b/twinstall.cpp new file mode 100644 index 000000000..0c3d8375c --- /dev/null +++ b/twinstall.cpp @@ -0,0 +1,580 @@ +/* + * Copyright (C) 2007 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 <ctype.h> +#include <errno.h> +#include <fcntl.h> +#include <limits.h> +#include <sys/stat.h> +#include <sys/wait.h> +#include <unistd.h> + +#include <string.h> +#include <stdio.h> + +#include "common.h" +#include "twmincrypt/twrsa.h" +#include "twmincrypt/twsha.h" +#include "minui/minui.h" +#include "minzip/SysUtil.h" +#include "minzip/Zip.h" +#include "mtdutils/mounts.h" +#include "mtdutils/mtdutils.h" +#include "roots.h" +#include "verifier.h" +#include "ui.h" +#include "variables.h" +#include "data.hpp" +#include "partitions.hpp" + +extern "C" { +#include "extra-functions.h" +int __system(const char *command); +}; + +extern RecoveryUI* ui; + +#define ASSUMED_UPDATE_BINARY_NAME "META-INF/com/google/android/update-binary" +#define PUBLIC_KEYS_FILE "/res/keys" + +// Default allocation of progress bar segments to operations +static const int VERIFICATION_PROGRESS_TIME = 60; +static const float VERIFICATION_PROGRESS_FRACTION = 0.25; +static const float DEFAULT_FILES_PROGRESS_FRACTION = 0.4; +static const float DEFAULT_IMAGE_PROGRESS_FRACTION = 0.1; + +enum { INSTALL_SUCCESS, INSTALL_ERROR, INSTALL_CORRUPT }; + +// Look for an RSA signature embedded in the .ZIP file comment given +// the path to the zip. Verify it matches one of the given public +// keys. +// +// Return VERIFY_SUCCESS, VERIFY_FAILURE (if any error is encountered +// or no key matches the signature). + +int TWverify_file(const char* path, const RSAPublicKey *pKeys, unsigned int numKeys) { + ui->SetProgress(0.0); + + FILE* f = fopen(path, "rb"); + if (f == NULL) { + LOGE("failed to open %s (%s)\n", path, strerror(errno)); + return VERIFY_FAILURE; + } + + // An archive with a whole-file signature will end in six bytes: + // + // (2-byte signature start) $ff $ff (2-byte comment size) + // + // (As far as the ZIP format is concerned, these are part of the + // archive comment.) We start by reading this footer, this tells + // us how far back from the end we have to start reading to find + // the whole comment. + +#define FOOTER_SIZE 6 + + if (fseek(f, -FOOTER_SIZE, SEEK_END) != 0) { + LOGE("failed to seek in %s (%s)\n", path, strerror(errno)); + fclose(f); + return VERIFY_FAILURE; + } + + unsigned char footer[FOOTER_SIZE]; + if (fread(footer, 1, FOOTER_SIZE, f) != FOOTER_SIZE) { + LOGE("failed to read footer from %s (%s)\n", path, strerror(errno)); + fclose(f); + return VERIFY_FAILURE; + } + + if (footer[2] != 0xff || footer[3] != 0xff) { + fclose(f); + return VERIFY_FAILURE; + } + + size_t comment_size = footer[4] + (footer[5] << 8); + size_t signature_start = footer[0] + (footer[1] << 8); + LOGI("comment is %d bytes; signature %d bytes from end\n", + comment_size, signature_start); + + if (signature_start - FOOTER_SIZE < RSANUMBYTES) { + // "signature" block isn't big enough to contain an RSA block. + LOGE("signature is too short\n"); + fclose(f); + return VERIFY_FAILURE; + } + +#define EOCD_HEADER_SIZE 22 + + // The end-of-central-directory record is 22 bytes plus any + // comment length. + size_t eocd_size = comment_size + EOCD_HEADER_SIZE; + + if (fseek(f, -eocd_size, SEEK_END) != 0) { + LOGE("failed to seek in %s (%s)\n", path, strerror(errno)); + fclose(f); + return VERIFY_FAILURE; + } + + // Determine how much of the file is covered by the signature. + // This is everything except the signature data and length, which + // includes all of the EOCD except for the comment length field (2 + // bytes) and the comment data. + size_t signed_len = ftell(f) + EOCD_HEADER_SIZE - 2; + + unsigned char* eocd = (unsigned char*)malloc(eocd_size); + if (eocd == NULL) { + LOGE("malloc for EOCD record failed\n"); + fclose(f); + return VERIFY_FAILURE; + } + if (fread(eocd, 1, eocd_size, f) != eocd_size) { + LOGE("failed to read eocd from %s (%s)\n", path, strerror(errno)); + fclose(f); + return VERIFY_FAILURE; + } + + // If this is really is the EOCD record, it will begin with the + // magic number $50 $4b $05 $06. + if (eocd[0] != 0x50 || eocd[1] != 0x4b || + eocd[2] != 0x05 || eocd[3] != 0x06) { + LOGE("signature length doesn't match EOCD marker\n"); + fclose(f); + return VERIFY_FAILURE; + } + + size_t i; + for (i = 4; i < eocd_size-3; ++i) { + if (eocd[i ] == 0x50 && eocd[i+1] == 0x4b && + eocd[i+2] == 0x05 && eocd[i+3] == 0x06) { + // if the sequence $50 $4b $05 $06 appears anywhere after + // the real one, minzip will find the later (wrong) one, + // which could be exploitable. Fail verification if + // this sequence occurs anywhere after the real one. + LOGE("EOCD marker occurs after start of EOCD\n"); + fclose(f); + return VERIFY_FAILURE; + } + } + +#define BUFFER_SIZE 4096 + + SHA_CTX ctx; + SHA_init(&ctx); + unsigned char* buffer = (unsigned char*)malloc(BUFFER_SIZE); + if (buffer == NULL) { + LOGE("failed to alloc memory for sha1 buffer\n"); + fclose(f); + return VERIFY_FAILURE; + } + + double frac = -1.0; + size_t so_far = 0; + fseek(f, 0, SEEK_SET); + while (so_far < signed_len) { + size_t size = BUFFER_SIZE; + if (signed_len - so_far < size) size = signed_len - so_far; + if (fread(buffer, 1, size, f) != size) { + LOGE("failed to read data from %s (%s)\n", path, strerror(errno)); + fclose(f); + return VERIFY_FAILURE; + } + SHA_update(&ctx, buffer, size); + so_far += size; + double f = so_far / (double)signed_len; + if (f > frac + 0.02 || size == so_far) { + ui->SetProgress(f); + frac = f; + } + } + fclose(f); + free(buffer); + + const uint8_t* sha1 = SHA_final(&ctx); + for (i = 0; i < numKeys; ++i) { + // The 6 bytes is the "(signature_start) $ff $ff (comment_size)" that + // the signing tool appends after the signature itself. + if (RSA_verify(pKeys+i, eocd + eocd_size - 6 - RSANUMBYTES, + RSANUMBYTES, sha1)) { + LOGI("whole-file signature verified against key %d\n", i); + free(eocd); + return VERIFY_SUCCESS; + } + } + free(eocd); + LOGE("failed to verify whole-file signature\n"); + return VERIFY_FAILURE; +} + +// If the package contains an update binary, extract it and run it. +static int +try_update_binary(const char *path, ZipArchive *zip, int* wipe_cache) { + const ZipEntry* binary_entry = + mzFindZipEntry(zip, ASSUMED_UPDATE_BINARY_NAME); + if (binary_entry == NULL) { + mzCloseZipArchive(zip); + return INSTALL_CORRUPT; + } + + const char* binary = "/tmp/update_binary"; + unlink(binary); + int fd = creat(binary, 0755); + if (fd < 0) { + mzCloseZipArchive(zip); + LOGE("Can't make %s\n", binary); + return INSTALL_ERROR; + } + bool ok = mzExtractZipEntryToFile(zip, binary_entry, fd); + close(fd); + mzCloseZipArchive(zip); + + if (!ok) { + LOGE("Can't copy %s\n", ASSUMED_UPDATE_BINARY_NAME); + return INSTALL_ERROR; + } + + int pipefd[2]; + pipe(pipefd); + + // When executing the update binary contained in the package, the + // arguments passed are: + // + // - the version number for this interface + // + // - an fd to which the program can write in order to update the + // progress bar. The program can write single-line commands: + // + // progress <frac> <secs> + // fill up the next <frac> part of of the progress bar + // over <secs> seconds. If <secs> is zero, use + // set_progress commands to manually control the + // progress of this segment of the bar + // + // set_progress <frac> + // <frac> should be between 0.0 and 1.0; sets the + // progress bar within the segment defined by the most + // recent progress command. + // + // firmware <"hboot"|"radio"> <filename> + // arrange to install the contents of <filename> in the + // given partition on reboot. + // + // (API v2: <filename> may start with "PACKAGE:" to + // indicate taking a file from the OTA package.) + // + // (API v3: this command no longer exists.) + // + // ui_print <string> + // display <string> on the screen. + // + // - the name of the package zip file. + // + + const char** args = (const char**)malloc(sizeof(char*) * 5); + args[0] = binary; + args[1] = EXPAND(RECOVERY_API_VERSION); // defined in Android.mk + char* temp = (char*)malloc(10); + sprintf(temp, "%d", pipefd[1]); + args[2] = temp; + args[3] = (char*)path; + args[4] = NULL; + + pid_t pid = fork(); + if (pid == 0) { + close(pipefd[0]); + execv(binary, (char* const*)args); + fprintf(stdout, "E:Can't run %s (%s)\n", binary, strerror(errno)); + _exit(-1); + } + close(pipefd[1]); + + *wipe_cache = 0; + + char buffer[1024]; + FILE* from_child = fdopen(pipefd[0], "r"); + while (fgets(buffer, sizeof(buffer), from_child) != NULL) { + char* command = strtok(buffer, " \n"); + if (command == NULL) { + continue; + } else if (strcmp(command, "progress") == 0) { + char* fraction_s = strtok(NULL, " \n"); + char* seconds_s = strtok(NULL, " \n"); + + float fraction = strtof(fraction_s, NULL); + int seconds = strtol(seconds_s, NULL, 10); + + ui->ShowProgress(fraction * (1-VERIFICATION_PROGRESS_FRACTION), seconds); + } else if (strcmp(command, "set_progress") == 0) { + char* fraction_s = strtok(NULL, " \n"); + float fraction = strtof(fraction_s, NULL); + ui->SetProgress(fraction); + } else if (strcmp(command, "ui_print") == 0) { + char* str = strtok(NULL, "\n"); + if (str) { + ui->Print("%s", str); + } else { + ui->Print("\n"); + } + } else if (strcmp(command, "wipe_cache") == 0) { + *wipe_cache = 1; + } else if (strcmp(command, "clear_display") == 0) { + //ui->SetBackground(RecoveryUI::NONE); + } else { + LOGE("unknown command [%s]\n", command); + } + } + fclose(from_child); + + int status; + waitpid(pid, &status, 0); + if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { + LOGE("Error in %s\n(Status %d)\n", path, WEXITSTATUS(status)); + return INSTALL_ERROR; + } + + return INSTALL_SUCCESS; +} + +// Reads a file containing one or more public keys as produced by +// DumpPublicKey: this is an RSAPublicKey struct as it would appear +// as a C source literal, eg: +// +// "{64,0xc926ad21,{1795090719,...,-695002876},{-857949815,...,1175080310}}" +// +// (Note that the braces and commas in this example are actual +// characters the parser expects to find in the file; the ellipses +// indicate more numbers omitted from this example.) +// +// The file may contain multiple keys in this format, separated by +// commas. The last key must not be followed by a comma. +// +// Returns NULL if the file failed to parse, or if it contain zero keys. +static RSAPublicKey* +load_keys(const char* filename, int* numKeys) { + RSAPublicKey* out = NULL; + *numKeys = 0; + + FILE* f = fopen(filename, "r"); + if (f == NULL) { + LOGE("opening %s: %s\n", filename, strerror(errno)); + goto exit; + } + + { + int i; + bool done = false; + while (!done) { + ++*numKeys; + out = (RSAPublicKey*)realloc(out, *numKeys * sizeof(RSAPublicKey)); + RSAPublicKey* key = out + (*numKeys - 1); + if (fscanf(f, " { %i , 0x%x , { %u", + &(key->len), &(key->n0inv), &(key->n[0])) != 3) { + goto exit; + } + if (key->len != RSANUMWORDS) { + LOGE("key length (%d) does not match expected size\n", key->len); + goto exit; + } + for (i = 1; i < key->len; ++i) { + if (fscanf(f, " , %u", &(key->n[i])) != 1) goto exit; + } + if (fscanf(f, " } , { %u", &(key->rr[0])) != 1) goto exit; + for (i = 1; i < key->len; ++i) { + if (fscanf(f, " , %u", &(key->rr[i])) != 1) goto exit; + } + fscanf(f, " } } "); + + // if the line ends in a comma, this file has more keys. + switch (fgetc(f)) { + case ',': + // more keys to come. + break; + + case EOF: + done = true; + break; + + default: + LOGE("unexpected character between keys\n"); + goto exit; + } + } + } + + fclose(f); + return out; + +exit: + if (f) fclose(f); + free(out); + *numKeys = 0; + return NULL; +} + +char* get_path (char* path) { + char *s; + + /* Go to the end of the string. */ + s = path + strlen(path) - 1; + + /* Strip off trailing /s (unless it is also the leading /). */ + while (path < s && s[0] == '/') + s--; + + /* Strip the last component. */ + while (path <= s && s[0] != '/') + s--; + + while (path < s && s[0] == '/') + s--; + + if (s < path) + return (char*)("."); + + s[1] = '\0'; + return path; +} + +/* + Checks md5 for a path + Return values: + -1 : MD5 does not exist + 0 : Failed + 1 : Success +*/ +int check_md5(const char* path) { + FILE* fp; + char command[255], line[512], actual_md5[512], md5[512]; + char md5file[PATH_MAX + 40]; + char *ptr; + unsigned int line_len, index = 0; + struct stat st; + + // Check to see if the filename.zip.md5 file exists + strcpy(md5file, path); + strcat(md5file, ".md5"); + if (stat(md5file, &st) != 0) + return -1; // no MD5 file found + + // Dump the md5 of the zip to a text file for reading + sprintf(command, "md5sum '%s' > /tmp/md5output.txt", path); + __system(command); + fp = fopen("/tmp/md5output.txt", "rt"); + if (fp == NULL) { + LOGI("Unable to open /tmp/md5output.txt.\n"); + return false; + } + + while (fgets(line, sizeof(line), fp) != NULL) + { + line_len = strlen(line); + for (index = 0; index < line_len; index++) { + if (line[index] <= 32) + line[index] = '\0'; + } + strcpy(actual_md5, line); + break; + } + fclose(fp); + + // Read the filename.zip.md5 file + fp = fopen(md5file, "rt"); + if (fp == NULL) { + LOGI("Unable to open '%s'.\n", md5file); + return false; + } + + while (fgets(line, sizeof(line), fp) != NULL) + { + line_len = strlen(line); + for (index = 0; index < line_len; index++) { + if (line[index] <= 32) + line[index] = '\0'; + } + strcpy(md5, line); + break; + } + fclose(fp); + + // Comare the 2 MD5 values + if (strcmp(actual_md5, md5) == 0) + return 1; + LOGI("MD5 did not match: '%s' != '%s'\n", actual_md5, md5); + return 0; +} + +extern "C" int TWinstall_zip(const char* path, int* wipe_cache) { + int err, zip_verify, md5_return, md5_verify; + + ui_print("Installing '%s'...\n", path); + + if (!PartitionManager.Mount_By_Path(path, 0)) { + LOGE("Failed to mount '%s'\n", path); + return -1; + } + + ui_print("Checking for MD5 file...\n"); + md5_return = check_md5(path); + if (md5_return == 0) { + // MD5 did not match. + LOGE("Zip MD5 does not match.\nUnable to install zip.\n"); + return INSTALL_CORRUPT; + } else if (md5_return == -1) { + DataManager::GetValue(TW_FORCE_MD5_CHECK_VAR, md5_verify); + if (md5_verify == 1) { + // Forced MD5 checking is on and no MD5 file found. + LOGE("No MD5 file found for '%s'.\nDisable force MD5 check to avoid this error.\n", path); + return INSTALL_CORRUPT; + } else + ui_print("No MD5 file found, this is not an error.\n"); + } else if (md5_return == 1) + ui_print("Zip MD5 matched.\n"); // MD5 found and matched. + + DataManager::GetValue(TW_SIGNED_ZIP_VERIFY_VAR, zip_verify); + if (zip_verify) { + ui_print("Verifying zip signature...\n"); + int numKeys; + RSAPublicKey* loadedKeys = load_keys(PUBLIC_KEYS_FILE, &numKeys); + if (loadedKeys == NULL) { + LOGE("Failed to load keys\n"); + return -1; + } + LOGI("%d key(s) loaded from %s\n", numKeys, PUBLIC_KEYS_FILE); + + // Give verification half the progress bar... + ui->Print("Verifying update package...\n"); + ui->SetProgressType(RecoveryUI::DETERMINATE); + ui->ShowProgress(VERIFICATION_PROGRESS_FRACTION, VERIFICATION_PROGRESS_TIME); + + err = TWverify_file(path, loadedKeys, numKeys); + free(loadedKeys); + LOGI("verify_file returned %d\n", err); + if (err != VERIFY_SUCCESS) { + LOGE("signature verification failed\n"); + return -1; + } + } + /* Try to open the package. + */ + ZipArchive zip; + err = mzOpenZipArchive(path, &zip); + if (err != 0) { + LOGE("Can't open %s\n(%s)\n", path, err != -1 ? strerror(err) : "bad"); + return INSTALL_CORRUPT; + } + + /* Verify and install the contents of the package. + */ + return try_update_binary(path, &zip, wipe_cache); +} |