putty/pageant.h

/*
 * pageant.h: header for pageant.c.
 */

#include <stdarg.h>

/*
 * FIXME: it would be nice not to have this arbitrary limit. It's
 * currently needed because the Windows Pageant IPC system needs an
 * upper bound known to the client, but it's also reused as a basic
 * sanity check on incoming messages' length fields.
 */
#define AGENT_MAX_MSGLEN  8192

typedef void (*pageant_logfn_t)(void *logctx, const char *fmt, va_list ap);

/*
 * Initial setup.
 */
void pageant_init(void);

/*
 * The main agent function that answers messages.
 *
 * Expects a message/length pair as input, minus its initial length
 * field but still with its type code on the front.
 *
 * Returns a fully formatted message as output, *with* its initial
 * length field, and sets *outlen to the full size of that message.
 */
void *pageant_handle_msg(const void *msg, int msglen, int *outlen,
                         void *logctx, pageant_logfn_t logfn);

/*
 * Construct a failure response. Useful for agent front ends which
 * suffer a problem before they even get to pageant_handle_msg.
 */
void *pageant_failure_msg(int *outlen);

/*
 * Construct a list of public keys, just as the two LIST_IDENTITIES
 * requests would have returned them.
 */
void *pageant_make_keylist1(int *length);
void *pageant_make_keylist2(int *length);

/*
 * Accessor functions for Pageant's internal key lists. Fetch the nth
 * key; count the keys; attempt to add a key (returning true on
 * success, in which case the ownership of the key structure has been
 * taken over by pageant.c); attempt to delete a key (returning true
 * on success, in which case the ownership of the key structure is
 * passed back to the client).
 */
struct RSAKey *pageant_nth_ssh1_key(int i);
struct ssh2_userkey *pageant_nth_ssh2_key(int i);
int pageant_count_ssh1_keys(void);
int pageant_count_ssh2_keys(void);
int pageant_add_ssh1_key(struct RSAKey *rkey);
int pageant_add_ssh2_key(struct ssh2_userkey *skey);
int pageant_delete_ssh1_key(struct RSAKey *rkey);
int pageant_delete_ssh2_key(struct ssh2_userkey *skey);

/*
 * This callback must be provided by the Pageant front end code.
 * pageant_handle_msg calls it to indicate that the message it's just
 * handled has changed the list of keys held by the agent. Front ends
 * which expose that key list through dedicated UI may need to refresh
 * that UI's state in this function; other front ends can leave it
 * empty.
 */
void keylist_update(void);

/*
 * Functions to establish a listening socket speaking the SSH agent
 * protocol. Call pageant_listener_new() to set up a state; then
 * create a socket using the returned pointer as a Plug; then call
 * pageant_listener_got_socket() to give the listening state its own
 * socket pointer. Also, provide a logging function later if you want
 * to.
 */
struct pageant_listen_state;
struct pageant_listen_state *pageant_listener_new(void);
void pageant_listener_got_socket(struct pageant_listen_state *pl, Socket sock);
void pageant_listener_set_logfn(struct pageant_listen_state *pl,
                                void *logctx, pageant_logfn_t logfn);
void pageant_listener_free(struct pageant_listen_state *pl);