eCryptfs: check for eCryptfs cipher support at mount

[firefly-linux-kernel-4.4.55.git] / fs / ecryptfs / keystore.c

diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 27a7fefb83eb07f04d092416654b3b3f4142e55d..89dc18e7e9578053166fb014a4c17f907e384530 100644 (file)
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -1868,11 +1868,6 @@ int ecryptfs_parse_packet_set(struct ecryptfs_crypt_stat *crypt_stat,
         * just one will be sufficient to decrypt to get the FEK. */
 find_next_matching_auth_tok:
        found_auth_tok = 0;
-       if (auth_tok_key) {
-               up_write(&(auth_tok_key->sem));
-               key_put(auth_tok_key);
-               auth_tok_key = NULL;
-       }
        list_for_each_entry(auth_tok_list_item, &auth_tok_list, list) {
                candidate_auth_tok = &auth_tok_list_item->auth_tok;
                if (unlikely(ecryptfs_verbosity > 0)) {
@@ -1909,14 +1904,22 @@ found_matching_auth_tok:
                memcpy(&(candidate_auth_tok->token.private_key),
                       &(matching_auth_tok->token.private_key),
                       sizeof(struct ecryptfs_private_key));
+               up_write(&(auth_tok_key->sem));
+               key_put(auth_tok_key);
                rc = decrypt_pki_encrypted_session_key(candidate_auth_tok,
                                                       crypt_stat);
        } else if (candidate_auth_tok->token_type == ECRYPTFS_PASSWORD) {
                memcpy(&(candidate_auth_tok->token.password),
                       &(matching_auth_tok->token.password),
                       sizeof(struct ecryptfs_password));
+               up_write(&(auth_tok_key->sem));
+               key_put(auth_tok_key);
                rc = decrypt_passphrase_encrypted_session_key(
                        candidate_auth_tok, crypt_stat);
+       } else {
+               up_write(&(auth_tok_key->sem));
+               key_put(auth_tok_key);
+               rc = -EINVAL;
        }
        if (rc) {
                struct ecryptfs_auth_tok_list_item *auth_tok_list_item_tmp;
@@ -1956,15 +1959,12 @@ found_matching_auth_tok:
 out_wipe_list:
        wipe_auth_tok_list(&auth_tok_list);
 out:
-       if (auth_tok_key) {
-               up_write(&(auth_tok_key->sem));
-               key_put(auth_tok_key);
-       }
        return rc;
 }
 
 static int
-pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
+pki_encrypt_session_key(struct key *auth_tok_key,
+                       struct ecryptfs_auth_tok *auth_tok,
                        struct ecryptfs_crypt_stat *crypt_stat,
                        struct ecryptfs_key_record *key_rec)
 {
@@ -1979,6 +1979,8 @@ pki_encrypt_session_key(struct ecryptfs_auth_tok *auth_tok,
                                         crypt_stat->cipher,
                                         crypt_stat->key_size),
                                 crypt_stat, &payload, &payload_len);
+       up_write(&(auth_tok_key->sem));
+       key_put(auth_tok_key);
        if (rc) {
                ecryptfs_printk(KERN_ERR, "Error generating tag 66 packet\n");
                goto out;
@@ -2008,6 +2010,8 @@ out:
  * write_tag_1_packet - Write an RFC2440-compatible tag 1 (public key) packet
  * @dest: Buffer into which to write the packet
  * @remaining_bytes: Maximum number of bytes that can be writtn
+ * @auth_tok_key: The authentication token key to unlock and put when done with
+ *                @auth_tok
  * @auth_tok: The authentication token used for generating the tag 1 packet
  * @crypt_stat: The cryptographic context
  * @key_rec: The key record struct for the tag 1 packet
@@ -2018,7 +2022,7 @@ out:
  */
 static int
 write_tag_1_packet(char *dest, size_t *remaining_bytes,
-                  struct ecryptfs_auth_tok *auth_tok,
+                  struct key *auth_tok_key, struct ecryptfs_auth_tok *auth_tok,
                   struct ecryptfs_crypt_stat *crypt_stat,
                   struct ecryptfs_key_record *key_rec, size_t *packet_size)
 {
@@ -2039,12 +2043,15 @@ write_tag_1_packet(char *dest, size_t *remaining_bytes,
                memcpy(key_rec->enc_key,
                       auth_tok->session_key.encrypted_key,
                       auth_tok->session_key.encrypted_key_size);
+               up_write(&(auth_tok_key->sem));
+               key_put(auth_tok_key);
                goto encrypted_session_key_set;
        }
        if (auth_tok->session_key.encrypted_key_size == 0)
                auth_tok->session_key.encrypted_key_size =
                        auth_tok->token.private_key.key_size;
-       rc = pki_encrypt_session_key(auth_tok, crypt_stat, key_rec);
+       rc = pki_encrypt_session_key(auth_tok_key, auth_tok, crypt_stat,
+                                    key_rec);
        if (rc) {
                printk(KERN_ERR "Failed to encrypt session key via a key "
                       "module; rc = [%d]\n", rc);
@@ -2421,6 +2428,8 @@ ecryptfs_generate_key_packet_set(char *dest_base,
                                                &max, auth_tok,
                                                crypt_stat, key_rec,
                                                &written);
+                       up_write(&(auth_tok_key->sem));
+                       key_put(auth_tok_key);
                        if (rc) {
                                ecryptfs_printk(KERN_WARNING, "Error "
                                                "writing tag 3 packet\n");
@@ -2438,8 +2447,8 @@ ecryptfs_generate_key_packet_set(char *dest_base,
                        }
                        (*len) += written;
                } else if (auth_tok->token_type == ECRYPTFS_PRIVATE_KEY) {
-                       rc = write_tag_1_packet(dest_base + (*len),
-                                               &max, auth_tok,
+                       rc = write_tag_1_packet(dest_base + (*len), &max,
+                                               auth_tok_key, auth_tok,
                                                crypt_stat, key_rec, &written);
                        if (rc) {
                                ecryptfs_printk(KERN_WARNING, "Error "
@@ -2448,14 +2457,13 @@ ecryptfs_generate_key_packet_set(char *dest_base,
                        }
                        (*len) += written;
                } else {
+                       up_write(&(auth_tok_key->sem));
+                       key_put(auth_tok_key);
                        ecryptfs_printk(KERN_WARNING, "Unsupported "
                                        "authentication token type\n");
                        rc = -EINVAL;
                        goto out_free;
                }
-               up_write(&(auth_tok_key->sem));
-               key_put(auth_tok_key);
-               auth_tok_key = NULL;
        }
        if (likely(max > 0)) {
                dest_base[(*len)] = 0x00;
@@ -2468,11 +2476,6 @@ out_free:
 out:
        if (rc)
                (*len) = 0;
-       if (auth_tok_key) {
-               up_write(&(auth_tok_key->sem));
-               key_put(auth_tok_key);
-       }
-
        mutex_unlock(&crypt_stat->keysig_list_mutex);
        return rc;
 }