diff options
Diffstat (limited to 'agent/command.c')
| -rw-r--r-- | agent/command.c | 278 |
1 files changed, 230 insertions, 48 deletions
diff --git a/agent/command.c b/agent/command.c index 082e730bd..9bd5ce5c3 100644 --- a/agent/command.c +++ b/agent/command.c @@ -38,10 +38,14 @@ #include <assuan.h> #include "i18n.h" -/* maximum allowed size of the inquired ciphertext */ +/* Maximum allowed size of the inquired ciphertext. */ #define MAXLEN_CIPHERTEXT 4096 -/* maximum allowed size of the key parameters */ +/* Maximum allowed size of the key parameters. */ #define MAXLEN_KEYPARAM 1024 +/* Maximum allowed size of key data as used in inquiries (bytes). */ +#define MAXLEN_KEYDATA 4096 +/* The size of the import/export KEK key (in bytes). */ +#define KEYWRAP_KEYSIZE (128/8) #define set_error(e,t) assuan_set_error (ctx, gpg_error (e), (t)) @@ -63,6 +67,8 @@ struct server_local_s 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. */ }; @@ -340,6 +346,26 @@ agent_inq_pinentry_launched (ctrl_t ctrl, unsigned long pid) } +/* Helper to print a message while leaving a command. */ +static gpg_error_t +leave_cmd (assuan_context_t ctx, gpg_error_t err) +{ + if (err) + { + const char *name = assuan_get_command_name (ctx); + if (!name) + name = "?"; + if (gpg_err_source (err) == GPG_ERR_SOURCE_DEFAULT) + log_error ("command '%s' failed: %s\n", name, + gpg_strerror (err)); + else + log_error ("command '%s' failed: %s <%s>\n", name, + gpg_strerror (err), gpg_strsource (err)); + } + return err; +} + + static const char hlp_geteventcounter[] = "GETEVENTCOUNTER\n" @@ -432,10 +458,7 @@ cmd_istrusted (assuan_context_t ctx, char *line) else if (rc == -1 || gpg_err_code (rc) == GPG_ERR_EOF ) return gpg_error (GPG_ERR_NOT_TRUSTED); else - { - log_error ("command is_trusted failed: %s\n", gpg_strerror (rc)); - return rc; - } + return leave_cmd (ctx, rc); } @@ -451,9 +474,7 @@ cmd_listtrusted (assuan_context_t ctx, char *line) (void)line; rc = agent_listtrusted (ctx); - if (rc) - log_error ("command listtrusted failed: %s\n", gpg_strerror (rc)); - return rc; + return leave_cmd (ctx, rc); } @@ -494,9 +515,7 @@ cmd_marktrusted (assuan_context_t ctx, char *line) p++; rc = agent_marktrusted (ctrl, p, fpr, flag); - if (rc) - log_error ("command marktrusted failed: %s\n", gpg_strerror (rc)); - return rc; + return leave_cmd (ctx, rc); } @@ -695,11 +714,9 @@ cmd_pksign (assuan_context_t ctx, char *line) clear_outbuf (&outbuf); else rc = write_and_clear_outbuf (ctx, &outbuf); - if (rc) - log_error ("command pksign failed: %s\n", gpg_strerror (rc)); xfree (ctrl->server_local->keydesc); ctrl->server_local->keydesc = NULL; - return rc; + return leave_cmd (ctx, rc); } @@ -734,11 +751,9 @@ cmd_pkdecrypt (assuan_context_t ctx, char *line) clear_outbuf (&outbuf); else rc = write_and_clear_outbuf (ctx, &outbuf); - if (rc) - log_error ("command pkdecrypt failed: %s\n", gpg_strerror (rc)); xfree (ctrl->server_local->keydesc); ctrl->server_local->keydesc = NULL; - return rc; + return leave_cmd (ctx, rc); } @@ -780,9 +795,7 @@ cmd_genkey (assuan_context_t ctx, char *line) clear_outbuf (&outbuf); else rc = write_and_clear_outbuf (ctx, &outbuf); - if (rc) - log_error ("command genkey failed: %s\n", gpg_strerror (rc)); - return rc; + return leave_cmd (ctx, rc); } @@ -825,9 +838,7 @@ cmd_readkey (assuan_context_t ctx, char *line) gcry_sexp_release (s_pkey); } - if (rc) - log_error ("command readkey failed: %s\n", gpg_strerror (rc)); - return rc; + return leave_cmd (ctx, rc); } @@ -967,7 +978,7 @@ cmd_keyinfo (assuan_context_t ctx, char *line) if (dir) closedir (dir); if (err && gpg_err_code (err) != GPG_ERR_NOT_FOUND) - log_error ("command keyinfo failed: %s\n", gpg_strerror (err)); + leave_cmd (ctx, err); return err; } @@ -1167,9 +1178,7 @@ cmd_get_passphrase (assuan_context_t ctx, char *line) } } - if (rc) - log_error ("command get_passphrase failed: %s\n", gpg_strerror (rc)); - return rc; + return leave_cmd (ctx, rc); } @@ -1240,9 +1249,7 @@ cmd_get_confirmation (assuan_context_t ctx, char *line) plus_to_blank (desc); rc = agent_get_confirmation (ctrl, desc, NULL, NULL, 0); - if (rc) - log_error ("command get_confirmation failed: %s\n", gpg_strerror (rc)); - return rc; + return leave_cmd (ctx, rc); } @@ -1259,9 +1266,7 @@ cmd_learn (assuan_context_t ctx, char *line) int rc; rc = agent_handle_learn (ctrl, has_option (line, "--send")? ctx : NULL); - if (rc) - log_error ("command learn failed: %s\n", gpg_strerror (rc)); - return rc; + return leave_cmd (ctx, rc); } @@ -1304,9 +1309,7 @@ cmd_passwd (assuan_context_t ctx, char *line) leave: gcry_sexp_release (s_skey); xfree (shadow_info); - if (rc) - log_error ("command passwd failed: %s\n", gpg_strerror (rc)); - return rc; + return leave_cmd (ctx, rc); } @@ -1371,10 +1374,7 @@ cmd_preset_passphrase (assuan_context_t ctx, char *line) if (!rc) rc = agent_put_cache (grip_clear, CACHE_MODE_ANY, passphrase, ttl); - if (rc) - log_error ("command preset_passphrase failed: %s\n", gpg_strerror (rc)); - - return rc; + return leave_cmd (ctx, rc); } @@ -1397,6 +1397,186 @@ cmd_scd (assuan_context_t ctx, char *line) +static const char hlp_keywrap_key[] = + "KEYWRAP_KEY [--clear] <mode>\n" + "\n" + "Return a key to wrap another key. For now the key is returned\n" + "verbatim and and thus makes not much sense because an eavesdropper on\n" + "the gpg-agent connection will see the key as well as the wrapped key.\n" + "However, this function may either be equipped with a public key\n" + "mechanism or not used at all if the key is a pre-shared key. In any\n" + "case wrapping the import and export of keys is a requirement for\n" + "certain cryptographic validations and thus useful. The key persists\n" + "a RESET command but may be cleared using the option --clear.\n" + "\n" + "Supported modes are:\n" + " --import - Return a key to import a key into gpg-agent\n" + " --export - Return a key to export a key from gpg-agent"; +static gpg_error_t +cmd_keywrap_key (assuan_context_t ctx, char *line) +{ + ctrl_t ctrl = assuan_get_pointer (ctx); + gpg_error_t err = 0; + int clearopt = has_option (line, "--clear"); + + + assuan_begin_confidential (ctx); + if (has_option (line, "--import")) + { + xfree (ctrl->server_local->import_key); + if (clearopt) + ctrl->server_local->import_key = NULL; + else if (!(ctrl->server_local->import_key = + gcry_random_bytes (KEYWRAP_KEYSIZE, GCRY_STRONG_RANDOM))) + err = gpg_error_from_syserror (); + else + err = assuan_send_data (ctx, ctrl->server_local->import_key, + KEYWRAP_KEYSIZE); + } + else if (has_option (line, "--export")) + { + xfree (ctrl->server_local->export_key); + if (clearopt) + ctrl->server_local->export_key = NULL; + else if (!(ctrl->server_local->export_key = + gcry_random_bytes (KEYWRAP_KEYSIZE, GCRY_STRONG_RANDOM))) + err = gpg_error_from_syserror (); + else + err = assuan_send_data (ctx, ctrl->server_local->export_key, + KEYWRAP_KEYSIZE); + } + else + err = set_error (GPG_ERR_ASS_PARAMETER, "unknown value for MODE"); + assuan_end_confidential (ctx); + + return leave_cmd (ctx, err); +} + + + +static const char hlp_import_key[] = + "IMPORT_KEY\n" + "\n" + "Import a secret key into the key store. The key is expected to be\n" + "encrypted using the current session's key wrapping key (cf. command\n" + "KEYWRAP_KEY) using the AESWRAP-128 algorithm. This function takes\n" + "no arguments but uses the inquiry \"KEYDATA\" to ask for the actual\n" + "key data. The unwrapped key must be a canonical S-expression."; +static gpg_error_t +cmd_import_key (assuan_context_t ctx, char *line) +{ + ctrl_t ctrl = assuan_get_pointer (ctx); + gpg_error_t err; + unsigned char *wrappedkey = NULL; + size_t wrappedkeylen; + gcry_cipher_hd_t cipherhd = NULL; + unsigned char *key = NULL; + size_t keylen, realkeylen; + char *passphrase = NULL; + unsigned char *finalkey = NULL; + size_t finalkeylen; + unsigned char grip[20]; + + (void)line; + + if (!ctrl->server_local->import_key) + { + err = gpg_error (GPG_ERR_BAD_KEY); + goto leave; + } + + assuan_begin_confidential (ctx); + err = assuan_inquire (ctx, "KEYDATA", + &wrappedkey, &wrappedkeylen, MAXLEN_KEYDATA); + assuan_end_confidential (ctx); + if (err) + goto leave; + if (wrappedkeylen < 24) + { + err = gpg_error (GPG_ERR_INV_LENGTH); + goto leave; + } + keylen = wrappedkeylen - 8; + key = xtrymalloc_secure (keylen); + if (!key) + { + err = gpg_error_from_syserror (); + goto leave; + } + + err = gcry_cipher_open (&cipherhd, GCRY_CIPHER_AES128, + GCRY_CIPHER_MODE_AESWRAP, 0); + if (err) + goto leave; + err = gcry_cipher_setkey (cipherhd, + ctrl->server_local->import_key, KEYWRAP_KEYSIZE); + if (err) + goto leave; + err = gcry_cipher_decrypt (cipherhd, key, keylen, wrappedkey, wrappedkeylen); + if (err) + goto leave; + gcry_cipher_close (cipherhd); + cipherhd = NULL; + xfree (wrappedkey); + wrappedkey = NULL; + + realkeylen = gcry_sexp_canon_len (key, keylen, NULL, &err); + if (!realkeylen) + goto leave; /* Invalid canonical encoded S-expression. */ + + err = keygrip_from_canon_sexp (key, realkeylen, grip); + if (err) + goto leave; + + if (!agent_key_available (grip)) + { + err = gpg_error (GPG_ERR_EEXIST); + goto leave; + } + + err = agent_ask_new_passphrase + (ctrl, _("Please enter the passphrase to protect the " + "imported object within the GnuPG system."), + &passphrase); + if (err) + goto leave; + + if (passphrase) + { + err = agent_protect (key, passphrase, &finalkey, &finalkeylen); + if (!err) + err = agent_write_private_key (grip, finalkey, finalkeylen, 0); + } + else + err = agent_write_private_key (grip, key, realkeylen, 0); + + leave: + xfree (finalkey); + xfree (passphrase); + xfree (key); + gcry_cipher_close (cipherhd); + xfree (wrappedkey); + return leave_cmd (ctx, err); +} + + + +static const char hlp_export_key[] = + "EXPORT_KEY\n" + "\n"; +static gpg_error_t +cmd_export_key (assuan_context_t ctx, char *line) +{ + gpg_error_t err = gpg_error (GPG_ERR_NOT_IMPLEMENTED); + + + /* leave: */ + return leave_cmd (ctx, err); +} + + + + static const char hlp_getval[] = "GETVAL <key>\n" "\n" @@ -1435,9 +1615,7 @@ cmd_getval (assuan_context_t ctx, char *line) else return gpg_error (GPG_ERR_NO_DATA); - if (rc) - log_error ("command getval failed: %s\n", gpg_strerror (rc)); - return rc; + return leave_cmd (ctx, rc); } @@ -1520,9 +1698,7 @@ cmd_putval (assuan_context_t ctx, char *line) } } - if (rc) - log_error ("command putval failed: %s\n", gpg_strerror (rc)); - return rc; + return leave_cmd (ctx, rc); } @@ -1641,7 +1817,7 @@ static const char hlp_getinfo[] = " std_session_env - List the standard session environment.\n" " std_startup_env - List the standard startup environment.\n" " cmd_has_option\n" - " - Returns OK if the command CMD implements the option OPT."; + " - Returns OK if the command CMD implements the option OPT\n."; static gpg_error_t cmd_getinfo (assuan_context_t ctx, char *line) { @@ -1910,6 +2086,9 @@ register_commands (assuan_context_t ctx) { "INPUT", NULL }, { "OUTPUT", NULL }, { "SCD", cmd_scd, hlp_scd }, + { "KEYWRAP_KEY", cmd_keywrap_key, hlp_keywrap_key }, + { "IMPORT_KEY", cmd_import_key, hlp_import_key }, + { "EXPORT_KEY", cmd_export_key, hlp_export_key }, { "GETVAL", cmd_getval, hlp_getval }, { "PUTVAL", cmd_putval, hlp_putval }, { "UPDATESTARTUPTTY", cmd_updatestartuptty, hlp_updatestartuptty }, @@ -2021,6 +2200,9 @@ start_command_handler (ctrl_t ctrl, gnupg_fd_t listen_fd, gnupg_fd_t fd) /* Cleanup. */ assuan_release (ctx); + xfree (ctrl->server_local->keydesc); + xfree (ctrl->server_local->import_key); + xfree (ctrl->server_local->export_key); if (ctrl->server_local->stopme) agent_exit (0); xfree (ctrl->server_local); |