/* command.c - SCdaemon command handler * Copyright (C) 2001, 2002, 2003, 2004, 2005, * 2007 Free Software Foundation, Inc. * * 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 . */ #include #include #include #include #include #include #include #include #ifdef USE_GNU_PTH # include #endif #include #include "scdaemon.h" #include #include "app-common.h" #include "apdu.h" /* Required for apdu_*_reader (). */ #include "exechelp.h" #ifdef HAVE_LIBUSB #include "ccid-driver.h" #endif /* Maximum length allowed as a PIN; used for INQUIRE NEEDPIN */ #define MAXLEN_PIN 100 /* Maximum allowed size of key data as used in inquiries. */ #define MAXLEN_KEYDATA 4096 #define set_error(e,t) assuan_set_error (ctx, gpg_error (e), (t)) /* Macro to flag a removed card. */ #define TEST_CARD_REMOVAL(c,r) \ do { \ int _r = (r); \ if (gpg_err_code (_r) == GPG_ERR_CARD_NOT_PRESENT \ || gpg_err_code (_r) == GPG_ERR_CARD_REMOVED) \ update_card_removed ((c)->reader_slot, 1); \ } while (0) #define IS_LOCKED(c) \ (locked_session && locked_session != (c)->server_local \ && (c)->reader_slot != -1 && locked_session->ctrl_backlink \ && (c)->reader_slot == locked_session->ctrl_backlink->reader_slot) /* This structure is used to keep track of open readers (slots). */ struct slot_status_s { int valid; /* True if the other objects are valid. */ int slot; /* Slot number of the reader or -1 if not open. */ int reset_failed; /* A reset failed. */ int any; /* Flag indicating whether any status check has been done. This is set once to indicate that the status tracking for the slot has been initialized. */ unsigned int status; /* Last status of the slot. */ unsigned int changed; /* Last change counter of teh slot. */ }; /* Data used to associate an Assuan context with local server data. This object describes the local properties of one session. */ struct server_local_s { /* We keep a list of all active sessions with the anchor at SESSION_LIST (see below). This field is used for linking. */ struct server_local_s *next_session; /* This object is usually assigned to a CTRL object (which is globally visible). While enumerating all sessions we sometimes need to access data of the CTRL object; thus we keep a backpointer here. */ ctrl_t ctrl_backlink; /* The Assuan context used by this session/server. */ assuan_context_t assuan_ctx; int event_signal; /* Or 0 if not used. */ /* True if the card has been removed and a reset is required to continue operation. */ int card_removed; }; /* The table with information on all used slots. FIXME: This is a different slot number than the one used by the APDU layer, and should be renamed. */ static struct slot_status_s slot_table[10]; /* To keep track of all running sessions, we link all active server contexts and the anchor in this variable. */ static struct server_local_s *session_list; /* If a session has been locked we store a link to its server object in this variable. */ static struct server_local_s *locked_session; /* While doing a reset we need to make sure that the ticker does not call scd_update_reader_status_file while we are using it. */ static pth_mutex_t status_file_update_lock; /*-- Local prototypes --*/ static void update_reader_status_file (void); /* This function must be called once to initialize this module. This has to be done before a second thread is spawned. We can't do the static initialization because Pth emulation code might not be able to do a static init; in particular, it is not possible for W32. */ void initialize_module_command (void) { static int initialized; if (!initialized) { if (pth_mutex_init (&status_file_update_lock)) initialized = 1; } } /* Update the CARD_REMOVED element of all sessions using the reader given by SLOT to VALUE */ static void update_card_removed (int slot, int value) { struct server_local_s *sl; for (sl=session_list; sl; sl = sl->next_session) if (sl->ctrl_backlink && sl->ctrl_backlink->reader_slot == slot) { sl->card_removed = value; } if (value) application_notify_card_removed (slot); } /* Check whether the option NAME appears in LINE */ static int has_option (const char *line, const char *name) { const char *s; int n = strlen (name); s = strstr (line, 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 a pointer for "--hash" as well as for "--hash=foo". If thhere is no such option NULL is returned. The pointer returned points right behind the option name, this may be an equal sign, Nul or a space. */ static const char * has_option_name (const char *line, const char *name) { const char *s; int n = strlen (name); s = strstr (line, name); return (s && (s == line || spacep (s-1)) && (!s[n] || spacep (s+n) || s[n] == '=')) ? (s+n) : NULL; } /* Skip over options. It is assumed that leading spaces have been removed (this is the case for lines passed to a handler from assuan). Blanks after the options are also removed. */ static char * skip_options (char *line) { while ( *line == '-' && line[1] == '-' ) { while (*line && !spacep (line)) line++; while (spacep (line)) line++; } return line; } /* Convert the STRING into a newly allocated buffer while translating the hex numbers. Stops at the first invalid character. Blanks and colons are allowed to separate the hex digits. Returns NULL on error or a newly malloced buffer and its length in LENGTH. */ static unsigned char * hex_to_buffer (const char *string, size_t *r_length) { unsigned char *buffer; const char *s; size_t n; buffer = xtrymalloc (strlen (string)+1); if (!buffer) return NULL; for (s=string, n=0; *s; s++) { if (spacep (s) || *s == ':') continue; if (hexdigitp (s) && hexdigitp (s+1)) { buffer[n++] = xtoi_2 (s); s++; } else break; } *r_length = n; return buffer; } /* Reset the card and free the application context. With SEND_RESET set to true actually send a RESET to the reader. */ static void do_reset (ctrl_t ctrl, int send_reset) { int slot = ctrl->reader_slot; if (!(slot == -1 || (slot >= 0 && slot < DIM(slot_table)))) BUG (); if (ctrl->app_ctx) { release_application (ctrl->app_ctx); ctrl->app_ctx = NULL; } if (slot != -1 && send_reset && !IS_LOCKED (ctrl) ) { if (apdu_reset (slot)) { slot_table[slot].reset_failed = 1; } } /* If we hold a lock, unlock now. */ if (locked_session && ctrl->server_local == locked_session) { locked_session = NULL; log_info ("implicitly unlocking due to RESET\n"); } /* Reset card removed flag for the current reader. We need to take the lock here so that the ticker thread won't concurrently try to update the file. Note that the update function will set the card removed flag and we will later reset it - not a particualar nice way of implementing it but it works. */ if (!pth_mutex_acquire (&status_file_update_lock, 0, NULL)) { log_error ("failed to acquire status_fle_update lock\n"); ctrl->reader_slot = -1; return; } update_reader_status_file (); update_card_removed (slot, 0); if (!pth_mutex_release (&status_file_update_lock)) log_error ("failed to release status_file_update lock\n"); /* Do this last, so that update_card_removed does its job. */ ctrl->reader_slot = -1; } static void reset_notify (assuan_context_t ctx) { ctrl_t ctrl = assuan_get_pointer (ctx); do_reset (ctrl, 1); } static int option_handler (assuan_context_t ctx, const char *key, const char *value) { ctrl_t ctrl = assuan_get_pointer (ctx); if (!strcmp (key, "event-signal")) { /* A value of 0 is allowed to reset the event signal. */ int i = *value? atoi (value) : -1; if (i < 0) return gpg_error (GPG_ERR_ASS_PARAMETER); ctrl->server_local->event_signal = i; } return 0; } /* Return the slot of the current reader or open the reader if no other sessions are using a reader. Note, that we currently support only one reader but most of the code (except for this function) should be able to cope with several readers. */ static int get_reader_slot (void) { struct slot_status_s *ss; ss = &slot_table[0]; /* One reader for now. */ /* Initialize the item if needed. */ if (!ss->valid) { ss->slot = -1; ss->valid = 1; } /* Try to open the reader. */ if (ss->slot == -1) ss->slot = apdu_open_reader (opt.reader_port); /* Return the slot_table index. */ return 0; } /* If the card has not yet been opened, do it. Note that this function returns an Assuan error, so don't map the error a second time. */ static assuan_error_t open_card (ctrl_t ctrl, const char *apptype) { gpg_error_t err; int slot; /* If we ever got a card not present error code, return that. Only the SERIALNO command and a reset are able to clear from that state. */ if (ctrl->server_local->card_removed) return gpg_error (GPG_ERR_CARD_REMOVED); if ( IS_LOCKED (ctrl) ) return gpg_error (GPG_ERR_LOCKED); if (ctrl->app_ctx) { /* Already initialized for one specific application. Need to check that the client didn't requested a specific application different from the one in use. */ return check_application_conflict (ctrl, apptype); } if (ctrl->reader_slot != -1) slot = ctrl->reader_slot; else slot = get_reader_slot (); ctrl->reader_slot = slot; if (slot == -1) err = gpg_error (GPG_ERR_CARD); else err = select_application (ctrl, slot, apptype, &ctrl->app_ctx); TEST_CARD_REMOVAL (ctrl, err); return err; } /* Do the percent and plus/space unescaping in place and return the length of the valid buffer. */ static size_t percent_plus_unescape (unsigned char *string) { unsigned char *p = string; size_t n = 0; while (*string) { if (*string == '%' && string[1] && string[2]) { string++; *p++ = xtoi_2 (string); n++; string+= 2; } else if (*string == '+') { *p++ = ' '; n++; string++; } else { *p++ = *string++; n++; } } return n; } /* SERIALNO [APPTYPE] Return the serial number of the card using a status reponse. This functon should be used to check for the presence of a card. If APPTYPE is given, an application of that type is selected and an error is returned if the application is not supported or available. The default is to auto-select the application using a hardwired preference system. Note, that a future extension to this function may allow to specify a list and order of applications to try. This function is special in that it can be used to reset the card. Most other functions will return an error when a card change has been detected and the use of this function is therefore required. Background: We want to keep the client clear of handling card changes between operations; i.e. the client can assume that all operations are done on the same card unless he calls this function. */ static int cmd_serialno (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc = 0; char *serial_and_stamp; char *serial; time_t stamp; /* Clear the remove flag so that the open_card is able to reread it. */ if (ctrl->server_local->card_removed) { if ( IS_LOCKED (ctrl) ) return gpg_error (GPG_ERR_LOCKED); do_reset (ctrl, 1); } if ((rc = open_card (ctrl, *line? line:NULL))) return rc; rc = app_get_serial_and_stamp (ctrl->app_ctx, &serial, &stamp); if (rc) return rc; rc = asprintf (&serial_and_stamp, "%s %lu", serial, (unsigned long)stamp); xfree (serial); if (rc < 0) return out_of_core (); rc = 0; assuan_write_status (ctx, "SERIALNO", serial_and_stamp); free (serial_and_stamp); return 0; } /* LEARN [--force] Learn all useful information of the currently inserted card. When used without the force options, the command might do an INQUIRE like this: INQUIRE KNOWNCARDP The client should just send an "END" if the processing should go on or a "CANCEL" to force the function to terminate with a Cancel error message. The response of this command is a list of status lines formatted as this: S APPTYPE This returns the type of the application, currently the strings: P15 = PKCS-15 structure used DINSIG = DIN SIG OPENPGP = OpenPGP card are implemented. These strings are aliases for the AID S KEYPAIRINFO If there is no certificate yet stored on the card a single "X" is returned as the keygrip. In addition to the keypair info, information about all certificates stored on the card is also returned: S CERTINFO Where CERTTYPE is a number indicating the type of certificate: 0 := Unknown 100 := Regular X.509 cert 101 := Trusted X.509 cert 102 := Useful X.509 cert 110 := Root CA cert (DINSIG) For certain cards, more information will be returned: S KEY-FPR For OpenPGP cards this returns the stored fingerprints of the keys. This can be used check whether a key is available on the card. NO may be 1, 2 or 3. S CA-FPR Similar to above, these are the fingerprints of keys assumed to be ultimately trusted. S DISP-NAME The name of the card holder as stored on the card; percent escaping takes place, spaces are encoded as '+' S PUBKEY-URL The URL to be used for locating the entire public key. Note, that this function may be even be used on a locked card. */ static int cmd_learn (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc = 0; if ((rc = open_card (ctrl, NULL))) return rc; /* Unless the force option is used we try a shortcut by identifying the card using a serial number and inquiring the client with that. The client may choose to cancel the operation if he already knows about this card */ { char *serial_and_stamp; char *serial; time_t stamp; rc = app_get_serial_and_stamp (ctrl->app_ctx, &serial, &stamp); if (rc) return rc; rc = asprintf (&serial_and_stamp, "%s %lu", serial, (unsigned long)stamp); xfree (serial); if (rc < 0) return out_of_core (); rc = 0; assuan_write_status (ctx, "SERIALNO", serial_and_stamp); if (!has_option (line, "--force")) { char *command; rc = asprintf (&command, "KNOWNCARDP %s", serial_and_stamp); if (rc < 0) { free (serial_and_stamp); return out_of_core (); } rc = 0; rc = assuan_inquire (ctx, command, NULL, NULL, 0); free (command); /* (must use standard free here) */ if (rc) { if (gpg_err_code (rc) != GPG_ERR_ASS_CANCELED) log_error ("inquire KNOWNCARDP failed: %s\n", gpg_strerror (rc)); free (serial_and_stamp); return rc; } /* not canceled, so we have to proceeed */ } free (serial_and_stamp); } /* Let the application print out its collection of useful status information. */ if (!rc) rc = app_write_learn_status (ctrl->app_ctx, ctrl); TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* READCERT Note, that this function may even be used on a locked card. */ static int cmd_readcert (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; unsigned char *cert; size_t ncert; if ((rc = open_card (ctrl, NULL))) return rc; line = xstrdup (line); /* Need a copy of the line. */ rc = app_readcert (ctrl->app_ctx, line, &cert, &ncert); if (rc) log_error ("app_readcert failed: %s\n", gpg_strerror (rc)); xfree (line); line = NULL; if (!rc) { rc = assuan_send_data (ctx, cert, ncert); xfree (cert); if (rc) return rc; } TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* READKEY Return the public key for the given cert or key ID as an standard S-Expression. Note, that this function may even be used on a locked card. */ static int cmd_readkey (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; unsigned char *cert = NULL; size_t ncert, n; ksba_cert_t kc = NULL; ksba_sexp_t p; unsigned char *pk; size_t pklen; if ((rc = open_card (ctrl, NULL))) return rc; line = xstrdup (line); /* Need a copy of the line. */ /* If the application supports the READKEY function we use that. Otherwise we use the old way by extracting it from the certificate. */ rc = app_readkey (ctrl->app_ctx, line, &pk, &pklen); if (!rc) { /* Yeah, got that key - send it back. */ rc = assuan_send_data (ctx, pk, pklen); xfree (pk); xfree (line); line = NULL; goto leave; } if (gpg_err_code (rc) != GPG_ERR_UNSUPPORTED_OPERATION) log_error ("app_readkey failed: %s\n", gpg_strerror (rc)); else { rc = app_readcert (ctrl->app_ctx, line, &cert, &ncert); if (rc) log_error ("app_readcert failed: %s\n", gpg_strerror (rc)); } xfree (line); line = NULL; if (rc) goto leave; rc = ksba_cert_new (&kc); if (rc) { xfree (cert); goto leave; } rc = ksba_cert_init_from_mem (kc, cert, ncert); if (rc) { log_error ("failed to parse the certificate: %s\n", gpg_strerror (rc)); goto leave; } p = ksba_cert_get_public_key (kc); if (!p) { rc = gpg_error (GPG_ERR_NO_PUBKEY); goto leave; } n = gcry_sexp_canon_len (p, 0, NULL, NULL); rc = assuan_send_data (ctx, p, n); xfree (p); leave: ksba_cert_release (kc); xfree (cert); TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* SETDATA The client should use this command to tell us the data he want to sign. */ static int cmd_setdata (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int n; char *p; unsigned char *buf; if (locked_session && locked_session != ctrl->server_local) return gpg_error (GPG_ERR_LOCKED); /* Parse the hexstring. */ for (p=line,n=0; hexdigitp (p); p++, n++) ; if (*p) return set_error (GPG_ERR_ASS_PARAMETER, "invalid hexstring"); if (!n) return set_error (GPG_ERR_ASS_PARAMETER, "no data given"); if ((n&1)) return set_error (GPG_ERR_ASS_PARAMETER, "odd number of digits"); n /= 2; buf = xtrymalloc (n); if (!buf) return out_of_core (); ctrl->in_data.value = buf; ctrl->in_data.valuelen = n; for (p=line, n=0; n < ctrl->in_data.valuelen; p += 2, n++) buf[n] = xtoi_2 (p); return 0; } static gpg_error_t pin_cb (void *opaque, const char *info, char **retstr) { assuan_context_t ctx = opaque; char *command; int rc; unsigned char *value; size_t valuelen; if (!retstr) { /* We prompt for keypad entry. To make sure that the popup has been show we use an inquire and not just a status message. We ignore any value returned. */ if (info) { log_debug ("prompting for keypad entry '%s'\n", info); rc = asprintf (&command, "POPUPKEYPADPROMPT %s", info); if (rc < 0) return gpg_error (gpg_err_code_from_errno (errno)); rc = assuan_inquire (ctx, command, &value, &valuelen, MAXLEN_PIN); free (command); } else { log_debug ("dismiss keypad entry prompt\n"); rc = assuan_inquire (ctx, "DISMISSKEYPADPROMPT", &value, &valuelen, MAXLEN_PIN); } if (!rc) xfree (value); return rc; } *retstr = NULL; log_debug ("asking for PIN '%s'\n", info); rc = asprintf (&command, "NEEDPIN %s", info); if (rc < 0) return gpg_error (gpg_err_code_from_errno (errno)); /* Fixme: Write an inquire function which returns the result in secure memory and check all further handling of the PIN. */ rc = assuan_inquire (ctx, command, &value, &valuelen, MAXLEN_PIN); free (command); if (rc) return rc; if (!valuelen || value[valuelen-1]) { /* We require that the returned value is an UTF-8 string */ xfree (value); return gpg_error (GPG_ERR_INV_RESPONSE); } *retstr = (char*)value; return 0; } /* PKSIGN [--hash=[rmd160|sha1|md5]] The --hash option is optional; the default is SHA1. */ static int cmd_pksign (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; unsigned char *outdata; size_t outdatalen; char *keyidstr; int hash_algo; if (has_option (line, "--hash=rmd160")) hash_algo = GCRY_MD_RMD160; else if (has_option (line, "--hash=sha1")) hash_algo = GCRY_MD_SHA1; else if (has_option (line, "--hash=md5")) hash_algo = GCRY_MD_MD5; else if (!strstr (line, "--")) hash_algo = GCRY_MD_SHA1; else return set_error (GPG_ERR_ASS_PARAMETER, "invalid hash algorithm"); /* Skip over options. */ while ( *line == '-' && line[1] == '-' ) { while (*line && !spacep (line)) line++; while (spacep (line)) line++; } if ( IS_LOCKED (ctrl) ) return gpg_error (GPG_ERR_LOCKED); if ((rc = open_card (ctrl, NULL))) return rc; /* We have to use a copy of the key ID because the function may use the pin_cb which in turn uses the assuan line buffer and thus overwriting the original line with the keyid */ keyidstr = xtrystrdup (line); if (!keyidstr) return out_of_core (); rc = app_sign (ctrl->app_ctx, keyidstr, hash_algo, pin_cb, ctx, ctrl->in_data.value, ctrl->in_data.valuelen, &outdata, &outdatalen); xfree (keyidstr); if (rc) { log_error ("card_sign failed: %s\n", gpg_strerror (rc)); } else { rc = assuan_send_data (ctx, outdata, outdatalen); xfree (outdata); if (rc) return rc; /* that is already an assuan error code */ } TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* PKAUTH */ static int cmd_pkauth (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; unsigned char *outdata; size_t outdatalen; char *keyidstr; if ( IS_LOCKED (ctrl) ) return gpg_error (GPG_ERR_LOCKED); if ((rc = open_card (ctrl, NULL))) return rc; if (!ctrl->app_ctx) return gpg_error (GPG_ERR_UNSUPPORTED_OPERATION); /* We have to use a copy of the key ID because the function may use the pin_cb which in turn uses the assuan line buffer and thus overwriting the original line with the keyid */ keyidstr = xtrystrdup (line); if (!keyidstr) return out_of_core (); rc = app_auth (ctrl->app_ctx, keyidstr, pin_cb, ctx, ctrl->in_data.value, ctrl->in_data.valuelen, &outdata, &outdatalen); xfree (keyidstr); if (rc) { log_error ("app_auth_sign failed: %s\n", gpg_strerror (rc)); } else { rc = assuan_send_data (ctx, outdata, outdatalen); xfree (outdata); if (rc) return rc; /* that is already an assuan error code */ } TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* PKDECRYPT */ static int cmd_pkdecrypt (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; unsigned char *outdata; size_t outdatalen; char *keyidstr; if ( IS_LOCKED (ctrl) ) return gpg_error (GPG_ERR_LOCKED); if ((rc = open_card (ctrl, NULL))) return rc; keyidstr = xtrystrdup (line); if (!keyidstr) return out_of_core (); rc = app_decipher (ctrl->app_ctx, keyidstr, pin_cb, ctx, ctrl->in_data.value, ctrl->in_data.valuelen, &outdata, &outdatalen); xfree (keyidstr); if (rc) { log_error ("card_create_signature failed: %s\n", gpg_strerror (rc)); } else { rc = assuan_send_data (ctx, outdata, outdatalen); xfree (outdata); if (rc) return rc; /* that is already an assuan error code */ } TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* GETATTR This command is used to retrieve data from a smartcard. The allowed names depend on the currently selected smartcard application. NAME must be percent and '+' escaped. The value is returned through status message, see the LEARN command for details. However, the current implementation assumes that Name is not escaped; this works as long as noone uses arbitrary escaping. Note, that this function may even be used on a locked card. */ static int cmd_getattr (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; const char *keyword; if ((rc = open_card (ctrl, NULL))) return rc; keyword = line; for (; *line && !spacep (line); line++) ; if (*line) *line++ = 0; /* (We ignore any garbage for now.) */ /* FIXME: Applications should not return sensitive data if the card is locked. */ rc = app_getattr (ctrl->app_ctx, ctrl, keyword); TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* SETATTR This command is used to store data on a a smartcard. The allowed names and values are depend on the currently selected smartcard application. NAME and VALUE must be percent and '+' escaped. However, the curent implementation assumes that Name is not escaped; this works as long as noone uses arbitrary escaping. A PIN will be requested for most NAMEs. See the corresponding setattr function of the actually used application (app-*.c) for details. */ static int cmd_setattr (assuan_context_t ctx, char *orig_line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *keyword; int keywordlen; size_t nbytes; char *line, *linebuf; if ( IS_LOCKED (ctrl) ) return gpg_error (GPG_ERR_LOCKED); if ((rc = open_card (ctrl, NULL))) return rc; /* We need to use a copy of LINE, because PIN_CB uses the same context and thus reuses the Assuan provided LINE. */ line = linebuf = xtrystrdup (orig_line); if (!line) return out_of_core (); keyword = line; for (keywordlen=0; *line && !spacep (line); line++, keywordlen++) ; if (*line) *line++ = 0; while (spacep (line)) line++; nbytes = percent_plus_unescape ((unsigned char*)line); rc = app_setattr (ctrl->app_ctx, keyword, pin_cb, ctx, (const unsigned char*)line, nbytes); xfree (linebuf); TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* WRITEKEY [--force] This command is used to store a secret key on a a smartcard. The allowed keyids depend on the currently selected smartcard application. The actual keydata is requested using the inquiry "KETDATA" and need to be provided without any protection. With --force set an existing key under this KEYID will get overwritten. The keydata is expected to be the usual canonical encoded S-expression. A PIN will be requested for most NAMEs. See the corresponding writekey function of the actually used application (app-*.c) for details. */ static int cmd_writekey (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *keyid; int force = has_option (line, "--force"); unsigned char *keydata; size_t keydatalen; if ( IS_LOCKED (ctrl) ) return gpg_error (GPG_ERR_LOCKED); /* Skip over options. */ while ( *line == '-' && line[1] == '-' ) { while (*line && !spacep (line)) line++; while (spacep (line)) line++; } if (!*line) return set_error (GPG_ERR_ASS_PARAMETER, "no keyid given"); keyid = line; while (*line && !spacep (line)) line++; *line = 0; if ((rc = open_card (ctrl, NULL))) return rc; if (!ctrl->app_ctx) return gpg_error (GPG_ERR_UNSUPPORTED_OPERATION); keyid = xtrystrdup (keyid); if (!keyid) return out_of_core (); /* Now get the actual keydata. */ assuan_begin_confidential (ctx); rc = assuan_inquire (ctx, "KEYDATA", &keydata, &keydatalen, MAXLEN_KEYDATA); assuan_end_confidential (ctx); if (rc) { xfree (keyid); return rc; } /* Write the key to the card. */ rc = app_writekey (ctrl->app_ctx, ctrl, keyid, force? 1:0, pin_cb, ctx, keydata, keydatalen); xfree (keyid); xfree (keydata); TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* GENKEY [--force] [--timestamp=] Generate a key on-card identified by NO, which is application specific. Return values are application specific. For OpenPGP cards 2 status lines are returned: S KEY-FPR S KEY-CREATED-AT S KEY-DATA [p|n] --force is required to overwrite an already existing key. The KEY-CREATED-AT is required for further processing because it is part of the hashed key material for the fingerprint. If --timestamp is given an OpenPGP key will be created using this value. The value needs to be in ISO Format; e.g. "--timestamp=20030316T120000" and after 1970-01-01 00:00:00. The public part of the key can also later be retrieved using the READKEY command. */ static int cmd_genkey (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *keyno; int force; const char *s; time_t timestamp; if ( IS_LOCKED (ctrl) ) return gpg_error (GPG_ERR_LOCKED); force = has_option (line, "--force"); if ((s=has_option_name (line, "--timestamp"))) { if (*s != '=') return set_error (GPG_ERR_ASS_PARAMETER, "missing value for option"); timestamp = isotime2epoch (s+1); if (timestamp < 1) return set_error (GPG_ERR_ASS_PARAMETER, "invalid time value"); } else timestamp = 0; line = skip_options (line); if (!*line) return set_error (GPG_ERR_ASS_PARAMETER, "no key number given"); keyno = line; while (*line && !spacep (line)) line++; *line = 0; if ((rc = open_card (ctrl, NULL))) return rc; if (!ctrl->app_ctx) return gpg_error (GPG_ERR_UNSUPPORTED_OPERATION); keyno = xtrystrdup (keyno); if (!keyno) return out_of_core (); rc = app_genkey (ctrl->app_ctx, ctrl, keyno, force? 1:0, timestamp, pin_cb, ctx); xfree (keyno); TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* RANDOM Get NBYTES of random from the card and send them back as data. Note, that this function may be even be used on a locked card. */ static int cmd_random (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; size_t nbytes; unsigned char *buffer; if (!*line) return set_error (GPG_ERR_ASS_PARAMETER, "number of requested bytes missing"); nbytes = strtoul (line, NULL, 0); if ((rc = open_card (ctrl, NULL))) return rc; if (!ctrl->app_ctx) return gpg_error (GPG_ERR_UNSUPPORTED_OPERATION); buffer = xtrymalloc (nbytes); if (!buffer) return out_of_core (); rc = app_get_challenge (ctrl->app_ctx, nbytes, buffer); if (!rc) { rc = assuan_send_data (ctx, buffer, nbytes); xfree (buffer); return rc; /* that is already an assuan error code */ } xfree (buffer); TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* PASSWD [--reset] Change the PIN or reset the retry counter of the card holder verfication vector CHVNO. */ static int cmd_passwd (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *chvnostr; int reset_mode = has_option (line, "--reset"); if ( IS_LOCKED (ctrl) ) return gpg_error (GPG_ERR_LOCKED); /* Skip over options. */ while (*line == '-' && line[1] == '-') { while (*line && !spacep (line)) line++; while (spacep (line)) line++; } if (!*line) return set_error (GPG_ERR_ASS_PARAMETER, "no CHV number given"); chvnostr = line; while (*line && !spacep (line)) line++; *line = 0; if ((rc = open_card (ctrl, NULL))) return rc; if (!ctrl->app_ctx) return gpg_error (GPG_ERR_UNSUPPORTED_OPERATION); chvnostr = xtrystrdup (chvnostr); if (!chvnostr) return out_of_core (); rc = app_change_pin (ctrl->app_ctx, ctrl, chvnostr, reset_mode, pin_cb, ctx); if (rc) log_error ("command passwd failed: %s\n", gpg_strerror (rc)); xfree (chvnostr); TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* CHECKPIN Perform a VERIFY operation without doing anything else. This may be used to initialize a the PIN cache earlier to long lasting operations. Its use is highly application dependent. For OpenPGP: Perform a simple verify operation for CHV1 and CHV2, so that further operations won't ask for CHV2 and it is possible to do a cheap check on the PIN: If there is something wrong with the PIN entry system, only the regular CHV will get blocked and not the dangerous CHV3. IDSTR is the usual card's serial number in hex notation; an optional fingerprint part will get ignored. There is however a special mode if the IDSTR is sffixed with the literal string "[CHV3]": In this case the Admin PIN is checked if and only if the retry counter is still at 3. */ static int cmd_checkpin (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; char *keyidstr; if ( IS_LOCKED (ctrl) ) return gpg_error (GPG_ERR_LOCKED); if ((rc = open_card (ctrl, NULL))) return rc; if (!ctrl->app_ctx) return gpg_error (GPG_ERR_UNSUPPORTED_OPERATION); /* We have to use a copy of the key ID because the function may use the pin_cb which in turn uses the assuan line buffer and thus overwriting the original line with the keyid. */ keyidstr = xtrystrdup (line); if (!keyidstr) return out_of_core (); rc = app_check_pin (ctrl->app_ctx, keyidstr, pin_cb, ctx); xfree (keyidstr); if (rc) log_error ("app_check_pin failed: %s\n", gpg_strerror (rc)); TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* LOCK [--wait] Grant exclusive card access to this session. Note that there is no lock counter used and a second lock from the same session will be ignored. A single unlock (or RESET) unlocks the session. Return GPG_ERR_LOCKED if another session has locked the reader. If the option --wait is given the command will wait until a lock has been released. */ static int cmd_lock (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc = 0; retry: if (locked_session) { if (locked_session != ctrl->server_local) rc = gpg_error (GPG_ERR_LOCKED); } else locked_session = ctrl->server_local; #ifdef USE_GNU_PTH if (rc && has_option (line, "--wait")) { rc = 0; pth_sleep (1); /* Better implement an event mechanism. However, for card operations this should be sufficient. */ /* FIXME: Need to check that the connection is still alive. This can be done by issuing status messages. */ goto retry; } #endif /*USE_GNU_PTH*/ if (rc) log_error ("cmd_lock failed: %s\n", gpg_strerror (rc)); return rc; } /* UNLOCK Release exclusive card access. */ static int cmd_unlock (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc = 0; if (locked_session) { if (locked_session != ctrl->server_local) rc = gpg_error (GPG_ERR_LOCKED); else locked_session = NULL; } else rc = gpg_error (GPG_ERR_NOT_LOCKED); if (rc) log_error ("cmd_unlock failed: %s\n", gpg_strerror (rc)); return rc; } /* GETINFO Multi purpose command to return certain information. Supported values of WHAT are: version - Return the version of the program. pid - Return the process id of the server. socket_name - Return the name of the socket. status - Return the status of the current slot (in the future, may also return the status of all slots). The status is a list of one-character flags. The following flags are currently defined: 'u' Usable card present. This is the normal state during operation. 'r' Card removed. A reset is necessary. These flags are exclusive. reader_list - Return a list of detected card readers. Does currently only work with the internal CCID driver. */ static int cmd_getinfo (assuan_context_t ctx, char *line) { int rc = 0; if (!strcmp (line, "version")) { const char *s = VERSION; rc = assuan_send_data (ctx, s, strlen (s)); } else if (!strcmp (line, "pid")) { char numbuf[50]; snprintf (numbuf, sizeof numbuf, "%lu", (unsigned long)getpid ()); rc = assuan_send_data (ctx, numbuf, strlen (numbuf)); } else if (!strcmp (line, "socket_name")) { const char *s = scd_get_socket_name (); if (s) rc = assuan_send_data (ctx, s, strlen (s)); else rc = gpg_error (GPG_ERR_NO_DATA); } else if (!strcmp (line, "status")) { ctrl_t ctrl = assuan_get_pointer (ctx); int slot = ctrl->reader_slot; char flag = 'r'; if (!ctrl->server_local->card_removed && slot != -1) { struct slot_status_s *ss; if (!(slot >= 0 && slot < DIM(slot_table))) BUG (); ss = &slot_table[slot]; if (!ss->valid) BUG (); if (ss->any && (ss->status & 1)) flag = 'u'; } rc = assuan_send_data (ctx, &flag, 1); } else if (!strcmp (line, "reader_list")) { #ifdef HAVE_LIBUSB char *s = ccid_get_reader_list (); #else char *s = NULL; #endif if (s) rc = assuan_send_data (ctx, s, strlen (s)); else rc = gpg_error (GPG_ERR_NO_DATA); xfree (s); } else rc = set_error (GPG_ERR_ASS_PARAMETER, "unknown value for WHAT"); return rc; } /* RESTART Restart the current connection; this is a kind of warm reset. It deletes the context used by this connection but does not send a RESET to the card. Thus the card itself won't get reset. This is used by gpg-agent to reuse a primary pipe connection and may be used by clients to backup from a conflict in the serial command; i.e. to select another application. */ static int cmd_restart (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); if (ctrl->app_ctx) { release_application (ctrl->app_ctx); ctrl->app_ctx = NULL; } if (locked_session && ctrl->server_local == locked_session) { locked_session = NULL; log_info ("implicitly unlocking due to RESTART\n"); } return 0; } /* APDU [--atr] [--more] [hexstring] Send an APDU to the current reader. This command bypasses the high level functions and sends the data directly to the card. HEXSTRING is expected to be a proper APDU. If HEXSTRING is not given no commands are set to the card but the command will implictly check whether the card is ready for use. Using the option "--atr" returns the ATR of the card as a status message before any data like this: S CARD-ATR 3BFA1300FF813180450031C173C00100009000B1 Using the option --more handles the card status word MORE_DATA (61xx) and concatenate all reponses to one block. */ static int cmd_apdu (assuan_context_t ctx, char *line) { ctrl_t ctrl = assuan_get_pointer (ctx); int rc; unsigned char *apdu; size_t apdulen; int with_atr; int handle_more; with_atr = has_option (line, "--atr"); handle_more = has_option (line, "--more"); /* Skip over options. */ while ( *line == '-' && line[1] == '-' ) { while (*line && !spacep (line)) line++; while (spacep (line)) line++; } if ( IS_LOCKED (ctrl) ) return gpg_error (GPG_ERR_LOCKED); if ((rc = open_card (ctrl, NULL))) return rc; if (with_atr) { unsigned char *atr; size_t atrlen; int i; char hexbuf[400]; atr = apdu_get_atr (ctrl->reader_slot, &atrlen); if (!atr || atrlen > sizeof hexbuf - 2 ) { rc = gpg_error (GPG_ERR_INV_CARD); goto leave; } for (i=0; i < atrlen; i++) sprintf (hexbuf+2*i, "%02X", atr[i]); xfree (atr); send_status_info (ctrl, "CARD-ATR", hexbuf, strlen (hexbuf), NULL, 0); } apdu = hex_to_buffer (line, &apdulen); if (!apdu) { rc = gpg_error_from_syserror (); goto leave; } if (apdulen) { unsigned char *result = NULL; size_t resultlen; rc = apdu_send_direct (ctrl->reader_slot, apdu, apdulen, handle_more, &result, &resultlen); if (rc) log_error ("apdu_send_direct failed: %s\n", gpg_strerror (rc)); else { rc = assuan_send_data (ctx, result, resultlen); xfree (result); } } xfree (apdu); leave: TEST_CARD_REMOVAL (ctrl, rc); return rc; } /* Tell the assuan library about our commands */ static int register_commands (assuan_context_t ctx) { static struct { const char *name; int (*handler)(assuan_context_t, char *line); } table[] = { { "SERIALNO", cmd_serialno }, { "LEARN", cmd_learn }, { "READCERT", cmd_readcert }, { "READKEY", cmd_readkey }, { "SETDATA", cmd_setdata }, { "PKSIGN", cmd_pksign }, { "PKAUTH", cmd_pkauth }, { "PKDECRYPT", cmd_pkdecrypt }, { "INPUT", NULL }, { "OUTPUT", NULL }, { "GETATTR", cmd_getattr }, { "SETATTR", cmd_setattr }, { "WRITEKEY", cmd_writekey }, { "GENKEY", cmd_genkey }, { "RANDOM", cmd_random }, { "PASSWD", cmd_passwd }, { "CHECKPIN", cmd_checkpin }, { "LOCK", cmd_lock }, { "UNLOCK", cmd_unlock }, { "GETINFO", cmd_getinfo }, { "RESTART", cmd_restart }, { "APDU", cmd_apdu }, { NULL } }; int i, rc; for (i=0; table[i].name; i++) { rc = assuan_register_command (ctx, table[i].name, table[i].handler); if (rc) return rc; } assuan_set_hello_line (ctx, "GNU Privacy Guard's Smartcard server ready"); assuan_register_reset_notify (ctx, reset_notify); assuan_register_option_handler (ctx, option_handler); return 0; } /* Startup the server. If FD is given as -1 this is simple pipe server, otherwise it is a regular server. */ void scd_command_handler (ctrl_t ctrl, int fd) { int rc; assuan_context_t ctx; if (fd == -1) { int filedes[2]; filedes[0] = 0; filedes[1] = 1; rc = assuan_init_pipe_server (&ctx, filedes); } else { rc = assuan_init_socket_server_ext (&ctx, fd, 2); } if (rc) { log_error ("failed to initialize the server: %s\n", gpg_strerror(rc)); scd_exit (2); } rc = register_commands (ctx); if (rc) { log_error ("failed to register commands with Assuan: %s\n", gpg_strerror(rc)); scd_exit (2); } assuan_set_pointer (ctx, ctrl); /* Allocate and initialize the server object. Put it into the list of active sessions. */ ctrl->server_local = xcalloc (1, sizeof *ctrl->server_local); ctrl->server_local->next_session = session_list; session_list = ctrl->server_local; ctrl->server_local->ctrl_backlink = ctrl; ctrl->server_local->assuan_ctx = ctx; if (DBG_ASSUAN) assuan_set_log_stream (ctx, log_get_stream ()); /* We open the reader right at startup so that the ticker is able to update the status file. */ if (ctrl->reader_slot == -1) { ctrl->reader_slot = get_reader_slot (); } /* Command processing loop. */ for (;;) { rc = assuan_accept (ctx); if (rc == -1) { break; } else if (rc) { log_info ("Assuan accept problem: %s\n", gpg_strerror (rc)); break; } rc = assuan_process (ctx); if (rc) { log_info ("Assuan processing failed: %s\n", gpg_strerror (rc)); continue; } } /* Cleanup. */ do_reset (ctrl, 0); /* Release the server object. */ if (session_list == ctrl->server_local) session_list = ctrl->server_local->next_session; else { struct server_local_s *sl; for (sl=session_list; sl->next_session; sl = sl->next_session) if (sl->next_session == ctrl->server_local) break; if (!sl->next_session) BUG (); sl->next_session = ctrl->server_local->next_session; } xfree (ctrl->server_local); ctrl->server_local = NULL; /* Release the Assuan context. */ assuan_deinit_server (ctx); } /* Send a line with status information via assuan and escape all given buffers. The variable elements are pairs of (char *, size_t), terminated with a (NULL, 0). */ void send_status_info (ctrl_t ctrl, const char *keyword, ...) { va_list arg_ptr; const unsigned char *value; size_t valuelen; char buf[950], *p; size_t n; assuan_context_t ctx = ctrl->server_local->assuan_ctx; va_start (arg_ptr, keyword); p = buf; n = 0; while ( (value = va_arg (arg_ptr, const unsigned char *)) ) { valuelen = va_arg (arg_ptr, size_t); if (!valuelen) continue; /* empty buffer */ if (n) { *p++ = ' '; n++; } for ( ; valuelen && n < DIM (buf)-2; n++, valuelen--, value++) { if (*value < ' ' || *value == '+') { sprintf (p, "%%%02X", *value); p += 3; } else if (*value == ' ') *p++ = '+'; else *p++ = *value; } } *p = 0; assuan_write_status (ctx, keyword, buf); va_end (arg_ptr); } /* This is the core of scd_update_reader_status_file but the caller needs to take care of the locking. */ static void update_reader_status_file (void) { int idx; unsigned int status, changed; /* Note, that we only try to get the status, because it does not make sense to wait here for a operation to complete. If we are busy working with a card, delays in the status file update should be acceptable. */ for (idx=0; idx < DIM(slot_table); idx++) { struct slot_status_s *ss = slot_table + idx; if (!ss->valid || ss->slot == -1) continue; /* Not valid or reader not yet open. */ if ( apdu_get_status (ss->slot, 0, &status, &changed) ) continue; /* Get status failed. */ if (!ss->any || ss->status != status || ss->changed != changed ) { char *fname; char templ[50]; FILE *fp; struct server_local_s *sl; log_info ("updating status of slot %d to 0x%04X\n", ss->slot, status); /* FIXME: Should this be IDX instead of ss->slot? This depends on how client sessions will associate the reader status with their session. */ sprintf (templ, "reader_%d.status", ss->slot); fname = make_filename (opt.homedir, templ, NULL ); fp = fopen (fname, "w"); if (fp) { fprintf (fp, "%s\n", (status & 1)? "USABLE": (status & 4)? "ACTIVE": (status & 2)? "PRESENT": "NOCARD"); fclose (fp); } xfree (fname); /* If a status script is executable, run it. */ { const char *args[9], *envs[2]; char numbuf1[30], numbuf2[30], numbuf3[30]; char *homestr, *envstr; gpg_error_t err; homestr = make_filename (opt.homedir, NULL); if (asprintf (&envstr, "GNUPGHOME=%s", homestr) < 0) log_error ("out of core while building environment\n"); else { envs[0] = envstr; envs[1] = NULL; sprintf (numbuf1, "%d", ss->slot); sprintf (numbuf2, "0x%04X", ss->status); sprintf (numbuf3, "0x%04X", status); args[0] = "--reader-port"; args[1] = numbuf1; args[2] = "--old-code"; args[3] = numbuf2; args[4] = "--new-code"; args[5] = numbuf3; args[6] = "--status"; args[7] = ((status & 1)? "USABLE": (status & 4)? "ACTIVE": (status & 2)? "PRESENT": "NOCARD"); args[8] = NULL; fname = make_filename (opt.homedir, "scd-event", NULL); err = gnupg_spawn_process_detached (fname, args, envs); if (err && gpg_err_code (err) != GPG_ERR_ENOENT) log_error ("failed to run event handler `%s': %s\n", fname, gpg_strerror (err)); xfree (fname); free (envstr); } xfree (homestr); } /* Set the card removed flag for all current sessions. We will set this on any card change because a reset or SERIALNO request must be done in any case. */ if (ss->any) update_card_removed (idx, 1); ss->any = 1; ss->status = status; ss->changed = changed; /* Send a signal to all clients who applied for it. */ for (sl=session_list; sl; sl = sl->next_session) if (sl->event_signal && sl->assuan_ctx) { pid_t pid = assuan_get_pid (sl->assuan_ctx); int signo = sl->event_signal; log_info ("client pid is %d, sending signal %d\n", pid, signo); #ifndef HAVE_W32_SYSTEM if (pid != (pid_t)(-1) && pid && signo > 0) kill (pid, signo); #endif } } } } /* This function is called by the ticker thread to check for changes of the reader stati. It updates the reader status files and if requested by the caller also send a signal to the caller. */ void scd_update_reader_status_file (void) { if (!pth_mutex_acquire (&status_file_update_lock, 1, NULL)) return; /* locked - give up. */ update_reader_status_file (); if (!pth_mutex_release (&status_file_update_lock)) log_error ("failed to release status_file_update lock\n"); }