/* Authenticate a certificate key against TrustedUserCAKeys */ static int user_cert_trusted_ca(struct passwd *pw, Key *key) { char *ca_fp, *principals_file = NULL; const char *reason; int ret = 0, found_principal = 0, use_authorized_principals; if (!key_is_cert(key) || options.trusted_user_ca_keys == NULL) return 0; if ((ca_fp = sshkey_fingerprint(key->cert->signature_key, options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) return 0; if (sshkey_in_file(key->cert->signature_key, options.trusted_user_ca_keys, 1, 0) != 0) { debug2("%s: CA %s %s is not listed in %s", __func__, key_type(key->cert->signature_key), ca_fp, options.trusted_user_ca_keys); 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)) found_principal = 1; } /* Try querying command if specified */ if (!found_principal && match_principals_command(pw, key->cert)) found_principal = 1; /* If principals file or command is specified, then require a match */ use_authorized_principals = principals_file != NULL || options.authorized_principals_command != NULL; if (!found_principal && use_authorized_principals) { reason = "Certificate does not contain an authorized principal"; fail_reason: error("%s", reason); auth_debug_add("%s", reason); goto out; } if (key_cert_check_authority(key, 0, 1, use_authorized_principals ? NULL : pw->pw_name, &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", key->cert->key_id, key_type(key->cert->signature_key), ca_fp, options.trusted_user_ca_keys); ret = 1; out: free(principals_file); free(ca_fp); return ret; }
/* Authenticate a certificate key against TrustedUserCAKeys */ static int user_cert_trusted_ca(struct passwd *pw, Key *key) { char *ca_fp, *principals_file = NULL; const char *reason; int ret = 0; if (!key_is_cert(key) || options.trusted_user_ca_keys == NULL) return 0; ca_fp = key_fingerprint(key->cert->signature_key, SSH_FP_MD5, SSH_FP_HEX); if (key_in_file(key->cert->signature_key, options.trusted_user_ca_keys, 1) != 1) { debug2("%s: CA %s %s is not listed in %s", __func__, key_type(key->cert->signature_key), ca_fp, options.trusted_user_ca_keys); 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 (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", key->cert->key_id, key_type(key->cert->signature_key), ca_fp, options.trusted_user_ca_keys); ret = 1; out: if (principals_file != NULL) xfree(principals_file); if (ca_fp != NULL) xfree(ca_fp); return ret; }
static int check_host_cert(const char *host, const Key *host_key) { const char *reason; if (key_cert_check_authority(host_key, 1, 0, host, &reason) != 0) { error("%s", reason); return 0; } if (buffer_len(host_key->cert->critical) != 0) { error("Certificate for %s contains unsupported " "critical options(s)", host); return 0; } return 1; }
/* return 1 if user allows given key */ static int user_key_allowed2(struct passwd *pw, Key *key, char *file) { char line[SSH_MAX_PUBKEY_BYTES]; const char *reason; int found_key = 0; FILE *f; u_long linenum = 0; Key *found; char *fp; /* Temporarily use the user's uid. */ temporarily_use_uid(pw); debug("trying public key file %s", file); f = auth_openkeyfile(file, pw, options.strict_modes); if (!f) { restore_uid(); return 0; } found_key = 0; found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type); while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) { char *cp, *key_options = NULL; auth_clear_options(); /* Skip leading whitespace, empty and comment lines. */ for (cp = line; *cp == ' ' || *cp == '\t'; cp++) ; if (!*cp || *cp == '\n' || *cp == '#') continue; if (key_read(found, &cp) != 1) { /* no key? check if there are options for this key */ int quoted = 0; debug2("user_key_allowed: check options: '%s'", cp); key_options = cp; for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) { if (*cp == '\\' && cp[1] == '"') cp++; /* Skip both */ else if (*cp == '"') quoted = !quoted; } /* Skip remaining whitespace. */ for (; *cp == ' ' || *cp == '\t'; cp++) ; if (key_read(found, &cp) != 1) { debug2("user_key_allowed: advance: '%s'", cp); /* still no key? advance to next line*/ 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 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 (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; } verbose("Accepted certificate ID \"%s\" " "signed by %s CA %s via %s", key->cert->key_id, key_type(found), fp, file); xfree(fp); found_key = 1; break; } 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); fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); verbose("Found matching %s key: %s", key_type(found), fp); xfree(fp); break; } } restore_uid(); fclose(f); key_free(found); if (!found_key) debug2("key not found"); return found_key; }
/* return 1 if given hostkey is allowed */ int hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost, Key *key) { const char *resolvedname, *ipaddr, *lookup, *reason; HostStatus host_status; int len; char *fp; if (auth_key_is_revoked(key)) return 0; resolvedname = get_canonical_hostname(options.use_dns); ipaddr = get_remote_ipaddr(); debug2("userauth_hostbased: chost %s resolvedname %s ipaddr %s", chost, resolvedname, ipaddr); if (((len = strlen(chost)) > 0) && chost[len - 1] == '.') { debug2("stripping trailing dot from chost %s", chost); chost[len - 1] = '\0'; } if (options.hostbased_uses_name_from_packet_only) { if (auth_rhosts2(pw, cuser, chost, chost) == 0) return 0; lookup = chost; } else { if (strcasecmp(resolvedname, chost) != 0) logit("userauth_hostbased mismatch: " "client sends %s, but we resolve %s to %s", chost, ipaddr, resolvedname); if (auth_rhosts2(pw, cuser, resolvedname, ipaddr) == 0) return 0; lookup = resolvedname; } debug2("userauth_hostbased: access allowed by auth_rhosts2"); if (key_is_cert(key) && key_cert_check_authority(key, 1, 0, lookup, &reason)) { error("%s", reason); auth_debug_add("%s", reason); return 0; } host_status = check_key_in_hostfiles(pw, key, lookup, _PATH_SSH_SYSTEM_HOSTFILE, options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE); /* backward compat if no key has been found. */ if (host_status == HOST_NEW) { host_status = check_key_in_hostfiles(pw, key, lookup, _PATH_SSH_SYSTEM_HOSTFILE2, options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE2); } if (host_status == HOST_OK) { if (key_is_cert(key)) { fp = key_fingerprint(key->cert->signature_key, SSH_FP_MD5, SSH_FP_HEX); verbose("Accepted certificate ID \"%s\" signed by " "%s CA %s from %s@%s", key->cert->key_id, key_type(key->cert->signature_key), fp, cuser, lookup); } else { fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); verbose("Accepted %s public key %s from %s@%s", key_type(key), fp, cuser, lookup); } xfree(fp); } return (host_status == HOST_OK); }
/* * Checks whether key is allowed in authorized_keys-format file, * returns 1 if the key is allowed or 0 otherwise. */ static int check_authkeys_file(FILE *f, char *file, Key* key, struct passwd *pw) { char line[SSH_MAX_PUBKEY_BYTES]; int found_key = 0; u_long linenum = 0; Key *found; found_key = 0; found = NULL; while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) { char *cp, *key_options = NULL, *fp = NULL; const char *reason = NULL; /* Always consume entrire file */ if (found_key) continue; if (found != NULL) key_free(found); found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type); auth_clear_options(); /* Skip leading whitespace, empty and comment lines. */ for (cp = line; *cp == ' ' || *cp == '\t'; cp++) ; if (!*cp || *cp == '\n' || *cp == '#') continue; if (key_read(found, &cp) != 1) { /* no key? check if there are options for this key */ int quoted = 0; debug2("user_key_allowed: check options: '%s'", cp); key_options = cp; for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) { if (*cp == '\\' && cp[1] == '"') cp++; /* Skip both */ else if (*cp == '"') quoted = !quoted; } /* Skip remaining whitespace. */ for (; *cp == ' ' || *cp == '\t'; cp++) ; if (key_read(found, &cp) != 1) { debug2("user_key_allowed: advance: '%s'", cp); /* still no key? advance to next line*/ 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; if ((fp = sshkey_fingerprint(found, options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) continue; debug("matching CA found: file %s, line %lu, %s %s", file, linenum, key_type(found), fp); /* * 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: free(fp); error("%s", reason); auth_debug_add("%s", reason); continue; } 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, &reason) != 0) goto fail_reason; verbose("Accepted certificate ID \"%s\" (serial %llu) " "signed by %s CA %s via %s", key->cert->key_id, (unsigned long long)key->cert->serial, key_type(found), fp, file); free(fp); found_key = 1; break; } else if (key_equal(found, key)) { if (auth_parse_options(pw, key_options, file, linenum) != 1) continue; if (key_is_cert_authority) continue; if ((fp = sshkey_fingerprint(found, options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL) continue; debug("matching key found: file %s, line %lu %s %s", file, linenum, key_type(found), fp); free(fp); found_key = 1; continue; } } if (found != NULL) key_free(found); if (!found_key) debug2("key not found"); return found_key; }
/* return 1 if user allows given key */ static int user_key_allowed2(struct passwd *pw, Key *key, char *file) { char line[SSH_MAX_PUBKEY_BYTES]; const char *reason; int found_key = 0; FILE *f; u_long linenum = 0; Key *found; char *fp; #ifdef WITH_LDAP_PUBKEY ldap_key_t * k; unsigned int i = 0; #endif /* Temporarily use the user's uid. */ temporarily_use_uid(pw); #ifdef WITH_LDAP_PUBKEY found_key = 0; /* allocate a new key type */ found = key_new(key->type); /* first check if the options is enabled, then try.. */ if (options.lpk.on) { debug("[LDAP] trying LDAP first uid=%s",pw->pw_name); if (ldap_ismember(&options.lpk, pw->pw_name) > 0) { if ((k = ldap_getuserkey(&options.lpk, pw->pw_name)) != NULL) { /* Skip leading whitespace, empty and comment lines. */ for (i = 0 ; i < k->num ; i++) { /* dont forget if multiple keys to reset options */ char *cp, *xoptions = NULL; for (cp = (char *)k->keys[i]->bv_val; *cp == ' ' || *cp == '\t'; cp++) ; if (!*cp || *cp == '\n' || *cp == '#') continue; if (key_read(found, &cp) != 1) { /* no key? check if there are options for this key */ int quoted = 0; debug2("[LDAP] user_key_allowed: check options: '%s'", cp); xoptions = cp; for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) { if (*cp == '\\' && cp[1] == '"') cp++; /* Skip both */ else if (*cp == '"') quoted = !quoted; } /* Skip remaining whitespace. */ for (; *cp == ' ' || *cp == '\t'; cp++) ; if (key_read(found, &cp) != 1) { debug2("[LDAP] user_key_allowed: advance: '%s'", cp); /* still no key? advance to next line*/ continue; } } if (key_equal(found, key) && auth_parse_options(pw, xoptions, file, linenum) == 1) { found_key = 1; debug("[LDAP] matching key found"); fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); verbose("[LDAP] Found matching %s key: %s", key_type(found), fp); /* restoring memory */ ldap_keys_free(k); xfree(fp); restore_uid(); key_free(found); return found_key; break; } }/* end of LDAP for() */ } else { logit("[LDAP] no keys found for '%s'!", pw->pw_name); } } else { logit("[LDAP] '%s' is not in '%s'", pw->pw_name, options.lpk.sgroup); } } #endif debug("trying public key file %s", file); f = auth_openkeyfile(file, pw, options.strict_modes); if (!f) { restore_uid(); return 0; } found_key = 0; found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type); while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) { char *cp, *key_options = NULL; auth_clear_options(); /* Skip leading whitespace, empty and comment lines. */ for (cp = line; *cp == ' ' || *cp == '\t'; cp++) ; if (!*cp || *cp == '\n' || *cp == '#') continue; if (key_read(found, &cp) != 1) { /* no key? check if there are options for this key */ int quoted = 0; debug2("user_key_allowed: check options: '%s'", cp); key_options = cp; for (; *cp && (quoted || (*cp != ' ' && *cp != '\t')); cp++) { if (*cp == '\\' && cp[1] == '"') cp++; /* Skip both */ else if (*cp == '"') quoted = !quoted; } /* Skip remaining whitespace. */ for (; *cp == ' ' || *cp == '\t'; cp++) ; if (key_read(found, &cp) != 1) { debug2("user_key_allowed: advance: '%s'", cp); /* still no key? advance to next line*/ 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 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 (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; } verbose("Accepted certificate ID \"%s\" " "signed by %s CA %s via %s", key->cert->key_id, key_type(found), fp, file); xfree(fp); found_key = 1; break; } 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); fp = key_fingerprint(found, SSH_FP_MD5, SSH_FP_HEX); verbose("Found matching %s key: %s", key_type(found), fp); xfree(fp); break; } } restore_uid(); fclose(f); key_free(found); if (!found_key) debug2("key not found"); return found_key; }