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-rw-r--r--crypto/ext4crypt/Decrypt.cpp286
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