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Diffstat (limited to 'agent/command.c')
| -rw-r--r-- | agent/command.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/agent/command.c b/agent/command.c new file mode 100644 index 000000000..62950b365 --- /dev/null +++ b/agent/command.c @@ -0,0 +1,229 @@ +/* command.c - gpg-agent command handler + * Copyright (C) 2001 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 2 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, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +/* FIXME: we should not use the default assuan buffering but setup + some buffering in secure mempory to protect session keys etc. */ + +#include <config.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <ctype.h> +#include <unistd.h> + +#include "agent.h" +#include "../assuan/assuan.h" + +#define set_error(e,t) assuan_set_error (ctx, ASSUAN_ ## e, (t)) +#define digitp(a) ((a) >= '0' && (a) <= '9') +#define hexdigitp(a) (digitp (a) \ + || ((a) >= 'A' && (a) <= 'F') \ + || ((a) >= 'a' && (a) <= 'f')) +#define atoi_1(p) (*(p) - '0' ) +#define atoi_2(p) ((atoi_1(p) * 10) + atoi_1((p)+1)) +/* assumes ASCII and pre-checked values */ +#define xtoi_1(p) (*(p) <= '9'? (*(p)- '0'): \ + *(p) <= 'F'? (*(p)-'A'+10):(*(p)-'a'+10)) +#define xtoi_2(p) ((xtoi_1(p) * 16) + xtoi_1((p)+1)) + +/* Data used to associate an Assuan context with local server data */ +struct server_local_s { + ASSUAN_CONTEXT assuan_ctx; + int message_fd; +}; + +/* SETHASH <hexstring> + + The client can use this command to tell the server about the data + (which usually is a hash) to be signed. */ +static int +cmd_sethash (ASSUAN_CONTEXT ctx, char *line) +{ + int n; + char *p; + CTRL ctrl = assuan_get_pointer (ctx); + unsigned char *buf; + + /* parse the hash value */ + for (p=line,n=0; hexdigitp (*p); p++, n++) + ; + if (*p) + return set_error (Parameter_Error, "invalid hexstring"); + if ((n&1)) + return set_error (Parameter_Error, "odd number of digits"); + n /= 2; + if (n != 16 && n != 20 && n != 24 && n != 32) + return set_error (Parameter_Error, "unsupported length of hash"); + if (n > MAX_DIGEST_LEN) + return set_error (Parameter_Error, "hash value to long"); + + buf = ctrl->digest.value; + ctrl->digest.valuelen = n; + for (p=line, n=0; n < ctrl->digest.valuelen; p += 2, n++) + buf[n] = xtoi_2 (p); + for (; n < ctrl->digest.valuelen; n++) + buf[n] = 0; + return 0; +} + + +/* PKSIGN <options> + + Perform the actual sign operation. Neither input nor output are + sensitive to to eavesdropping */ +static int +cmd_pksign (ASSUAN_CONTEXT ctx, char *line) +{ + int rc; + CTRL ctrl = assuan_get_pointer (ctx); + + /* fixme: check that all required data is available */ + rc = agent_pksign (ctrl, assuan_get_data_fp (ctx)); + /* fixme: return an error */ + return 0; +} + + +/* MESSAGE FD=<n> + + Set the file descriptor to read a message which is used with + detached signatures */ +static int +cmd_message (ASSUAN_CONTEXT ctx, char *line) +{ +#if 0 + char *endp; + int fd; + CTRL ctrl = assuan_get_pointer (ctx); + + if (strncmp (line, "FD=", 3)) + return set_error (Syntax_Error, "FD=<n> expected"); + line += 3; + if (!digitp (*line)) + return set_error (Syntax_Error, "number required"); + fd = strtoul (line, &endp, 10); + if (*endp) + return set_error (Syntax_Error, "garbage found"); + if (fd == -1) + return set_error (No_Input, NULL); + + ctrl->server_local->message_fd = fd; + return 0; +#endif + return set_error (Not_Implemented, NULL); +} + + + +/* Tell the assuan library about our commands */ +static int +register_commands (ASSUAN_CONTEXT ctx) +{ + static struct { + const char *name; + int cmd_id; + int (*handler)(ASSUAN_CONTEXT, char *line); + } table[] = { + { "SETHASH", 0, cmd_sethash }, + { "PKSIGN", 0, cmd_pksign }, + { "", ASSUAN_CMD_INPUT, NULL }, + { "", ASSUAN_CMD_OUTPUT, NULL }, + { "MESSAGE", 0, cmd_message }, + { NULL } + }; + int i, j, rc; + + for (i=j=0; table[i].name; i++) + { + rc = assuan_register_command (ctx, + table[i].cmd_id? table[i].cmd_id + : (ASSUAN_CMD_USER + j++), + table[i].name, table[i].handler); + if (rc) + return rc; + } + return 0; +} + + +/* Startup the server */ +void +start_command_handler (void) +{ + int rc; + int filedes[2]; + ASSUAN_CONTEXT ctx; + struct server_control_s ctrl; + + memset (&ctrl, 0, sizeof ctrl); + + /* For now we use a simple pipe based server so that we can work + from scripts. We will later add options to run as a daemon and + wait for requests on a Unix domain socket */ + filedes[0] = 0; + filedes[1] = 1; + rc = assuan_init_pipe_server (&ctx, filedes); + if (rc) + { + log_error ("failed to initialize the server: %s\n", + assuan_strerror(rc)); + agent_exit (2); + } + rc = register_commands (ctx); + if (rc) + { + log_error ("failed to the register commands with Assuan: %s\n", + assuan_strerror(rc)); + agent_exit (2); + } + + 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; + + log_info ("Assuan started\n"); + for (;;) + { + rc = assuan_accept (ctx); + if (rc == -1) + { + log_info ("Assuan terminated\n"); + break; + } + else if (rc) + { + log_info ("Assuan accept problem: %s\n", assuan_strerror (rc)); + break; + } + + rc = assuan_process (ctx); + if (rc) + { + log_info ("Assuan processing failed: %s\n", assuan_strerror (rc)); + continue; + } + } + + + assuan_deinit_pipe_server (ctx); +} + |