Fixed MTP to work with TWRP

security/keys/encrypted-keys/Makefile

@@ -0,0 +1,10 @@
+#
+# Makefile for encrypted keys
+#
+
+obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys.o
+
+encrypted-keys-y := encrypted.o ecryptfs_format.o
+masterkey-$(CONFIG_TRUSTED_KEYS) := masterkey_trusted.o
+masterkey-$(CONFIG_TRUSTED_KEYS)-$(CONFIG_ENCRYPTED_KEYS) := masterkey_trusted.o
+encrypted-keys-y += $(masterkey-y) $(masterkey-m-m)

security/keys/encrypted-keys/ecryptfs_format.c

@@ -0,0 +1,81 @@
+/*
+ * ecryptfs_format.c: helper functions for the encrypted key type
+ *
+ * Copyright (C) 2006 International Business Machines Corp.
+ * Copyright (C) 2010 Politecnico di Torino, Italy
+ *                    TORSEC group -- http://security.polito.it
+ *
+ * Authors:
+ * Michael A. Halcrow <mahalcro@us.ibm.com>
+ * Tyler Hicks <tyhicks@ou.edu>
+ * Roberto Sassu <roberto.sassu@polito.it>
+ *
+ * This program 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, version 2 of the License.
+ */
+
+#include <linux/module.h>
+#include "ecryptfs_format.h"
+
+u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok)
+{
+	return auth_tok->token.password.session_key_encryption_key;
+}
+EXPORT_SYMBOL(ecryptfs_get_auth_tok_key);
+
+/*
+ * ecryptfs_get_versions()
+ *
+ * Source code taken from the software 'ecryptfs-utils' version 83.
+ *
+ */
+void ecryptfs_get_versions(int *major, int *minor, int *file_version)
+{
+	*major = ECRYPTFS_VERSION_MAJOR;
+	*minor = ECRYPTFS_VERSION_MINOR;
+	if (file_version)
+		*file_version = ECRYPTFS_SUPPORTED_FILE_VERSION;
+}
+EXPORT_SYMBOL(ecryptfs_get_versions);
+
+/*
+ * ecryptfs_fill_auth_tok - fill the ecryptfs_auth_tok structure
+ *
+ * Fill the ecryptfs_auth_tok structure with required ecryptfs data.
+ * The source code is inspired to the original function generate_payload()
+ * shipped with the software 'ecryptfs-utils' version 83.
+ *
+ */
+int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok,
+			   const char *key_desc)
+{
+	int major, minor;
+
+	ecryptfs_get_versions(&major, &minor, NULL);
+	auth_tok->version = (((uint16_t)(major << 8) & 0xFF00)
+			     | ((uint16_t)minor & 0x00FF));
+	auth_tok->token_type = ECRYPTFS_PASSWORD;
+	strncpy((char *)auth_tok->token.password.signature, key_desc,
+		ECRYPTFS_PASSWORD_SIG_SIZE);
+	auth_tok->token.password.session_key_encryption_key_bytes =
+		ECRYPTFS_MAX_KEY_BYTES;
+	/*
+	 * Removed auth_tok->token.password.salt and
+	 * auth_tok->token.password.session_key_encryption_key
+	 * initialization from the original code
+	 */
+	/* TODO: Make the hash parameterizable via policy */
+	auth_tok->token.password.flags |=
+		ECRYPTFS_SESSION_KEY_ENCRYPTION_KEY_SET;
+	/* The kernel code will encrypt the session key. */
+	auth_tok->session_key.encrypted_key[0] = 0;
+	auth_tok->session_key.encrypted_key_size = 0;
+	/* Default; subject to change by kernel eCryptfs */
+	auth_tok->token.password.hash_algo = PGP_DIGEST_ALGO_SHA512;
+	auth_tok->token.password.flags &= ~(ECRYPTFS_PERSISTENT_PASSWORD);
+	return 0;
+}
+EXPORT_SYMBOL(ecryptfs_fill_auth_tok);
+
+MODULE_LICENSE("GPL");

security/keys/encrypted-keys/ecryptfs_format.h

@@ -0,0 +1,30 @@
+/*
+ * ecryptfs_format.h: helper functions for the encrypted key type
+ *
+ * Copyright (C) 2006 International Business Machines Corp.
+ * Copyright (C) 2010 Politecnico di Torino, Italy
+ *                    TORSEC group -- http://security.polito.it
+ *
+ * Authors:
+ * Michael A. Halcrow <mahalcro@us.ibm.com>
+ * Tyler Hicks <tyhicks@ou.edu>
+ * Roberto Sassu <roberto.sassu@polito.it>
+ *
+ * This program 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, version 2 of the License.
+ */
+
+#ifndef __KEYS_ECRYPTFS_H
+#define __KEYS_ECRYPTFS_H
+
+#include <linux/ecryptfs.h>
+
+#define PGP_DIGEST_ALGO_SHA512   10
+
+u8 *ecryptfs_get_auth_tok_key(struct ecryptfs_auth_tok *auth_tok);
+void ecryptfs_get_versions(int *major, int *minor, int *file_version);
+int ecryptfs_fill_auth_tok(struct ecryptfs_auth_tok *auth_tok,
+			   const char *key_desc);
+
+#endif /* __KEYS_ECRYPTFS_H */

security/keys/encrypted-keys/encrypted.h

@@ -0,0 +1,66 @@
+#ifndef __ENCRYPTED_KEY_H
+#define __ENCRYPTED_KEY_H
+
+#define ENCRYPTED_DEBUG 0
+#if defined(CONFIG_TRUSTED_KEYS) || \
+  (defined(CONFIG_TRUSTED_KEYS_MODULE) && defined(CONFIG_ENCRYPTED_KEYS_MODULE))
+extern struct key *request_trusted_key(const char *trusted_desc,
+				       u8 **master_key, size_t *master_keylen);
+#else
+static inline struct key *request_trusted_key(const char *trusted_desc,
+					      u8 **master_key,
+					      size_t *master_keylen)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+#endif
+
+#if ENCRYPTED_DEBUG
+static inline void dump_master_key(const u8 *master_key, size_t master_keylen)
+{
+	print_hex_dump(KERN_ERR, "master key: ", DUMP_PREFIX_NONE, 32, 1,
+		       master_key, master_keylen, 0);
+}
+
+static inline void dump_decrypted_data(struct encrypted_key_payload *epayload)
+{
+	print_hex_dump(KERN_ERR, "decrypted data: ", DUMP_PREFIX_NONE, 32, 1,
+		       epayload->decrypted_data,
+		       epayload->decrypted_datalen, 0);
+}
+
+static inline void dump_encrypted_data(struct encrypted_key_payload *epayload,
+				       unsigned int encrypted_datalen)
+{
+	print_hex_dump(KERN_ERR, "encrypted data: ", DUMP_PREFIX_NONE, 32, 1,
+		       epayload->encrypted_data, encrypted_datalen, 0);
+}
+
+static inline void dump_hmac(const char *str, const u8 *digest,
+			     unsigned int hmac_size)
+{
+	if (str)
+		pr_info("encrypted_key: %s", str);
+	print_hex_dump(KERN_ERR, "hmac: ", DUMP_PREFIX_NONE, 32, 1, digest,
+		       hmac_size, 0);
+}
+#else
+static inline void dump_master_key(const u8 *master_key, size_t master_keylen)
+{
+}
+
+static inline void dump_decrypted_data(struct encrypted_key_payload *epayload)
+{
+}
+
+static inline void dump_encrypted_data(struct encrypted_key_payload *epayload,
+				       unsigned int encrypted_datalen)
+{
+}
+
+static inline void dump_hmac(const char *str, const u8 *digest,
+			     unsigned int hmac_size)
+{
+}
+#endif
+#endif

security/keys/encrypted-keys/masterkey_trusted.c

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2010 IBM Corporation
+ * Copyright (C) 2010 Politecnico di Torino, Italy
+ *                    TORSEC group -- http://security.polito.it
+ *
+ * Authors:
+ * Mimi Zohar <zohar@us.ibm.com>
+ * Roberto Sassu <roberto.sassu@polito.it>
+ *
+ * This program 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, version 2 of the License.
+ *
+ * See Documentation/security/keys-trusted-encrypted.txt
+ */
+
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <keys/trusted-type.h>
+#include <keys/encrypted-type.h>
+#include "encrypted.h"
+
+/*
+ * request_trusted_key - request the trusted key
+ *
+ * Trusted keys are sealed to PCRs and other metadata. Although userspace
+ * manages both trusted/encrypted key-types, like the encrypted key type
+ * data, trusted key type data is not visible decrypted from userspace.
+ */
+struct key *request_trusted_key(const char *trusted_desc,
+				u8 **master_key, size_t *master_keylen)
+{
+	struct trusted_key_payload *tpayload;
+	struct key *tkey;
+
+	tkey = request_key(&key_type_trusted, trusted_desc, NULL);
+	if (IS_ERR(tkey))
+		goto error;
+
+	down_read(&tkey->sem);
+	tpayload = tkey->payload.data;
+	*master_key = tpayload->key;
+	*master_keylen = tpayload->key_len;
+error:
+	return tkey;
+}