eCryptfs: add key list structure; search keyring
[pandora-kernel.git] / fs / ecryptfs / crypto.c
index 6ac6306..4f7d895 100644 (file)
@@ -204,6 +204,8 @@ void
 ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat)
 {
        memset((void *)crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat));
+       INIT_LIST_HEAD(&crypt_stat->keysig_list);
+       mutex_init(&crypt_stat->keysig_list_mutex);
        mutex_init(&crypt_stat->cs_mutex);
        mutex_init(&crypt_stat->cs_tfm_mutex);
        mutex_init(&crypt_stat->cs_hash_tfm_mutex);
@@ -218,20 +220,41 @@ ecryptfs_init_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat)
  */
 void ecryptfs_destruct_crypt_stat(struct ecryptfs_crypt_stat *crypt_stat)
 {
+       struct ecryptfs_key_sig *key_sig, *key_sig_tmp;
+
        if (crypt_stat->tfm)
                crypto_free_blkcipher(crypt_stat->tfm);
        if (crypt_stat->hash_tfm)
                crypto_free_hash(crypt_stat->hash_tfm);
+       mutex_lock(&crypt_stat->keysig_list_mutex);
+       list_for_each_entry_safe(key_sig, key_sig_tmp,
+                                &crypt_stat->keysig_list, crypt_stat_list) {
+               list_del(&key_sig->crypt_stat_list);
+               kmem_cache_free(ecryptfs_key_sig_cache, key_sig);
+       }
+       mutex_unlock(&crypt_stat->keysig_list_mutex);
        memset(crypt_stat, 0, sizeof(struct ecryptfs_crypt_stat));
 }
 
 void ecryptfs_destruct_mount_crypt_stat(
        struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
 {
-       if (mount_crypt_stat->global_auth_tok_key)
-               key_put(mount_crypt_stat->global_auth_tok_key);
-       if (mount_crypt_stat->global_key_tfm)
-               crypto_free_blkcipher(mount_crypt_stat->global_key_tfm);
+       struct ecryptfs_global_auth_tok *auth_tok, *auth_tok_tmp;
+
+       if (!(mount_crypt_stat->flags & ECRYPTFS_MOUNT_CRYPT_STAT_INITIALIZED))
+               return;
+       mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
+       list_for_each_entry_safe(auth_tok, auth_tok_tmp,
+                                &mount_crypt_stat->global_auth_tok_list,
+                                mount_crypt_stat_list) {
+               list_del(&auth_tok->mount_crypt_stat_list);
+               mount_crypt_stat->num_global_auth_toks--;
+               if (auth_tok->global_auth_tok_key
+                   && !(auth_tok->flags & ECRYPTFS_AUTH_TOK_INVALID))
+                       key_put(auth_tok->global_auth_tok_key);
+               kmem_cache_free(ecryptfs_global_auth_tok_cache, auth_tok);
+       }
+       mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
        memset(mount_crypt_stat, 0, sizeof(struct ecryptfs_mount_crypt_stat));
 }
 
@@ -931,6 +954,30 @@ static void ecryptfs_copy_mount_wide_flags_to_inode_flags(
                crypt_stat->flags |= ECRYPTFS_VIEW_AS_ENCRYPTED;
 }
 
+static int ecryptfs_copy_mount_wide_sigs_to_inode_sigs(
+       struct ecryptfs_crypt_stat *crypt_stat,
+       struct ecryptfs_mount_crypt_stat *mount_crypt_stat)
+{
+       struct ecryptfs_global_auth_tok *global_auth_tok;
+       int rc = 0;
+
+       mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
+       list_for_each_entry(global_auth_tok,
+                           &mount_crypt_stat->global_auth_tok_list,
+                           mount_crypt_stat_list) {
+               rc = ecryptfs_add_keysig(crypt_stat, global_auth_tok->sig);
+               if (rc) {
+                       printk(KERN_ERR "Error adding keysig; rc = [%d]\n", rc);
+                       mutex_unlock(
+                               &mount_crypt_stat->global_auth_tok_list_mutex);
+                       goto out;
+               }
+       }
+       mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
+out:
+       return rc;
+}
+
 /**
  * ecryptfs_set_default_crypt_stat_vals
  * @crypt_stat
@@ -973,46 +1020,44 @@ static void ecryptfs_set_default_crypt_stat_vals(
 /* Associate an authentication token(s) with the file */
 int ecryptfs_new_file_context(struct dentry *ecryptfs_dentry)
 {
-       int rc = 0;
        struct ecryptfs_crypt_stat *crypt_stat =
            &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
        struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
            &ecryptfs_superblock_to_private(
                    ecryptfs_dentry->d_sb)->mount_crypt_stat;
        int cipher_name_len;
+       int rc = 0;
 
        ecryptfs_set_default_crypt_stat_vals(crypt_stat, mount_crypt_stat);
-       /* See if there are mount crypt options */
-       if (mount_crypt_stat->global_auth_tok) {
-               ecryptfs_printk(KERN_DEBUG, "Initializing context for new "
-                               "file using mount_crypt_stat\n");
-               crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
-               crypt_stat->flags |= ECRYPTFS_KEY_VALID;
-               ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat,
-                                                             mount_crypt_stat);
-               memcpy(crypt_stat->keysigs[crypt_stat->num_keysigs++],
-                      mount_crypt_stat->global_auth_tok_sig,
-                      ECRYPTFS_SIG_SIZE_HEX);
-               cipher_name_len =
-                   strlen(mount_crypt_stat->global_default_cipher_name);
-               memcpy(crypt_stat->cipher,
-                      mount_crypt_stat->global_default_cipher_name,
-                      cipher_name_len);
-               crypt_stat->cipher[cipher_name_len] = '\0';
-               crypt_stat->key_size =
-                       mount_crypt_stat->global_default_cipher_key_size;
-               ecryptfs_generate_new_key(crypt_stat);
-       } else
-               /* We should not encounter this scenario since we
-                * should detect lack of global_auth_tok at mount time
-                * TODO: Applies to 0.1 release only; remove in future
-                * release */
-               BUG();
+       mutex_lock(&mount_crypt_stat->global_auth_tok_list_mutex);
+       BUG_ON(mount_crypt_stat->num_global_auth_toks == 0);
+       mutex_unlock(&mount_crypt_stat->global_auth_tok_list_mutex);
+       crypt_stat->flags |= ECRYPTFS_ENCRYPTED;
+       crypt_stat->flags |= ECRYPTFS_KEY_VALID;
+       ecryptfs_copy_mount_wide_flags_to_inode_flags(crypt_stat,
+                                                     mount_crypt_stat);
+       rc = ecryptfs_copy_mount_wide_sigs_to_inode_sigs(crypt_stat,
+                                                        mount_crypt_stat);
+       if (rc) {
+               printk(KERN_ERR "Error attempting to copy mount-wide key sigs "
+                      "to the inode key sigs; rc = [%d]\n", rc);
+               goto out;
+       }
+       cipher_name_len =
+               strlen(mount_crypt_stat->global_default_cipher_name);
+       memcpy(crypt_stat->cipher,
+              mount_crypt_stat->global_default_cipher_name,
+              cipher_name_len);
+       crypt_stat->cipher[cipher_name_len] = '\0';
+       crypt_stat->key_size =
+               mount_crypt_stat->global_default_cipher_key_size;
+       ecryptfs_generate_new_key(crypt_stat);
        rc = ecryptfs_init_crypt_ctx(crypt_stat);
        if (rc)
                ecryptfs_printk(KERN_ERR, "Error initializing cryptographic "
                                "context for cipher [%s]: rc = [%d]\n",
                                crypt_stat->cipher, rc);
+out:
        return rc;
 }
 
@@ -1776,7 +1821,7 @@ out:
 }
 
 /**
- * ecryptfs_process_cipher - Perform cipher initialization.
+ * ecryptfs_process_key_cipher - Perform key cipher initialization.
  * @key_tfm: Crypto context for key material, set by this function
  * @cipher_name: Name of the cipher
  * @key_size: Size of the key in bytes
@@ -1786,8 +1831,8 @@ out:
  * event, regardless of whether this function succeeds for fails.
  */
 int
-ecryptfs_process_cipher(struct crypto_blkcipher **key_tfm, char *cipher_name,
-                       size_t *key_size)
+ecryptfs_process_key_cipher(struct crypto_blkcipher **key_tfm,
+                           char *cipher_name, size_t *key_size)
 {
        char dummy_key[ECRYPTFS_MAX_KEY_BYTES];
        char *full_alg_name;
@@ -1829,3 +1874,98 @@ ecryptfs_process_cipher(struct crypto_blkcipher **key_tfm, char *cipher_name,
 out:
        return rc;
 }
+
+struct kmem_cache *ecryptfs_key_tfm_cache;
+struct list_head key_tfm_list;
+struct mutex key_tfm_list_mutex;
+
+int ecryptfs_init_crypto(void)
+{
+       mutex_init(&key_tfm_list_mutex);
+       INIT_LIST_HEAD(&key_tfm_list);
+       return 0;
+}
+
+int ecryptfs_destruct_crypto(void)
+{
+       struct ecryptfs_key_tfm *key_tfm, *key_tfm_tmp;
+
+       mutex_lock(&key_tfm_list_mutex);
+       list_for_each_entry_safe(key_tfm, key_tfm_tmp, &key_tfm_list,
+                                key_tfm_list) {
+               list_del(&key_tfm->key_tfm_list);
+               if (key_tfm->key_tfm)
+                       crypto_free_blkcipher(key_tfm->key_tfm);
+               kmem_cache_free(ecryptfs_key_tfm_cache, key_tfm);
+       }
+       mutex_unlock(&key_tfm_list_mutex);
+       return 0;
+}
+
+int
+ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
+                        size_t key_size)
+{
+       struct ecryptfs_key_tfm *tmp_tfm;
+       int rc = 0;
+
+       tmp_tfm = kmem_cache_alloc(ecryptfs_key_tfm_cache, GFP_KERNEL);
+       if (key_tfm != NULL)
+               (*key_tfm) = tmp_tfm;
+       if (!tmp_tfm) {
+               rc = -ENOMEM;
+               printk(KERN_ERR "Error attempting to allocate from "
+                      "ecryptfs_key_tfm_cache\n");
+               goto out;
+       }
+       mutex_init(&tmp_tfm->key_tfm_mutex);
+       strncpy(tmp_tfm->cipher_name, cipher_name,
+               ECRYPTFS_MAX_CIPHER_NAME_SIZE);
+       tmp_tfm->key_size = key_size;
+       if ((rc = ecryptfs_process_key_cipher(&tmp_tfm->key_tfm,
+                                             tmp_tfm->cipher_name,
+                                             &tmp_tfm->key_size))) {
+               printk(KERN_ERR "Error attempting to initialize key TFM "
+                      "cipher with name = [%s]; rc = [%d]\n",
+                      tmp_tfm->cipher_name, rc);
+               kmem_cache_free(ecryptfs_key_tfm_cache, tmp_tfm);
+               if (key_tfm != NULL)
+                       (*key_tfm) = NULL;
+               goto out;
+       }
+       mutex_lock(&key_tfm_list_mutex);
+       list_add(&tmp_tfm->key_tfm_list, &key_tfm_list);
+       mutex_unlock(&key_tfm_list_mutex);
+out:
+       return rc;
+}
+
+int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm,
+                                              struct mutex **tfm_mutex,
+                                              char *cipher_name)
+{
+       struct ecryptfs_key_tfm *key_tfm;
+       int rc = 0;
+
+       (*tfm) = NULL;
+       (*tfm_mutex) = NULL;
+       mutex_lock(&key_tfm_list_mutex);
+       list_for_each_entry(key_tfm, &key_tfm_list, key_tfm_list) {
+               if (strcmp(key_tfm->cipher_name, cipher_name) == 0) {
+                       (*tfm) = key_tfm->key_tfm;
+                       (*tfm_mutex) = &key_tfm->key_tfm_mutex;
+                       mutex_unlock(&key_tfm_list_mutex);
+                       goto out;
+               }
+       }
+       mutex_unlock(&key_tfm_list_mutex);
+       if ((rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0))) {
+               printk(KERN_ERR "Error adding new key_tfm to list; rc = [%d]\n",
+                      rc);
+               goto out;
+       }
+       (*tfm) = key_tfm->key_tfm;
+       (*tfm_mutex) = &key_tfm->key_tfm_mutex;
+out:
+       return rc;
+}