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openssh.17528
openssh-8.1p1-audit.patch
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File openssh-8.1p1-audit.patch of Package openssh.17528
diff --git a/Makefile.in b/Makefile.in index 02bafbc..4ee4ab2 100644 --- a/Makefile.in +++ b/Makefile.in @@ -110,7 +110,8 @@ LIBSSH_OBJS=${LIBOPENSSH_OBJS} \ kexgexc.o kexgexs.o \ sntrup4591761.o kexsntrup4591761x25519.o kexgen.o \ kexgssc.o \ - platform-pledge.o platform-tracing.o platform-misc.o + platform-pledge.o platform-tracing.o platform-misc.o \ + auditstub.o LIBSSH_OBJS += fips.o diff --git a/audit-bsm.c b/audit-bsm.c index 0ba16c7..d5e9cda 100644 --- a/audit-bsm.c +++ b/audit-bsm.c @@ -372,12 +372,25 @@ audit_connection_from(const char *host, int port) #endif } +int +audit_run_command(struct ssh *ssh, const char *command) +{ + /* not implemented */ + return 0; +} + void -audit_run_command(const char *command) +audit_end_command(struct ssh *ssh, int handle, const char *command) { /* not implemented */ } +void +audit_count_session_open(void) +{ + /* not necessary */ +} + void audit_session_open(struct logininfo *li) { @@ -390,6 +403,12 @@ audit_session_close(struct logininfo *li) /* not implemented */ } +int +audit_keyusage(struct ssh *ssh, int host_user, char *fp, int rv) +{ + /* not implemented */ +} + void audit_event(struct ssh *ssh, ssh_audit_event_t event) { @@ -451,4 +470,28 @@ audit_event(struct ssh *ssh, ssh_audit_event_t event) debug("%s: unhandled event %d", __func__, event); } } + +void +audit_unsupported_body(struct ssh *ssh, int what) +{ + /* not implemented */ +} + +void +audit_kex_body(struct ssh *ssh, int ctos, char *enc, char *mac, char *compress, char *pfs, pid_t pid, uid_t uid) +{ + /* not implemented */ +} + +void +audit_session_key_free_body(struct ssh * ssh, int ctos, pid_t pid, uid_t uid) +{ + /* not implemented */ +} + +void +audit_destroy_sensitive_data(struct ssh *ssh, const char *fp, pid_t pid, uid_t uid) +{ + /* not implemented */ +} #endif /* BSM */ diff --git a/audit-linux.c b/audit-linux.c index 3fcbe5c..a823c30 100644 --- a/audit-linux.c +++ b/audit-linux.c @@ -33,27 +33,40 @@ #include "log.h" #include "audit.h" +#include "sshkey.h" +#include "hostfile.h" +#include "auth.h" +#include "misc.h" /* servconf.h needs misc.h for struct ForwardOptions */ +#include "servconf.h" #include "canohost.h" #include "packet.h" +#include "cipher.h" +#include "channels.h" +#include "session.h" +#define AUDIT_LOG_SIZE 256 + +extern ServerOptions options; +extern Authctxt *the_authctxt; +extern u_int utmp_len; const char *audit_username(void); -int -linux_audit_record_event(int uid, const char *username, const char *hostname, - const char *ip, const char *ttyn, int success) +static void +linux_audit_user_logxxx(int uid, const char *username, + const char *ip, const char *ttyn, int success, int event) { int audit_fd, rc, saved_errno; if ((audit_fd = audit_open()) < 0) { if (errno == EINVAL || errno == EPROTONOSUPPORT || errno == EAFNOSUPPORT) - return 1; /* No audit support in kernel */ + return; /* No audit support in kernel */ else - return 0; /* Must prevent login */ + goto fatal_report; /* Must prevent login */ } - rc = audit_log_acct_message(audit_fd, AUDIT_USER_LOGIN, + rc = audit_log_acct_message(audit_fd, event, NULL, "login", username ? username : "(unknown)", - username == NULL ? uid : -1, hostname, ip, ttyn, success); + username == NULL ? uid : -1, NULL, ip, ttyn, success); saved_errno = errno; close(audit_fd); @@ -65,9 +78,96 @@ linux_audit_record_event(int uid, const char *username, const char *hostname, rc = 0; errno = saved_errno; - return rc >= 0; + if (rc < 0) { +fatal_report: + fatal("linux_audit_write_entry failed: %s", strerror(errno)); + } +} + +static void +linux_audit_user_auth(int uid, const char *username, + const char *ip, const char *ttyn, int success, int event) +{ + int audit_fd, rc, saved_errno; + static const char *event_name[] = { + "maxtries exceeded", + "root denied", + "success", + "none", + "password", + "challenge-response", + "pubkey", + "hostbased", + "gssapi", + "invalid user", + "nologin", + "connection closed", + "connection abandoned", + "unknown" + }; + + audit_fd = audit_open(); + if (audit_fd < 0) { + if (errno == EINVAL || errno == EPROTONOSUPPORT || + errno == EAFNOSUPPORT) + return; /* No audit support in kernel */ + else + goto fatal_report; /* Must prevent login */ + } + + if ((event < 0) || (event > SSH_AUDIT_UNKNOWN)) + event = SSH_AUDIT_UNKNOWN; + + rc = audit_log_acct_message(audit_fd, AUDIT_USER_AUTH, + NULL, event_name[event], username ? username : "(unknown)", + username == NULL ? uid : -1, NULL, ip, ttyn, success); + saved_errno = errno; + close(audit_fd); + /* + * Do not report error if the error is EPERM and sshd is run as non + * root user. + */ + if ((rc == -EPERM) && (geteuid() != 0)) + rc = 0; + errno = saved_errno; + if (rc < 0) { +fatal_report: + fatal("linux_audit_write_entry failed: %s", strerror(errno)); + } +} + +int +audit_keyusage(struct ssh *ssh, int host_user, char *fp, int rv) +{ + char buf[AUDIT_LOG_SIZE]; + int audit_fd, rc, saved_errno; + + audit_fd = audit_open(); + if (audit_fd < 0) { + if (errno == EINVAL || errno == EPROTONOSUPPORT || + errno == EAFNOSUPPORT) + return 1; /* No audit support in kernel */ + else + return 0; /* Must prevent login */ + } + snprintf(buf, sizeof(buf), "%s_auth grantors=auth-key", host_user ? "pubkey" : "hostbased"); + rc = audit_log_acct_message(audit_fd, AUDIT_USER_AUTH, NULL, + buf, audit_username(), -1, NULL, ssh_remote_ipaddr(ssh), NULL, rv); + if ((rc < 0) && ((rc != -1) || (getuid() == 0))) + goto out; + snprintf(buf, sizeof(buf), "op=negotiate kind=auth-key fp=%s", fp); + rc = audit_log_user_message(audit_fd, AUDIT_CRYPTO_KEY_USER, buf, NULL, + ssh_remote_ipaddr(ssh), NULL, rv); +out: + saved_errno = errno; + audit_close(audit_fd); + errno = saved_errno; + /* do not report error if the error is EPERM and sshd is run as non root user */ + return (rc >= 0) || ((rc == -EPERM) && (getuid() != 0)); } +static int user_login_count = 0; + /* Below is the sshd audit API code */ void @@ -76,49 +176,210 @@ audit_connection_from(const char *host, int port) /* not implemented */ } +int +audit_run_command(struct ssh *ssh, const char *command) +{ + if (!user_login_count++) + linux_audit_user_logxxx(the_authctxt->pw->pw_uid, NULL, + ssh_remote_ipaddr(ssh), + "ssh", 1, AUDIT_USER_LOGIN); + linux_audit_user_logxxx(the_authctxt->pw->pw_uid, NULL, + ssh_remote_ipaddr(ssh), + "ssh", 1, AUDIT_USER_START); + return 0; +} + void -audit_run_command(const char *command) +audit_end_command(struct ssh *ssh, int handle, const char *command) { - /* not implemented */ + linux_audit_user_logxxx(the_authctxt->pw->pw_uid, NULL, + ssh_remote_ipaddr(ssh), + "ssh", 1, AUDIT_USER_END); + if (user_login_count && !--user_login_count) + linux_audit_user_logxxx(the_authctxt->pw->pw_uid, NULL, + ssh_remote_ipaddr(ssh), + "ssh", 1, AUDIT_USER_LOGOUT); +} + +void +audit_count_session_open(void) +{ + user_login_count++; } void audit_session_open(struct logininfo *li) { - if (linux_audit_record_event(li->uid, NULL, li->hostname, NULL, - li->line, 1) == 0) - fatal("linux_audit_write_entry failed: %s", strerror(errno)); + if (!user_login_count++) + linux_audit_user_logxxx(li->uid, NULL, li->hostname, + li->line, 1, AUDIT_USER_LOGIN); + linux_audit_user_logxxx(li->uid, NULL, li->hostname, + li->line, 1, AUDIT_USER_START); } void audit_session_close(struct logininfo *li) { - /* not implemented */ + linux_audit_user_logxxx(li->uid, NULL, li->hostname, + li->line, 1, AUDIT_USER_END); + if (user_login_count && !--user_login_count) + linux_audit_user_logxxx(li->uid, NULL, li->hostname, + li->line, 1, AUDIT_USER_LOGOUT); } void audit_event(struct ssh *ssh, ssh_audit_event_t event) { switch(event) { - case SSH_AUTH_SUCCESS: - case SSH_CONNECTION_CLOSE: case SSH_NOLOGIN: - case SSH_LOGIN_EXCEED_MAXTRIES: case SSH_LOGIN_ROOT_DENIED: + linux_audit_user_auth(-1, audit_username(), + ssh_remote_ipaddr(ssh), "ssh", 0, event); + linux_audit_user_logxxx(-1, audit_username(), + ssh_remote_ipaddr(ssh), "ssh", 0, AUDIT_USER_LOGIN); break; - case SSH_AUTH_FAIL_NONE: case SSH_AUTH_FAIL_PASSWD: + if (options.use_pam) + break; + case SSH_LOGIN_EXCEED_MAXTRIES: case SSH_AUTH_FAIL_KBDINT: case SSH_AUTH_FAIL_PUBKEY: case SSH_AUTH_FAIL_HOSTBASED: case SSH_AUTH_FAIL_GSSAPI: + linux_audit_user_auth(-1, audit_username(), + ssh_remote_ipaddr(ssh), "ssh", 0, event); + break; + + case SSH_CONNECTION_CLOSE: + if (user_login_count) { + while (user_login_count--) + linux_audit_user_logxxx(the_authctxt->pw->pw_uid, NULL, + ssh_remote_ipaddr(ssh), + "ssh", 1, AUDIT_USER_END); + linux_audit_user_logxxx(the_authctxt->pw->pw_uid, NULL, + ssh_remote_ipaddr(ssh), + "ssh", 1, AUDIT_USER_LOGOUT); + } + break; + + case SSH_CONNECTION_ABANDON: case SSH_INVALID_USER: - linux_audit_record_event(-1, audit_username(), NULL, - ssh_remote_ipaddr(ssh), "sshd", 0); + linux_audit_user_logxxx(-1, audit_username(), + ssh_remote_ipaddr(ssh), "ssh", 0, AUDIT_USER_LOGIN); break; default: debug("%s: unhandled event %d", __func__, event); break; } } + +void +audit_unsupported_body(struct ssh *ssh, int what) +{ +#ifdef AUDIT_CRYPTO_SESSION + char buf[AUDIT_LOG_SIZE]; + const static char *name[] = { "cipher", "mac", "comp" }; + char *s; + int audit_fd; + + snprintf(buf, sizeof(buf), "op=unsupported-%s direction=? cipher=? ksize=? rport=%d laddr=%s lport=%d ", + name[what], ssh_remote_port(ssh), (s = get_local_ipaddr(ssh_packet_get_connection_in(ssh))), + ssh_local_port(ssh)); + free(s); + audit_fd = audit_open(); + if (audit_fd < 0) + /* no problem, the next instruction will be fatal() */ + return; + audit_log_user_message(audit_fd, AUDIT_CRYPTO_SESSION, + buf, NULL, ssh_remote_ipaddr(ssh), NULL, 0); + audit_close(audit_fd); +#endif +} + +const static char *direction[] = { "from-server", "from-client", "both" }; + +void +audit_kex_body(struct ssh *ssh, int ctos, char *enc, char *mac, char *compress, + char *pfs, pid_t pid, uid_t uid) +{ +#ifdef AUDIT_CRYPTO_SESSION + char buf[AUDIT_LOG_SIZE]; + int audit_fd, audit_ok; + const struct sshcipher *cipher = cipher_by_name(enc); + char *s; + + snprintf(buf, sizeof(buf), "op=start direction=%s cipher=%s ksize=%d mac=%s pfs=%s spid=%jd suid=%jd rport=%d laddr=%s lport=%d ", + direction[ctos], enc, cipher ? 8 * cipher->key_len : 0, mac, pfs, + (intmax_t)pid, (intmax_t)uid, + ssh_remote_port(ssh), (s = get_local_ipaddr(ssh_packet_get_connection_in(ssh))), ssh_local_port(ssh)); + free(s); + audit_fd = audit_open(); + if (audit_fd < 0) { + if (errno == EINVAL || errno == EPROTONOSUPPORT || + errno == EAFNOSUPPORT) + return; /* No audit support in kernel */ + else + fatal("cannot open audit"); /* Must prevent login */ + } + audit_ok = audit_log_user_message(audit_fd, AUDIT_CRYPTO_SESSION, + buf, NULL, ssh_remote_ipaddr(ssh), NULL, 1); + audit_close(audit_fd); + /* do not abort if the error is EPERM and sshd is run as non root user */ + if ((audit_ok < 0) && ((audit_ok != -1) || (getuid() == 0))) + fatal("cannot write into audit"); /* Must prevent login */ +#endif +} + +void +audit_session_key_free_body(struct ssh *ssh, int ctos, pid_t pid, uid_t uid) +{ + char buf[AUDIT_LOG_SIZE]; + int audit_fd, audit_ok; + char *s; + + snprintf(buf, sizeof(buf), "op=destroy kind=session fp=? direction=%s spid=%jd suid=%jd rport=%d laddr=%s lport=%d ", + direction[ctos], (intmax_t)pid, (intmax_t)uid, + ssh_remote_port(ssh), + (s = get_local_ipaddr(ssh_packet_get_connection_in(ssh))), + ssh_local_port(ssh)); + free(s); + audit_fd = audit_open(); + if (audit_fd < 0) { + if (errno != EINVAL && errno != EPROTONOSUPPORT && + errno != EAFNOSUPPORT) + error("cannot open audit"); + return; + } + audit_ok = audit_log_user_message(audit_fd, AUDIT_CRYPTO_KEY_USER, + buf, NULL, ssh_remote_ipaddr(ssh), NULL, 1); + audit_close(audit_fd); + /* do not abort if the error is EPERM and sshd is run as non root user */ + if ((audit_ok < 0) && ((audit_ok != -1) || (getuid() == 0))) + error("cannot write into audit"); +} + +void +audit_destroy_sensitive_data(struct ssh *ssh, const char *fp, pid_t pid, uid_t uid) +{ + char buf[AUDIT_LOG_SIZE]; + int audit_fd, audit_ok; + + snprintf(buf, sizeof(buf), "op=destroy kind=server fp=%s direction=? spid=%jd suid=%jd ", + fp, (intmax_t)pid, (intmax_t)uid); + audit_fd = audit_open(); + if (audit_fd < 0) { + if (errno != EINVAL && errno != EPROTONOSUPPORT && + errno != EAFNOSUPPORT) + error("cannot open audit"); + return; + } + audit_ok = audit_log_user_message(audit_fd, AUDIT_CRYPTO_KEY_USER, + buf, NULL, + listening_for_clients() ? NULL : ssh_remote_ipaddr(ssh), + NULL, 1); + audit_close(audit_fd); + /* do not abort if the error is EPERM and sshd is run as non root user */ + if ((audit_ok < 0) && ((audit_ok != -1) || (getuid() == 0))) + error("cannot write into audit"); +} #endif /* USE_LINUX_AUDIT */ diff --git a/audit.c b/audit.c index dd2f035..c8d54b1 100644 --- a/audit.c +++ b/audit.c @@ -34,6 +34,12 @@ #include "log.h" #include "hostfile.h" #include "auth.h" +#include "ssh-gss.h" +#include "monitor_wrap.h" +#include "xmalloc.h" +#include "misc.h" +#include "servconf.h" +#include "ssherr.h" /* * Care must be taken when using this since it WILL NOT be initialized when @@ -41,6 +47,7 @@ * audit_event(CONNECTION_ABANDON) is called. Test for NULL before using. */ extern Authctxt *the_authctxt; +extern ServerOptions options; /* Maybe add the audit class to struct Authmethod? */ ssh_audit_event_t @@ -69,13 +76,10 @@ audit_classify_auth(const char *method) const char * audit_username(void) { - static const char unknownuser[] = "(unknown user)"; - static const char invaliduser[] = "(invalid user)"; + static const char unknownuser[] = "(unknown)"; - if (the_authctxt == NULL || the_authctxt->user == NULL) + if (the_authctxt == NULL || the_authctxt->user == NULL || !the_authctxt->valid) return (unknownuser); - if (!the_authctxt->valid) - return (invaliduser); return (the_authctxt->user); } @@ -109,6 +113,35 @@ audit_event_lookup(ssh_audit_event_t ev) return(event_lookup[i].name); } +void +audit_key(struct ssh *ssh, int host_user, int *rv, const struct sshkey *key) +{ + char *fp; + + fp = sshkey_fingerprint(key, options.fingerprint_hash, SSH_FP_HEX); + if (audit_keyusage(ssh, host_user, fp, (*rv == 0)) == 0) + *rv = -SSH_ERR_INTERNAL_ERROR; + free(fp); +} + +void +audit_unsupported(struct ssh *ssh, int what) +{ + PRIVSEP(audit_unsupported_body(ssh, what)); +} + +void +audit_kex(struct ssh *ssh, int ctos, char *enc, char *mac, char *comp, char *pfs) +{ + PRIVSEP(audit_kex_body(ssh, ctos, enc, mac, comp, pfs, getpid(), getuid())); +} + +void +audit_session_key_free(struct ssh *ssh, int ctos) +{ + PRIVSEP(audit_session_key_free_body(ssh, ctos, getpid(), getuid())); +} + # ifndef CUSTOM_SSH_AUDIT_EVENTS /* * Null implementations of audit functions. @@ -137,6 +170,17 @@ audit_event(struct ssh *ssh, ssh_audit_event_t event) audit_username(), event, audit_event_lookup(event)); } +/* + * Called when a child process has called, or will soon call, + * audit_session_open. + */ +void +audit_count_session_open(void) +{ + debug("audit count session open euid %d user %s", geteuid(), + audit_username()); +} + /* * Called when a user session is started. Argument is the tty allocated to * the session, or NULL if no tty was allocated. @@ -172,13 +216,82 @@ audit_session_close(struct logininfo *li) /* * This will be called when a user runs a non-interactive command. Note that * it may be called multiple times for a single connection since SSH2 allows - * multiple sessions within a single connection. + * multiple sessions within a single connection. Returns a "handle" for + * audit_end_command. */ -void -audit_run_command(const char *command) +int +audit_run_command(struct ssh *ssh, const char *command) { debug("audit run command euid %d user %s command '%.200s'", geteuid(), audit_username(), command); + return 0; +} + +/* + * This will be called when the non-interactive command finishes. Note that + * it may be called multiple times for a single connection since SSH2 allows + * multiple sessions within a single connection. "handle" should come from + * the corresponding audit_run_command. + */ +void +audit_end_command(struct ssh *ssh, int handle, const char *command) +{ + debug("audit end nopty exec euid %d user %s command '%.200s'", geteuid(), + audit_username(), command); +} + +/* + * This will be called when user is successfully autherized by the RSA1/RSA/DSA key. + * + * Type is the key type, len is the key length(byte) and fp is the fingerprint of the key. + */ +int +audit_keyusage(struct ssh *ssh, int host_user, char *fp, int rv) +{ + debug("audit %s key usage euid %d user %s fingerprint %s, result %d", + host_user ? "pubkey" : "hostbased", geteuid(), audit_username(), + fp, rv); +} + +/* + * This will be called when the protocol negotiation fails. + */ +void +audit_unsupported_body(struct ssh *ssh, int what) +{ + debug("audit unsupported protocol euid %d type %d", geteuid(), what); +} + +/* + * This will be called on succesfull protocol negotiation. + */ +void +audit_kex_body(struct ssh *ssh, int ctos, char *enc, char *mac, char *compress, char *pfs, pid_t pid, + uid_t uid) +{ + debug("audit protocol negotiation euid %d direction %d cipher %s mac %s compresion %s pfs %s from pid %ld uid %u", + (unsigned)geteuid(), ctos, enc, mac, compress, pfs, (long)pid, + (unsigned)uid); +} + +/* + * This will be called on succesfull session key discard + */ +void +audit_session_key_free_body(struct ssh *, int ctos, pid_t pid, uid_t uid) +{ + debug("audit session key discard euid %u direction %d from pid %ld uid %u", + (unsigned)geteuid(), ctos, (long)pid, (unsigned)uid); +} + +/* + * This will be called on destroy private part of the server key + */ +void +audit_destroy_sensitive_data(struct ssh *ssh, const char *fp, pid_t pid, uid_t uid) +{ + debug("audit destroy sensitive data euid %d fingerprint %s from pid %ld uid %u", + geteuid(), fp, (long)pid, (unsigned)uid); } # endif /* !defined CUSTOM_SSH_AUDIT_EVENTS */ #endif /* SSH_AUDIT_EVENTS */ diff --git a/audit.h b/audit.h index 38cb5ad..45d66cc 100644 --- a/audit.h +++ b/audit.h @@ -26,6 +26,7 @@ # define _SSH_AUDIT_H #include "loginrec.h" +#include "sshkey.h" struct ssh; @@ -45,13 +46,32 @@ enum ssh_audit_event_type { SSH_CONNECTION_ABANDON, /* closed without completing auth */ SSH_AUDIT_UNKNOWN }; + +enum ssh_audit_kex { + SSH_AUDIT_UNSUPPORTED_CIPHER, + SSH_AUDIT_UNSUPPORTED_MAC, + SSH_AUDIT_UNSUPPORTED_COMPRESSION +}; typedef enum ssh_audit_event_type ssh_audit_event_t; +int listening_for_clients(void); + void audit_connection_from(const char *, int); void audit_event(struct ssh *, ssh_audit_event_t); +void audit_count_session_open(void); void audit_session_open(struct logininfo *); void audit_session_close(struct logininfo *); -void audit_run_command(const char *); +int audit_run_command(struct ssh *, const char *); +void audit_end_command(struct ssh *, int, const char *); ssh_audit_event_t audit_classify_auth(const char *); +int audit_keyusage(struct ssh *, int, char *, int); +void audit_key(struct ssh *, int, int *, const struct sshkey *); +void audit_unsupported(struct ssh *, int); +void audit_kex(struct ssh *, int, char *, char *, char *, char *); +void audit_unsupported_body(struct ssh *, int); +void audit_kex_body(struct ssh *, int, char *, char *, char *, char *, pid_t, uid_t); +void audit_session_key_free(struct ssh *, int ctos); +void audit_session_key_free_body(struct ssh *, int ctos, pid_t, uid_t); +void audit_destroy_sensitive_data(struct ssh *, const char *, pid_t, uid_t); #endif /* _SSH_AUDIT_H */ diff --git a/auditstub.c b/auditstub.c new file mode 100644 index 0000000..639a798 --- /dev/null +++ b/auditstub.c @@ -0,0 +1,52 @@ +/* $Id: auditstub.c,v 1.1 jfch Exp $ */ + +/* + * Copyright 2010 Red Hat, Inc. All rights reserved. + * Use is subject to license terms. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Red Hat author: Jan F. Chadima <jchadima@redhat.com> + */ + +#include <sys/types.h> + +struct ssh; + +void +audit_unsupported(struct ssh *ssh, int n) +{ +} + +void +audit_kex(struct ssh *ssh, int ctos, char *enc, char *mac, char *comp, char *pfs) +{ +} + +void +audit_session_key_free(struct ssh *ssh, int ctos) +{ +} + +void +audit_session_key_free_body(struct ssh *ssh, int ctos, pid_t pid, uid_t uid) +{ +} diff --git a/auth.c b/auth.c index ab43955..5a4d11a 100644 --- a/auth.c +++ b/auth.c @@ -366,7 +366,7 @@ auth_log(struct ssh *ssh, int authenticated, int partial, # endif #endif #ifdef SSH_AUDIT_EVENTS - if (authenticated == 0 && !authctxt->postponed) + if (authenticated == 0 && !authctxt->postponed && !partial) audit_event(ssh, audit_classify_auth(method)); #endif } @@ -592,9 +592,6 @@ getpwnamallow(struct ssh *ssh, const char *user) record_failed_login(ssh, user, auth_get_canonical_hostname(ssh, options.use_dns), "ssh"); #endif -#ifdef SSH_AUDIT_EVENTS - audit_event(ssh, SSH_INVALID_USER); -#endif /* SSH_AUDIT_EVENTS */ return (NULL); } if (!allowed_user(ssh, pw)) diff --git a/auth.h b/auth.h index becc672..84532d0 100644 --- a/auth.h +++ b/auth.h @@ -189,6 +189,8 @@ struct passwd * getpwnamallow(struct ssh *, const char *user); char *expand_authorized_keys(const char *, struct passwd *pw); char *authorized_principals_file(struct passwd *); +int user_key_verify(struct ssh *, const struct sshkey *, const u_char *, size_t, + const u_char *, size_t, const char *, u_int); FILE *auth_openkeyfile(const char *, struct passwd *, int); FILE *auth_openprincipals(const char *, struct passwd *, int); @@ -208,6 +210,8 @@ struct sshkey *get_hostkey_private_by_type(int, int, struct ssh *); int get_hostkey_index(struct sshkey *, int, struct ssh *); int sshd_hostkey_sign(struct ssh *, struct sshkey *, struct sshkey *, u_char **, size_t *, const u_char *, size_t, const char *); +int hostbased_key_verify(struct ssh *, const struct sshkey *, const u_char *, size_t, + const u_char *, size_t, const char *, u_int); /* Key / cert options linkage to auth layer */ const struct sshauthopt *auth_options(struct ssh *); diff --git a/auth2-hostbased.c b/auth2-hostbased.c index d460470..de26444 100644 --- a/auth2-hostbased.c +++ b/auth2-hostbased.c @@ -150,7 +150,7 @@ userauth_hostbased(struct ssh *ssh) authenticated = 0; if (PRIVSEP(hostbased_key_allowed(ssh, authctxt->pw, cuser, chost, key)) && - PRIVSEP(sshkey_verify(key, sig, slen, + PRIVSEP(hostbased_key_verify(ssh, key, sig, slen, sshbuf_ptr(b), sshbuf_len(b), pkalg, ssh->compat)) == 0) authenticated = 1; @@ -167,6 +167,19 @@ done: return authenticated; } +int +hostbased_key_verify(struct ssh *ssh, const struct sshkey *key, const u_char *sig, + size_t slen, const u_char *data, size_t datalen, const char *pkalg, u_int compat) +{ + int rv; + + rv = sshkey_verify(key, sig, slen, data, datalen, pkalg, compat); +#ifdef SSH_AUDIT_EVENTS + audit_key(ssh, 0, &rv, key); +#endif + return rv; +} + /* return 1 if given hostkey is allowed */ int hostbased_key_allowed(struct ssh *ssh, struct passwd *pw, diff --git a/auth2-pubkey.c b/auth2-pubkey.c index df12c2c..6062b8b 100644 --- a/auth2-pubkey.c +++ b/auth2-pubkey.c @@ -210,7 +210,7 @@ userauth_pubkey(struct ssh *ssh) /* test for correct signature */ authenticated = 0; if (PRIVSEP(user_key_allowed(ssh, pw, key, 1, &authopts)) && - PRIVSEP(sshkey_verify(key, sig, slen, + PRIVSEP(user_key_verify(ssh, key, sig, slen, sshbuf_ptr(b), sshbuf_len(b), (ssh->compat & SSH_BUG_SIGTYPE) == 0 ? pkalg : NULL, ssh->compat)) == 0) { @@ -269,6 +269,19 @@ done: return authenticated; } +int +user_key_verify(struct ssh *ssh, const struct sshkey *key, const u_char *sig, + size_t slen, const u_char *data, size_t datalen, const char *pkalg, u_int compat) +{ + int rv; + + rv = sshkey_verify(key, sig, slen, data, datalen, pkalg, compat); +#ifdef SSH_AUDIT_EVENTS + audit_key(ssh, 1, &rv, key); +#endif + return rv; +} + static int match_principals_option(const char *principal_list, struct sshkey_cert *cert) { diff --git a/auth2.c b/auth2.c index 1c21726..e54509a 100644 --- a/auth2.c +++ b/auth2.c @@ -293,9 +293,6 @@ input_userauth_request(int type, u_int32_t seq, struct ssh *ssh) } else { /* Invalid user, fake password information */ authctxt->pw = fakepw(); -#ifdef SSH_AUDIT_EVENTS - PRIVSEP(audit_event(ssh, SSH_INVALID_USER)); -#endif } #ifdef USE_PAM if (options.use_pam) diff --git a/cipher.c b/cipher.c index b67a4ff..e0d23a5 100644 --- a/cipher.c +++ b/cipher.c @@ -58,25 +58,6 @@ #define EVP_CIPHER_CTX void #endif -struct sshcipher { - char *name; - u_int block_size; - u_int key_len; - u_int iv_len; /* defaults to block_size */ - u_int auth_len; - u_int flags; -#define CFLAG_CBC (1<<0) -#define CFLAG_CHACHAPOLY (1<<1) -#define CFLAG_AESCTR (1<<2) -#define CFLAG_NONE (1<<3) -#define CFLAG_INTERNAL CFLAG_NONE /* Don't use "none" for packets */ -#ifdef WITH_OPENSSL - const EVP_CIPHER *(*evptype)(void); -#else - void *ignored; -#endif -}; - static const struct sshcipher ciphers_all[] = { #ifdef WITH_OPENSSL #ifndef OPENSSL_NO_DES @@ -451,7 +432,7 @@ cipher_get_length(struct sshcipher_ctx *cc, u_int *plenp, u_int seqnr, void cipher_free(struct sshcipher_ctx *cc) { - if (cc == NULL) + if (cc == NULL || cc->cipher == NULL) return; if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) explicit_bzero(&cc->cp_ctx, sizeof(cc->cp_ctx)); diff --git a/cipher.h b/cipher.h index d7d8c89..2341068 100644 --- a/cipher.h +++ b/cipher.h @@ -47,7 +47,25 @@ #define CIPHER_ENCRYPT 1 #define CIPHER_DECRYPT 0 -struct sshcipher; +struct sshcipher { + char *name; + u_int block_size; + u_int key_len; + u_int iv_len; /* defaults to block_size */ + u_int auth_len; + u_int flags; +#define CFLAG_CBC (1<<0) +#define CFLAG_CHACHAPOLY (1<<1) +#define CFLAG_AESCTR (1<<2) +#define CFLAG_NONE (1<<3) +#define CFLAG_INTERNAL CFLAG_NONE /* Don't use "none" for packets */ +#ifdef WITH_OPENSSL + const EVP_CIPHER *(*evptype)(void); +#else + void *ignored; +#endif +}; + struct sshcipher_ctx { int plaintext; int encrypt; diff --git a/kex.c b/kex.c index 92d8ee0..96e44a5 100644 --- a/kex.c +++ b/kex.c @@ -60,6 +60,7 @@ #include "ssherr.h" #include "sshbuf.h" #include "digest.h" +#include "audit.h" #ifdef GSSAPI #include "ssh-gss.h" @@ -856,12 +857,16 @@ kex_start_rekex(struct ssh *ssh) } static int -choose_enc(struct sshenc *enc, char *client, char *server) +choose_enc(struct ssh *ssh, struct sshenc *enc, char *client, char *server) { char *name = match_list(client, server, NULL); - if (name == NULL) + if (name == NULL) { +#ifdef SSH_AUDIT_EVENTS + audit_unsupported(ssh, SSH_AUDIT_UNSUPPORTED_CIPHER); +#endif return SSH_ERR_NO_CIPHER_ALG_MATCH; + } if ((enc->cipher = cipher_by_name(name)) == NULL) { error("%s: unsupported cipher %s", __func__, name); free(name); @@ -882,8 +887,12 @@ choose_mac(struct ssh *ssh, struct sshmac *mac, char *client, char *server) { char *name = match_list(client, server, NULL); - if (name == NULL) + if (name == NULL) { +#ifdef SSH_AUDIT_EVENTS + audit_unsupported(ssh, SSH_AUDIT_UNSUPPORTED_MAC); +#endif return SSH_ERR_NO_MAC_ALG_MATCH; + } if (mac_setup(mac, name) < 0) { error("%s: unsupported MAC %s", __func__, name); free(name); @@ -896,12 +905,16 @@ choose_mac(struct ssh *ssh, struct sshmac *mac, char *client, char *server) } static int -choose_comp(struct sshcomp *comp, char *client, char *server) +choose_comp(struct ssh *ssh, struct sshcomp *comp, char *client, char *server) { char *name = match_list(client, server, NULL); - if (name == NULL) + if (name == NULL) { +#ifdef SSH_AUDIT_EVENTS + audit_unsupported(ssh, SSH_AUDIT_UNSUPPORTED_COMPRESSION); +#endif return SSH_ERR_NO_COMPRESS_ALG_MATCH; + } if (strcmp(name, "zlib@openssh.com") == 0) { comp->type = COMP_DELAYED; } else if (strcmp(name, "zlib") == 0) { @@ -1039,7 +1052,7 @@ kex_choose_conf(struct ssh *ssh) nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC; nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC; ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC; - if ((r = choose_enc(&newkeys->enc, cprop[nenc], + if ((r = choose_enc(ssh, &newkeys->enc, cprop[nenc], sprop[nenc])) != 0) { kex->failed_choice = peer[nenc]; peer[nenc] = NULL; @@ -1054,7 +1067,7 @@ kex_choose_conf(struct ssh *ssh) peer[nmac] = NULL; goto out; } - if ((r = choose_comp(&newkeys->comp, cprop[ncomp], + if ((r = choose_comp(ssh, &newkeys->comp, cprop[ncomp], sprop[ncomp])) != 0) { kex->failed_choice = peer[ncomp]; peer[ncomp] = NULL; @@ -1077,6 +1090,10 @@ kex_choose_conf(struct ssh *ssh) dh_need = MAXIMUM(dh_need, newkeys->enc.block_size); dh_need = MAXIMUM(dh_need, newkeys->enc.iv_len); dh_need = MAXIMUM(dh_need, newkeys->mac.key_len); + debug("kex: %s need=%d dh_need=%d", kex->name, need, dh_need); +#ifdef SSH_AUDIT_EVENTS + audit_kex(ssh, mode, newkeys->enc.name, newkeys->mac.name, newkeys->comp.name, kex->name); +#endif } /* XXX need runden? */ kex->we_need = need; @@ -1241,6 +1258,36 @@ dump_digest(const char *msg, const u_char *digest, int len) } #endif +static void +enc_destroy(struct sshenc *enc) +{ + if (enc == NULL) + return; + + if (enc->key) { + memset(enc->key, 0, enc->key_len); + free(enc->key); + } + + if (enc->iv) { + memset(enc->iv, 0, enc->iv_len); + free(enc->iv); + } + + memset(enc, 0, sizeof(*enc)); +} + +void +newkeys_destroy(struct newkeys *newkeys) +{ + if (newkeys == NULL) + return; + + enc_destroy(&newkeys->enc); + mac_destroy(&newkeys->mac); + memset(&newkeys->comp, 0, sizeof(newkeys->comp)); +} + /* * Send a plaintext error message to the peer, suffixed by \r\n. * Only used during banner exchange, and there only for the server. diff --git a/kex.h b/kex.h index 4dc48fd..fdf0cf6 100644 --- a/kex.h +++ b/kex.h @@ -226,6 +226,8 @@ int kexgss_client(struct ssh *); int kexgss_server(struct ssh *); #endif +void newkeys_destroy(struct newkeys *newkeys); + int kex_dh_keypair(struct kex *); int kex_dh_enc(struct kex *, const struct sshbuf *, struct sshbuf **, struct sshbuf **); diff --git a/mac.c b/mac.c index 90d71c8..6d87a80 100644 --- a/mac.c +++ b/mac.c @@ -277,6 +277,20 @@ mac_clear(struct sshmac *mac) mac->umac_ctx = NULL; } +void +mac_destroy(struct sshmac *mac) +{ + if (mac == NULL) + return; + + if (mac->key) { + memset(mac->key, 0, mac->key_len); + free(mac->key); + } + + memset(mac, 0, sizeof(*mac)); +} + /* XXX copied from ciphers_valid */ #define MAC_SEP "," int diff --git a/mac.h b/mac.h index 0b119d7..5fb593b 100644 --- a/mac.h +++ b/mac.h @@ -49,5 +49,6 @@ int mac_compute(struct sshmac *, u_int32_t, const u_char *, int, int mac_check(struct sshmac *, u_int32_t, const u_char *, size_t, const u_char *, size_t); void mac_clear(struct sshmac *); +void mac_destroy(struct sshmac *); #endif /* SSHMAC_H */ diff --git a/monitor.c b/monitor.c index 20812fa..2e421cf 100644 --- a/monitor.c +++ b/monitor.c @@ -93,6 +93,7 @@ #include "compat.h" #include "ssh2.h" #include "authfd.h" +#include "audit.h" #include "match.h" #include "ssherr.h" @@ -107,6 +108,8 @@ extern u_char session_id[]; extern struct sshbuf *loginmsg; extern struct sshauthopt *auth_opts; /* XXX move to permanent ssh->authctxt? */ +extern void destroy_sensitive_data(struct ssh *, int); + /* State exported from the child */ static struct sshbuf *child_state; @@ -154,6 +157,11 @@ int mm_answer_gss_updatecreds(struct ssh*, int, struct sshbuf *); #ifdef SSH_AUDIT_EVENTS int mm_answer_audit_event(struct ssh *, int, struct sshbuf *); int mm_answer_audit_command(struct ssh *, int, struct sshbuf *); +int mm_answer_audit_end_command(struct ssh *, int, struct sshbuf *); +int mm_answer_audit_unsupported_body(struct ssh *, int, struct sshbuf *); +int mm_answer_audit_kex_body(struct ssh *, int, struct sshbuf *); +int mm_answer_audit_session_key_free_body(struct ssh *, int, struct sshbuf *); +int mm_answer_audit_server_key_free(struct ssh *, int, struct sshbuf *); #endif static Authctxt *authctxt; @@ -209,6 +217,10 @@ struct mon_table mon_dispatch_proto20[] = { #endif #ifdef SSH_AUDIT_EVENTS {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, + {MONITOR_REQ_AUDIT_UNSUPPORTED, MON_PERMIT, mm_answer_audit_unsupported_body}, + {MONITOR_REQ_AUDIT_KEX, MON_PERMIT, mm_answer_audit_kex_body}, + {MONITOR_REQ_AUDIT_SESSION_KEY_FREE, MON_PERMIT, mm_answer_audit_session_key_free_body}, + {MONITOR_REQ_AUDIT_SERVER_KEY_FREE, MON_PERMIT, mm_answer_audit_server_key_free}, #endif #ifdef BSD_AUTH {MONITOR_REQ_BSDAUTHQUERY, MON_ISAUTH, mm_answer_bsdauthquery}, @@ -243,6 +255,11 @@ struct mon_table mon_dispatch_postauth20[] = { #ifdef SSH_AUDIT_EVENTS {MONITOR_REQ_AUDIT_EVENT, MON_PERMIT, mm_answer_audit_event}, {MONITOR_REQ_AUDIT_COMMAND, MON_PERMIT, mm_answer_audit_command}, + {MONITOR_REQ_AUDIT_END_COMMAND, MON_PERMIT, mm_answer_audit_end_command}, + {MONITOR_REQ_AUDIT_UNSUPPORTED, MON_PERMIT, mm_answer_audit_unsupported_body}, + {MONITOR_REQ_AUDIT_KEX, MON_PERMIT, mm_answer_audit_kex_body}, + {MONITOR_REQ_AUDIT_SESSION_KEY_FREE, MON_PERMIT, mm_answer_audit_session_key_free_body}, + {MONITOR_REQ_AUDIT_SERVER_KEY_FREE, MON_PERMIT, mm_answer_audit_server_key_free}, #endif {0, 0, NULL} }; @@ -1408,8 +1425,10 @@ mm_answer_keyverify(struct ssh *ssh, int sock, struct sshbuf *m) char *sigalg; size_t signaturelen, datalen, bloblen; int r, ret, valid_data = 0, encoded_ret; + int type = 0; - if ((r = sshbuf_get_string(m, &blob, &bloblen)) != 0 || + if ((r = sshbuf_get_u32(m, &type)) != 0 || + (r = sshbuf_get_string(m, &blob, &bloblen)) != 0 || (r = sshbuf_get_string(m, &signature, &signaturelen)) != 0 || (r = sshbuf_get_string(m, &data, &datalen)) != 0 || (r = sshbuf_get_cstring(m, &sigalg, NULL)) != 0) @@ -1418,6 +1437,8 @@ mm_answer_keyverify(struct ssh *ssh, int sock, struct sshbuf *m) if (hostbased_cuser == NULL || hostbased_chost == NULL || !monitor_allowed_key(blob, bloblen)) fatal("%s: bad key, not previously allowed", __func__); + if (type != key_blobtype) + fatal("%s: bad key type", __func__); /* Empty signature algorithm means NULL. */ if (*sigalg == '\0') { @@ -1433,21 +1454,24 @@ mm_answer_keyverify(struct ssh *ssh, int sock, struct sshbuf *m) case MM_USERKEY: valid_data = monitor_valid_userblob(data, datalen); auth_method = "publickey"; + ret = user_key_verify(ssh, key, signature, signaturelen, data, + datalen, sigalg, ssh->compat); break; case MM_HOSTKEY: valid_data = monitor_valid_hostbasedblob(data, datalen, hostbased_cuser, hostbased_chost); + ret = hostbased_key_verify(ssh, key, signature, signaturelen, data, + datalen, sigalg, ssh->compat); auth_method = "hostbased"; break; default: valid_data = 0; + ret = 0; break; } if (!valid_data) fatal("%s: bad signature data blob", __func__); - ret = sshkey_verify(key, signature, signaturelen, data, datalen, - sigalg, ssh->compat); debug3("%s: %s %p signature %s", __func__, auth_method, key, (ret == 0) ? "verified" : "unverified"); auth2_record_key(authctxt, ret == 0, key); @@ -1499,13 +1523,19 @@ mm_record_login(struct ssh *ssh, Session *s, struct passwd *pw) } static void -mm_session_close(Session *s) +mm_session_close(struct ssh *ssh, Session *s) { debug3("%s: session %d pid %ld", __func__, s->self, (long)s->pid); if (s->ttyfd != -1) { debug3("%s: tty %s ptyfd %d", __func__, s->tty, s->ptyfd); session_pty_cleanup2(s); } +#ifdef SSH_AUDIT_EVENTS + if (s->command != NULL) { + debug3("%s: command %d", __func__, s->command_handle); + session_end_command2(ssh, s); + } +#endif session_unused(s->self); } @@ -1572,7 +1602,7 @@ mm_answer_pty(struct ssh *ssh, int sock, struct sshbuf *m) error: if (s != NULL) - mm_session_close(s); + mm_session_close(ssh, s); if ((r = sshbuf_put_u32(m, 0)) != 0) fatal("%s: buffer error: %s", __func__, ssh_err(r)); mm_request_send(sock, MONITOR_ANS_PTY, m); @@ -1591,7 +1621,7 @@ mm_answer_pty_cleanup(struct ssh *ssh, int sock, struct sshbuf *m) if ((r = sshbuf_get_cstring(m, &tty, NULL)) != 0) fatal("%s: buffer error: %s", __func__, ssh_err(r)); if ((s = session_by_tty(tty)) != NULL) - mm_session_close(s); + mm_session_close(ssh, s); sshbuf_reset(m); free(tty); return (0); @@ -1613,6 +1643,8 @@ mm_answer_term(struct ssh *ssh, int sock, struct sshbuf *req) sshpam_cleanup(); #endif + destroy_sensitive_data(ssh, 0); + while (waitpid(pmonitor->m_pid, &status, 0) == -1) if (errno != EINTR) exit(1); @@ -1659,12 +1691,47 @@ mm_answer_audit_command(struct ssh *ssh, int socket, struct sshbuf *m) { char *cmd; int r; + Session *s; debug3("%s entering", __func__); if ((r = sshbuf_get_cstring(m, &cmd, NULL)) != 0) fatal("%s: buffer error: %s", __func__, ssh_err(r)); + /* sanity check command, if so how? */ - audit_run_command(cmd); + s = session_new(); + if (s == NULL) + fatal("%s: error allocating a session", __func__); + s->command = cmd; +#ifdef SSH_AUDIT_EVENTS + s->command_handle = audit_run_command(ssh, cmd); +#endif + + sshbuf_reset(m); + sshbuf_put_u32(m, s->self); + + mm_request_send(socket, MONITOR_ANS_AUDIT_COMMAND, m); + + return (0); +} + +int +mm_answer_audit_end_command(struct ssh *ssh, int socket, struct sshbuf *m) +{ + int handle, r; + size_t len; + u_char *cmd = NULL; + Session *s; + + debug3("%s entering", __func__); + if ((r = sshbuf_get_u32(m, &handle)) != 0 || + (r = sshbuf_get_string(m, &cmd, &len)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + + s = session_by_id(handle); + if (s == NULL || s->ttyfd != -1 || s->command == NULL || + strcmp(s->command, cmd) != 0) + fatal("%s: invalid handle", __func__); + mm_session_close(ssh, s); free(cmd); return (0); } @@ -1730,6 +1797,7 @@ monitor_apply_keystate(struct ssh *ssh, struct monitor *pmonitor) void mm_get_keystate(struct ssh *ssh, struct monitor *pmonitor) { + struct sshbuf *m; debug3("%s: Waiting for new keys", __func__); if ((child_state = sshbuf_new()) == NULL) @@ -1737,6 +1805,19 @@ mm_get_keystate(struct ssh *ssh, struct monitor *pmonitor) mm_request_receive_expect(pmonitor->m_sendfd, MONITOR_REQ_KEYEXPORT, child_state); debug3("%s: GOT new keys", __func__); + +#ifdef SSH_AUDIT_EVENTS + m = sshbuf_new(); + mm_request_receive_expect(pmonitor->m_sendfd, + MONITOR_REQ_AUDIT_SESSION_KEY_FREE, m); + mm_answer_audit_session_key_free_body(ssh, pmonitor->m_sendfd, m); + sshbuf_free(m); +#endif + + /* Drain any buffered messages from the child */ + while (pmonitor->m_log_recvfd >= 0 && monitor_read_log(pmonitor) == 0) + ; + } @@ -2014,3 +2095,102 @@ mm_answer_gss_updatecreds(struct ssh *ssh, int socket, struct sshbuf *m) { #endif /* GSSAPI */ +#ifdef SSH_AUDIT_EVENTS +int +mm_answer_audit_unsupported_body(struct ssh *ssh, int sock, struct sshbuf *m) +{ + int what, r; + + if ((r = sshbuf_get_u32(m, &what)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + + audit_unsupported_body(ssh, what); + + sshbuf_reset(m); + + mm_request_send(sock, MONITOR_ANS_AUDIT_UNSUPPORTED, m); + return 0; +} + +int +mm_answer_audit_kex_body(struct ssh *ssh, int sock, struct sshbuf *m) +{ + int ctos, r; + char *cipher, *mac, *compress, *pfs; + u_int64_t tmp; + pid_t pid; + uid_t uid; + + if ((r = sshbuf_get_u32(m, &ctos)) != 0 || + (r = sshbuf_get_cstring(m, &cipher, NULL)) != 0 || + (r = sshbuf_get_cstring(m, &mac, NULL)) != 0 || + (r = sshbuf_get_cstring(m, &compress, NULL)) != 0 || + (r = sshbuf_get_cstring(m, &pfs, NULL)) != 0 || + (r = sshbuf_get_u64(m, &tmp)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + pid = (pid_t) tmp; + if ((r = sshbuf_get_u64(m, &tmp)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + uid = (pid_t) tmp; + + audit_kex_body(ssh, ctos, cipher, mac, compress, pfs, pid, uid); + + free(cipher); + free(mac); + free(compress); + free(pfs); + sshbuf_reset(m); + + mm_request_send(sock, MONITOR_ANS_AUDIT_KEX, m); + return 0; +} + +int +mm_answer_audit_session_key_free_body(struct ssh *ssh, int sock, struct sshbuf *m) +{ + int ctos, r; + u_int64_t tmp; + pid_t pid; + uid_t uid; + + if ((r = sshbuf_get_u32(m, &ctos)) != 0 || + (r = sshbuf_get_u64(m, &tmp)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + pid = (pid_t) tmp; + if ((r = sshbuf_get_u64(m, &tmp)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + uid = (uid_t) tmp; + + audit_session_key_free_body(ssh, ctos, pid, uid); + + sshbuf_reset(m); + + mm_request_send(sock, MONITOR_ANS_AUDIT_SESSION_KEY_FREE, m); + return 0; +} + +int +mm_answer_audit_server_key_free(struct ssh *ssh, int sock, struct sshbuf *m) +{ + size_t len, r; + char *fp; + u_int64_t tmp; + pid_t pid; + uid_t uid; + + if ((r = sshbuf_get_cstring(m, &fp, &len)) != 0 || + (r = sshbuf_get_u64(m, &tmp)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + pid = (pid_t) tmp; + if ((r = sshbuf_get_u64(m, &tmp)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + uid = (uid_t) tmp; + + audit_destroy_sensitive_data(ssh, fp, pid, uid); + + free(fp); + sshbuf_reset(m); + + return 0; +} +#endif /* SSH_AUDIT_EVENTS */ diff --git a/monitor.h b/monitor.h index 2b1a2d5..7817990 100644 --- a/monitor.h +++ b/monitor.h @@ -61,7 +61,13 @@ enum monitor_reqtype { MONITOR_REQ_PAM_QUERY = 106, MONITOR_ANS_PAM_QUERY = 107, MONITOR_REQ_PAM_RESPOND = 108, MONITOR_ANS_PAM_RESPOND = 109, MONITOR_REQ_PAM_FREE_CTX = 110, MONITOR_ANS_PAM_FREE_CTX = 111, - MONITOR_REQ_AUDIT_EVENT = 112, MONITOR_REQ_AUDIT_COMMAND = 113, + MONITOR_REQ_AUDIT_EVENT = 112, + MONITOR_REQ_AUDIT_COMMAND = 114, MONITOR_ANS_AUDIT_COMMAND = 115, + MONITOR_REQ_AUDIT_END_COMMAND = 116, + MONITOR_REQ_AUDIT_UNSUPPORTED = 118, MONITOR_ANS_AUDIT_UNSUPPORTED = 119, + MONITOR_REQ_AUDIT_KEX = 120, MONITOR_ANS_AUDIT_KEX = 121, + MONITOR_REQ_AUDIT_SESSION_KEY_FREE = 122, MONITOR_ANS_AUDIT_SESSION_KEY_FREE = 123, + MONITOR_REQ_AUDIT_SERVER_KEY_FREE = 124, MONITOR_REQ_GSSSIGN = 150, MONITOR_ANS_GSSSIGN = 151, MONITOR_REQ_GSSUPCREDS = 152, MONITOR_ANS_GSSUPCREDS = 153, diff --git a/monitor_wrap.c b/monitor_wrap.c index fdca39a..b427dd6 100644 --- a/monitor_wrap.c +++ b/monitor_wrap.c @@ -492,7 +492,7 @@ mm_key_allowed(enum mm_keytype type, const char *user, const char *host, */ int -mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, +mm_sshkey_verify(enum mm_keytype type, const struct sshkey *key, const u_char *sig, size_t siglen, const u_char *data, size_t datalen, const char *sigalg, u_int compat) { struct sshbuf *m; @@ -504,7 +504,8 @@ mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, if ((m = sshbuf_new()) == NULL) fatal("%s: sshbuf_new failed", __func__); - if ((r = sshkey_puts(key, m)) != 0 || + if ((r = sshbuf_put_u32(m, type)) != 0 || + (r = sshkey_puts(key, m)) != 0 || (r = sshbuf_put_string(m, sig, siglen)) != 0 || (r = sshbuf_put_string(m, data, datalen)) != 0 || (r = sshbuf_put_cstring(m, sigalg == NULL ? "" : sigalg)) != 0) @@ -526,6 +527,20 @@ mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, return 0; } +int +mm_hostbased_key_verify(struct ssh *ssh, const struct sshkey *key, const u_char *sig, size_t siglen, + const u_char *data, size_t datalen, const char *pkalg, u_int compat) +{ + return mm_sshkey_verify(MM_HOSTKEY, key, sig, siglen, data, datalen, pkalg, compat); +} + +int +mm_user_key_verify(struct ssh *ssh, const struct sshkey *key, const u_char *sig, size_t siglen, + const u_char *data, size_t datalen, const char *pkalg, u_int compat) +{ + return mm_sshkey_verify(MM_USERKEY, key, sig, siglen, data, datalen, pkalg, compat); +} + void mm_send_keystate(struct ssh *ssh, struct monitor *monitor) { @@ -879,11 +894,12 @@ mm_audit_event(struct ssh *ssh, ssh_audit_event_t event) sshbuf_free(m); } -void -mm_audit_run_command(const char *command) +int +mm_audit_run_command(struct ssh *ssh, const char *command) { struct sshbuf *m; int r; + int handle; debug3("%s entering command %s", __func__, command); @@ -893,6 +909,30 @@ mm_audit_run_command(const char *command) fatal("%s: buffer error: %s", __func__, ssh_err(r)); mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_COMMAND, m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUDIT_COMMAND, m); + + if ((r = sshbuf_get_u32(m, &handle)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + sshbuf_free(m); + + return (handle); +} + +void +mm_audit_end_command(struct ssh *ssh, int handle, const char *command) +{ + int r; + struct sshbuf *m; + + debug3("%s entering command %s", __func__, command); + + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); + if ((r = sshbuf_put_u32(m, handle)) != 0 || + (r = sshbuf_put_cstring(m, command)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_END_COMMAND, m); sshbuf_free(m); } #endif /* SSH_AUDIT_EVENTS */ @@ -1053,3 +1093,83 @@ mm_ssh_gssapi_update_creds(ssh_gssapi_ccache *store) } #endif /* GSSAPI */ +#ifdef SSH_AUDIT_EVENTS +void +mm_audit_unsupported_body(struct ssh *ssh, int what) +{ + int r; + struct sshbuf *m; + + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); + if ((r = sshbuf_put_u32(m, what)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_UNSUPPORTED, m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUDIT_UNSUPPORTED, + m); + + sshbuf_free(m); +} + +void +mm_audit_kex_body(struct ssh *ssh, int ctos, char *cipher, char *mac, char *compress, char *fps, pid_t pid, + uid_t uid) +{ + int r; + struct sshbuf *m; + + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); + if ((r = sshbuf_put_u32(m, ctos)) != 0 || + (r = sshbuf_put_cstring(m, cipher)) != 0 || + (r = sshbuf_put_cstring(m, (mac ? mac : "<implicit>"))) != 0 || + (r = sshbuf_put_cstring(m, compress)) != 0 || + (r = sshbuf_put_cstring(m, fps)) != 0 || + (r = sshbuf_put_u64(m, pid)) != 0 || + (r = sshbuf_put_u64(m, uid)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_KEX, m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUDIT_KEX, + m); + + sshbuf_free(m); +} + +void +mm_audit_session_key_free_body(struct ssh *ssh, int ctos, pid_t pid, uid_t uid) +{ + int r; + struct sshbuf *m; + + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); + if ((r = sshbuf_put_u32(m, ctos)) != 0 || + (r = sshbuf_put_u64(m, pid)) != 0 || + (r = sshbuf_put_u64(m, uid)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_SESSION_KEY_FREE, m); + mm_request_receive_expect(pmonitor->m_recvfd, MONITOR_ANS_AUDIT_SESSION_KEY_FREE, + m); + sshbuf_free(m); +} + +void +mm_audit_destroy_sensitive_data(struct ssh *ssh, const char *fp, pid_t pid, uid_t uid) +{ + int r; + struct sshbuf *m; + + if ((m = sshbuf_new()) == NULL) + fatal("%s: sshbuf_new failed", __func__); + if ((r = sshbuf_put_cstring(m, fp)) != 0 || + (r = sshbuf_put_u64(m, pid)) != 0 || + (r = sshbuf_put_u64(m, uid)) != 0) + fatal("%s: buffer error: %s", __func__, ssh_err(r)); + + mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_AUDIT_SERVER_KEY_FREE, m); + sshbuf_free(m); +} +#endif /* SSH_AUDIT_EVENTS */ diff --git a/monitor_wrap.h b/monitor_wrap.h index 92dda57..d413dac 100644 --- a/monitor_wrap.h +++ b/monitor_wrap.h @@ -56,7 +56,9 @@ int mm_user_key_allowed(struct ssh *, struct passwd *, struct sshkey *, int, struct sshauthopt **); int mm_hostbased_key_allowed(struct ssh *, struct passwd *, const char *, const char *, struct sshkey *); -int mm_sshkey_verify(const struct sshkey *, const u_char *, size_t, +int mm_hostbased_key_verify(struct ssh *, const struct sshkey *, const u_char *, size_t, + const u_char *, size_t, const char *, u_int); +int mm_user_key_verify(struct ssh*, const struct sshkey *, const u_char *, size_t, const u_char *, size_t, const char *, u_int); #ifdef GSSAPI @@ -81,7 +83,12 @@ void mm_sshpam_free_ctx(void *); #ifdef SSH_AUDIT_EVENTS #include "audit.h" void mm_audit_event(struct ssh *, ssh_audit_event_t); -void mm_audit_run_command(const char *); +int mm_audit_run_command(struct ssh *ssh, const char *); +void mm_audit_end_command(struct ssh *ssh, int, const char *); +void mm_audit_unsupported_body(struct ssh *, int); +void mm_audit_kex_body(struct ssh *, int, char *, char *, char *, char *, pid_t, uid_t); +void mm_audit_session_key_free_body(struct ssh *, int, pid_t, uid_t); +void mm_audit_destroy_sensitive_data(struct ssh *, const char *, pid_t, uid_t); #endif struct Session; diff --git a/packet.c b/packet.c index 817da43..aec02e4 100644 --- a/packet.c +++ b/packet.c @@ -77,6 +77,7 @@ #include <zlib.h> #include "xmalloc.h" +#include "audit.h" #include "compat.h" #include "ssh2.h" #include "cipher.h" @@ -509,6 +510,13 @@ ssh_packet_get_connection_out(struct ssh *ssh) return ssh->state->connection_out; } +static int +packet_state_has_keys (const struct session_state *state) +{ + return state != NULL && + (state->newkeys[MODE_IN] != NULL || state->newkeys[MODE_OUT] != NULL); +} + /* * Returns the IP-address of the remote host as a string. The returned * string must not be freed. @@ -586,22 +594,19 @@ ssh_packet_close_internal(struct ssh *ssh, int do_close) { struct session_state *state = ssh->state; u_int mode; + u_int had_keys = packet_state_has_keys(state); if (!state->initialized) return; state->initialized = 0; - if (do_close) { - if (state->connection_in == state->connection_out) { - close(state->connection_out); - } else { - close(state->connection_in); - close(state->connection_out); - } - } sshbuf_free(state->input); + state->input = NULL; sshbuf_free(state->output); + state->output = NULL; sshbuf_free(state->outgoing_packet); + state->outgoing_packet = NULL; sshbuf_free(state->incoming_packet); + state->incoming_packet = NULL; for (mode = 0; mode < MODE_MAX; mode++) { kex_free_newkeys(state->newkeys[mode]); /* current keys */ state->newkeys[mode] = NULL; @@ -635,8 +640,18 @@ ssh_packet_close_internal(struct ssh *ssh, int do_close) } cipher_free(state->send_context); cipher_free(state->receive_context); + if (had_keys && state->server_side) { + /* Assuming this is called only from privsep child */ + audit_session_key_free(ssh, MODE_MAX); + } state->send_context = state->receive_context = NULL; if (do_close) { + if (state->connection_in == state->connection_out) { + close(state->connection_out); + } else { + close(state->connection_in); + close(state->connection_out); + } free(ssh->local_ipaddr); ssh->local_ipaddr = NULL; free(ssh->remote_ipaddr); @@ -863,6 +878,7 @@ ssh_set_newkeys(struct ssh *ssh, int mode) (unsigned long long)state->p_send.bytes, (unsigned long long)state->p_send.blocks); kex_free_newkeys(state->newkeys[mode]); + audit_session_key_free(ssh, mode); state->newkeys[mode] = NULL; } /* note that both bytes and the seqnr are not reset */ @@ -2166,6 +2182,71 @@ ssh_packet_get_output(struct ssh *ssh) return (void *)ssh->state->output; } +static void +newkeys_destroy_and_free(struct newkeys *newkeys) +{ + if (newkeys == NULL) + return; + + free(newkeys->enc.name); + + if (newkeys->mac.enabled) { + mac_clear(&newkeys->mac); + free(newkeys->mac.name); + } + + free(newkeys->comp.name); + + newkeys_destroy(newkeys); + free(newkeys); +} + +static void +packet_destroy_state(struct session_state *state) +{ + if (state == NULL) + return; + + cipher_free(state->receive_context); + cipher_free(state->send_context); + + sshbuf_free(state->input); + state->input = NULL; + sshbuf_free(state->output); + state->output = NULL; + sshbuf_free(state->outgoing_packet); + state->outgoing_packet = NULL; + sshbuf_free(state->incoming_packet); + state->incoming_packet = NULL; + if (state->compression_buffer) { + sshbuf_free(state->compression_buffer); + state->compression_buffer = NULL; + } + newkeys_destroy_and_free(state->newkeys[MODE_IN]); + state->newkeys[MODE_IN] = NULL; + newkeys_destroy_and_free(state->newkeys[MODE_OUT]); + state->newkeys[MODE_OUT] = NULL; + mac_destroy(state->packet_discard_mac); +// TAILQ_HEAD(, packet) outgoing; +// memset(state, 0, sizeof(state)); +} + +void +packet_destroy_all(struct ssh *ssh, int audit_it, int privsep) +{ + if (audit_it) + audit_it = packet_state_has_keys(ssh->state); + packet_destroy_state(ssh->state); + if (audit_it) { +#ifdef SSH_AUDIT_EVENTS + if (privsep) + audit_session_key_free(ssh, MODE_MAX); + else + audit_session_key_free_body(ssh, MODE_MAX, getpid(), getuid()); +#endif + } +} + /* Reset after_authentication and reset compression in post-auth privsep */ static int ssh_packet_set_postauth(struct ssh *ssh) diff --git a/packet.h b/packet.h index 8ccfd2e..cfd9ebe 100644 --- a/packet.h +++ b/packet.h @@ -217,4 +217,5 @@ const u_char *sshpkt_ptr(struct ssh *, size_t *lenp); # undef EC_POINT #endif +void packet_destroy_all(struct ssh *, int, int); #endif /* PACKET_H */ diff --git a/session.c b/session.c index 89f9539..07411f3 100644 --- a/session.c +++ b/session.c @@ -136,7 +136,7 @@ extern char *__progname; extern int debug_flag; extern u_int utmp_len; extern int startup_pipe; -extern void destroy_sensitive_data(void); +extern void destroy_sensitive_data(struct ssh *, int); extern struct sshbuf *loginmsg; extern struct sshauthopt *auth_opts; extern char *tun_fwd_ifnames; /* serverloop.c */ @@ -647,6 +647,14 @@ do_exec_pty(struct ssh *ssh, Session *s, const char *command) /* Parent. Close the slave side of the pseudo tty. */ close(ttyfd); +#if !defined(HAVE_OSF_SIA) && defined(SSH_AUDIT_EVENTS) + /* do_login in the child did not affect state in this process, + compensate. From an architectural standpoint, this is extremely + ugly. */ + if (command != NULL) + audit_count_session_open(); +#endif + /* Enter interactive session. */ s->ptymaster = ptymaster; ssh_packet_set_interactive(ssh, 1, @@ -711,15 +719,19 @@ do_exec(struct ssh *ssh, Session *s, const char *command) s->self); #ifdef SSH_AUDIT_EVENTS + if (s->command != NULL || s->command_handle != -1) + fatal("do_exec: command already set"); if (command != NULL) - PRIVSEP(audit_run_command(command)); + s->command = xstrdup(command); else if (s->ttyfd == -1) { char *shell = s->pw->pw_shell; if (shell[0] == '\0') /* empty shell means /bin/sh */ shell =_PATH_BSHELL; - PRIVSEP(audit_run_command(shell)); + s->command = xstrdup(shell); } + if (s->command != NULL && s->ptyfd == -1) + s->command_handle = PRIVSEP(audit_run_command(ssh, s->command)); #endif if (s->ttyfd != -1) ret = do_exec_pty(ssh, s, command); @@ -1531,8 +1543,11 @@ do_child(struct ssh *ssh, Session *s, const char *command) sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id)); /* remove hostkey from the child's memory */ - destroy_sensitive_data(); + destroy_sensitive_data(ssh, 1); ssh_packet_clear_keys(ssh); + /* Don't audit this - both us and the parent would be talking to the + monitor over a single socket, with no synchronization. */ + packet_destroy_all(ssh, 0, 1); /* Force a password change */ if (s->authctxt->force_pwchange) { @@ -1741,6 +1756,9 @@ session_unused(int id) sessions[id].ttyfd = -1; sessions[id].ptymaster = -1; sessions[id].x11_chanids = NULL; +#ifdef SSH_AUDIT_EVENTS + sessions[id].command_handle = -1; +#endif sessions[id].next_unused = sessions_first_unused; sessions_first_unused = id; } @@ -1822,6 +1840,19 @@ session_open(Authctxt *authctxt, int chanid) return 1; } +Session * +session_by_id(int id) +{ + if (id >= 0 && id < sessions_nalloc) { + Session *s = &sessions[id]; + if (s->used) + return s; + } + debug("%s: unknown id %d", __func__, id); + session_dump(); + return NULL; +} + Session * session_by_tty(char *tty) { @@ -2433,6 +2464,32 @@ session_exit_message(struct ssh *ssh, Session *s, int status) chan_write_failed(ssh, c); } +#ifdef SSH_AUDIT_EVENTS +void +session_end_command2(struct ssh *ssh, Session *s) +{ + if (s->command != NULL) { + if (s->command_handle != -1) + audit_end_command(ssh, s->command_handle, s->command); + free(s->command); + s->command = NULL; + s->command_handle = -1; + } +} + +static void +session_end_command(struct ssh *ssh, Session *s) +{ + if (s->command != NULL) { + if (s->command_handle != -1) + PRIVSEP(audit_end_command(ssh, s->command_handle, s->command)); + free(s->command); + s->command = NULL; + s->command_handle = -1; + } +} +#endif + void session_close(struct ssh *ssh, Session *s) { @@ -2474,6 +2531,10 @@ session_close(struct ssh *ssh, Session *s) if (s->ttyfd != -1) session_pty_cleanup(s); +#ifdef SSH_AUDIT_EVENTS + if (s->command) + session_end_command(ssh, s); +#endif free(s->term); free(s->display); free(s->x11_chanids); @@ -2549,14 +2610,14 @@ session_close_by_channel(struct ssh *ssh, int id, void *arg) } void -session_destroy_all(struct ssh *ssh, void (*closefunc)(Session *)) +session_destroy_all(struct ssh *ssh, void (*closefunc)(struct ssh *ssh, Session *)) { int i; for (i = 0; i < sessions_nalloc; i++) { Session *s = &sessions[i]; if (s->used) { if (closefunc != NULL) - closefunc(s); + closefunc(ssh, s); else session_close(ssh, s); } @@ -2682,6 +2743,15 @@ do_authenticated2(struct ssh *ssh, Authctxt *authctxt) server_loop2(ssh, authctxt); } +static void +do_cleanup_one_session(struct ssh *ssh, Session *s) +{ + session_pty_cleanup2(s); +#ifdef SSH_AUDIT_EVENTS + session_end_command2(ssh, s); +#endif +} + void do_cleanup(struct ssh *ssh, Authctxt *authctxt) { @@ -2745,7 +2815,7 @@ do_cleanup(struct ssh *ssh, Authctxt *authctxt) * or if running in monitor. */ if (!use_privsep || mm_is_monitor()) - session_destroy_all(ssh, session_pty_cleanup2); + session_destroy_all(ssh, do_cleanup_one_session); } /* Return a name for the remote host that fits inside utmp_size */ diff --git a/session.h b/session.h index ce59dab..bcd4b1d 100644 --- a/session.h +++ b/session.h @@ -61,6 +61,12 @@ struct Session { char *name; char *val; } *env; + + /* exec */ +#ifdef SSH_AUDIT_EVENTS + int command_handle; + char *command; +#endif }; void do_authenticated(struct ssh *, Authctxt *); @@ -71,10 +77,12 @@ void session_unused(int); int session_input_channel_req(struct ssh *, Channel *, const char *); void session_close_by_pid(struct ssh *ssh, pid_t, int); void session_close_by_channel(struct ssh *, int, void *); -void session_destroy_all(struct ssh *, void (*)(Session *)); +void session_destroy_all(struct ssh *, void (*)(struct ssh*, Session *)); void session_pty_cleanup2(Session *); +void session_end_command2(struct ssh *ssh, Session *); Session *session_new(void); +Session *session_by_id(int); Session *session_by_tty(char *); void session_close(struct ssh *, Session *); void do_setusercontext(struct passwd *); diff --git a/sshd.c b/sshd.c index 0d5c4c4..dca7b1e 100644 --- a/sshd.c +++ b/sshd.c @@ -124,6 +124,7 @@ #include "ssh-gss.h" #endif #include "monitor_wrap.h" +#include "audit.h" #include "ssh-sandbox.h" #include "auth-options.h" #include "version.h" @@ -272,8 +273,8 @@ struct sshbuf *loginmsg; struct passwd *privsep_pw = NULL; /* Prototypes for various functions defined later in this file. */ -void destroy_sensitive_data(void); -void demote_sensitive_data(void); +void destroy_sensitive_data(struct ssh *, int); +void demote_sensitive_data(struct ssh *); static void do_ssh2_kex(struct ssh *); /* @@ -289,6 +290,15 @@ close_listen_socks(void) num_listen_socks = -1; } +/* + * Is this process listening for clients (i.e. not specific to any specific + * client connection?) + */ +int listening_for_clients(void) +{ + return num_listen_socks >= 0; +} + static void close_startup_pipes(void) { @@ -395,18 +405,45 @@ grace_alarm_handler(int sig) ssh_remote_port(the_active_state)); } -/* Destroy the host and server keys. They will no longer be needed. */ +/* + * Destroy the host and server keys. They will no longer be needed. Careful, + * this can be called from cleanup_exit() - i.e. from just about anywhere. + */ void -destroy_sensitive_data(void) +destroy_sensitive_data(struct ssh *ssh, int privsep) { u_int i; +#ifdef SSH_AUDIT_EVENTS + pid_t pid; + uid_t uid; + pid = getpid(); + uid = getuid(); +#endif for (i = 0; i < options.num_host_key_files; i++) { if (sensitive_data.host_keys[i]) { + char *fp; + + if (sshkey_is_private(sensitive_data.host_keys[i])) + fp = sshkey_fingerprint(sensitive_data.host_keys[i], options.fingerprint_hash, SSH_FP_HEX); + else + fp = NULL; sshkey_free(sensitive_data.host_keys[i]); sensitive_data.host_keys[i] = NULL; + if (fp != NULL) { +#ifdef SSH_AUDIT_EVENTS + if (privsep) + PRIVSEP(audit_destroy_sensitive_data(ssh, fp, + pid, uid)); + else + audit_destroy_sensitive_data(ssh, fp, + pid, uid); +#endif + free(fp); + } } - if (sensitive_data.host_certificates[i]) { + if (sensitive_data.host_certificates + && sensitive_data.host_certificates[i]) { sshkey_free(sensitive_data.host_certificates[i]); sensitive_data.host_certificates[i] = NULL; } @@ -415,14 +452,26 @@ destroy_sensitive_data(void) /* Demote private to public keys for network child */ void -demote_sensitive_data(void) +demote_sensitive_data(struct ssh *ssh) { struct sshkey *tmp; u_int i; int r; +#ifdef SSH_AUDIT_EVENTS + pid_t pid; + uid_t uid; + pid = getpid(); + uid = getuid(); +#endif for (i = 0; i < options.num_host_key_files; i++) { if (sensitive_data.host_keys[i]) { + char *fp; + + if (sshkey_is_private(sensitive_data.host_keys[i])) + fp = sshkey_fingerprint(sensitive_data.host_keys[i], options.fingerprint_hash, SSH_FP_HEX); + else + fp = NULL; if ((r = sshkey_from_private( sensitive_data.host_keys[i], &tmp)) != 0) fatal("could not demote host %s key: %s", @@ -430,6 +479,12 @@ demote_sensitive_data(void) ssh_err(r)); sshkey_free(sensitive_data.host_keys[i]); sensitive_data.host_keys[i] = tmp; + if (fp != NULL) { +#ifdef SSH_AUDIT_EVENTS + audit_destroy_sensitive_data(ssh, fp, pid, uid); +#endif + free(fp); + } } /* Certs do not need demotion */ } @@ -457,7 +512,7 @@ reseed_prngs(void) } static void -privsep_preauth_child(void) +privsep_preauth_child(struct ssh *ssh) { gid_t gidset[1]; @@ -472,7 +527,7 @@ privsep_preauth_child(void) reseed_prngs(); /* Demote the private keys to public keys. */ - demote_sensitive_data(); + demote_sensitive_data(ssh); /* Demote the child */ if (privsep_chroot) { @@ -507,7 +562,7 @@ privsep_preauth(struct ssh *ssh) if (use_privsep == PRIVSEP_ON) box = ssh_sandbox_init(pmonitor); - pid = fork(); + pmonitor->m_pid = pid = fork(); if (pid == -1) { fatal("fork of unprivileged child failed"); } else if (pid != 0) { @@ -553,7 +608,7 @@ privsep_preauth(struct ssh *ssh) /* Arrange for logging to be sent to the monitor */ set_log_handler(mm_log_handler, pmonitor); - privsep_preauth_child(); + privsep_preauth_child(ssh); setproctitle("%s", "[net]"); if (box != NULL) ssh_sandbox_child(box); @@ -597,7 +652,7 @@ privsep_postauth(struct ssh *ssh, Authctxt *authctxt) pmonitor->m_sendfd = -1; /* Demote the private keys to public keys. */ - demote_sensitive_data(); + demote_sensitive_data(ssh); reseed_prngs(); @@ -1060,7 +1115,7 @@ server_listen(void) * from this function are in a forked subprocess. */ static void -server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) +server_accept_loop(struct ssh *ssh, int *sock_in, int *sock_out, int *newsock, int *config_s) { fd_set *fdset; int i, j, ret, maxfd; @@ -1115,6 +1170,7 @@ server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) if (received_sigterm) { logit("Received signal %d; terminating.", (int) received_sigterm); + destroy_sensitive_data(ssh, 0); close_listen_socks(); if (options.pid_file != NULL) unlink(options.pid_file); @@ -1973,7 +2029,7 @@ main(int ac, char **av) #endif /* Accept a connection and return in a forked child */ - server_accept_loop(&sock_in, &sock_out, + server_accept_loop(ssh, &sock_in, &sock_out, &newsock, config_s); } @@ -2212,6 +2268,9 @@ main(int ac, char **av) do_authenticated(ssh, authctxt); /* The connection has been terminated. */ + packet_destroy_all(ssh, 1, 1); + destroy_sensitive_data(ssh, 1); + ssh_packet_get_bytes(ssh, &ibytes, &obytes); verbose("Transferred: sent %llu, received %llu bytes", (unsigned long long)obytes, (unsigned long long)ibytes); @@ -2393,6 +2452,15 @@ do_ssh2_kex(struct ssh *ssh) void cleanup_exit(int i) { + static int in_cleanup = 0; + int is_privsep_child; + + /* cleanup_exit can be called at the very least from the privsep + wrappers used for auditing. Make sure we don't recurse + indefinitely. */ + if (in_cleanup) + _exit(i); + in_cleanup = 1; if (the_active_state != NULL && the_authctxt != NULL) { do_cleanup(the_active_state, the_authctxt); if (use_privsep && privsep_is_preauth && @@ -2404,9 +2472,16 @@ cleanup_exit(int i) pmonitor->m_pid, strerror(errno)); } } + is_privsep_child = use_privsep && pmonitor != NULL && pmonitor->m_pid == 0; + if (sensitive_data.host_keys != NULL && the_active_state != NULL) + destroy_sensitive_data(the_active_state, is_privsep_child); + if (the_active_state != NULL) + packet_destroy_all(the_active_state, 1, is_privsep_child); #ifdef SSH_AUDIT_EVENTS /* done after do_cleanup so it can cancel the PAM auth 'thread' */ - if (the_active_state != NULL && (!use_privsep || mm_is_monitor())) + if (the_active_state != NULL && + (the_authctxt == NULL || !the_authctxt->authenticated) && + (!use_privsep || mm_is_monitor())) audit_event(the_active_state, SSH_CONNECTION_ABANDON); #endif _exit(i); diff --git a/sshkey.c b/sshkey.c index 4d2048b..142dc09 100644 --- a/sshkey.c +++ b/sshkey.c @@ -340,6 +340,38 @@ sshkey_type_is_valid_ca(int type) } } +int +sshkey_is_private(const struct sshkey *k) +{ + switch (k->type) { +#ifdef WITH_OPENSSL + case KEY_RSA_CERT: + case KEY_RSA: { + const BIGNUM *d; + RSA_get0_key(k->rsa, NULL, NULL, &d); + return d != NULL; + } + case KEY_DSA_CERT: + case KEY_DSA: { + const BIGNUM *priv_key; + DSA_get0_key(k->dsa, NULL, &priv_key); + return priv_key != NULL; + } +#ifdef OPENSSL_HAS_ECC + case KEY_ECDSA_CERT: + case KEY_ECDSA: + return EC_KEY_get0_private_key(k->ecdsa) != NULL; +#endif /* OPENSSL_HAS_ECC */ +#endif /* WITH_OPENSSL */ + case KEY_ED25519_CERT: + case KEY_ED25519: + return (k->ed25519_pk != NULL); + default: + /* fatal("key_is_private: bad key type %d", k->type); */ + return 0; + } +} + int sshkey_is_cert(const struct sshkey *k) { diff --git a/sshkey.h b/sshkey.h index 1bf30d0..065ef0b 100644 --- a/sshkey.h +++ b/sshkey.h @@ -164,6 +164,7 @@ int sshkey_shield_private(struct sshkey *); int sshkey_unshield_private(struct sshkey *); int sshkey_type_from_name(const char *); +int sshkey_is_private(const struct sshkey *); int sshkey_is_cert(const struct sshkey *); int sshkey_type_is_cert(int); int sshkey_type_plain(int);
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