/* keydb.h - Key database
 * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
 *               2006, 2010 Free Software Foundation, Inc.
 * Copyright (C) 2015, 2016 g10 Code GmbH
 *
 * This file is part of GnuPG.
 *
 * GnuPG 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; either version 3 of the License, or
 * (at your option) any later version.
 *
 * GnuPG is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#ifndef G10_KEYDB_H
#define G10_KEYDB_H

#include "types.h"
#include "util.h"
#include "packet.h"

/* What qualifies as a certification (rather than a signature?) */
#define IS_CERT(s)       (IS_KEY_SIG(s) || IS_UID_SIG(s) || IS_SUBKEY_SIG(s) \
                         || IS_KEY_REV(s) || IS_UID_REV(s) || IS_SUBKEY_REV(s))
#define IS_SIG(s)        (!IS_CERT(s))
#define IS_KEY_SIG(s)    ((s)->sig_class == 0x1f)
#define IS_UID_SIG(s)    (((s)->sig_class & ~3) == 0x10)
#define IS_SUBKEY_SIG(s) ((s)->sig_class == 0x18)
#define IS_KEY_REV(s)    ((s)->sig_class == 0x20)
#define IS_UID_REV(s)    ((s)->sig_class == 0x30)
#define IS_SUBKEY_REV(s) ((s)->sig_class == 0x28)

struct getkey_ctx_s;
typedef struct getkey_ctx_s *GETKEY_CTX;
typedef struct getkey_ctx_s *getkey_ctx_t;

/****************
 * A Keyblock is all packets which form an entire certificate;
 * i.e. the public key, certificate, trust packets, user ids,
 * signatures, and subkey.
 *
 * This structure is also used to bind arbitrary packets together.
 */

struct kbnode_struct {
    KBNODE next;
    PACKET *pkt;
    int flag;
    int private_flag;
    ulong recno;  /* used while updating the trustdb */
};

#define is_deleted_kbnode(a)  ((a)->private_flag & 1)
#define is_cloned_kbnode(a)   ((a)->private_flag & 2)


enum resource_type {
    rt_UNKNOWN = 0,
    rt_RING = 1
};


/* Bit flags used with build_pk_list.  */
enum
  {
    PK_LIST_ENCRYPT_TO = 1, /* This is an encrypt-to recipient.    */
    PK_LIST_HIDDEN     = 2, /* This is a hidden recipient.         */
    PK_LIST_CONFIG     = 4, /* Specified via config file.          */
    PK_LIST_FROM_FILE  = 8  /* Take key from file with that name.  */
  };
/* To store private data in the flags the private data must be left
   shifted by this value.  */
enum
  {
    PK_LIST_SHIFT = 4
  };

/****************
 * A data structure to hold information about the external position
 * of a keyblock.
 */
struct keyblock_pos_struct {
    int   resno;     /* resource number */
    enum resource_type rt;
    off_t offset;    /* position information */
    unsigned count;  /* length of the keyblock in packets */
    iobuf_t  fp;     /* Used by enum_keyblocks. */
    int secret;      /* working on a secret keyring */
    PACKET *pkt;     /* ditto */
    int valid;
};
typedef struct keyblock_pos_struct KBPOS;

/* Structure to hold a couple of public key certificates. */
typedef struct pk_list *PK_LIST;  /* Deprecated. */
typedef struct pk_list *pk_list_t;
struct pk_list
{
  PK_LIST next;
  PKT_public_key *pk;
  int flags;           /* See PK_LIST_ constants. */
};

/* Structure to hold a list of secret key certificates.  */
typedef struct sk_list *SK_LIST;
struct sk_list
{
  SK_LIST next;
  PKT_public_key *pk;
  int mark; /* not used */
};

/* structure to collect all information which can be used to
 * identify a public key */
typedef struct pubkey_find_info *PUBKEY_FIND_INFO;
struct pubkey_find_info {
    u32  keyid[2];
    unsigned nbits;
    byte pubkey_algo;
    byte fingerprint[MAX_FINGERPRINT_LEN];
    char userid[1];
};


typedef struct keydb_handle *KEYDB_HANDLE;


/* Helper type for preference fucntions. */
union pref_hint
{
  int digest_length;
};


/*-- keydb.c --*/

#define KEYDB_RESOURCE_FLAG_PRIMARY  2  /* The primary resource.  */
#define KEYDB_RESOURCE_FLAG_DEFAULT  4  /* The default one.  */
#define KEYDB_RESOURCE_FLAG_READONLY 8  /* Open in read only mode.  */
#define KEYDB_RESOURCE_FLAG_GPGVDEF 16  /* Default file for gpgv.  */

/* Format a search term for debugging output.  The caller must free
   the result.  */
char *keydb_search_desc_dump (struct keydb_search_desc *desc);

/* Register a resource (keyring or keybox).  */
gpg_error_t keydb_add_resource (const char *url, unsigned int flags);

/* Dump some statistics to the log.  */
void keydb_dump_stats (void);

/* Create a new database handle.  Returns NULL on error, sets ERRNO,
   and prints an error diagnostic. */
KEYDB_HANDLE keydb_new (void);

/* Free all resources owned by the database handle.  */
void keydb_release (KEYDB_HANDLE hd);

/* Set a flag on the handle to suppress use of cached results.  This
   is required for updating a keyring and for key listings.  Fixme:
   Using a new parameter for keydb_new might be a better solution.  */
void keydb_disable_caching (KEYDB_HANDLE hd);

/* Save the last found state and invalidate the current selection.  */
void keydb_push_found_state (KEYDB_HANDLE hd);

/* Restore the previous save state.  */
void keydb_pop_found_state (KEYDB_HANDLE hd);

/* Return the file name of the resource.  */
const char *keydb_get_resource_name (KEYDB_HANDLE hd);

/* Return the keyblock last found by keydb_search.  */
gpg_error_t keydb_get_keyblock (KEYDB_HANDLE hd, KBNODE *ret_kb);

/* Update the keyblock KB.  */
gpg_error_t keydb_update_keyblock (KEYDB_HANDLE hd, kbnode_t kb);

/* Insert a keyblock into one of the underlying keyrings or keyboxes.  */
gpg_error_t keydb_insert_keyblock (KEYDB_HANDLE hd, kbnode_t kb);

/* Delete the currently selected keyblock.  */
gpg_error_t keydb_delete_keyblock (KEYDB_HANDLE hd);

/* Find the first writable resource.  */
gpg_error_t keydb_locate_writable (KEYDB_HANDLE hd);

/* Rebuild the on-disk caches of all key resources.  */
void keydb_rebuild_caches (int noisy);

/* Return the number of skipped blocks (because they were to large to
   read from a keybox) since the last search reset.  */
unsigned long keydb_get_skipped_counter (KEYDB_HANDLE hd);

/* Clears the current search result and resets the handle's position.  */
gpg_error_t keydb_search_reset (KEYDB_HANDLE hd);

/* Search the database for keys matching the search description.  */
gpg_error_t keydb_search (KEYDB_HANDLE hd, KEYDB_SEARCH_DESC *desc,
                          size_t ndesc, size_t *descindex);

/* Return the first non-legacy key in the database.  */
gpg_error_t keydb_search_first (KEYDB_HANDLE hd);

/* Return the next key (not the next matching key!).  */
gpg_error_t keydb_search_next (KEYDB_HANDLE hd);

/* This is a convenience function for searching for keys with a long
   key id.  */
gpg_error_t keydb_search_kid (KEYDB_HANDLE hd, u32 *kid);

/* This is a convenience function for searching for keys with a long
   (20 byte) fingerprint.  */
gpg_error_t keydb_search_fpr (KEYDB_HANDLE hd, const byte *fpr);


/*-- pkclist.c --*/
void show_revocation_reason( PKT_public_key *pk, int mode );
int  check_signatures_trust (ctrl_t ctrl, PKT_signature *sig);

void release_pk_list (PK_LIST pk_list);
int  build_pk_list (ctrl_t ctrl, strlist_t rcpts, PK_LIST *ret_pk_list);
gpg_error_t find_and_check_key (ctrl_t ctrl,
                                const char *name, unsigned int use,
                                int mark_hidden, int from_file,
                                pk_list_t *pk_list_addr);

int  algo_available( preftype_t preftype, int algo,
		     const union pref_hint *hint );
int  select_algo_from_prefs( PK_LIST pk_list, int preftype,
			     int request, const union pref_hint *hint);
int  select_mdc_from_pklist (PK_LIST pk_list);
void warn_missing_mdc_from_pklist (PK_LIST pk_list);
void warn_missing_aes_from_pklist (PK_LIST pk_list);

/*-- skclist.c --*/
int  random_is_faked (void);
void release_sk_list( SK_LIST sk_list );
gpg_error_t build_sk_list (ctrl_t ctrl, strlist_t locusr,
                           SK_LIST *ret_sk_list, unsigned use);

/*-- passphrase.h --*/
unsigned char encode_s2k_iterations (int iterations);
int  have_static_passphrase(void);
const char *get_static_passphrase (void);
void set_passphrase_from_string(const char *pass);
void read_passphrase_from_fd( int fd );
void passphrase_clear_cache (const char *cacheid);
DEK *passphrase_to_dek_ext(u32 *keyid, int pubkey_algo,
                           int cipher_algo, STRING2KEY *s2k, int mode,
                           const char *tryagain_text,
                           const char *custdesc, const char *custprompt,
                           int *canceled);
DEK *passphrase_to_dek (int cipher_algo, STRING2KEY *s2k,
                        int create, int nocache,
                        const char *tryagain_text, int *canceled);
void set_next_passphrase( const char *s );
char *get_last_passphrase(void);
void next_to_last_passphrase(void);

void emit_status_need_passphrase (u32 *keyid, u32 *mainkeyid, int pubkey_algo);

#define FORMAT_KEYDESC_NORMAL  0
#define FORMAT_KEYDESC_IMPORT  1
#define FORMAT_KEYDESC_EXPORT  2
#define FORMAT_KEYDESC_DELKEY  3
char *gpg_format_keydesc (PKT_public_key *pk, int mode, int escaped);


/*-- getkey.c --*/

/* Cache a copy of a public key in the public key cache.  */
void cache_public_key( PKT_public_key *pk );

/* Disable and drop the public key cache.  */
void getkey_disable_caches(void);

/* Return the public key with the key id KEYID and store it at PK.  */
int get_pubkey( PKT_public_key *pk, u32 *keyid );

/* Similar to get_pubkey, but it does not take PK->REQ_USAGE into
   account nor does it merge in the self-signed data.  This function
   also only considers primary keys.  */
int get_pubkey_fast (PKT_public_key *pk, u32 *keyid);

/* Return the key block for the key with KEYID.  */
kbnode_t get_pubkeyblock (u32 *keyid);

/* A list used by get_pubkeys to gather all of the matches.  */
struct pubkey_s
{
  struct pubkey_s *next;
  /* The key to use (either the public key or the subkey).  */
  PKT_public_key *pk;
  kbnode_t keyblock;
};
typedef struct pubkey_s *pubkey_t;

/* Free a single key.  This does not remove key from any list!  */
void pubkey_free (pubkey_t key);

/* Free a list of public keys.  */
void pubkeys_free (pubkey_t keys);

/* Returns all keys that match the search specfication SEARCH_TERMS.
   The returned keys should be freed using pubkeys_free.  */
gpg_error_t
get_pubkeys (ctrl_t ctrl,
             char *search_terms, int use, int include_unusable, char *source,
             int warn_possibly_ambiguous,
             pubkey_t *r_keys);

/* Find a public key identified by NAME.  */
int get_pubkey_byname (ctrl_t ctrl,
                       GETKEY_CTX *retctx, PKT_public_key *pk,
		       const char *name,
                       KBNODE *ret_keyblock, KEYDB_HANDLE *ret_kdbhd,
		       int include_unusable, int no_akl );

/* Get a public key directly from file FNAME.  */
gpg_error_t get_pubkey_fromfile (ctrl_t ctrl,
                                 PKT_public_key *pk, const char *fname);

/* Return the public key with the key id KEYID iff the secret key is
 * available and store it at PK.  */
gpg_error_t get_seckey (PKT_public_key *pk, u32 *keyid);

/* Lookup a key with the specified fingerprint.  */
int get_pubkey_byfprint (PKT_public_key *pk,  kbnode_t *r_keyblock,
                         const byte *fprint, size_t fprint_len);

/* This function is similar to get_pubkey_byfprint, but it doesn't
   merge the self-signed data into the public key and subkeys or into
   the user ids.  */
int get_pubkey_byfprint_fast (PKT_public_key *pk,
                              const byte *fprint, size_t fprint_len);

/* Returns true if a secret key is available for the public key with
   key id KEYID.  */
int have_secret_key_with_kid (u32 *keyid);

/* Parse the --default-key parameter.  Returns the last key (in terms
   of when the option is given) that is available.  */
const char *parse_def_secret_key (ctrl_t ctrl);

/* Look up a secret key.  */
gpg_error_t get_seckey_default (ctrl_t ctrl, PKT_public_key *pk);

/* Search for keys matching some criteria.  */
gpg_error_t getkey_bynames (getkey_ctx_t *retctx, PKT_public_key *pk,
                            strlist_t names, int want_secret,
                            kbnode_t *ret_keyblock);

/* Search for one key matching some criteria.  */
gpg_error_t getkey_byname (ctrl_t ctrl,
                           getkey_ctx_t *retctx, PKT_public_key *pk,
                           const char *name, int want_secret,
                           kbnode_t *ret_keyblock);

/* Return the next search result.  */
gpg_error_t getkey_next (getkey_ctx_t ctx, PKT_public_key *pk,
                         kbnode_t *ret_keyblock);

/* Release any resources used by a key listing context.  */
void getkey_end (getkey_ctx_t ctx);

/* Return the database handle used by this context.  The context still
   owns the handle.  */
KEYDB_HANDLE get_ctx_handle(GETKEY_CTX ctx);

/* Enumerate some secret keys.  */
gpg_error_t enum_secret_keys (ctrl_t ctrl, void **context, PKT_public_key *pk);

/* Set the mainkey_id fields for all keys in KEYBLOCK.  */
void setup_main_keyids (kbnode_t keyblock);

/* This function merges information from the self-signed data into the
   data structures.  */
void merge_keys_and_selfsig (kbnode_t keyblock);

char*get_user_id_string_native( u32 *keyid );
char*get_long_user_id_string( u32 *keyid );
char*get_user_id( u32 *keyid, size_t *rn );
char*get_user_id_native( u32 *keyid );
char *get_user_id_byfpr (const byte *fpr, size_t *rn);
char *get_user_id_byfpr_native (const byte *fpr);

void release_akl(void);
int parse_auto_key_locate(char *options);

/*-- keyid.c --*/
int pubkey_letter( int algo );
char *pubkey_string (PKT_public_key *pk, char *buffer, size_t bufsize);
#define PUBKEY_STRING_SIZE 32
u32 v3_keyid (gcry_mpi_t a, u32 *ki);
void hash_public_key( gcry_md_hd_t md, PKT_public_key *pk );
char *format_keyid (u32 *keyid, int format, char *buffer, int len);

/* Return PK's keyid.  The memory is owned by PK.  */
u32 *pk_keyid (PKT_public_key *pk);

/* Return the keyid of the primary key associated with PK.  The memory
   is owned by PK.  */
u32 *pk_main_keyid (PKT_public_key *pk);

/* Order A and B.  If A < B then return -1, if A == B then return 0,
   and if A > B then return 1.  */
static int GPGRT_ATTR_UNUSED
keyid_cmp (const u32 *a, const u32 *b)
{
  if (a[0] < b[0])
    return -1;
  if (a[0] > b[0])
    return 1;
  if (a[1] < b[1])
    return -1;
  if (a[1] > b[1])
    return 1;
  return 0;
}

/* Copy the keyid in SRC to DEST and return DEST.  */
u32 *keyid_copy (u32 *dest, const u32 *src);

size_t keystrlen(void);
const char *keystr(u32 *keyid);
const char *keystr_with_sub (u32 *main_kid, u32 *sub_kid);
const char *keystr_from_pk(PKT_public_key *pk);
const char *keystr_from_pk_with_sub (PKT_public_key *main_pk,
                                     PKT_public_key *sub_pk);

/* Return PK's key id as a string using the default format.  PK owns
   the storage.  */
const char *pk_keyid_str (PKT_public_key *pk);

const char *keystr_from_desc(KEYDB_SEARCH_DESC *desc);
u32 keyid_from_pk( PKT_public_key *pk, u32 *keyid );
u32 keyid_from_sig( PKT_signature *sig, u32 *keyid );
u32 keyid_from_fingerprint(const byte *fprint, size_t fprint_len, u32 *keyid);
byte *namehash_from_uid(PKT_user_id *uid);
unsigned nbits_from_pk( PKT_public_key *pk );
const char *datestr_from_pk( PKT_public_key *pk );
const char *datestr_from_sig( PKT_signature *sig );
const char *expirestr_from_pk( PKT_public_key *pk );
const char *expirestr_from_sig( PKT_signature *sig );
const char *revokestr_from_pk( PKT_public_key *pk );
const char *usagestr_from_pk (PKT_public_key *pk, int fill);
const char *colon_strtime (u32 t);
const char *colon_datestr_from_pk (PKT_public_key *pk);
const char *colon_datestr_from_sig (PKT_signature *sig);
const char *colon_expirestr_from_sig (PKT_signature *sig);
byte *fingerprint_from_pk( PKT_public_key *pk, byte *buf, size_t *ret_len );
char *hexfingerprint (PKT_public_key *pk, char *buffer, size_t buflen);
char *format_hexfingerprint (const char *fingerprint,
                             char *buffer, size_t buflen);
gpg_error_t keygrip_from_pk (PKT_public_key *pk, unsigned char *array);
gpg_error_t hexkeygrip_from_pk (PKT_public_key *pk, char **r_grip);


/*-- kbnode.c --*/
KBNODE new_kbnode( PACKET *pkt );
KBNODE clone_kbnode( KBNODE node );
void release_kbnode( KBNODE n );
void delete_kbnode( KBNODE node );
void add_kbnode( KBNODE root, KBNODE node );
void insert_kbnode( KBNODE root, KBNODE node, int pkttype );
void move_kbnode( KBNODE *root, KBNODE node, KBNODE where );
void remove_kbnode( KBNODE *root, KBNODE node );
KBNODE find_prev_kbnode( KBNODE root, KBNODE node, int pkttype );
KBNODE find_next_kbnode( KBNODE node, int pkttype );
KBNODE find_kbnode( KBNODE node, int pkttype );
KBNODE walk_kbnode( KBNODE root, KBNODE *context, int all );
void clear_kbnode_flags( KBNODE n );
int  commit_kbnode( KBNODE *root );
void dump_kbnode( KBNODE node );

#endif /*G10_KEYDB_H*/
