diff options
Diffstat (limited to 'crypto/ext4crypt/Decrypt.cpp')
| -rw-r--r-- | crypto/ext4crypt/Decrypt.cpp | 786 |
1 files changed, 767 insertions, 19 deletions
diff --git a/crypto/ext4crypt/Decrypt.cpp b/crypto/ext4crypt/Decrypt.cpp index 3b69d4651..2dab16646 100644 --- a/crypto/ext4crypt/Decrypt.cpp +++ b/crypto/ext4crypt/Decrypt.cpp @@ -26,10 +26,50 @@ #include <sys/stat.h> #include <sys/types.h> -#include "ext4_crypt.h" +#ifndef HAVE_LIBKEYUTILS #include "key_control.h" +#else +#include <keyutils.h> +#endif + +#ifdef HAVE_SYNTH_PWD_SUPPORT +#include "Weaver1.h" +#include "cutils/properties.h" + +#include <openssl/sha.h> +#include <openssl/aes.h> +#include <openssl/evp.h> +#include <openssl/rand.h> + +#include <dirent.h> +#include <stdio.h> +#include <stdint.h> +#include <string.h> +#include <sys/types.h> +#include <fstream> + +#include <ext4_utils/ext4_crypt.h> + +#include <keystore/IKeystoreService.h> +#include <binder/IPCThreadState.h> +#include <binder/IServiceManager.h> + +#include <keystore/keystore.h> +#include <keystore/authorization_set.h> + +#include <algorithm> +extern "C" { +#include "crypto_scrypt.h" +} +#else +#include "ext4_crypt.h" +#endif //ifdef HAVE_SYNTH_PWD_SUPPORT +#ifdef HAVE_GATEKEEPER1 +#include <android/hardware/gatekeeper/1.0/IGatekeeper.h> +#else #include <hardware/gatekeeper.h> +#endif #include "HashPassword.h" #include <android-base/file.h> @@ -67,7 +107,7 @@ extern "C" bool lookup_ref_key(const char* policy, char* policy_type) { extern "C" bool lookup_ref_tar(const char* policy_type, char* policy) { if (strncmp(policy_type, "1", 1) != 0) { - printf("Unexpected version %c\n", policy_type); + printf("Unexpected version %c\n", policy_type[0]); return false; } const char* ptr = policy_type + 1; // skip past the version number @@ -94,6 +134,7 @@ extern "C" bool lookup_ref_tar(const char* policy_type, char* policy) { return true; } +#ifndef HAVE_GATEKEEPER1 int gatekeeper_device_initialize(gatekeeper_device_t **dev) { int ret; const hw_module_t *mod; @@ -110,8 +151,685 @@ int gatekeeper_device_initialize(gatekeeper_device_t **dev) { printf("failed to open gatekeeper\n"); return ret; } +#endif //ifndef HAVE_GATEKEEPER1 + +bool Decrypt_DE() { + if (!e4crypt_initialize_global_de()) { // this deals with the overarching device encryption + printf("e4crypt_initialize_global_de returned fail\n"); + return false; + } + if (!e4crypt_init_user0()) { + printf("e4crypt_init_user0 returned fail\n"); + return false; + } + return true; +} + +#ifdef HAVE_SYNTH_PWD_SUPPORT +// Crappy functions for debugging, please ignore unless you need to debug +/*void output_hex(const std::string& in) { + const char *buf = in.data(); + char hex[in.size() * 2 + 1]; + unsigned int index; + for (index = 0; index < in.size(); index++) + sprintf(&hex[2 * index], "%02X", buf[index]); + printf("%s", hex); +} + +void output_hex(const char* buf, const int size) { + char hex[size * 2 + 1]; + int index; + for (index = 0; index < size; index++) + sprintf(&hex[2 * index], "%02X", buf[index]); + printf("%s", hex); +} + +void output_hex(const unsigned char* buf, const int size) { + char hex[size * 2 + 1]; + int index; + for (index = 0; index < size; index++) + sprintf(&hex[2 * index], "%02X", buf[index]); + printf("%s", hex); +} + +void output_hex(std::vector<uint8_t>* vec) { + char hex[3]; + unsigned int index; + for (index = 0; index < vec->size(); index++) { + sprintf(&hex[0], "%02X", vec->at(index)); + printf("%s", hex); + } +}*/ + +/* An alternative is to use: + * sqlite3 /data/system/locksettings.db "SELECT value FROM locksettings WHERE name='sp-handle' AND user=0;" + * but we really don't want to include the 1.1MB libsqlite in TWRP. We scan the spblob folder for the + * password data file (*.pwd) and get the handle from the filename instead. This is a replacement for + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/LockSettingsService.java#2017 + * We never use this data as an actual long. We always use it as a string. */ +bool Find_Handle(const std::string& spblob_path, std::string& handle_str) { + DIR* dir = opendir(spblob_path.c_str()); + if (!dir) { + printf("Error opening '%s'\n", spblob_path.c_str()); + return false; + } + + struct dirent* de = 0; + + while ((de = readdir(dir)) != 0) { + if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0) + continue; + size_t len = strlen(de->d_name); + if (len <= 4) + continue; + char* p = de->d_name; + p += len - 4; + if (strncmp(p, ".pwd", 4) == 0) { + handle_str = de->d_name; + handle_str = handle_str.substr(0, len - 4); + //*handle = strtoull(handle_str.c_str(), 0 , 16); + closedir(dir); + return true; + } + } + closedir(dir); + return false; +} + +// The password data is stored in big endian and has to be swapped on little endian ARM +template <class T> +void endianswap(T *objp) { + unsigned char *memp = reinterpret_cast<unsigned char*>(objp); + std::reverse(memp, memp + sizeof(T)); +} + +/* This is the structure of the data in the password data (*.pwd) file which the structure can be found + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#187 */ +struct password_data_struct { + int password_type; + unsigned char scryptN; + unsigned char scryptR; + unsigned char scryptP; + int salt_len; + void* salt; + int handle_len; + void* password_handle; +}; + +/* C++ replacement for + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#764 */ +bool Get_Password_Data(const std::string& spblob_path, const std::string& handle_str, password_data_struct *pwd) { + std::string pwd_file = spblob_path + handle_str + ".pwd"; + std::string pwd_data; + if (!android::base::ReadFileToString(pwd_file, &pwd_data)) { + printf("Failed to read '%s'\n", pwd_file.c_str()); + return false; + } + //output_hex(pwd_data.data(), pwd_data.size());printf("\n"); + const int* intptr = (const int*)pwd_data.data(); + pwd->password_type = *intptr; + endianswap(&pwd->password_type); + //printf("password type %i\n", pwd->password_type); // 2 was PIN, 1 for pattern, 2 also for password, -1 for default password + const unsigned char* byteptr = (const unsigned char*)pwd_data.data() + sizeof(int); + pwd->scryptN = *byteptr; + byteptr++; + pwd->scryptR = *byteptr; + byteptr++; + pwd->scryptP = *byteptr; + byteptr++; + intptr = (const int*)byteptr; + pwd->salt_len = *intptr; + endianswap(&pwd->salt_len); + if (pwd->salt_len != 0) { + pwd->salt = malloc(pwd->salt_len); + if (!pwd->salt) { + printf("Get_Password_Data malloc salt\n"); + return false; + } + memcpy(pwd->salt, intptr + 1, pwd->salt_len); + } else { + printf("Get_Password_Data salt_len is 0\n"); + return false; + } + return true; +} + +/* C++ replacement for + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#765 + * called here + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#1050 */ +bool Get_Password_Token(const password_data_struct *pwd, const std::string& Password, unsigned char* password_token) { + if (!password_token) { + printf("password_token is null\n"); + return false; + } + unsigned int N = 1 << pwd->scryptN; + unsigned int r = 1 << pwd->scryptR; + unsigned int p = 1 << pwd->scryptP; + //printf("N %i r %i p %i\n", N, r, p); + int ret = crypto_scrypt(reinterpret_cast<const uint8_t*>(Password.data()), Password.size(), + reinterpret_cast<const uint8_t*>(pwd->salt), pwd->salt_len, + N, r, p, + password_token, 32); + if (ret != 0) { + printf("scrypt error\n"); + return false; + } + return true; +} + +// Data structure for the *.weaver file, see Get_Weaver_Data below +struct weaver_data_struct { + unsigned char version; + int slot; +}; + +/* C++ replacement for + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#501 + * called here + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#768 */ +bool Get_Weaver_Data(const std::string& spblob_path, const std::string& handle_str, weaver_data_struct *wd) { + std::string weaver_file = spblob_path + handle_str + ".weaver"; + std::string weaver_data; + if (!android::base::ReadFileToString(weaver_file, &weaver_data)) { + printf("Failed to read '%s'\n", weaver_file.c_str()); + return false; + } + //output_hex(weaver_data.data(), weaver_data.size());printf("\n"); + const unsigned char* byteptr = (const unsigned char*)weaver_data.data(); + wd->version = *byteptr; + //printf("weaver version %i\n", wd->version); + const int* intptr = (const int*)weaver_data.data() + sizeof(unsigned char); + wd->slot = *intptr; + //endianswap(&wd->slot); not needed + //printf("weaver slot %i\n", wd->slot); + return true; +} + +namespace android { + +// On Android 8.0 for some reason init can't seem to completely stop keystore +// so we have to kill it too if it doesn't die on its own. +static void kill_keystore() { + DIR* dir = opendir("/proc"); + if (dir) { + struct dirent* de = 0; + + while ((de = readdir(dir)) != 0) { + if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0) + continue; + + int pid = -1; + int ret = sscanf(de->d_name, "%d", &pid); + + if (ret == 1) { + char cmdpath[PATH_MAX]; + sprintf(cmdpath, "/proc/%d/cmdline", pid); + + FILE* file = fopen(cmdpath, "r"); + size_t task_size = PATH_MAX; + char task[PATH_MAX]; + char* p = task; + if (getline(&p, &task_size, file) > 0) { + if (strstr(task, "keystore") != 0) { + printf("keystore pid %d found, sending kill.\n", pid); + kill(pid, SIGINT); + usleep(5000); + kill(pid, SIGKILL); + } + } + fclose(file); + } + } + closedir(dir); + } +} + +// The keystore holds a file open on /data so we have to stop / kill it +// if we want to be able to unmount /data for things like formatting. +static void stop_keystore() { + printf("Stopping keystore...\n"); + property_set("ctl.stop", "keystore"); + usleep(5000); + kill_keystore(); +} + +/* These next 2 functions try to get the keystore service 50 times because + * the keystore is not always ready when TWRP boots */ +sp<IBinder> getKeystoreBinder() { + sp<IServiceManager> sm = defaultServiceManager(); + return sm->getService(String16("android.security.keystore")); +} + +sp<IBinder> getKeystoreBinderRetry() { + printf("Starting keystore...\n"); + property_set("ctl.start", "keystore"); + int retry_count = 50; + sp<IBinder> binder = getKeystoreBinder(); + while (binder == NULL && retry_count) { + printf("Waiting for keystore service... %i\n", retry_count--); + sleep(1); + binder = getKeystoreBinder(); + } + return binder; +} + +namespace keystore { + +#define SYNTHETIC_PASSWORD_VERSION 1 +#define SYNTHETIC_PASSWORD_PASSWORD_BASED 0 +#define SYNTHETIC_PASSWORD_KEY_PREFIX "USRSKEY_synthetic_password_" + +/* The keystore alias subid is sometimes the same as the handle, but not always. + * In the case of handle 0c5303fd2010fe29, the alias subid used c5303fd2010fe29 + * without the leading 0. We could try to parse the data from a previous + * keystore request, but I think this is an easier solution because there + * is little to no documentation on the format of data we get back from + * the keystore in this instance. We also want to copy everything to a temp + * folder so that any key upgrades that might take place do not actually + * upgrade the keys on the data partition. We rename all 1000 uid files to 0 + * to pass the keystore permission checks. */ +bool Find_Keystore_Alias_SubID_And_Prep_Files(const userid_t user_id, std::string& keystoreid) { + char path_c[PATH_MAX]; + sprintf(path_c, "/data/misc/keystore/user_%d", user_id); + char user_dir[PATH_MAX]; + sprintf(user_dir, "user_%d", user_id); + std::string source_path = "/data/misc/keystore/"; + source_path += user_dir; + + mkdir("/tmp/misc", 0755); + mkdir("/tmp/misc/keystore", 0755); + std::string destination_path = "/tmp/misc/keystore/"; + destination_path += user_dir; + if (mkdir(destination_path.c_str(), 0755) && errno != EEXIST) { + printf("failed to mkdir '%s' %s\n", destination_path.c_str(), strerror(errno)); + return false; + } + destination_path += "/"; + + DIR* dir = opendir(source_path.c_str()); + if (!dir) { + printf("Error opening '%s'\n", source_path.c_str()); + return false; + } + source_path += "/"; + + struct dirent* de = 0; + size_t prefix_len = strlen(SYNTHETIC_PASSWORD_KEY_PREFIX); + bool found_subid = false; + + while ((de = readdir(dir)) != 0) { + if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0) + continue; + if (!found_subid) { + size_t len = strlen(de->d_name); + if (len <= prefix_len) + continue; + if (!strstr(de->d_name, SYNTHETIC_PASSWORD_KEY_PREFIX)) + continue; + std::string file = de->d_name; + std::size_t found = file.find_last_of("_"); + if (found != std::string::npos) { + keystoreid = file.substr(found + 1); + printf("keystoreid: '%s'\n", keystoreid.c_str()); + found_subid = true; + } + } + std::string src = source_path; + src += de->d_name; + std::ifstream srcif(src.c_str(), std::ios::binary); + std::string dst = destination_path; + dst += de->d_name; + std::size_t source_uid = dst.find("1000"); + if (source_uid != std::string::npos) + dst.replace(source_uid, 4, "0"); + std::ofstream dstof(dst.c_str(), std::ios::binary); + printf("copying '%s' to '%s'\n", src.c_str(), dst.c_str()); + dstof << srcif.rdbuf(); + srcif.close(); + dstof.close(); + } + closedir(dir); + return found_subid; +} + +/* C++ replacement for function of the same name + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#867 + * returning an empty string indicates an error */ +std::string unwrapSyntheticPasswordBlob(const std::string& spblob_path, const std::string& handle_str, const userid_t user_id, const void* application_id, const size_t application_id_size) { + std::string disk_decryption_secret_key = ""; + + std::string keystore_alias_subid; + if (!Find_Keystore_Alias_SubID_And_Prep_Files(user_id, keystore_alias_subid)) { + printf("failed to scan keystore alias subid and prep keystore files\n"); + return disk_decryption_secret_key; + } + + // First get the keystore service + sp<IBinder> binder = getKeystoreBinderRetry(); + sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder); + if (service == NULL) { + printf("error: could not connect to keystore service\n"); + return disk_decryption_secret_key; + } + + // Read the data from the .spblob file per: https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#869 + std::string spblob_file = spblob_path + handle_str + ".spblob"; + std::string spblob_data; + if (!android::base::ReadFileToString(spblob_file, &spblob_data)) { + printf("Failed to read '%s'\n", spblob_file.c_str()); + return disk_decryption_secret_key; + } + const unsigned char* byteptr = (const unsigned char*)spblob_data.data(); + if (*byteptr != SYNTHETIC_PASSWORD_VERSION) { + printf("SYNTHETIC_PASSWORD_VERSION does not match\n"); + return disk_decryption_secret_key; + } + byteptr++; + if (*byteptr != SYNTHETIC_PASSWORD_PASSWORD_BASED) { + printf("spblob data is not SYNTHETIC_PASSWORD_PASSWORD_BASED\n"); + return disk_decryption_secret_key; + } + byteptr++; // Now we're pointing to the blob data itself + /* We're now going to handle decryptSPBlob: https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordCrypto.java#115 + * Called from https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#879 + * This small function ends up being quite a headache. The call to get data from the keystore basically is not needed in TWRP at this time. + * The keystore data seems to be the serialized data from an entire class in Java. Specifically I think it represents: + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/keystore/java/android/security/keystore/AndroidKeyStoreCipherSpiBase.java + * or perhaps + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/keystore/java/android/security/keystore/AndroidKeyStoreAuthenticatedAESCipherSpi.java + * but the only things we "need" from this keystore are a user ID and the keyAlias which ends up being USRSKEY_synthetic_password_{handle_str} + * the latter of which we already have. We may need to figure out how to get the user ID if we ever support decrypting mulitple users. + * There are 2 calls to a Java decrypt funcion that is overloaded. These 2 calls go in completely different directions despite the seemingly + * similar use of decrypt() and decrypt parameters. To figure out where things were going, I added logging to: + * https://android.googlesource.com/platform/libcore/+/android-8.0.0_r23/ojluni/src/main/java/javax/crypto/Cipher.java#2575 + * Logger.global.severe("Cipher tryCombinations " + prov.getName() + " - " + prov.getInfo()); + * To make logging work in libcore, import java.util.logging.Logger; and either set a better logging level or modify the framework to log everything + * regardless of logging level. This will give you some strings that you can grep for and find the actual crypto provider in use. In our case there were + * 2 different providers in use. The first stage to get the intermediate key used: + * https://android.googlesource.com/platform/external/conscrypt/+/android-8.0.0_r23/common/src/main/java/org/conscrypt/OpenSSLProvider.java + * which is a pretty straight-forward OpenSSL implementation of AES/GCM/NoPadding. */ + // First we personalize as seen https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordCrypto.java#102 + void* personalized_application_id = PersonalizedHashBinary(PERSONALISATION_APPLICATION_ID, (const char*)application_id, application_id_size); + if (!personalized_application_id) { + printf("malloc personalized_application_id\n"); + return disk_decryption_secret_key; + } + //printf("personalized application id: "); output_hex((unsigned char*)personalized_application_id, SHA512_DIGEST_LENGTH); printf("\n"); + // Now we'll decrypt using openssl AES/GCM/NoPadding + OpenSSL_add_all_ciphers(); + int actual_size=0, final_size=0; + EVP_CIPHER_CTX *d_ctx = EVP_CIPHER_CTX_new(); + const unsigned char* iv = (const unsigned char*)byteptr; // The IV is the first 12 bytes of the spblob + //printf("iv: "); output_hex((const unsigned char*)iv, 12); printf("\n"); + const unsigned char* cipher_text = (const unsigned char*)byteptr + 12; // The cipher text comes immediately after the IV + //printf("cipher_text: "); output_hex((const unsigned char*)cipher_text, spblob_data.size() - 2 - 12); printf("\n"); + const unsigned char* key = (const unsigned char*)personalized_application_id; // The key is the now personalized copy of the application ID + //printf("key: "); output_hex((const unsigned char*)key, 32); printf("\n"); + EVP_DecryptInit(d_ctx, EVP_aes_256_gcm(), key, iv); + std::vector<unsigned char> intermediate_key; + intermediate_key.resize(spblob_data.size() - 2 - 12, '\0'); + EVP_DecryptUpdate(d_ctx, &intermediate_key[0], &actual_size, cipher_text, spblob_data.size() - 2 - 12); + unsigned char tag[AES_BLOCK_SIZE]; + EVP_CIPHER_CTX_ctrl(d_ctx, EVP_CTRL_GCM_SET_TAG, 16, tag); + EVP_DecryptFinal_ex(d_ctx, &intermediate_key[actual_size], &final_size); + EVP_CIPHER_CTX_free(d_ctx); + free(personalized_application_id); + //printf("spblob_data size: %lu actual_size %i, final_size: %i\n", spblob_data.size(), actual_size, final_size); + intermediate_key.resize(actual_size + final_size - 16, '\0');// not sure why we have to trim the size by 16 as I don't see where this is done in Java side + //printf("intermediate key: "); output_hex((const unsigned char*)intermediate_key.data(), intermediate_key.size()); printf("\n"); + + int32_t ret; + + /* We only need a keyAlias which is USRSKEY_synthetic_password_b6f71045af7bd042 which we find and a uid which is -1 or 1000, I forget which + * as the key data will be read again by the begin function later via the keystore. + * The data is in a hidl_vec format which consists of a type and a value. */ + /*::keystore::hidl_vec<uint8_t> data; + std::string keystoreid = SYNTHETIC_PASSWORD_KEY_PREFIX; + keystoreid += handle_str; + + ret = service->get(String16(keystoreid.c_str()), user_id, &data); + if (ret < 0) { + printf("Could not connect to keystore service %i\n", ret); + return disk_decryption_secret_key; + } else if (ret != 1 /*android::keystore::ResponseCode::NO_ERROR*//*) { + printf("keystore error: (%d)\n", /*responses[ret],*//* ret); + return disk_decryption_secret_key; + } else { + printf("keystore returned: "); output_hex(&data[0], data.size()); printf("\n"); + }*/ + + // Now we'll break up the intermediate key into the IV (first 12 bytes) and the cipher text (the rest of it). + std::vector<unsigned char> nonce = intermediate_key; + nonce.resize(12); + intermediate_key.erase (intermediate_key.begin(),intermediate_key.begin()+12); + //printf("nonce: "); output_hex((const unsigned char*)nonce.data(), nonce.size()); printf("\n"); + //printf("cipher text: "); output_hex((const unsigned char*)intermediate_key.data(), intermediate_key.size()); printf("\n"); + + /* Now we will begin the second decrypt call found in + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordCrypto.java#122 + * This time we will use https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/keystore/java/android/security/keystore/AndroidKeyStoreCipherSpiBase.java + * and https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/keystore/java/android/security/keystore/AndroidKeyStoreAuthenticatedAESCipherSpi.java + * First we set some algorithm parameters as seen in two places: + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/keystore/java/android/security/keystore/AndroidKeyStoreAuthenticatedAESCipherSpi.java#297 + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/keystore/java/android/security/keystore/AndroidKeyStoreAuthenticatedAESCipherSpi.java#216 */ + size_t maclen = 128; + ::keystore::AuthorizationSetBuilder begin_params; + begin_params.Authorization(::keystore::TAG_ALGORITHM, ::keystore::Algorithm::AES); + begin_params.Authorization(::keystore::TAG_BLOCK_MODE, ::keystore::BlockMode::GCM); + begin_params.Padding(::keystore::PaddingMode::NONE); + begin_params.Authorization(::keystore::TAG_NONCE, nonce); + begin_params.Authorization(::keystore::TAG_MAC_LENGTH, maclen); + //keymasterArgs.addEnum(KeymasterDefs.KM_TAG_ALGORITHM, KeymasterDefs.KM_ALGORITHM_AES); + //keymasterArgs.addEnum(KeymasterDefs.KM_TAG_BLOCK_MODE, mKeymasterBlockMode); + //keymasterArgs.addEnum(KeymasterDefs.KM_TAG_PADDING, mKeymasterPadding); + //keymasterArgs.addUnsignedInt(KeymasterDefs.KM_TAG_MAC_LENGTH, mTagLengthBits); + ::keystore::hidl_vec<uint8_t> entropy; // No entropy is needed for decrypt + entropy.resize(0); + std::string keystore_alias = SYNTHETIC_PASSWORD_KEY_PREFIX; + keystore_alias += keystore_alias_subid; + String16 keystore_alias16(keystore_alias.c_str()); + ::keystore::KeyPurpose purpose = ::keystore::KeyPurpose::DECRYPT; + OperationResult begin_result; + // These parameters are mostly driven by the cipher.init call https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordCrypto.java#63 + service->begin(binder, keystore_alias16, purpose, true, begin_params.hidl_data(), entropy, -1, &begin_result); + ret = begin_result.resultCode; + if (ret != 1 /*android::keystore::ResponseCode::NO_ERROR*/) { + printf("keystore begin error: (%d)\n", /*responses[ret],*/ ret); + return disk_decryption_secret_key; + } else { + //printf("keystore begin operation successful\n"); + } + ::keystore::hidl_vec<::keystore::KeyParameter> empty_params; + empty_params.resize(0); + OperationResult update_result; + // The cipher.doFinal call triggers an update to the keystore followed by a finish https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordCrypto.java#64 + // See also https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/keystore/java/android/security/keystore/KeyStoreCryptoOperationChunkedStreamer.java#208 + service->update(begin_result.token, empty_params, intermediate_key, &update_result); + ret = update_result.resultCode; + if (ret != 1 /*android::keystore::ResponseCode::NO_ERROR*/) { + printf("keystore update error: (%d)\n", /*responses[ret],*/ ret); + return disk_decryption_secret_key; + } else { + //printf("keystore update operation successful\n"); + //printf("keystore update returned: "); output_hex(&update_result.data[0], update_result.data.size()); printf("\n"); // this ends up being the synthetic password + } + // We must use the data in update_data.data before we call finish below or the data will be gone + // The payload data from the keystore update is further personalized at https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#153 + // We now have the disk decryption key! + disk_decryption_secret_key = PersonalizedHash(PERSONALIZATION_FBE_KEY, (const char*)&update_result.data[0], update_result.data.size()); + //printf("disk_decryption_secret_key: '%s'\n", disk_decryption_secret_key.c_str()); + ::keystore::hidl_vec<uint8_t> signature; + OperationResult finish_result; + service->finish(begin_result.token, empty_params, signature, entropy, &finish_result); + ret = finish_result.resultCode; + if (ret != 1 /*android::keystore::ResponseCode::NO_ERROR*/) { + printf("keystore finish error: (%d)\n", /*responses[ret],*/ ret); + return disk_decryption_secret_key; + } else { + //printf("keystore finish operation successful\n"); + } + stop_keystore(); + return disk_decryption_secret_key; +} + +}} + +#define PASSWORD_TOKEN_SIZE 32 + +bool Free_Return(bool retval, void* weaver_key, void* pwd_salt) { + if (weaver_key) + free(weaver_key); + if (pwd_salt) + free(pwd_salt); + return retval; +} + +/* Decrypt_User_Synth_Pass is the TWRP C++ equivalent to spBasedDoVerifyCredential + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/LockSettingsService.java#1998 */ +bool Decrypt_User_Synth_Pass(const userid_t user_id, const std::string& Password) { + bool retval = false; + void* weaver_key = NULL; + password_data_struct pwd; + pwd.salt = NULL; + + std::string secret; // this will be the disk decryption key that is sent to vold + std::string token = "!"; // there is no token used for this kind of decrypt, key escrow is handled by weaver + int flags = FLAG_STORAGE_DE; + if (user_id == 0) + flags = FLAG_STORAGE_DE; + else + flags = FLAG_STORAGE_CE; + char spblob_path_char[PATH_MAX]; + sprintf(spblob_path_char, "/data/system_de/%d/spblob/", user_id); + std::string spblob_path = spblob_path_char; + long handle = 0; + std::string handle_str; + // Get the handle: https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/LockSettingsService.java#2017 + if (!Find_Handle(spblob_path, handle_str)) { + printf("Error getting handle\n"); + return Free_Return(retval, weaver_key, pwd.salt); + } + printf("Handle is '%s'\n", handle_str.c_str()); + // Now we begin driving unwrapPasswordBasedSyntheticPassword from: https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#758 + // First we read the password data which contains scrypt parameters + if (!Get_Password_Data(spblob_path, handle_str, &pwd)) { + printf("Failed to Get_Password_Data\n"); + return Free_Return(retval, weaver_key, pwd.salt); + } + //printf("pwd N %i R %i P %i salt ", pwd.scryptN, pwd.scryptR, pwd.scryptP); output_hex((char*)pwd.salt, pwd.salt_len); printf("\n"); + unsigned char password_token[PASSWORD_TOKEN_SIZE]; + //printf("Password: '%s'\n", Password.c_str()); + // The password token is the password scrypted with the parameters from the password data file + if (!Get_Password_Token(&pwd, Password, &password_token[0])) { + printf("Failed to Get_Password_Token\n"); + return Free_Return(retval, weaver_key, pwd.salt); + } + //output_hex(&password_token[0], PASSWORD_TOKEN_SIZE);printf("\n"); + // BEGIN PIXEL 2 WEAVER + // Get the weaver data from the .weaver file which tells us which slot to use when we ask weaver for the escrowed key + // https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#768 + weaver_data_struct wd; + if (!Get_Weaver_Data(spblob_path, handle_str, &wd)) { + printf("Failed to get weaver data\n"); + // Fail over to gatekeeper path for Pixel 1??? + return Free_Return(retval, weaver_key, pwd.salt); + } + // The weaver key is the the password token prefixed with "weaver-key" padded to 128 with nulls with the password token appended then SHA512 + // https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#1059 + weaver_key = PersonalizedHashBinary(PERSONALISATION_WEAVER_KEY, (char*)&password_token[0], PASSWORD_TOKEN_SIZE); + if (!weaver_key) { + printf("malloc error getting weaver_key\n"); + return Free_Return(retval, weaver_key, pwd.salt); + } + // Now we start driving weaverVerify: https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#343 + // Called from https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#776 + android::vold::Weaver weaver; + if (!weaver) { + printf("Failed to get weaver service\n"); + return Free_Return(retval, weaver_key, pwd.salt); + } + // Get the key size from weaver service + uint32_t weaver_key_size = 0; + if (!weaver.GetKeySize(&weaver_key_size)) { + printf("Failed to get weaver key size\n"); + return Free_Return(retval, weaver_key, pwd.salt); + } else { + //printf("weaver key size is %u\n", weaver_key_size); + } + //printf("weaver key: "); output_hex((unsigned char*)weaver_key, weaver_key_size); printf("\n"); + // Send the slot from the .weaver file, the computed weaver key, and get the escrowed key data + std::vector<uint8_t> weaver_payload; + // TODO: we should return more information about the status including time delays before the next retry + if (!weaver.WeaverVerify(wd.slot, weaver_key, &weaver_payload)) { + printf("failed to weaver verify\n"); + return Free_Return(retval, weaver_key, pwd.salt); + } + //printf("weaver payload: "); output_hex(&weaver_payload); printf("\n"); + // Done with weaverVerify + // Now we will compute the application ID + // https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#964 + // Called from https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#780 + // The escrowed weaver key data is prefixed with "weaver-pwd" padded to 128 with nulls with the weaver payload appended then SHA512 + void* weaver_secret = PersonalizedHashBinary(PERSONALISATION_WEAVER_PASSWORD, (const char*)weaver_payload.data(), weaver_payload.size()); + //printf("weaver secret: "); output_hex((unsigned char*)weaver_secret, SHA512_DIGEST_LENGTH); printf("\n"); + // The application ID is the password token and weaver secret appended to each other + char application_id[PASSWORD_TOKEN_SIZE + SHA512_DIGEST_LENGTH]; + memcpy((void*)&application_id[0], (void*)&password_token[0], PASSWORD_TOKEN_SIZE); + memcpy((void*)&application_id[PASSWORD_TOKEN_SIZE], weaver_secret, SHA512_DIGEST_LENGTH); + //printf("application ID: "); output_hex((unsigned char*)application_id, PASSWORD_TOKEN_SIZE + SHA512_DIGEST_LENGTH); printf("\n"); + // END PIXEL 2 WEAVER + // Now we will handle https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#816 + // Plus we will include the last bit that computes the disk decrypt key found in: + // https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#153 + secret = android::keystore::unwrapSyntheticPasswordBlob(spblob_path, handle_str, user_id, (const void*)&application_id[0], PASSWORD_TOKEN_SIZE + SHA512_DIGEST_LENGTH); + if (!secret.size()) { + printf("failed to unwrapSyntheticPasswordBlob\n"); + return Free_Return(retval, weaver_key, pwd.salt); + } + if (!e4crypt_unlock_user_key(user_id, 0, token.c_str(), secret.c_str())) { + printf("e4crypt_unlock_user_key returned fail\n"); + return Free_Return(retval, weaver_key, pwd.salt); + } + if (!e4crypt_prepare_user_storage(nullptr, user_id, 0, flags)) { + printf("failed to e4crypt_prepare_user_storage\n"); + return Free_Return(retval, weaver_key, pwd.salt); + } + printf("Decrypted Successfully!\n"); + retval = true; + return Free_Return(retval, weaver_key, pwd.salt); +} +#endif //HAVE_SYNTH_PWD_SUPPORT int Get_Password_Type(const userid_t user_id, std::string& filename) { + struct stat st; + char spblob_path_char[PATH_MAX]; + sprintf(spblob_path_char, "/data/system_de/%d/spblob/", user_id); + if (stat(spblob_path_char, &st) == 0) { +#ifdef HAVE_SYNTH_PWD_SUPPORT + printf("Using synthetic password method\n"); + std::string spblob_path = spblob_path_char; + std::string handle_str; + if (!Find_Handle(spblob_path, handle_str)) { + printf("Error getting handle\n"); + return 0; + } + printf("Handle is '%s'\n", handle_str.c_str()); + password_data_struct pwd; + if (!Get_Password_Data(spblob_path, handle_str, &pwd)) { + printf("Failed to Get_Password_Data\n"); + return 0; + } + if (pwd.password_type == 1) // In Android this means pattern + return 2; // In TWRP this means pattern + else if (pwd.password_type == 2) // In Android this means PIN or password + return 1; // In TWRP this means PIN or password + return 0; // We'll try the default password +#else + printf("Synthetic password support not present in TWRP\n"); + return -1; +#endif + } std::string path; if (user_id == 0) { path = "/data/system/"; @@ -123,7 +841,6 @@ int Get_Password_Type(const userid_t user_id, std::string& filename) { path += "/"; } filename = path + "gatekeeper.password.key"; - struct stat st; if (stat(filename.c_str(), &st) == 0 && st.st_size > 0) return 1; filename = path + "gatekeeper.pattern.key"; @@ -134,18 +851,6 @@ int Get_Password_Type(const userid_t user_id, std::string& filename) { return 0; } -bool Decrypt_DE() { - if (!e4crypt_initialize_global_de()) { // this deals with the overarching device encryption - printf("e4crypt_initialize_global_de returned fail\n"); - return false; - } - if (!e4crypt_init_user0()) { - printf("e4crypt_init_user0 returned fail\n"); - return false; - } - return true; -} - bool Decrypt_User(const userid_t user_id, const std::string& Password) { uint8_t *auth_token; uint32_t auth_token_len; @@ -167,8 +872,6 @@ bool Decrypt_User(const userid_t user_id, const std::string& Password) { flags = FLAG_STORAGE_DE; else flags = FLAG_STORAGE_CE; - gatekeeper_device_t *device; - ret = gatekeeper_device_initialize(&device); if (Default_Password) { if (!e4crypt_unlock_user_key(user_id, 0, "!", "!")) { printf("e4crypt_unlock_user_key returned fail\n"); @@ -181,8 +884,15 @@ bool Decrypt_User(const userid_t user_id, const std::string& Password) { printf("Decrypted Successfully!\n"); return true; } - if (ret!=0) + if (stat("/data/system_de/0/spblob", &st) == 0) { +#ifdef HAVE_SYNTH_PWD_SUPPORT + printf("Using synthetic password method\n"); + return Decrypt_User_Synth_Pass(user_id, Password); +#else + printf("Synthetic password support not present in TWRP\n"); return false; +#endif + } printf("password filename is '%s'\n", filename.c_str()); if (stat(filename.c_str(), &st) != 0) { printf("error stat'ing key file: %s\n", strerror(errno)); @@ -194,13 +904,51 @@ bool Decrypt_User(const userid_t user_id, const std::string& Password) { return false; } bool should_reenroll; - ret = device->verify(device, user_id, 0, (const uint8_t *)handle.c_str(), st.st_size, +#ifdef HAVE_GATEKEEPER1 + bool request_reenroll = false; + android::sp<android::hardware::gatekeeper::V1_0::IGatekeeper> gk_device; + gk_device = ::android::hardware::gatekeeper::V1_0::IGatekeeper::getService(); + if (gk_device == nullptr) + return false; + android::hardware::hidl_vec<uint8_t> curPwdHandle; + curPwdHandle.setToExternal(const_cast<uint8_t *>((const uint8_t *)handle.c_str()), st.st_size); + android::hardware::hidl_vec<uint8_t> enteredPwd; + enteredPwd.setToExternal(const_cast<uint8_t *>((const uint8_t *)Password.c_str()), Password.size()); + + android::hardware::Return<void> hwRet = + gk_device->verify(user_id, 0 /* challange */, + curPwdHandle, + enteredPwd, + [&ret, &request_reenroll, &auth_token, &auth_token_len] + (const android::hardware::gatekeeper::V1_0::GatekeeperResponse &rsp) { + ret = static_cast<int>(rsp.code); // propagate errors + if (rsp.code >= android::hardware::gatekeeper::V1_0::GatekeeperStatusCode::STATUS_OK) { + auth_token = new uint8_t[rsp.data.size()]; + auth_token_len = rsp.data.size(); + memcpy(auth_token, rsp.data.data(), auth_token_len); + request_reenroll = (rsp.code == android::hardware::gatekeeper::V1_0::GatekeeperStatusCode::STATUS_REENROLL); + ret = 0; // all success states are reported as 0 + } else if (rsp.code == android::hardware::gatekeeper::V1_0::GatekeeperStatusCode::ERROR_RETRY_TIMEOUT && rsp.timeout > 0) { + ret = rsp.timeout; + } + } + ); + if (!hwRet.isOk()) { + return false; + } +#else + gatekeeper_device_t *gk_device; + ret = gatekeeper_device_initialize(&gk_device); + if (ret!=0) + return false; + ret = gk_device->verify(gk_device, user_id, 0, (const uint8_t *)handle.c_str(), st.st_size, (const uint8_t *)Password.c_str(), (uint32_t)Password.size(), &auth_token, &auth_token_len, &should_reenroll); if (ret !=0) { printf("failed to verify\n"); return false; } +#endif char token_hex[(auth_token_len*2)+1]; token_hex[(auth_token_len*2)] = 0; uint32_t i; |