diff options
Diffstat (limited to 'agent/command.c')
| -rw-r--r-- | agent/command.c | 107 |
1 files changed, 79 insertions, 28 deletions
diff --git a/agent/command.c b/agent/command.c index f310a980c..ad86a3575 100644 --- a/agent/command.c +++ b/agent/command.c @@ -50,31 +50,57 @@ /* The size of the import/export KEK key (in bytes). */ #define KEYWRAP_KEYSIZE (128/8) +/* A shortcut to call assuan_set_error using an gpg_err_code_t and a + text string. */ #define set_error(e,t) assuan_set_error (ctx, gpg_error (e), (t)) - +/* Check that the maximum digest length we support has at least the + length of the keygrip. */ #if MAX_DIGEST_LEN < 20 #error MAX_DIGEST_LEN shorter than keygrip #endif -/* Data used to associate an Assuan context with local server data */ +/* Data used to associate an Assuan context with local server data. + This is this modules local part of the server_control_s struct. */ struct server_local_s { + /* Our Assuan context. */ assuan_context_t assuan_ctx; - int message_fd; + + /* If this flag is true, the passphrase cache is used for signing + operations. It defaults to true but may be set on a per + connection base. The global option opt.ignore_cache_for_signing + takes precedence over this flag. */ int use_cache_for_signing; - char *keydesc; /* Allocated description for the next key - operation. */ - int pause_io_logging; /* Used to suppress I/O logging during a command */ - int stopme; /* If set to true the agent will be terminated after - the end of this session. */ - int allow_pinentry_notify; /* Set if pinentry notifications should - be done. */ - void *import_key; /* Malloced KEK for the import_key command. */ - void *export_key; /* Malloced KEK for the export_key command. */ - int allow_fully_canceled; /* Client is aware of GPG_ERR_FULLY_CANCELED. */ - char *last_cache_nonce; /* Last CACHE_NOCNE sent as status (malloced). */ - char *last_passwd_nonce; /* Last PASSWD_NOCNE sent as status (malloced). */ + + /* An allocated description for the next key operation. This is + used if a pinnetry needs to be popped up. */ + char *keydesc; + + /* Flags to suppress I/O logging during a command. */ + int pause_io_logging; + + /* If this flags is set to true the agent will be terminated after + the end of the current session. */ + int stopme; + + /* Flag indicating whether pinentry notifications shall be done. */ + int allow_pinentry_notify; + + /* Malloced KEK (Key-Encryption-Key) for the import_key command. */ + void *import_key; + + /* Malloced KEK for the export_key command. */ + void *export_key; + + /* Client is aware of the error code GPG_ERR_FULLY_CANCELED. */ + int allow_fully_canceled; + + /* Last CACHE_NONCE sent as status (malloced). */ + char *last_cache_nonce; + + /* Last PASSWD_NONCE sent as status (malloced). */ + char *last_passwd_nonce; }; @@ -156,6 +182,8 @@ write_and_clear_outbuf (assuan_context_t ctx, membuf_t *mb) } +/* Clear the nonces used to enable the passphrase cache for certain + multi-command command sequences. */ static void clear_nonce_cache (ctrl_t ctrl) { @@ -176,6 +204,9 @@ clear_nonce_cache (ctrl_t ctrl) } +/* This function is called by Libassuan whenever thee client sends a + reset. It has been registered similar to the other Assuan + commands. */ static gpg_error_t reset_notify (assuan_context_t ctx, char *line) { @@ -196,8 +227,13 @@ reset_notify (assuan_context_t ctx, char *line) } -/* Skip over options. - Blanks after the options are also removed. */ +/* Skip over options in LINE. + + Blanks after the options are also removed. Options are indicated + by two leading dashes followed by a string consisting of non-space + characters. The special option "--" indicates an explicit end of + options; all what follows will not be considered an option. The + first no-option string also indicates the end of option parsing. */ static char * skip_options (const char *line) { @@ -213,7 +249,11 @@ skip_options (const char *line) return (char*)line; } -/* Check whether the option NAME appears in LINE */ + +/* Check whether the option NAME appears in LINE. An example for a + line with options is: + --algo=42 --data foo bar + This function would then only return true if NAME is "data". */ static int has_option (const char *line, const char *name) { @@ -226,6 +266,7 @@ has_option (const char *line, const char *name) return (s && (s == line || spacep (s-1)) && (!s[n] || spacep (s+n))); } + /* Same as has_option but does only test for the name of the option and ignores an argument, i.e. with NAME being "--hash" it would return true for "--hash" as well as for "--hash=foo". */ @@ -242,8 +283,9 @@ has_option_name (const char *line, const char *name) && (!s[n] || spacep (s+n) || s[n] == '=')); } + /* Return a pointer to the argument of the option with NAME. If such - an option is not given, it returns NULL. */ + an option is not given, NULL is retruned. */ static char * option_value (const char *line, const char *name) { @@ -265,7 +307,7 @@ option_value (const char *line, const char *name) } -/* Replace all '+' by a blank. */ +/* Replace all '+' by a blank in the string S. */ static void plus_to_blank (char *s) { @@ -296,8 +338,9 @@ parse_hexstring (assuan_context_t ctx, const char *string, size_t *len) return 0; } + /* Parse the keygrip in STRING into the provided buffer BUF. BUF must - provide space for 20 bytes. BUF is not changed if the function + provide space for 20 bytes. BUF is not changed if the function returns an error. */ static int parse_keygrip (assuan_context_t ctx, const char *string, unsigned char *buf) @@ -319,7 +362,11 @@ parse_keygrip (assuan_context_t ctx, const char *string, unsigned char *buf) } -/* Write an assuan status line. */ +/* Write an Assuan status line. KEYWORD is the first item on the + status line. The following arguments are all separated by a space + in the output. The last argument must be a NULL. Linefeeds and + carriage returns characters (which are not allowed in an Assuan + status line) are silently quoted in C-style. */ gpg_error_t agent_write_status (ctrl_t ctrl, const char *keyword, ...) { @@ -463,6 +510,7 @@ bump_key_eventcounter (void) eventcounter.any++; } + /* This function should be called for all card reader status changes. This function is assured not to do any context switches. */ @@ -1069,6 +1117,8 @@ do_one_keyinfo (ctrl_t ctrl, const unsigned char *grip, assuan_context_t ctx, } +/* Entry int for the command KEYINFO. This function handles the + command option processing. For details see hlp_keyinfo above. */ static gpg_error_t cmd_keyinfo (assuan_context_t ctx, char *line) { @@ -1140,6 +1190,7 @@ cmd_keyinfo (assuan_context_t ctx, char *line) +/* Helper for cmd_get_passphrase. */ static int send_back_passphrase (assuan_context_t ctx, int via_data, const char *pw) { @@ -2259,12 +2310,8 @@ cmd_killagent (assuan_context_t ctx, char *line) return set_error (GPG_ERR_NOT_SUPPORTED, "no --use-standard-socket"); ctrl->server_local->stopme = 1; -#ifdef ASSUAN_FORCE_CLOSE assuan_set_flag (ctx, ASSUAN_FORCE_CLOSE, 1); return 0; -#else - return gpg_error (GPG_ERR_EOF); -#endif } @@ -2415,6 +2462,8 @@ cmd_getinfo (assuan_context_t ctx, char *line) +/* This function is called by Libassuan to parse the OPTION command. + It has been registered similar to the other Assuan commands. */ static gpg_error_t option_handler (assuan_context_t ctx, const char *key, const char *value) { @@ -2574,7 +2623,8 @@ command_has_option (const char *cmd, const char *cmdopt) } -/* Tell the assuan library about our commands */ +/* Tell Libassuan about our commands. Also register the other Assuan + handlers. */ static int register_commands (assuan_context_t ctx) { @@ -2685,7 +2735,6 @@ start_command_handler (ctrl_t ctrl, gnupg_fd_t listen_fd, gnupg_fd_t fd) assuan_set_pointer (ctx, ctrl); ctrl->server_local = xcalloc (1, sizeof *ctrl->server_local); ctrl->server_local->assuan_ctx = ctx; - ctrl->server_local->message_fd = -1; ctrl->server_local->use_cache_for_signing = 1; ctrl->digest.raw_value = 0; @@ -2733,6 +2782,8 @@ start_command_handler (ctrl_t ctrl, gnupg_fd_t listen_fd, gnupg_fd_t fd) } +/* Helper for the pinentry loopback mode. It merely passes the + parameters on to the client. */ gpg_error_t pinentry_loopback(ctrl_t ctrl, const char *keyword, unsigned char **buffer, size_t *size, |