diff options
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/ext4crypt/Android.mk | 12 | ||||
| -rw-r--r-- | crypto/ext4crypt/Decrypt.cpp | 720 | ||||
| -rw-r--r-- | crypto/ext4crypt/HashPassword.h | 2 | ||||
| -rw-r--r-- | crypto/ext4crypt/keystore_auth.cpp | 90 |
4 files changed, 620 insertions, 204 deletions
diff --git a/crypto/ext4crypt/Android.mk b/crypto/ext4crypt/Android.mk index af5ab3af0..693b67518 100644 --- a/crypto/ext4crypt/Android.mk +++ b/crypto/ext4crypt/Android.mk @@ -28,6 +28,7 @@ ifeq ($(shell test $(PLATFORM_SDK_VERSION) -ge 26; echo $$?),0) LOCAL_CFLAGS += -DHAVE_LIBKEYUTILS LOCAL_SHARED_LIBRARIES += libkeyutils endif + LOCAL_ADDITIONAL_DEPENDENCIES := keystore_auth else LOCAL_SRC_FILES += Keymaster.cpp KeyStorage.cpp endif @@ -58,4 +59,15 @@ LOCAL_LDFLAGS += -Wl,-dynamic-linker,/sbin/linker64 include $(BUILD_EXECUTABLE) +include $(CLEAR_VARS) +LOCAL_MODULE := keystore_auth +LOCAL_MODULE_TAGS := optional +LOCAL_MODULE_CLASS := RECOVERY_EXECUTABLES +LOCAL_MODULE_PATH := $(TARGET_RECOVERY_ROOT_OUT)/sbin +LOCAL_SRC_FILES := keystore_auth.cpp +LOCAL_SHARED_LIBRARIES := libc libkeystore_binder libutils libbinder liblog +LOCAL_LDFLAGS += -Wl,-dynamic-linker,/sbin/linker64 + +include $(BUILD_EXECUTABLE) + endif diff --git a/crypto/ext4crypt/Decrypt.cpp b/crypto/ext4crypt/Decrypt.cpp index 2dab16646..c062f8ae4 100644 --- a/crypto/ext4crypt/Decrypt.cpp +++ b/crypto/ext4crypt/Decrypt.cpp @@ -287,10 +287,27 @@ bool Get_Password_Data(const std::string& spblob_path, const std::string& handle return false; } memcpy(pwd->salt, intptr + 1, pwd->salt_len); + intptr++; + byteptr = (const unsigned char*)intptr; + byteptr += pwd->salt_len; } else { printf("Get_Password_Data salt_len is 0\n"); return false; } + intptr = (const int*)byteptr; + pwd->handle_len = *intptr; + endianswap(&pwd->handle_len); + if (pwd->handle_len != 0) { + pwd->password_handle = malloc(pwd->handle_len); + if (!pwd->password_handle) { + printf("Get_Password_Data malloc password_handle\n"); + return false; + } + memcpy(pwd->password_handle, intptr + 1, pwd->handle_len); + } else { + printf("Get_Password_Data handle_len is 0\n"); + // Not an error if using weaver + } return true; } @@ -416,7 +433,8 @@ sp<IBinder> getKeystoreBinderRetry() { namespace keystore { -#define SYNTHETIC_PASSWORD_VERSION 1 +#define SYNTHETIC_PASSWORD_VERSION_V1 1 +#define SYNTHETIC_PASSWORD_VERSION 2 #define SYNTHETIC_PASSWORD_PASSWORD_BASED 0 #define SYNTHETIC_PASSWORD_KEY_PREFIX "USRSKEY_synthetic_password_" @@ -496,7 +514,7 @@ bool Find_Keystore_Alias_SubID_And_Prep_Files(const userid_t user_id, std::strin /* 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 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, uint32_t auth_token_len) { std::string disk_decryption_secret_key = ""; std::string keystore_alias_subid; @@ -513,6 +531,11 @@ std::string unwrapSyntheticPasswordBlob(const std::string& spblob_path, const st return disk_decryption_secret_key; } + if (auth_token_len > 0) { + printf("Starting keystore_auth service...\n"); + property_set("ctl.start", "keystore_auth"); + } + // 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; @@ -520,156 +543,339 @@ std::string unwrapSyntheticPasswordBlob(const std::string& spblob_path, const st 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"); + unsigned char* byteptr = (unsigned char*)spblob_data.data(); + if (*byteptr != SYNTHETIC_PASSWORD_VERSION && *byteptr != SYNTHETIC_PASSWORD_VERSION_V1) { + printf("Unsupported synthetic password version %i\n", *byteptr); return disk_decryption_secret_key; } + const unsigned char* synthetic_password_version = byteptr; 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); + if (*synthetic_password_version == SYNTHETIC_PASSWORD_VERSION_V1) { + printf("spblob v1\n"); + /* 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"); + + // When using secdis (aka not weaver) you must supply an auth token to the keystore prior to the begin operation + if (auth_token_len > 0) { + /*::keystore::KeyStoreServiceReturnCode auth_result = service->addAuthToken(auth_token, auth_token_len); + if (!auth_result.isOk()) { + // The keystore checks the uid of the calling process and will return a permission denied on this operation for user 0 + printf("keystore error adding auth token\n"); + return disk_decryption_secret_key; + }*/ + // The keystore refuses to allow the root user to supply auth tokens, so we write the auth token to a file earlier and + // run a separate service that runs user the system user to add the auth token. We wait for the auth token file to be + // deleted by the keymaster_auth service and check for a /auth_error file in case of errors. We quit after after a while if + // the /auth_token file never gets deleted. + int auth_wait_count = 20; + while (access("/auth_token", F_OK) == 0 && auth_wait_count-- > 0) + usleep(5000); + if (auth_wait_count == 0 || access("/auth_error", F_OK) == 0) { + printf("error during keymaster_auth service\n"); + /* If you are getting this error, make sure that you have the keymaster_auth service defined in your init scripts, preferrably in init.recovery.{ro.hardware}.rc + * service keystore_auth /sbin/keystore_auth + * disabled + * oneshot + * user system + * group root + * seclabel u:r:recovery:s0 + * + * And check dmesg for error codes regarding this service if needed. */ + return disk_decryption_secret_key; + } + } + + 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; - } 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); + } else if (*synthetic_password_version == SYNTHETIC_PASSWORD_VERSION) { + printf("spblob v2\n"); + /* Version 2 of the spblob is basically the same as version 1, but the order of getting the intermediate key and disk decryption key have been flip-flopped + * as seen in https://android.googlesource.com/platform/frameworks/base/+/5025791ac6d1538224e19189397de8d71dcb1a12 + */ + /* First decrypt call found in + * https://android.googlesource.com/platform/frameworks/base/+/android-8.1.0_r18/services/core/java/com/android/server/locksettings/SyntheticPasswordCrypto.java#135 + * 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 */ + // When using secdis (aka not weaver) you must supply an auth token to the keystore prior to the begin operation + if (auth_token_len > 0) { + /*::keystore::KeyStoreServiceReturnCode auth_result = service->addAuthToken(auth_token, auth_token_len); + if (!auth_result.isOk()) { + // The keystore checks the uid of the calling process and will return a permission denied on this operation for user 0 + printf("keystore error adding auth token\n"); + return disk_decryption_secret_key; + }*/ + // The keystore refuses to allow the root user to supply auth tokens, so we write the auth token to a file earlier and + // run a separate service that runs user the system user to add the auth token. We wait for the auth token file to be + // deleted by the keymaster_auth service and check for a /auth_error file in case of errors. We quit after after a while if + // the /auth_token file never gets deleted. + int auth_wait_count = 20; + while (access("/auth_token", F_OK) == 0 && auth_wait_count-- > 0) + usleep(5000); + if (auth_wait_count == 0 || access("/auth_error", F_OK) == 0) { + printf("error during keymaster_auth service\n"); + /* If you are getting this error, make sure that you have the keymaster_auth service defined in your init scripts, preferrably in init.recovery.{ro.hardware}.rc + * service keystore_auth /sbin/keystore_auth + * disabled + * oneshot + * user system + * group root + * seclabel u:r:recovery:s0 + * + * And check dmesg for error codes regarding this service if needed. */ + return disk_decryption_secret_key; + } + } + int32_t ret; + size_t maclen = 128; + unsigned char* iv = (unsigned char*)byteptr; // The IV is the first 12 bytes of the spblob + ::keystore::hidl_vec<uint8_t> iv_hidlvec; + iv_hidlvec.setToExternal((unsigned char*)byteptr, 12); + //printf("iv: "); output_hex((const unsigned char*)iv, 12); printf("\n"); + unsigned char* cipher_text = (unsigned char*)byteptr + 12; // The cipher text comes immediately after the IV + ::keystore::hidl_vec<uint8_t> cipher_text_hidlvec; + cipher_text_hidlvec.setToExternal(cipher_text, spblob_data.size() - 14 /* 1 each for version and SYNTHETIC_PASSWORD_PASSWORD_BASED and 12 for the iv */); + ::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, iv_hidlvec); + begin_params.Authorization(::keystore::TAG_MAC_LENGTH, maclen); + ::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, cipher_text_hidlvec, &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 + }*/ + //printf("keystore resulting data: "); output_hex((unsigned char*)&update_result.data[0], update_result.data.size()); printf("\n"); + // We must copy the data in update_data.data before we call finish below or the data will be gone + size_t keystore_result_size = update_result.data.size(); + unsigned char* keystore_result = (unsigned char*)malloc(keystore_result_size); + if (!keystore_result) { + printf("malloc on keystore_result\n"); + return disk_decryption_secret_key; + } + memcpy(keystore_result, &update_result.data[0], update_result.data.size()); + //printf("keystore_result data: "); output_hex(keystore_result, keystore_result_size); printf("\n"); + ::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); + free(keystore_result); + return disk_decryption_secret_key; + } /*else { + printf("keystore finish operation successful\n"); + }*/ + stop_keystore(); + + /* Now we do the second decrypt call as seen in: + * https://android.googlesource.com/platform/frameworks/base/+/android-8.1.0_r18/services/core/java/com/android/server/locksettings/SyntheticPasswordCrypto.java#136 + */ + const unsigned char* intermediate_iv = keystore_result; + //printf("intermediate_iv: "); output_hex((const unsigned char*)intermediate_iv, 12); printf("\n"); + const unsigned char* intermediate_cipher_text = (const unsigned char*)keystore_result + 12; // The cipher text comes immediately after the IV + int cipher_size = keystore_result_size - 12; + //printf("intermediate_cipher_text: "); output_hex((const unsigned char*)intermediate_cipher_text, cipher_size); printf("\n"); + // 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"); + free(keystore_result); + 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* 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, intermediate_iv); + unsigned char* secret_key = (unsigned char*)malloc(cipher_size); + EVP_DecryptUpdate(d_ctx, secret_key, &actual_size, intermediate_cipher_text, cipher_size); + unsigned char tag[AES_BLOCK_SIZE]; + EVP_CIPHER_CTX_ctrl(d_ctx, EVP_CTRL_GCM_SET_TAG, 16, tag); + EVP_DecryptFinal_ex(d_ctx, secret_key + actual_size, &final_size); + EVP_CIPHER_CTX_free(d_ctx); + free(personalized_application_id); + free(keystore_result); + int secret_key_real_size = actual_size - 16; + //printf("secret key: "); output_hex((const unsigned char*)secret_key, secret_key_real_size); printf("\n"); + // 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*)secret_key, secret_key_real_size); + //printf("disk_decryption_secret_key: '%s'\n", disk_decryption_secret_key.c_str()); + free(secret_key); return disk_decryption_secret_key; - } else { - //printf("keystore finish operation successful\n"); } - stop_keystore(); return disk_decryption_secret_key; } @@ -677,11 +883,40 @@ std::string unwrapSyntheticPasswordBlob(const std::string& spblob_path, const st #define PASSWORD_TOKEN_SIZE 32 -bool Free_Return(bool retval, void* weaver_key, void* pwd_salt) { +/* C++ replacement for + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#992 + * called here + * https://android.googlesource.com/platform/frameworks/base/+/android-8.0.0_r23/services/core/java/com/android/server/locksettings/SyntheticPasswordManager.java#813 */ +bool Get_Secdis(const std::string& spblob_path, const std::string& handle_str, std::string& secdis_data) { + std::string secdis_file = spblob_path + handle_str + ".secdis"; + if (!android::base::ReadFileToString(secdis_file, &secdis_data)) { + printf("Failed to read '%s'\n", secdis_file.c_str()); + return false; + } + //output_hex(secdis_data.data(), secdis_data.size());printf("\n"); + 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#1033 +userid_t fakeUid(const userid_t uid) { + return 100000 + uid; +} + +bool Is_Weaver(const std::string& spblob_path, const std::string& handle_str) { + std::string weaver_file = spblob_path + handle_str + ".weaver"; + struct stat st; + if (stat(weaver_file.c_str(), &st) == 0) + return true; + return false; +} + +bool Free_Return(bool retval, void* weaver_key, password_data_struct* pwd) { if (weaver_key) free(weaver_key); - if (pwd_salt) - free(pwd_salt); + if (pwd->salt) + free(pwd->salt); + if (pwd->password_handle) + free(pwd->password_handle); return retval; } @@ -692,6 +927,12 @@ bool Decrypt_User_Synth_Pass(const userid_t user_id, const std::string& Password void* weaver_key = NULL; password_data_struct pwd; pwd.salt = NULL; + pwd.salt_len = 0; + pwd.password_handle = NULL; + pwd.handle_len = 0; + char application_id[PASSWORD_TOKEN_SIZE + SHA512_DIGEST_LENGTH]; + + uint32_t auth_token_len = 0; 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 @@ -708,14 +949,14 @@ bool Decrypt_User_Synth_Pass(const userid_t user_id, const std::string& Password // 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); + return Free_Return(retval, weaver_key, &pwd); } 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); + return Free_Return(retval, weaver_key, &pwd); } //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]; @@ -723,81 +964,152 @@ bool Decrypt_User_Synth_Pass(const userid_t user_id, const std::string& Password // 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); + return Free_Return(retval, weaver_key, &pwd); } //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); + if (Is_Weaver(spblob_path, handle_str)) { + printf("using weaver\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"); + return Free_Return(retval, weaver_key, &pwd); + } + // 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); + } + // 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); + } + // 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); + } 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); + } + //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 + 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 } 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 + printf("using secdis\n"); + std::string secdis_data; + if (!Get_Secdis(spblob_path, handle_str, secdis_data)) { + printf("Failed to get secdis data\n"); + return Free_Return(retval, weaver_key, &pwd); + } + void* secdiscardable = PersonalizedHashBinary(PERSONALISATION_SECDISCARDABLE, (char*)secdis_data.data(), secdis_data.size()); + if (!secdiscardable) { + printf("malloc error getting secdiscardable\n"); + return Free_Return(retval, weaver_key, &pwd); + } + memcpy((void*)&application_id[0], (void*)&password_token[0], PASSWORD_TOKEN_SIZE); + memcpy((void*)&application_id[PASSWORD_TOKEN_SIZE], secdiscardable, SHA512_DIGEST_LENGTH); + + int ret = -1; + 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) { + printf("failed to get gatekeeper service\n"); + return Free_Return(retval, weaver_key, &pwd); + } + if (pwd.handle_len <= 0) { + printf("no password handle supplied\n"); + return Free_Return(retval, weaver_key, &pwd); + } + android::hardware::hidl_vec<uint8_t> pwd_handle_hidl; + pwd_handle_hidl.setToExternal(const_cast<uint8_t *>((const uint8_t *)pwd.password_handle), pwd.handle_len); + void* gk_pwd_token = PersonalizedHashBinary(PERSONALIZATION_USER_GK_AUTH, (char*)&password_token[0], PASSWORD_TOKEN_SIZE); + if (!gk_pwd_token) { + printf("malloc error getting gatekeeper_key\n"); + return Free_Return(retval, weaver_key, &pwd); + } + android::hardware::hidl_vec<uint8_t> gk_pwd_token_hidl; + gk_pwd_token_hidl.setToExternal(const_cast<uint8_t *>((const uint8_t *)gk_pwd_token), SHA512_DIGEST_LENGTH); + android::hardware::Return<void> hwRet = + gk_device->verify(fakeUid(user_id), 0 /* challange */, + pwd_handle_hidl, + gk_pwd_token_hidl, + [&ret, &request_reenroll, &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_len = rsp.data.size(); + request_reenroll = (rsp.code == android::hardware::gatekeeper::V1_0::GatekeeperStatusCode::STATUS_REENROLL); + ret = 0; // all success states are reported as 0 + // The keystore refuses to allow the root user to supply auth tokens, so we write the auth token to a file here and later + // run a separate service that runs as the system user to add the auth token. We wait for the auth token file to be + // deleted by the keymaster_auth service and check for a /auth_error file in case of errors. We quit after a while seconds if + // the /auth_token file never gets deleted. + unlink("/auth_token"); + FILE* auth_file = fopen("/auth_token","wb"); + if (auth_file != NULL) { + fwrite(rsp.data.data(), sizeof(uint8_t), rsp.data.size(), auth_file); + fclose(auth_file); + } else { + printf("failed to open /auth_token for writing\n"); + ret = -2; + } + } else if (rsp.code == android::hardware::gatekeeper::V1_0::GatekeeperStatusCode::ERROR_RETRY_TIMEOUT && rsp.timeout > 0) { + ret = rsp.timeout; + } + } + ); + free(gk_pwd_token); + if (!hwRet.isOk() || ret != 0) { + printf("gatekeeper verification failed\n"); + return Free_Return(retval, weaver_key, &pwd); + } + } // 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); + secret = android::keystore::unwrapSyntheticPasswordBlob(spblob_path, handle_str, user_id, (const void*)&application_id[0], PASSWORD_TOKEN_SIZE + SHA512_DIGEST_LENGTH, auth_token_len); if (!secret.size()) { printf("failed to unwrapSyntheticPasswordBlob\n"); - return Free_Return(retval, weaver_key, pwd.salt); + return Free_Return(retval, weaver_key, &pwd); } 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); + return Free_Return(retval, weaver_key, &pwd); } 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); + return Free_Return(retval, weaver_key, &pwd); } printf("Decrypted Successfully!\n"); retval = true; - return Free_Return(retval, weaver_key, pwd.salt); + return Free_Return(retval, weaver_key, &pwd); } #endif //HAVE_SYNTH_PWD_SUPPORT diff --git a/crypto/ext4crypt/HashPassword.h b/crypto/ext4crypt/HashPassword.h index 8abd0de71..4be107b51 100644 --- a/crypto/ext4crypt/HashPassword.h +++ b/crypto/ext4crypt/HashPassword.h @@ -24,6 +24,8 @@ #define PERSONALISATION_WEAVER_PASSWORD "weaver-pwd" #define PERSONALISATION_APPLICATION_ID "application-id" #define PERSONALIZATION_FBE_KEY "fbe-key" +#define PERSONALIZATION_USER_GK_AUTH "user-gk-authentication" +#define PERSONALISATION_SECDISCARDABLE "secdiscardable-transform" void* PersonalizedHashBinary(const char* prefix, const char* key, const size_t key_size); diff --git a/crypto/ext4crypt/keystore_auth.cpp b/crypto/ext4crypt/keystore_auth.cpp new file mode 100644 index 000000000..7d6eb24bf --- /dev/null +++ b/crypto/ext4crypt/keystore_auth.cpp @@ -0,0 +1,90 @@ +/* + Copyright 2018 bigbiff/Dees_Troy TeamWin + This file is part of TWRP/TeamWin Recovery Project. + + TWRP is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + TWRP is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with TWRP. If not, see <http://www.gnu.org/licenses/>. +*/ + +/* The keystore refuses to allow the root user to supply auth tokens, so + * we write the auth token to a file in TWRP and run a separate service + * (this) that runs as the system user to add the auth token. TWRP waits + * for /auth_token to be deleted and also looks for /auth_error to check + * for errors. TWRP will error out after a while if /auth_token does not + * get deleted. */ + +#include <stdio.h> +#include <string> + +#include <keystore/IKeystoreService.h> +#include <binder/IPCThreadState.h> +#include <binder/IServiceManager.h> + +#include <keystore/keystore.h> +#include <keystore/authorization_set.h> + +#define LOG_TAG "keystore_auth" + +using namespace android; + +void create_error_file() { + FILE* error_file = fopen("/auth_error", "wb"); + if (error_file == NULL) { + printf("Failed to open /auth_error\n"); + ALOGE("Failed to open /auth_error\n"); + return; + } + fwrite("1", 1, 1, error_file); + fclose(error_file); + unlink("/auth_token"); +} + +int main(int argc, char *argv[]) { + unlink("/auth_error"); + FILE* auth_file = fopen("/auth_token", "rb"); + if (auth_file == NULL) { + printf("Failed to open /auth_token\n"); + ALOGE("Failed to open /auth_token\n"); + create_error_file(); + return -1; + } + // Get the file size + fseek(auth_file, 0, SEEK_END); + int size = ftell(auth_file); + fseek(auth_file, 0, SEEK_SET); + uint8_t auth_token[size]; + fread(auth_token , sizeof(uint8_t), size, auth_file); + fclose(auth_file); + // First get the keystore service + sp<IServiceManager> sm = defaultServiceManager(); + sp<IBinder> binder = sm->getService(String16("android.security.keystore")); + sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder); + if (service == NULL) { + printf("error: could not connect to keystore service\n"); + ALOGE("error: could not connect to keystore service\n"); + create_error_file(); + return -2; + } + ::keystore::KeyStoreServiceReturnCode auth_result = service->addAuthToken(auth_token, size); + if (!auth_result.isOk()) { + // The keystore checks the uid of the calling process and will return a permission denied on this operation for user 0 + printf("keystore error adding auth token\n"); + ALOGE("keystore error adding auth token\n"); + create_error_file(); + return -3; + } + printf("successfully added auth token to keystore\n"); + ALOGD("successfully added auth token to keystore\n"); + unlink("/auth_token"); + return 0; +} |