Revert "Securely encrypt the master key"
This reverts commit 7053e9cd5ebbbb783bf4140381090e6bd0caa740.
Change-Id: I77ed4dbdff8643c80629d2126cb29f85c24c7b43
diff --git a/Android.mk b/Android.mk
index d4a178a..c913a1e 100644
--- a/Android.mk
+++ b/Android.mk
@@ -15,7 +15,6 @@
Devmapper.cpp \
ResponseCode.cpp \
CheckBattery.cpp \
- Ext4Crypt.cpp \
VoldUtil.c \
fstrim.c \
cryptfs.c
diff --git a/CommandListener.cpp b/CommandListener.cpp
index 73a26e4..c66b9d2 100644
--- a/CommandListener.cpp
+++ b/CommandListener.cpp
@@ -619,14 +619,6 @@
Process::killProcessesWithOpenFiles(DATA_MNT_POINT, 2);
}
}
- } else if (!strcmp(argv[1], "enablefilecrypto")) {
- const char* syntax = "Usage: cryptfs enablefilecrypto";
- if (argc != 2) {
- cli->sendMsg(ResponseCode::CommandSyntaxError, syntax, false);
- return 0;
- }
- dumpArgs(argc, argv, -1);
- rc = cryptfs_enable_file();
} else if (!strcmp(argv[1], "changepw")) {
const char* syntax = "Usage: cryptfs changepw "
"default|password|pin|pattern [newpasswd]";
diff --git a/Ext4Crypt.cpp b/Ext4Crypt.cpp
deleted file mode 100644
index 84393c9..0000000
--- a/Ext4Crypt.cpp
+++ /dev/null
@@ -1,377 +0,0 @@
-#include "Ext4Crypt.h"
-
-#include <string>
-#include <fstream>
-#include <map>
-
-#include <errno.h>
-#include <sys/mount.h>
-#include <cutils/properties.h>
-
-#include "unencrypted_properties.h"
-#include "key_control.h"
-#include "cryptfs.h"
-
-#define LOG_TAG "Ext4Crypt"
-#include "cutils/log.h"
-#include <cutils/klog.h>
-
-namespace {
- // Key length in bits
- const int key_length = 128;
-
- // How is device encrypted
- struct keys {
- std::string master_key;
- std::string password;
- };
- std::map<std::string, keys> s_key_store;
-
- // ext4enc:TODO Include structure from somewhere sensible
- // MUST be in sync with ext4_crypto.c in kernel
- const int EXT4_MAX_KEY_SIZE = 76;
- struct ext4_encryption_key {
- uint32_t mode;
- char raw[EXT4_MAX_KEY_SIZE];
- uint32_t size;
- };
-
- namespace tag {
- const char* magic = "magic";
- const char* major_version = "major_version";
- const char* minor_version = "minor_version";
- const char* flags = "flags";
- const char* crypt_type = "crypt_type";
- const char* failed_decrypt_count = "failed_decrypt_count";
- const char* crypto_type_name = "crypto_type_name";
- const char* master_key = "master_key";
- const char* salt = "salt";
- const char* kdf_type = "kdf_type";
- const char* N_factor = "N_factor";
- const char* r_factor = "r_factor";
- const char* p_factor = "p_factor";
- const char* keymaster_blob = "keymaster_blob";
- const char* scrypted_intermediate_key = "scrypted_intermediate_key";
- }
-}
-
-static int put_crypt_ftr_and_key(const crypt_mnt_ftr& crypt_ftr,
- UnencryptedProperties& props)
-{
- SLOGI("Putting crypt footer");
-
- bool success = props.Set<int>(tag::magic, crypt_ftr.magic)
- && props.Set<int>(tag::major_version, crypt_ftr.major_version)
- && props.Set<int>(tag::minor_version, crypt_ftr.minor_version)
- && props.Set<int>(tag::flags, crypt_ftr.flags)
- && props.Set<int>(tag::crypt_type, crypt_ftr.crypt_type)
- && props.Set<int>(tag::failed_decrypt_count,
- crypt_ftr.failed_decrypt_count)
- && props.Set<std::string>(tag::crypto_type_name,
- std::string(reinterpret_cast<const char*>(crypt_ftr.crypto_type_name)))
- && props.Set<std::string>(tag::master_key,
- std::string((const char*) crypt_ftr.master_key,
- crypt_ftr.keysize))
- && props.Set<std::string>(tag::salt,
- std::string((const char*) crypt_ftr.salt,
- SALT_LEN))
- && props.Set<int>(tag::kdf_type, crypt_ftr.kdf_type)
- && props.Set<int>(tag::N_factor, crypt_ftr.N_factor)
- && props.Set<int>(tag::r_factor, crypt_ftr.r_factor)
- && props.Set<int>(tag::p_factor, crypt_ftr.p_factor)
- && props.Set<std::string>(tag::keymaster_blob,
- std::string((const char*) crypt_ftr.keymaster_blob,
- crypt_ftr.keymaster_blob_size))
- && props.Set<std::string>(tag::scrypted_intermediate_key,
- std::string((const char*) crypt_ftr.scrypted_intermediate_key,
- SCRYPT_LEN));
- return success ? 0 : -1;
-}
-
-static int get_crypt_ftr_and_key(crypt_mnt_ftr& crypt_ftr,
- const UnencryptedProperties& props)
-{
- memset(&crypt_ftr, 0, sizeof(crypt_ftr));
- crypt_ftr.magic = props.Get<int>(tag::magic);
- crypt_ftr.major_version = props.Get<int>(tag::major_version);
- crypt_ftr.minor_version = props.Get<int>(tag::minor_version);
- crypt_ftr.flags = props.Get<int>(tag::flags);
- crypt_ftr.crypt_type = props.Get<int>(tag::crypt_type);
- crypt_ftr.failed_decrypt_count = props.Get<int>(tag::failed_decrypt_count);
- std::string crypto_type_name = props.Get<std::string>(tag::crypto_type_name);
- strlcpy(reinterpret_cast<char*>(crypt_ftr.crypto_type_name),
- crypto_type_name.c_str(),
- sizeof(crypt_ftr.crypto_type_name));
- std::string master_key = props.Get<std::string>(tag::master_key);
- crypt_ftr.keysize = master_key.size();
- if (crypt_ftr.keysize > sizeof(crypt_ftr.master_key)) {
- SLOGE("Master key size too long");
- return -1;
- }
- memcpy(crypt_ftr.master_key, &master_key[0], crypt_ftr.keysize);
- std::string salt = props.Get<std::string>(tag::salt);
- if (salt.size() != SALT_LEN) {
- SLOGE("Salt wrong length");
- return -1;
- }
- memcpy(crypt_ftr.salt, &salt[0], SALT_LEN);
- crypt_ftr.kdf_type = props.Get<int>(tag::kdf_type);
- crypt_ftr.N_factor = props.Get<int>(tag::N_factor);
- crypt_ftr.r_factor = props.Get<int>(tag::r_factor);
- crypt_ftr.p_factor = props.Get<int>(tag::p_factor);
- std::string keymaster_blob = props.Get<std::string>(tag::keymaster_blob);
- crypt_ftr.keymaster_blob_size = keymaster_blob.size();
- if (crypt_ftr.keymaster_blob_size > sizeof(crypt_ftr.keymaster_blob)) {
- SLOGE("Keymaster blob too long");
- return -1;
- }
- memcpy(crypt_ftr.keymaster_blob, &keymaster_blob[0],
- crypt_ftr.keymaster_blob_size);
- std::string scrypted_intermediate_key = props.Get<std::string>(tag::scrypted_intermediate_key);
- if (scrypted_intermediate_key.size() != SCRYPT_LEN) {
- SLOGE("scrypted intermediate key wrong length");
- return -1;
- }
- memcpy(crypt_ftr.scrypted_intermediate_key, &scrypted_intermediate_key[0],
- SCRYPT_LEN);
-
- return 0;
-}
-
-static UnencryptedProperties GetProps(const char* path)
-{
- return UnencryptedProperties(path);
-}
-
-static UnencryptedProperties GetAltProps(const char* path)
-{
- return UnencryptedProperties((std::string() + path + "/tmp_mnt").c_str());
-}
-
-static UnencryptedProperties GetPropsOrAltProps(const char* path)
-{
- UnencryptedProperties props = GetProps(path);
- if (props.OK()) {
- return props;
- }
- return GetAltProps(path);
-}
-
-int e4crypt_enable(const char* path)
-{
- // Already enabled?
- if (s_key_store.find(path) != s_key_store.end()) {
- return 0;
- }
-
- // Not an encryptable device?
- UnencryptedProperties key_props = GetProps(path).GetChild(properties::key);
- if (!key_props.OK()) {
- return 0;
- }
-
- if (key_props.Get<std::string>(tag::master_key).empty()) {
- crypt_mnt_ftr ftr;
- if (cryptfs_create_default_ftr(&ftr, key_length)) {
- SLOGE("Failed to create crypto footer");
- return -1;
- }
-
- if (put_crypt_ftr_and_key(ftr, key_props)) {
- SLOGE("Failed to write crypto footer");
- return -1;
- }
-
- crypt_mnt_ftr ftr2;
- if (get_crypt_ftr_and_key(ftr2, key_props)) {
- SLOGE("Failed to read crypto footer back");
- return -1;
- }
-
- if (memcmp(&ftr, &ftr2, sizeof(ftr)) != 0) {
- SLOGE("Crypto footer not correctly written");
- // ex4enc:TODO why is this failing?
- //return -1;
- }
- }
-
- if (!UnencryptedProperties(path).Remove(properties::ref)) {
- SLOGE("Failed to remove key ref");
- return -1;
- }
-
- return e4crypt_check_passwd(path, "");
-}
-
-int e4crypt_change_password(const char* path, int crypt_type,
- const char* password)
-{
- SLOGI("e4crypt_change_password");
-
- UnencryptedProperties key_props = GetProps(path).GetChild(properties::key);
-
- crypt_mnt_ftr ftr;
- if (get_crypt_ftr_and_key(ftr, key_props)) {
- SLOGE("Failed to read crypto footer back");
- return -1;
- }
-
- auto mki = s_key_store.find(path);
- if (mki == s_key_store.end()) {
- SLOGE("No stored master key - can't change password");
- return -1;
- }
-
- const unsigned char* master_key
- = reinterpret_cast<const unsigned char*>(&mki->second.master_key[0]);
-
- if (cryptfs_set_password(&ftr, password, master_key)) {
- SLOGE("Failed to set password");
- return -1;
- }
-
- ftr.crypt_type = crypt_type;
-
- if (put_crypt_ftr_and_key(ftr, key_props)) {
- SLOGE("Failed to write crypto footer");
- return -1;
- }
-
- if (!UnencryptedProperties(path).Set(properties::is_default,
- crypt_type == CRYPT_TYPE_DEFAULT)) {
- SLOGE("Failed to update default flag");
- return -1;
- }
-
- return 0;
-}
-
-int e4crypt_crypto_complete(const char* path)
-{
- SLOGI("ext4 crypto complete called on %s", path);
- UnencryptedProperties key_props
- = GetPropsOrAltProps(path).GetChild(properties::key);
- if (key_props.Get<std::string>(tag::master_key).empty()) {
- SLOGI("No master key, so not ext4enc");
- return -1;
- }
-
- return 0;
-}
-
-int e4crypt_check_passwd(const char* path, const char* password)
-{
- SLOGI("e4crypt_check_password");
-
- // ext4enc:TODO once we have password checking, fix this to be
- // GetKeyOrAltKey
- UnencryptedProperties props = *password ? GetAltProps(path)
- : GetProps(path);
- UnencryptedProperties key_props = props.GetChild(properties::key);
-
- crypt_mnt_ftr ftr;
- if (get_crypt_ftr_and_key(ftr, key_props)) {
- SLOGE("Failed to read crypto footer back");
- return -1;
- }
-
- unsigned char master_key[key_length / 8];
- if (cryptfs_get_master_key (&ftr, password, master_key)){
- SLOGI("Incorrect password");
- return -1;
- }
-
- s_key_store[path] = keys{std::string(reinterpret_cast<char*>(master_key),
- sizeof(master_key)),
- password};
-
- // Install password into global keyring
- ext4_encryption_key ext4_key = {0, {0}, key_length / 8};
- memcpy(ext4_key.raw, master_key, ext4_key.size);
-
- // ext4enc:TODO Use better reference not 1234567890
- key_serial_t device_keyring = keyctl_search(KEY_SPEC_SESSION_KEYRING,
- "keyring", "e4crypt", 0);
-
- SLOGI("Found device_keyring - id is %d", device_keyring);
-
- key_serial_t key_id = add_key("logon", "ext4-key:1234567890",
- (void*)&ext4_key, sizeof(ext4_key),
- device_keyring);
-
- if (key_id == -1) {
- SLOGE("Failed to insert key into keyring with error %s",
- strerror(errno));
- return -1;
- }
-
- SLOGI("Added key %d to keyring %d in process %d",
- key_id, device_keyring, getpid());
-
- // ext4enc:TODO set correct permissions
- long result = keyctl_setperm(key_id, 0x3f3f3f3f);
- if (result) {
- SLOGE("KEYCTL_SETPERM failed with error %ld", result);
- return -1;
- }
-
- // Save reference to key so we can set policy later
- if (!props.Set(properties::ref, "@s.ext4-key:1234567890")) {
- SLOGE("Cannot save key reference");
- return -1;
- }
-
- return 0;
-}
-
-int e4crypt_restart(const char* path)
-{
- SLOGI("e4crypt_restart");
-
- int rc = 0;
-
- SLOGI("ext4 restart called on %s", path);
- property_set("vold.decrypt", "trigger_reset_main");
- SLOGI("Just asked init to shut down class main");
- sleep(2);
-
- std::string tmp_path = std::string() + path + "/tmp_mnt";
-
- // ext4enc:TODO add retry logic
- rc = umount(tmp_path.c_str());
- if (rc) {
- SLOGE("umount %s failed with rc %d, msg %s",
- tmp_path.c_str(), rc, strerror(errno));
- return rc;
- }
-
- // ext4enc:TODO add retry logic
- rc = umount(path);
- if (rc) {
- SLOGE("umount %s failed with rc %d, msg %s",
- path, rc, strerror(errno));
- return rc;
- }
-
- return 0;
-}
-
-const char* e4crypt_get_password(const char* path)
-{
- SLOGI("e4crypt_get_password");
-
- // ext4enc:TODO scrub password after timeout
- auto i = s_key_store.find(path);
- if (i == s_key_store.end()) {
- return 0;
- } else {
- return i->second.password.c_str();
- }
-}
-
-int e4crypt_get_password_type(const char* path)
-{
- SLOGI("e4crypt_get_password_type");
- return GetPropsOrAltProps(path).GetChild(properties::key)
- .Get<int>(tag::crypt_type, CRYPT_TYPE_DEFAULT);
-}
diff --git a/Ext4Crypt.h b/Ext4Crypt.h
deleted file mode 100644
index 301639d..0000000
--- a/Ext4Crypt.h
+++ /dev/null
@@ -1,16 +0,0 @@
-#include <sys/cdefs.h>
-
-__BEGIN_DECLS
-
-// General functions
-int e4crypt_enable(const char* path);
-int e4crypt_main(int argc, char* argv[]);
-int e4crypt_change_password(const char* path, int crypt_type,
- const char* password);
-int e4crypt_crypto_complete(const char* path);
-int e4crypt_check_passwd(const char* path, const char* password);
-int e4crypt_get_password_type(const char* path);
-const char* e4crypt_get_password(const char* path);
-int e4crypt_restart(const char* path);
-
-__END_DECLS
diff --git a/cryptfs.c b/cryptfs.c
index 95b882f..91487ed 100644
--- a/cryptfs.c
+++ b/cryptfs.c
@@ -53,8 +53,7 @@
#include "VolumeManager.h"
#include "VoldUtil.h"
#include "crypto_scrypt.h"
-#include "Ext4Crypt.h"
-#include "ext4_crypt_init_extensions.h"
+#include "ext4_crypt.h"
#include "ext4_utils.h"
#include "f2fs_sparseblock.h"
#include "CheckBattery.h"
@@ -1311,7 +1310,7 @@
/* Encrypt the master key */
if (! EVP_EncryptUpdate(&e_ctx, encrypted_master_key, &encrypted_len,
- decrypted_master_key, KEY_LEN_BYTES)) {
+ decrypted_master_key, KEY_LEN_BYTES)) {
SLOGE("EVP_EncryptUpdate failed\n");
return -1;
}
@@ -1346,7 +1345,7 @@
return 0;
}
-static int decrypt_master_key_aux(const char *passwd, unsigned char *salt,
+static int decrypt_master_key_aux(char *passwd, unsigned char *salt,
unsigned char *encrypted_master_key,
unsigned char *decrypted_master_key,
kdf_func kdf, void *kdf_params,
@@ -1411,7 +1410,7 @@
}
}
-static int decrypt_master_key(const char *passwd, unsigned char *decrypted_master_key,
+static int decrypt_master_key(char *passwd, unsigned char *decrypted_master_key,
struct crypt_mnt_ftr *crypt_ftr,
unsigned char** intermediate_key,
size_t* intermediate_key_size)
@@ -3805,46 +3804,3 @@
password_expiry_time = 0;
}
}
-
-int cryptfs_enable_file()
-{
- return e4crypt_enable(DATA_MNT_POINT);
-}
-
-int cryptfs_create_default_ftr(struct crypt_mnt_ftr* crypt_ftr, __attribute__((unused))int key_length)
-{
- if (cryptfs_init_crypt_mnt_ftr(crypt_ftr)) {
- SLOGE("Failed to initialize crypt_ftr");
- return -1;
- }
-
- if (create_encrypted_random_key(DEFAULT_PASSWORD, crypt_ftr->master_key,
- crypt_ftr->salt, crypt_ftr)) {
- SLOGE("Cannot create encrypted master key\n");
- return -1;
- }
-
- //crypt_ftr->keysize = key_length / 8;
- return 0;
-}
-
-int cryptfs_get_master_key(struct crypt_mnt_ftr* ftr, const char* password,
- unsigned char* master_key)
-{
- int rc;
-
- // ext4enc:TODO check intermediate_key to see if this is valid key
- unsigned char* intermediate_key = 0;
- size_t intermediate_key_size = 0;
- rc = decrypt_master_key(password, master_key, ftr, &intermediate_key,
- &intermediate_key_size);
-
- return rc;
-}
-
-int cryptfs_set_password(struct crypt_mnt_ftr* ftr, const char* password,
- const unsigned char* master_key)
-{
- return encrypt_master_key(password, ftr->salt, master_key, ftr->master_key,
- ftr);
-}
diff --git a/cryptfs.h b/cryptfs.h
index e149061..1da6f94 100644
--- a/cryptfs.h
+++ b/cryptfs.h
@@ -235,7 +235,6 @@
int cryptfs_enable(char *flag, int type, char *passwd, int allow_reboot);
int cryptfs_changepw(int type, const char *newpw);
int cryptfs_enable_default(char *flag, int allow_reboot);
- int cryptfs_enable_file();
int cryptfs_setup_volume(const char *label, int major, int minor,
char *crypto_dev_path, unsigned int max_pathlen,
int *new_major, int *new_minor);
@@ -246,13 +245,6 @@
int cryptfs_get_password_type(void);
const char* cryptfs_get_password(void);
void cryptfs_clear_password(void);
-
- // Functions for file encryption to use to inherit our encryption logic
- int cryptfs_create_default_ftr(struct crypt_mnt_ftr* ftr, int key_length);
- int cryptfs_get_master_key(struct crypt_mnt_ftr* ftr, const char* password,
- unsigned char* master_key);
- int cryptfs_set_password(struct crypt_mnt_ftr* ftr, const char* password,
- const unsigned char* master_key);
#ifdef __cplusplus
}
#endif