1 files changed, 128 insertions, 17 deletions

diff --git a/auth2-pubkey.c b/auth2-pubkey.c
index c4cadf4e7..35cf79c9f 100644
--- a/auth2-pubkey.c
+++ b/auth2-pubkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2-pubkey.c,v 1.22 2010/03/10 23:27:17 djm Exp $ */
+/* $OpenBSD: auth2-pubkey.c,v 1.26 2010/06/29 23:16:46 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -57,6 +57,7 @@
 #include "monitor_wrap.h"
 #include "misc.h"
 #include "authfile.h"
+#include "match.h"
 
 /* import */
 extern ServerOptions options;
@@ -176,6 +177,83 @@ done:
         return authenticated;
 }
 
+static int
+match_principals_option(const char *principal_list, struct KeyCert *cert)
+{
+        char *result;
+        u_int i;
+
+        /* XXX percent_expand() sequences for authorized_principals? */
+
+        for (i = 0; i < cert->nprincipals; i++) {
+                if ((result = match_list(cert->principals[i],
+                    principal_list, NULL)) != NULL) {
+                        debug3("matched principal from key options \"%.100s\"",
+                            result);
+                        xfree(result);
+                        return 1;
+                }
+        }
+        return 0;
+}
+
+static int
+match_principals_file(char *file, struct passwd *pw, struct KeyCert *cert)
+{
+        FILE *f;
+        char line[SSH_MAX_PUBKEY_BYTES], *cp, *ep, *line_opts;
+        u_long linenum = 0;
+        u_int i;
+
+        temporarily_use_uid(pw);
+        debug("trying authorized principals file %s", file);
+        if ((f = auth_openprincipals(file, pw, options.strict_modes)) == NULL) {
+                restore_uid();
+                return 0;
+        }
+        while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
+                /* Skip leading whitespace. */
+                for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
+                        ;
+                /* Skip blank and comment lines. */
+                if ((ep = strchr(cp, '#')) != NULL)
+                        *ep = '\0';
+                if (!*cp || *cp == '\n')
+                        continue;
+                /* Trim trailing whitespace. */
+                ep = cp + strlen(cp) - 1;
+                while (ep > cp && (*ep == '\n' || *ep == ' ' || *ep == '\t'))
+                        *ep-- = '\0';
+                /*
+                 * If the line has internal whitespace then assume it has
+                 * key options.
+                 */
+                line_opts = NULL;
+                if ((ep = strrchr(cp, ' ')) != NULL ||
+                    (ep = strrchr(cp, '\t')) != NULL) {
+                        for (; *ep == ' ' || *ep == '\t'; ep++)
+                                ;;
+                        line_opts = cp;
+                        cp = ep;
+                }
+                for (i = 0; i < cert->nprincipals; i++) {
+                        if (strcmp(cp, cert->principals[i]) == 0) {
+                                debug3("matched principal from file \"%.100s\"",
+                                    cert->principals[i]);
+                                if (auth_parse_options(pw, line_opts,
+                                    file, linenum) != 1)
+                                        continue;
+                                fclose(f);
+                                restore_uid();
+                                return 1;
+                        }
+                }
+        }
+        fclose(f);
+        restore_uid();
+        return 0;
+}       
+
 /* return 1 if user allows given key */
 static int
 user_key_allowed2(struct passwd *pw, Key *key, char *file)
@@ -233,26 +311,39 @@ user_key_allowed2(struct passwd *pw, Key *key, char *file)
                                 continue;
                         }
                 }
-                if (auth_parse_options(pw, key_options, file, linenum) != 1)
-                        continue;
-                if (key->type == KEY_RSA_CERT || key->type == KEY_DSA_CERT) {
-                        if (!key_is_cert_authority)
-                                continue;
+                if (key_is_cert(key)) {
                         if (!key_equal(found, key->cert->signature_key))
                                 continue;
+                        if (auth_parse_options(pw, key_options, file,
+                            linenum) != 1)
+                                continue;
+                        if (!key_is_cert_authority)
+                                continue;
                         fp = key_fingerprint(found, SSH_FP_MD5,
                             SSH_FP_HEX);
                         debug("matching CA found: file %s, line %lu, %s %s",
                             file, linenum, key_type(found), fp);
-                        if (key_cert_check_authority(key, 0, 0, pw->pw_name,
-                            &reason) != 0) {
+                        /*
+                         * If the user has specified a list of principals as
+                         * a key option, then prefer that list to matching
+                         * their username in the certificate principals list.
+                         */
+                        if (authorized_principals != NULL &&
+                            !match_principals_option(authorized_principals,
+                            key->cert)) {
+                                reason = "Certificate does not contain an "
+                                    "authorized principal";
+ fail_reason:
                                 xfree(fp);
                                 error("%s", reason);
                                 auth_debug_add("%s", reason);
                                 continue;
                         }
-                        if (auth_cert_constraints(&key->cert->constraints,
-                            pw) != 0) {
+                        if (key_cert_check_authority(key, 0, 0,
+                            authorized_principals == NULL ? pw->pw_name : NULL,
+                            &reason) != 0)
+                                goto fail_reason;
+                        if (auth_cert_options(key, pw) != 0) {
                                 xfree(fp);
                                 continue;
                         }
@@ -262,7 +353,12 @@ user_key_allowed2(struct passwd *pw, Key *key, char *file)
                         xfree(fp);
                         found_key = 1;
                         break;
-                } else if (!key_is_cert_authority && key_equal(found, key)) {
+                } else if (key_equal(found, key)) {
+                        if (auth_parse_options(pw, key_options, file,
+                            linenum) != 1)
+                                continue;
+                        if (key_is_cert_authority)
+                                continue;
                         found_key = 1;
                         debug("matching key found: file %s, line %lu",
                             file, linenum);
@@ -285,7 +381,7 @@ user_key_allowed2(struct passwd *pw, Key *key, char *file)
 static int
 user_cert_trusted_ca(struct passwd *pw, Key *key)
 {
-        char *ca_fp;
+        char *ca_fp, *principals_file = NULL;
         const char *reason;
         int ret = 0;
 
@@ -302,12 +398,25 @@ user_cert_trusted_ca(struct passwd *pw, Key *key)
                     options.trusted_user_ca_keys);
                 goto out;
         }
-        if (key_cert_check_authority(key, 0, 1, pw->pw_name, &reason) != 0) {
-                error("%s", reason);
-                auth_debug_add("%s", reason);
-                goto out;
+        /*
+         * If AuthorizedPrincipals is in use, then compare the certificate
+         * principals against the names in that file rather than matching
+         * against the username.
+         */
+        if ((principals_file = authorized_principals_file(pw)) != NULL) {
+                if (!match_principals_file(principals_file, pw, key->cert)) {
+                        reason = "Certificate does not contain an "
+                            "authorized principal";
+ fail_reason:
+                        error("%s", reason);
+                        auth_debug_add("%s", reason);
+                        goto out;
+                }
         }
-        if (auth_cert_constraints(&key->cert->constraints, pw) != 0)
+        if (key_cert_check_authority(key, 0, 1,
+            principals_file == NULL ? pw->pw_name : NULL, &reason) != 0)
+                goto fail_reason;
+        if (auth_cert_options(key, pw) != 0)
                 goto out;
 
         verbose("Accepted certificate ID \"%s\" signed by %s CA %s via %s",
@@ -316,6 +425,8 @@ user_cert_trusted_ca(struct passwd *pw, Key *key)
         ret = 1;
 
  out:
+        if (principals_file != NULL)
+                xfree(principals_file);
         if (ca_fp != NULL)
                 xfree(ca_fp);
         return ret;