Changeset 370 for branches/samba-3.3.x/source/client/cifs.upcall.c

Timestamp:

Jan 15, 2010, 8:23:30 AM (16 years ago)

Author:

Herwig Bauernfeind

Message:

Update Samba 3.3 to 3.3.10 (source)

File:

• branches/samba-3.3.x/source/client/cifs.upcall.c (modified) (18 diffs)

branches/samba-3.3.x/source/client/cifs.upcall.c

@@ -2 +2 @@
 * CIFS user-space helper.
 * Copyright (C) Igor Mammedov ([email protected]) 2007
+
 *
 * Used by /sbin/request-key for handling
@@ -26 +27 @@
 
 #include "includes.h"
+
 #include <keyutils.h>
+
 
 #include "cifs_spnego.h"
 
-const char *CIFSSPNEGO_VERSION = "1.2";
+#define CIFS_DEFAULT_KRB5_DIR           "/tmp"
+#define CIFS_DEFAULT_KRB5_PREFIX        "krb5cc_"
+
+#define MAX_CCNAME_LEN                  PATH_MAX + 5
+
+const char *CIFSSPNEGO_VERSION = "1.3";
 static const char *prog = "cifs.upcall";
-typedef enum _secType {
+typedef enum _secype {
         NONE = 0,
         KRB5,
         MS_KRB5
-} secType_t;
+} sectype_t;
+
+/* does the ccache have a valid TGT? */
+static time_t
+get_tgt_time(const char *ccname) {
+        krb5_context context;
+        krb5_ccache ccache;
+        krb5_cc_cursor cur;
+        krb5_creds creds;
+        krb5_principal principal;
+        time_t credtime = 0;
+        char *realm = NULL;
+
+        if (krb5_init_context(&context)) {
+                syslog(LOG_DEBUG, "%s: unable to init krb5 context", __func__);
+                return 0;
+        }
+
+        if (krb5_cc_resolve(context, ccname, &ccache)) {
+                syslog(LOG_DEBUG, "%s: unable to resolve krb5 cache", __func__);
+                goto err_cache;
+        }
+
+        if (krb5_cc_set_flags(context, ccache, 0)) {
+                syslog(LOG_DEBUG, "%s: unable to set flags", __func__);
+                goto err_cache;
+        }
+
+        if (krb5_cc_get_principal(context, ccache, &principal)) {
+                syslog(LOG_DEBUG, "%s: unable to get principal", __func__);
+                goto err_princ;
+        }
+
+        if (krb5_cc_start_seq_get(context, ccache, &cur)) {
+                syslog(LOG_DEBUG, "%s: unable to seq start", __func__);
+                goto err_ccstart;
+        }
+
+        if ((realm = smb_krb5_principal_get_realm(context, principal)) == NULL) {
+                syslog(LOG_DEBUG, "%s: unable to get realm", __func__);
+                goto err_ccstart;
+        }
+
+        while (!credtime && !krb5_cc_next_cred(context, ccache, &cur, &creds)) {
+                char *name;
+                if (smb_krb5_unparse_name(context, creds.server, &name)) {
+                        syslog(LOG_DEBUG, "%s: unable to unparse name", __func__);
+                        goto err_endseq;
+                }
+                if (krb5_realm_compare(context, creds.server, principal) &&
+                    strnequal(name, KRB5_TGS_NAME, KRB5_TGS_NAME_SIZE) &&
+                    strnequal(name+KRB5_TGS_NAME_SIZE+1, realm, strlen(realm)) &&
+                    creds.times.endtime > time(NULL))
+                        credtime = creds.times.endtime;
+                krb5_free_cred_contents(context, &creds);
+                SAFE_FREE(name);
+        }
+err_endseq:
+        krb5_cc_end_seq_get(context, ccache, &cur);
+err_ccstart:
+        krb5_free_principal(context, principal);
+err_princ:
+#if defined(KRB5_TC_OPENCLOSE)
+        krb5_cc_set_flags(context, ccache, KRB5_TC_OPENCLOSE);
+#endif
+        krb5_cc_close(context, ccache);
+err_cache:
+        krb5_free_context(context);
+        return credtime;
+}
+
+static int
+krb5cc_filter(const struct dirent *dirent)
+{
+        if (strstr(dirent->d_name, CIFS_DEFAULT_KRB5_PREFIX))
+                return 1;
+        else
+                return 0;
+}
+
+/* search for a credcache that looks like a likely candidate */
+static char *
+find_krb5_cc(const char *dirname, uid_t uid)
+{
+        struct dirent **namelist;
+        struct stat sbuf;
+        char ccname[MAX_CCNAME_LEN], *credpath, *best_cache = NULL;
+        int i, n;
+        time_t cred_time, best_time = 0;
+
+        n = scandir(dirname, &namelist, krb5cc_filter, NULL);
+        if (n < 0) {
+                syslog(LOG_DEBUG, "%s: scandir error on directory '%s': %s",
+                                  __func__, dirname, strerror(errno));
+                return NULL;
+        }
+
+        for (i = 0; i < n; i++) {
+                snprintf(ccname, sizeof(ccname), "FILE:%s/%s", dirname,
+                         namelist[i]->d_name);
+                credpath = ccname + 5;
+                syslog(LOG_DEBUG, "%s: considering %s", __func__, credpath);
+
+                if (lstat(credpath, &sbuf)) {
+                        syslog(LOG_DEBUG, "%s: stat error on '%s': %s",
+                                          __func__, credpath, strerror(errno));
+                        free(namelist[i]);
+                        continue;
+                }
+                if (sbuf.st_uid != uid) {
+                        syslog(LOG_DEBUG, "%s: %s is owned by %u, not %u",
+                                        __func__, credpath, sbuf.st_uid, uid);
+                        free(namelist[i]);
+                        continue;
+                }
+                if (!S_ISREG(sbuf.st_mode)) {
+                        syslog(LOG_DEBUG, "%s: %s is not a regular file",
+                                        __func__, credpath);
+                        free(namelist[i]);
+                        continue;
+                }
+                if (!(cred_time = get_tgt_time(ccname))) {
+                        syslog(LOG_DEBUG, "%s: %s is not a valid credcache.",
+                                        __func__, ccname);
+                        free(namelist[i]);
+                        continue;
+                }
+
+                if (cred_time <= best_time) {
+                        syslog(LOG_DEBUG, "%s: %s expires sooner than current "
+                                          "best.", __func__, ccname);
+                        free(namelist[i]);
+                        continue;
+                }
+
+                syslog(LOG_DEBUG, "%s: %s is valid ccache", __func__, ccname);
+                free(best_cache);
+                best_cache = SMB_STRNDUP(ccname, MAX_CCNAME_LEN);
+                best_time = cred_time;
+                free(namelist[i]);
+        }
+        free(namelist);
+
+        return best_cache;
+}
 
 /*
@@ -57 +209 @@
  *
  * ret: 0 - success, others - failure
-*/
+*/
 static int
-handle_krb5_mech(const char *oid, const char *principal,
-                     DATA_BLOB * secblob, DATA_BLOB * sess_key)
+handle_krb5_mech(const char *oid, const char *principal,
+                 )
 {
         int retval;
         DATA_BLOB tkt, tkt_wrapped;
 
+
+
+
         /* get a kerberos ticket for the service and extract the session key */
-        retval = cli_krb5_get_ticket(principal, 0,
-                                     &tkt, sess_key, 0, NULL, NULL);
-
-        if (retval)
+        retval = cli_krb5_get_ticket(principal, 0, &tkt, sess_key, 0, ccname,
+                                     NULL);
+
+        if (retval) {
+                syslog(LOG_DEBUG, "%s: failed to obtain service ticket (%d)",
+                                  __func__, retval);
                 return retval;
+
+
+
 
         /* wrap that up in a nice GSS-API wrapping */
@@ -83 +243 @@
 }
 
-#define DKD_HAVE_HOSTNAME       1
-#define DKD_HAVE_VERSION        2
-#define DKD_HAVE_SEC            4
-#define DKD_HAVE_IPV4           8
-#define DKD_HAVE_IPV6           16
-#define DKD_HAVE_UID            32
+#define DKD_HAVE_HOSTNAME       1
+#define DKD_HAVE_VERSION        2
+#define DKD_HAVE_SEC            4
+#define DKD_HAVE_IP8
+#define DKD_HAVE_
+#define DKD_HAVE_
 #define DKD_MUSTHAVE_SET (DKD_HAVE_HOSTNAME|DKD_HAVE_VERSION|DKD_HAVE_SEC)
 
-static int
-decode_key_description(const char *desc, int *ver, secType_t * sec,
-                           char **hostname, uid_t * uid)
-{
+struct decoded_args {
+        int             ver;
+        char            *hostname;
+        char            *ip;
+        uid_t           uid;
+        pid_t           pid;
+        sectype_t       sec;
+};
+
+static unsigned int
+decode_key_description(const char *desc, struct decoded_args *arg)
+{
+        int len;
         int retval = 0;
         char *pos;
@@ -102 +271 @@
                 pos = index(tkn, ';');
                 if (strncmp(tkn, "host=", 5) == 0) {
-                        int len;
-
-                        if (pos == NULL) {
+
+                        if (pos == NULL)
                                 len = strlen(tkn);
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                         } else {
-                                len = pos - tkn;
+                                ;
                         }
-                        len -= 4;
-                        SAFE_FREE(*hostname);
-                        *hostname = SMB_XMALLOC_ARRAY(char, len);
-                        strlcpy(*hostname, tkn + 5, len);
-                        retval |= DKD_HAVE_HOSTNAME;
-                } else if (strncmp(tkn, "ipv4=", 5) == 0) {
-                        /* BB: do we need it if we have hostname already? */
-                } else if (strncmp(tkn, "ipv6=", 5) == 0) {
-                        /* BB: do we need it if we have hostname already? */
                 } else if (strncmp(tkn, "sec=", 4) == 0) {
                         if (strncmp(tkn + 4, "krb5", 4) == 0) {
                                 retval |= DKD_HAVE_SEC;
-                                *sec = KRB5;
+                                sec = KRB5;
                         } else if (strncmp(tkn + 4, "mskrb5", 6) == 0) {
                                 retval |= DKD_HAVE_SEC;
-                                *sec = MS_KRB5;
+                                sec = MS_KRB5;
                         }
                 } else if (strncmp(tkn, "uid=", 4) == 0) {
                         errno = 0;
-                        *uid = strtol(tkn + 4, NULL, 16);
+                        uid = strtol(tkn + 4, NULL, 16);
                         if (errno != 0) {
-                                syslog(LOG_WARNING, "Invalid uid format: %s",
+                                syslog(LOG_, "Invalid uid format: %s",
                                        strerror(errno));
                                 return 1;
@@ -138 +324 @@
                 } else if (strncmp(tkn, "ver=", 4) == 0) {      /* if version */
                         errno = 0;
-                        *ver = strtol(tkn + 4, NULL, 16);
+                        ver = strtol(tkn + 4, NULL, 16);
                         if (errno != 0) {
-                                syslog(LOG_WARNING,
-                                       "Invalid version format: %s",
+                                syslog(LOG_ERR, "Invalid version format: %s",
                                        strerror(errno));
                                 return 1;
@@ -167 +352 @@
                 keyend = index(keyend+1, ';');
                 if (!keyend) {
-                        syslog(LOG_WARNING, "invalid key description: %s",
+                        syslog(LOG_, "invalid key description: %s",
                                         key_descr);
                         return 1;
@@ -177 +362 @@
         c = getaddrinfo(keyend, NULL, NULL, &addr);
         if (c) {
-                syslog(LOG_WARNING, "unable to resolve hostname: %s [%s]",
+                syslog(LOG_, "unable to resolve hostname: %s [%s]",
                                 keyend, gai_strerror(c));
                 return 1;
@@ -183 +368 @@
 
         /* conver ip to string form */
-        if (addr->ai_family == AF_INET) {
+        if (addr->ai_family == AF_INET)
                 p = &(((struct sockaddr_in *)addr->ai_addr)->sin_addr);
-        } else {
+        
                 p = &(((struct sockaddr_in6 *)addr->ai_addr)->sin6_addr);
-        }
+
         if (!inet_ntop(addr->ai_family, p, ip, sizeof(ip))) {
-                syslog(LOG_WARNING, "%s: inet_ntop: %s",
-                                __FUNCTION__, strerror(errno));
+                syslog(LOG_ERR, "%s: inet_ntop: %s", __func__, strerror(errno));
                 freeaddrinfo(addr);
                 return 1;
@@ -198 +382 @@
         c = keyctl_instantiate(key, ip, strlen(ip)+1, 0);
         if (c == -1) {
-                syslog(LOG_WARNING, "%s: keyctl_instantiate: %s",
-                                __FUNCTION__, strerror(errno));
+                syslog(LOG_,
+                                strerror(errno));
                 freeaddrinfo(addr);
                 return 1;
@@ -208 +392 @@
 }
 
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 static void
 usage(void)
 {
-        syslog(LOG_WARNING, "Usage: %s [-c] [-v] key_serial", prog);
-        fprintf(stderr, "Usage: %s [-c] [-v] key_serial\n", prog);
-}
+        syslog(LOG_INFO, "Usage: %s [-t] [-v] key_serial", prog);
+        fprintf(stderr, "Usage: %s [-t] [-v] key_serial\n", prog);
+}
+
+const struct option long_options[] = {
+        { "trust-dns",  0, NULL, 't' },
+        { "version",    0, NULL, 'v' },
+        { NULL,         0, NULL, 0 }
+};
 
 int main(const int argc, char *const argv[])
@@ -220 +464 @@
         DATA_BLOB secblob = data_blob_null;
         DATA_BLOB sess_key = data_blob_null;
-        secType_t sectype = NONE;
         key_serial_t key = 0;
         size_t datalen;
+
         long rc = 1;
-        uid_t uid = 0;
-        int kernel_upcall_version = 0;
-        int c, use_cifs_service_prefix = 0;
-        char *buf, *hostname = NULL;
+         = 0;
+        ;
+        ;
+        ;
         const char *oid;
 
+
+
         openlog(prog, 0, LOG_DAEMON);
 
-        while ((c = getopt(argc, argv, "cv")) != -1) {
+        while ((c = getopt)) != -1) {
                 switch (c) {
-                case 'c':{
-                        use_cifs_service_prefix = 1;
-                        break;
-                        }
-                case 'v':{
+                case 'c':
+                        /* legacy option -- skip it */
+                        break;
+                case 't':
+                        try_dns++;
+                        break;
+                case 'v':
                         printf("version: %s\n", CIFSSPNEGO_VERSION);
                         goto out;
-                        }
-                default:{
-                        syslog(LOG_WARNING, "unknown option: %c", c);
+                default:
+                        syslog(LOG_ERR, "unknown option: %c", c);
                         goto out;
-                        }
                 }
         }
@@ -260 +506 @@
         if (errno != 0) {
                 key = 0;
-                syslog(LOG_WARNING, "Invalid key format: %s", strerror(errno));
+                syslog(LOG_, "Invalid key format: %s", strerror(errno));
                 goto out;
         }
@@ -266 +512 @@
         rc = keyctl_describe_alloc(key, &buf);
         if (rc == -1) {
-                syslog(LOG_WARNING, "keyctl_describe_alloc failed: %s",
+                syslog(LOG_, "keyctl_describe_alloc failed: %s",
                        strerror(errno));
                 rc = 1;
                 goto out;
         }
+
+
 
         if ((strncmp(buf, "cifs.resolver", sizeof("cifs.resolver")-1) == 0) ||
@@ -278 +526 @@
         }
 
-        rc = decode_key_description(buf, &kernel_upcall_version, &sectype,
-                                    &hostname, &uid);
-        if ((rc & DKD_MUSTHAVE_SET) != DKD_MUSTHAVE_SET) {
-                syslog(LOG_WARNING,
-                       "unable to get from description necessary params");
+        
+        );
+        if (( & DKD_MUSTHAVE_SET) != DKD_MUSTHAVE_SET) {
+                syslog(LOG_
+                );
                 rc = 1;
-                SAFE_FREE(buf);
-                goto out;
-        }
-        SAFE_FREE(buf);
-
-        if (kernel_upcall_version > CIFS_SPNEGO_UPCALL_VERSION) {
-                syslog(LOG_WARNING,
-                       "incompatible kernel upcall version: 0x%x",
-                       kernel_upcall_version);
+                goto out;
+        }
+
+        if (arg.ver > CIFS_SPNEGO_UPCALL_VERSION) {
+                syslog(LOG_ERR, "incompatible kernel upcall version: 0x%x",
+                                arg.ver);
                 rc = 1;
                 goto out;
         }
 
-        if (rc & DKD_HAVE_UID) {
-                rc = setuid(uid);
+        if ( & DKD_HAVE_UID) {
+                rc = setuid(uid);
                 if (rc == -1) {
-                        syslog(LOG_WARNING, "setuid: %s", strerror(errno));
+                        syslog(LOG_, "setuid: %s", strerror(errno));
                         goto out;
                 }
-        }
-
-        /* BB: someday upcall SPNEGO blob could be checked here to decide
-         * what mech to use */
+
+                ccname = find_krb5_cc(CIFS_DEFAULT_KRB5_DIR, arg.uid);
+        }
+
+        host = arg.hostname;
 
         // do mech specific authorization
-        switch (sectype) {
+        switch () {
         case MS_KRB5:
-        case KRB5:{
-                        char *princ;
-                        size_t len;
-
-                        /* for "cifs/" service name + terminating 0 */
-                        len = strlen(hostname) + 5 + 1;
-                        princ = SMB_XMALLOC_ARRAY(char, len);
-                        if (!princ) {
-                                rc = 1;
-                                break;
-                        }
-                        if (use_cifs_service_prefix) {
-                                strlcpy(princ, "cifs/", len);
-                        } else {
-                                strlcpy(princ, "host/", len);
-                        }
-                        strlcpy(princ + 5, hostname, len - 5);
-
-                        if (sectype == MS_KRB5)
-                                oid = OID_KERBEROS5_OLD;
-                        else
-                                oid = OID_KERBEROS5;
-
-                        rc = handle_krb5_mech(oid, princ, &secblob, &sess_key);
-                        SAFE_FREE(princ);
-                        break;
-                }
-        default:{
-                        syslog(LOG_WARNING, "sectype: %d is not implemented",
-                               sectype);
-                        rc = 1;
-                        break;
-                }
-        }
-
-        if (rc) {
-                goto out;
-        }
+        case KRB5:
+retry_new_hostname:
+                /* for "cifs/" service name + terminating 0 */
+                datalen = strlen(host) + 5 + 1;
+                princ = SMB_XMALLOC_ARRAY(char, datalen);
+                if (!princ) {
+                        rc = -ENOMEM;
+                        break;
+                }
+
+                if (arg.sec == MS_KRB5)
+                        oid = OID_KERBEROS5_OLD;
+                else
+                        oid = OID_KERBEROS5;
+
+                /*
+                 * try getting a cifs/ principal first and then fall back to
+                 * getting a host/ principal if that doesn't work.
+                 */
+                strlcpy(princ, "cifs/", datalen);
+                strlcpy(princ + 5, host, datalen - 5);
+                rc = handle_krb5_mech(oid, princ, &secblob, &sess_key, ccname);
+                if (!rc)
+                        break;
+
+                memcpy(princ, "host/", 5);
+                rc = handle_krb5_mech(oid, princ, &secblob, &sess_key, ccname);
+                if (!rc)
+                        break;
+
+                if (!try_dns || !(have & DKD_HAVE_IP))
+                        break;
+
+                rc = ip_to_fqdn(arg.ip, hostbuf, sizeof(hostbuf));
+                if (rc)
+                        break;
+
+                SAFE_FREE(princ);
+                try_dns = 0;
+                host = hostbuf;
+                goto retry_new_hostname;
+        default:
+                syslog(LOG_ERR, "sectype: %d is not implemented", arg.sec);
+                rc = 1;
+                break;
+        }
+
+        SAFE_FREE(princ);
+
+        if (rc)
+                goto out;
 
         /* pack SecurityBLob and SessionKey into downcall packet */
@@ -358 +617 @@
                 goto out;
         }
-        keydata->version = kernel_upcall_version;
+        keydata->version = ;
         keydata->flags = 0;
         keydata->sesskey_len = sess_key.length;
@@ -369 +628 @@
         rc = keyctl_instantiate(key, keydata, datalen, 0);
         if (rc == -1) {
-                syslog(LOG_WARNING, "keyctl_instantiate: %s", strerror(errno));
+                syslog(LOG_, "keyctl_instantiate: %s", strerror(errno));
                 goto out;
         }
@@ -386 +645 @@
         data_blob_free(&secblob);
         data_blob_free(&sess_key);
-        SAFE_FREE(hostname);
+        SAFE_FREE(ccname);
+        SAFE_FREE(arg.hostname);
+        SAFE_FREE(arg.ip);
         SAFE_FREE(keydata);
         return rc;