upstream) and a number of security fixes which we had already backported. MFC after: 1 week
243 lines
5.2 KiB
C
243 lines
5.2 KiB
C
/* $OpenBSD: ssh-pkcs11-client.c,v 1.5 2014/06/24 01:13:21 djm Exp $ */
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/*
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* Copyright (c) 2010 Markus Friedl. All rights reserved.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include "includes.h"
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#ifdef ENABLE_PKCS11
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#include <sys/types.h>
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#ifdef HAVE_SYS_TIME_H
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# include <sys/time.h>
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#endif
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#include <sys/socket.h>
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#include <stdarg.h>
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#include <string.h>
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#include <unistd.h>
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#include <errno.h>
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#include <openssl/rsa.h>
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#include "pathnames.h"
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#include "xmalloc.h"
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#include "buffer.h"
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#include "log.h"
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#include "misc.h"
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#include "key.h"
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#include "authfd.h"
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#include "atomicio.h"
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#include "ssh-pkcs11.h"
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/* borrows code from sftp-server and ssh-agent */
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int fd = -1;
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pid_t pid = -1;
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static void
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send_msg(Buffer *m)
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{
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u_char buf[4];
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int mlen = buffer_len(m);
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put_u32(buf, mlen);
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if (atomicio(vwrite, fd, buf, 4) != 4 ||
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atomicio(vwrite, fd, buffer_ptr(m),
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buffer_len(m)) != buffer_len(m))
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error("write to helper failed");
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buffer_consume(m, mlen);
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}
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static int
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recv_msg(Buffer *m)
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{
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u_int l, len;
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u_char buf[1024];
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if ((len = atomicio(read, fd, buf, 4)) != 4) {
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error("read from helper failed: %u", len);
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return (0); /* XXX */
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}
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len = get_u32(buf);
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if (len > 256 * 1024)
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fatal("response too long: %u", len);
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/* read len bytes into m */
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buffer_clear(m);
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while (len > 0) {
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l = len;
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if (l > sizeof(buf))
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l = sizeof(buf);
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if (atomicio(read, fd, buf, l) != l) {
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error("response from helper failed.");
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return (0); /* XXX */
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}
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buffer_append(m, buf, l);
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len -= l;
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}
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return (buffer_get_char(m));
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}
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int
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pkcs11_init(int interactive)
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{
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return (0);
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}
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void
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pkcs11_terminate(void)
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{
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close(fd);
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}
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static int
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pkcs11_rsa_private_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa,
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int padding)
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{
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Key key;
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u_char *blob, *signature = NULL;
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u_int blen, slen = 0;
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int ret = -1;
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Buffer msg;
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if (padding != RSA_PKCS1_PADDING)
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return (-1);
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key.type = KEY_RSA;
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key.rsa = rsa;
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if (key_to_blob(&key, &blob, &blen) == 0)
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return -1;
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buffer_init(&msg);
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buffer_put_char(&msg, SSH2_AGENTC_SIGN_REQUEST);
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buffer_put_string(&msg, blob, blen);
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buffer_put_string(&msg, from, flen);
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buffer_put_int(&msg, 0);
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free(blob);
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send_msg(&msg);
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buffer_clear(&msg);
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if (recv_msg(&msg) == SSH2_AGENT_SIGN_RESPONSE) {
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signature = buffer_get_string(&msg, &slen);
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if (slen <= (u_int)RSA_size(rsa)) {
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memcpy(to, signature, slen);
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ret = slen;
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}
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free(signature);
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}
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buffer_free(&msg);
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return (ret);
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}
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/* redirect the private key encrypt operation to the ssh-pkcs11-helper */
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static int
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wrap_key(RSA *rsa)
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{
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static RSA_METHOD helper_rsa;
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memcpy(&helper_rsa, RSA_get_default_method(), sizeof(helper_rsa));
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helper_rsa.name = "ssh-pkcs11-helper";
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helper_rsa.rsa_priv_enc = pkcs11_rsa_private_encrypt;
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RSA_set_method(rsa, &helper_rsa);
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return (0);
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}
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static int
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pkcs11_start_helper(void)
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{
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int pair[2];
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if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) {
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error("socketpair: %s", strerror(errno));
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return (-1);
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}
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if ((pid = fork()) == -1) {
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error("fork: %s", strerror(errno));
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return (-1);
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} else if (pid == 0) {
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if ((dup2(pair[1], STDIN_FILENO) == -1) ||
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(dup2(pair[1], STDOUT_FILENO) == -1)) {
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fprintf(stderr, "dup2: %s\n", strerror(errno));
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_exit(1);
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}
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close(pair[0]);
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close(pair[1]);
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execlp(_PATH_SSH_PKCS11_HELPER, _PATH_SSH_PKCS11_HELPER,
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(char *) 0);
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fprintf(stderr, "exec: %s: %s\n", _PATH_SSH_PKCS11_HELPER,
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strerror(errno));
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_exit(1);
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}
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close(pair[1]);
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fd = pair[0];
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return (0);
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}
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int
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pkcs11_add_provider(char *name, char *pin, Key ***keysp)
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{
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Key *k;
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int i, nkeys;
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u_char *blob;
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u_int blen;
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Buffer msg;
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if (fd < 0 && pkcs11_start_helper() < 0)
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return (-1);
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buffer_init(&msg);
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buffer_put_char(&msg, SSH_AGENTC_ADD_SMARTCARD_KEY);
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buffer_put_cstring(&msg, name);
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buffer_put_cstring(&msg, pin);
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send_msg(&msg);
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buffer_clear(&msg);
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if (recv_msg(&msg) == SSH2_AGENT_IDENTITIES_ANSWER) {
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nkeys = buffer_get_int(&msg);
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*keysp = xcalloc(nkeys, sizeof(Key *));
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for (i = 0; i < nkeys; i++) {
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blob = buffer_get_string(&msg, &blen);
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free(buffer_get_string(&msg, NULL));
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k = key_from_blob(blob, blen);
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wrap_key(k->rsa);
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(*keysp)[i] = k;
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free(blob);
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}
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} else {
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nkeys = -1;
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}
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buffer_free(&msg);
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return (nkeys);
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}
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int
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pkcs11_del_provider(char *name)
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{
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int ret = -1;
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Buffer msg;
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buffer_init(&msg);
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buffer_put_char(&msg, SSH_AGENTC_REMOVE_SMARTCARD_KEY);
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buffer_put_cstring(&msg, name);
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buffer_put_cstring(&msg, "");
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send_msg(&msg);
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buffer_clear(&msg);
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if (recv_msg(&msg) == SSH_AGENT_SUCCESS)
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ret = 0;
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buffer_free(&msg);
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return (ret);
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}
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#endif /* ENABLE_PKCS11 */
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