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/****************************************************************
* *
* Copyright (c) 2009-2016 Fidelity National Information *
* Services, Inc. and/or its subsidiaries. All rights reserved. *
* *
* This source code contains the intellectual property *
* of its copyright holder(s), and is made available *
* under a license. If you do not know the terms of *
* the license, please stop and do not read further. *
* *
****************************************************************/
#ifndef GTMCRYPT_DBK_REF_H
#define GTMCRYPT_DBK_REF_H
/*
* This file defines several structures that store information about every symmetric key that we load as well the encryption /
* decryption context for any database or device that uses that particular key. The information about the key includes its raw
* content and its hash; those are stored in gtm_keystore_t->typed objects malloced invdividually. To assist lookups based on the
* key's hash, name, or path, we have tree structures consisting of gtm_keystore_hash_link_t-, gtm_keystore_keyname_link_t-, and
* gtm_keystore_keypath_linkt_t-typed nodes, respectively. Since we expect hashes to be unique along with the path of each key, the
* hash and path information is already stored in gtm_keystore_t nodes, and the hash- and path- based trees' nodes contain no
* additional information and have a one-to-one and onto relationship with the gtm_keystore_t nodes. The keyname-based tree's nodes,
* on the other hand, also contain the key name information, which may correspond to the database's name or a user-chosen string in
* case of device encryption. Additionally, several databases or devices may use the same key, in which case one gtm_keystore_t
* element may be referenced by multiple keyname tree's nodes. An example is given below:
*
* keystore_by_hash_head keystore_by_keyname_head / keystore_by_keypath_head
* (gtm_keystore_hash_link_t *) (gtm_keystore_t *) (gtm_keystore_keyname_link_t * / gtm_keystore_keypath_link_t *)
* | ________ |
* ______|_____ | | ______|_____
* | link ---|-------------> | key #1 | <-----. .------------------|--- link |
* | left right | |________| \ / | left right |
* |_/_______\__| \/ |_/_______\__|
* / \ ________ /\ / \
* _______/____ \ | | / \ ______/_____ \
* | link ---|-------\-------------> | key #2 | <-----` `-----------|--- link | \
* | left right | \ |________| | left right | \
* |_/_______\__| \ |_/_______\__| \
* ... ... \ ________ / ... \
* _____\______ | | / _____\______
* | link ---|--> | key #3 | <-.-------------------/------------------|--- link |
* | left right | |________| \ / | left right |
* |_/_______\__| \ ______/_____ |_/_______\__|
* ... ... `-------|--- link | ... ...
* | left right |
* |_/_______\__|
* ... ...
*
* Because we do not want to decrypt every key from the configuration file just as we read it, we first store whatever information
* we processed in an unresolved key list. The list is singly-linked and consists of gtm_keystore_keyname_link_t-typed elements;
* each element contains information about the key name, path, index in the configuration file, and whether it is a key for a device
* encryption, database whose address we already resolved, or the one that awaits resolution. (Certain database files referenced in
* the configuration file may not actually exist, such as during MUPIP CREATE time or when loading an extract.)
*
* As for gtm_keystore_t elements, in addition to the key data they host a pointer to the head of the encryption / decryption state
* list as well as to the one element of that list that is specific to database encryption. (Because database encryption does not
* preserve its state beyond one block, we only ever create one database encryption and one database decryption state object, which
* gets reused continuously.) Unlike devices, which can activate encryption and decryption individually, databases have to have both
* encryption and decryption enabled at once. For that reason, if there is a database encryption context entry in one key's contexts
* list, there is a database decryption context right after.
*
* The encryption / decryption contexts list is doubly-linked and consists of gtm_cipher_ctx_t-typed elements. Each element contains
* the algorithm-specific (such as OpenSSL or GCRYPT) encryption or decryption state object, initialization vector (used only when
* initializing the encryption / decryption state) and a pointer back to its respective key structure. An example is given below:
*
* ___________________________________________________
* | cipher_head db_cipher_entry |
* .-->| (gtm_cipher_ctx_t *) (gtm_cipher_ctx_t *) |
* | |________|_______________________________|__________|
* | | |
* | | (DB ENCR) ----> (DB DECR)
* | | |
* | ____v____ _________ ____v____ _________
* | | prev |<----|- prev |<----|- prev |<----|- prev |
* | | next --|---->| next --|---->| next --|---->| next |
* | | store | | store | | store | | store |
* | |____|____| |____|____| |____|____| |____|____|
* | | | | |
* `-------------'---------------'---------------'---------------'
*
* For the actual implementation of the above design please refer to gtmcrypt_dbk_ref.c.
*/
/* Principal structure for storing key information required to perform encryption / decryption. */
typedef struct gtm_keystore_struct
{
unsigned char key[SYMMETRIC_KEY_MAX]; /* Raw symmetric key contents. */
unsigned char key_hash[GTMCRYPT_HASH_LEN]; /* SHA-512 hash of symmetric key. */
char key_path[GTM_PATH_MAX]; /* Path to the key file. */
struct gtm_cipher_ctx_struct *cipher_head; /* Linked list of cipher handles for
* either encryption or decryption. A list
* is needed because multiple devices or
* databases can map to the same key, but
* the internal encryption / decryption
* state cannot be shared. */
struct gtm_cipher_ctx_struct *db_cipher_entry; /* Direct pointer to the (only) DB
* encryption cipher entry (followed by the
* DB decryption entry). */
} gtm_keystore_t;
/* Structure for storing the encryption / decryption state for one device or any DB using the key pointed to by the store field. */
typedef struct gtm_cipher_ctx_struct
{
crypt_key_t handle; /* Encryption / decryption state. */
unsigned char iv[GTMCRYPT_IV_LEN]; /* Initialization vector. */
gtm_keystore_t *store; /* Pointer to master key object. */
struct gtm_cipher_ctx_struct *prev; /* Pointer to previous element. */
struct gtm_cipher_ctx_struct *next; /* Pointer to next element. */
} gtm_cipher_ctx_t;
/* Structure to organize references to the key object by the key name, in a binary search tree fashion. */
typedef struct gtm_keystore_keyname_link_struct
{
gtm_keystore_t *link; /* Link to respective key object. */
char key_name[GTM_PATH_MAX]; /* Logical entity that the symmetric key
* maps to. For databases it is the name of
* the database file. For devices it is a
* user-chosen string. */
struct gtm_keystore_keyname_link_struct *left; /* Pointer to left child. */
struct gtm_keystore_keyname_link_struct *right; /* Pointer to right child. */
} gtm_keystore_keyname_link_t;
/* Structure to organize references to the key object by the key path, in a binary search tree fashion. */
typedef struct gtm_keystore_keypath_link_struct
{
gtm_keystore_t *link; /* Link to respective key object. */
struct gtm_keystore_keypath_link_struct *left; /* Pointer to left child. */
struct gtm_keystore_keypath_link_struct *right; /* Pointer to right child. */
} gtm_keystore_keypath_link_t;
/* Structure to organize references to the key object by the key hash, in a binary search tree fashion. */
typedef struct gtm_keystore_hash_link_struct
{
gtm_keystore_t *link; /* Link to respective key object. */
struct gtm_keystore_hash_link_struct *left; /* Pointer to left child. */
struct gtm_keystore_hash_link_struct *right; /* Pointer to right child. */
} gtm_keystore_hash_link_t;
/* Structure to temporarily store key information if the real path of the respective database file name could not be obtained. */
typedef struct gtm_keystore_unres_key_link_struct
{
char key_name[GTM_PATH_MAX]; /* Logical entity that the symmetric key
* maps to. For databases it is the name of
* the database file. For devices it is a
* user-chosen string. */
char key_path[GTM_PATH_MAX]; /* Path to the key file. */
int index; /* Index in the configuration file */
int status; /* Indication of whether it is for a device,
* unresolved, or resolved database. */
struct gtm_keystore_unres_key_link_struct *next; /* Pointer to next element. */
} gtm_keystore_unres_key_link_t;
STATICFNDEF int keystore_refresh(void);
STATICFNDEF int read_files_section(config_t *cfgp);
STATICFNDEF int read_database_section(config_t *cfgp);
STATICFNDEF int gtm_keystore_cleanup_node(gtm_keystore_t *);
int gtm_keystore_cleanup_all(void);
STATICFNDEF int gtm_keystore_cleanup_hash_tree(gtm_keystore_hash_link_t *entry);
STATICFNDEF void gtm_keystore_cleanup_keyname_tree(gtm_keystore_keyname_link_t *entry);
STATICFNDEF void gtm_keystore_cleanup_keypath_tree(gtm_keystore_keypath_link_t *entry);
STATICFNDEF void gtm_keystore_cleanup_unres_key_list(void);
int gtmcrypt_getkey_by_keyname(char *keyname, char *keypath, gtm_keystore_t **entry, int database);
int gtmcrypt_getkey_by_hash(unsigned char *hash, char *dbpath, gtm_keystore_t **entry);
STATICFNDEF gtm_keystore_t *gtmcrypt_decrypt_key(char *key_path, int path_length, char *key_name, int name_length);
STATICFNDEF void insert_unresolved_key_link(char *keyname, char *keypath, int index, int status);
STATICFNDEF gtm_keystore_t *keystore_lookup_by_hash(unsigned char *hash);
STATICFNDEF gtm_keystore_t *keystore_lookup_by_keyname(char *keyname);
STATICFNDEF gtm_keystore_t *keystore_lookup_by_keyname_plus(char *keyname, char *search_field, int search_type);
STATICFNDEF gtm_keystore_t *keystore_lookup_by_keypath(char *keypath);
STATICFNDEF gtm_keystore_t *keystore_lookup_by_unres_key(char *search_field1, int search_field1_type,
char *search_field2, int search_field2_type, int database, int *error);
int keystore_new_cipher_ctx(gtm_keystore_t *entry, char *iv, int length, int action);
int keystore_remove_cipher_ctx(gtm_cipher_ctx_t *ctx);
STATICFNDEF void print_debug(void);
#endif /* GTMCRYPT_DBK_REF_H */
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