From 7ea845e48df6d34a333ebbe79380cba0938d02a5 Mon Sep 17 00:00:00 2001 From: Damien Miller Date: Fri, 12 Feb 2010 09:21:02 +1100 Subject: - markus@cvs.openbsd.org 2010/02/08 10:50:20 [pathnames.h readconf.c readconf.h scp.1 sftp.1 ssh-add.1 ssh-add.c] [ssh-agent.c ssh-keygen.1 ssh-keygen.c ssh.1 ssh.c ssh_config.5] replace our obsolete smartcard code with PKCS#11. ftp://ftp.rsasecurity.com/pub/pkcs/pkcs-11/v2-20/pkcs-11v2-20.pdf ssh(1) and ssh-keygen(1) use dlopen(3) directly to talk to a PKCS#11 provider (shared library) while ssh-agent(1) delegates PKCS#11 to a forked a ssh-pkcs11-helper process. PKCS#11 is currently a compile time option. feedback and ok djm@; inspired by patches from Alon Bar-Lev ` --- ssh-pkcs11-client.c | 229 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 229 insertions(+) create mode 100644 ssh-pkcs11-client.c (limited to 'ssh-pkcs11-client.c') diff --git a/ssh-pkcs11-client.c b/ssh-pkcs11-client.c new file mode 100644 index 000000000..6ffdd9364 --- /dev/null +++ b/ssh-pkcs11-client.c @@ -0,0 +1,229 @@ +/* + * Copyright (c) 2010 Markus Friedl. All rights reserved. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include +#include +#include + +#include +#include +#include +#include + +#include "pathnames.h" +#include "xmalloc.h" +#include "buffer.h" +#include "log.h" +#include "misc.h" +#include "key.h" +#include "authfd.h" +#include "atomicio.h" +#include "ssh-pkcs11.h" + +/* borrows code from sftp-server and ssh-agent */ + +int fd = -1; +pid_t pid = -1; + +static void +send_msg(Buffer *m) +{ + u_char buf[4]; + int mlen = buffer_len(m); + + put_u32(buf, mlen); + if (atomicio(vwrite, fd, buf, 4) != 4 || + atomicio(vwrite, fd, buffer_ptr(m), + buffer_len(m)) != buffer_len(m)) + error("write to helper failed"); + buffer_consume(m, mlen); +} + +static int +recv_msg(Buffer *m) +{ + u_int l, len; + u_char buf[1024]; + + if ((len = atomicio(read, fd, buf, 4)) != 4) { + error("read from helper failed: %u", len); + return (0); /* XXX */ + } + len = get_u32(buf); + if (len > 256 * 1024) + fatal("response too long: %u", len); + /* read len bytes into m */ + buffer_clear(m); + while (len > 0) { + l = len; + if (l > sizeof(buf)) + l = sizeof(buf); + if (atomicio(read, fd, buf, l) != l) { + error("response from helper failed."); + return (0); /* XXX */ + } + buffer_append(m, buf, l); + len -= l; + } + return (buffer_get_char(m)); +} + +int +pkcs11_init(int interactive) +{ + return (0); +} + +void +pkcs11_terminate(void) +{ + close(fd); +} + +static int +pkcs11_rsa_private_encrypt(int flen, const u_char *from, u_char *to, RSA *rsa, + int padding) +{ + Key key; + u_char *blob, *signature = NULL; + u_int blen, slen = 0; + int ret = -1; + Buffer msg; + + if (padding != RSA_PKCS1_PADDING) + return (-1); + key.type = KEY_RSA; + key.rsa = rsa; + if (key_to_blob(&key, &blob, &blen) == 0) + return -1; + buffer_init(&msg); + buffer_put_char(&msg, SSH2_AGENTC_SIGN_REQUEST); + buffer_put_string(&msg, blob, blen); + buffer_put_string(&msg, from, flen); + buffer_put_int(&msg, 0); + xfree(blob); + send_msg(&msg); + + if (recv_msg(&msg) == SSH2_AGENT_SIGN_RESPONSE) { + signature = buffer_get_string(&msg, &slen); + if (slen <= (u_int)RSA_size(rsa)) { + memcpy(to, signature, slen); + ret = slen; + } + xfree(signature); + } + return (ret); +} + +/* redirect the private key encrypt operation to the ssh-pkcs11-helper */ +static int +wrap_key(RSA *rsa) +{ + static RSA_METHOD helper_rsa; + + memcpy(&helper_rsa, RSA_get_default_method(), sizeof(helper_rsa)); + helper_rsa.name = "ssh-pkcs11-helper"; + helper_rsa.rsa_priv_enc = pkcs11_rsa_private_encrypt; + RSA_set_method(rsa, &helper_rsa); + return (0); +} + +static int +pkcs11_start_helper(void) +{ + int pair[2]; + + if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) { + error("socketpair: %s", strerror(errno)); + return (-1); + } + if ((pid = fork()) == -1) { + error("fork: %s", strerror(errno)); + return (-1); + } else if (pid == 0) { + if ((dup2(pair[1], STDIN_FILENO) == -1) || + (dup2(pair[1], STDOUT_FILENO) == -1)) { + fprintf(stderr, "dup2: %s\n", strerror(errno)); + _exit(1); + } + close(pair[0]); + close(pair[1]); + execlp(_PATH_SSH_PKCS11_HELPER, _PATH_SSH_PKCS11_HELPER, + (char *) 0); + fprintf(stderr, "exec: %s: %s\n", _PATH_SSH_PKCS11_HELPER, + strerror(errno)); + _exit(1); + } + close(pair[1]); + fd = pair[0]; + return (0); +} + +int +pkcs11_add_provider(char *name, char *pin, Key ***keysp) +{ + Key *k; + int i, nkeys; + u_char *blob; + u_int blen; + Buffer msg; + + if (fd < 0 && pkcs11_start_helper() < 0) + return (-1); + + buffer_init(&msg); + buffer_put_char(&msg, SSH_AGENTC_ADD_SMARTCARD_KEY); + buffer_put_cstring(&msg, name); + buffer_put_cstring(&msg, pin); + send_msg(&msg); + buffer_clear(&msg); + + if (recv_msg(&msg) == SSH2_AGENT_IDENTITIES_ANSWER) { + nkeys = buffer_get_int(&msg); + *keysp = xcalloc(nkeys, sizeof(Key *)); + for (i = 0; i < nkeys; i++) { + blob = buffer_get_string(&msg, &blen); + xfree(buffer_get_string(&msg, NULL)); + k = key_from_blob(blob, blen); + wrap_key(k->rsa); + (*keysp)[i] = k; + xfree(blob); + } + } else { + nkeys = -1; + } + buffer_free(&msg); + return (nkeys); +} + +int +pkcs11_del_provider(char *name) +{ + int ret = -1; + Buffer msg; + + buffer_init(&msg); + buffer_put_char(&msg, SSH_AGENTC_REMOVE_SMARTCARD_KEY); + buffer_put_cstring(&msg, name); + buffer_put_cstring(&msg, ""); + send_msg(&msg); + buffer_clear(&msg); + + if (recv_msg(&msg) == SSH_AGENT_SUCCESS) + ret = 0; + buffer_free(&msg); + return (ret); +} -- cgit v1.2.3