diff options
Diffstat (limited to '')
| -rw-r--r-- | crypto/ext4crypt/Decrypt.cpp | 286 |
1 files changed, 222 insertions, 64 deletions
diff --git a/crypto/ext4crypt/Decrypt.cpp b/crypto/ext4crypt/Decrypt.cpp index 2dab16646..4a8494e5e 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; } @@ -496,7 +513,7 @@ 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 +530,11 @@ 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; @@ -579,6 +601,36 @@ std::string unwrapSyntheticPasswordBlob(const std::string& spblob_path, const st 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 @@ -677,11 +729,40 @@ 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 +773,12 @@ 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 +795,14 @@ 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 +810,152 @@ 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 |