Adding upstream version 2.4.38.upstream/2.4.38

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 508 insertions, 0 deletions

diff --git a/modules/aaa/mod_auth_basic.c b/modules/aaa/mod_auth_basic.c
new file mode 100644
index 0000000..e8163d0
--- /dev/null
+++ b/modules/aaa/mod_auth_basic.c
@@ -0,0 +1,508 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "apr_strings.h"
+#include "apr_lib.h"            /* for apr_isspace */
+#include "apr_base64.h"         /* for apr_base64_decode et al */
+#define APR_WANT_STRFUNC        /* for strcasecmp */
+#include "apr_want.h"
+
+#include "ap_config.h"
+#include "httpd.h"
+#include "http_config.h"
+#include "http_core.h"
+#include "http_log.h"
+#include "http_protocol.h"
+#include "http_request.h"
+#include "util_md5.h"
+#include "ap_provider.h"
+#include "ap_expr.h"
+
+#include "mod_auth.h"
+
+typedef struct {
+    authn_provider_list *providers;
+    char *dir; /* unused variable */
+    int authoritative;
+    ap_expr_info_t *fakeuser;
+    ap_expr_info_t *fakepass;
+    const char *use_digest_algorithm;
+    int fake_set:1;
+    int use_digest_algorithm_set:1;
+    int authoritative_set:1;
+} auth_basic_config_rec;
+
+static void *create_auth_basic_dir_config(apr_pool_t *p, char *d)
+{
+    auth_basic_config_rec *conf = apr_pcalloc(p, sizeof(*conf));
+
+    /* Any failures are fatal. */
+    conf->authoritative = 1;
+
+    return conf;
+}
+
+static void *merge_auth_basic_dir_config(apr_pool_t *p, void *basev, void *overridesv)
+{
+    auth_basic_config_rec *newconf = apr_pcalloc(p, sizeof(*newconf));
+    auth_basic_config_rec *base = basev;
+    auth_basic_config_rec *overrides = overridesv;
+
+    newconf->authoritative =
+            overrides->authoritative_set ? overrides->authoritative :
+                    base->authoritative;
+    newconf->authoritative_set = overrides->authoritative_set
+            || base->authoritative_set;
+
+    newconf->fakeuser =
+            overrides->fake_set ? overrides->fakeuser : base->fakeuser;
+    newconf->fakepass =
+            overrides->fake_set ? overrides->fakepass : base->fakepass;
+    newconf->fake_set = overrides->fake_set || base->fake_set;
+
+    newconf->use_digest_algorithm =
+        overrides->use_digest_algorithm_set ? overrides->use_digest_algorithm
+                                            : base->use_digest_algorithm;
+    newconf->use_digest_algorithm_set =
+        overrides->use_digest_algorithm_set || base->use_digest_algorithm_set;
+
+    newconf->providers = overrides->providers ? overrides->providers : base->providers;
+
+    return newconf;
+}
+
+static const char *add_authn_provider(cmd_parms *cmd, void *config,
+                                      const char *arg)
+{
+    auth_basic_config_rec *conf = (auth_basic_config_rec*)config;
+    authn_provider_list *newp;
+
+    newp = apr_pcalloc(cmd->pool, sizeof(authn_provider_list));
+    newp->provider_name = arg;
+
+    /* lookup and cache the actual provider now */
+    newp->provider = ap_lookup_provider(AUTHN_PROVIDER_GROUP,
+                                        newp->provider_name,
+                                        AUTHN_PROVIDER_VERSION);
+
+    if (newp->provider == NULL) {
+        /* by the time they use it, the provider should be loaded and
+           registered with us. */
+        return apr_psprintf(cmd->pool,
+                            "Unknown Authn provider: %s",
+                            newp->provider_name);
+    }
+
+    if (!newp->provider->check_password) {
+        /* if it doesn't provide the appropriate function, reject it */
+        return apr_psprintf(cmd->pool,
+                            "The '%s' Authn provider doesn't support "
+                            "Basic Authentication", newp->provider_name);
+    }
+
+    /* Add it to the list now. */
+    if (!conf->providers) {
+        conf->providers = newp;
+    }
+    else {
+        authn_provider_list *last = conf->providers;
+
+        while (last->next) {
+            last = last->next;
+        }
+        last->next = newp;
+    }
+
+    return NULL;
+}
+
+static const char *set_authoritative(cmd_parms * cmd, void *config, int flag)
+{
+    auth_basic_config_rec *conf = (auth_basic_config_rec *) config;
+
+    conf->authoritative = flag;
+    conf->authoritative_set = 1;
+
+    return NULL;
+}
+
+static const char *add_basic_fake(cmd_parms * cmd, void *config,
+        const char *user, const char *pass)
+{
+    auth_basic_config_rec *conf = (auth_basic_config_rec *) config;
+    const char *err;
+
+    if (!strcasecmp(user, "off")) {
+        conf->fakeuser = NULL;
+        conf->fakepass = NULL;
+        conf->fake_set = 1;
+    }
+    else {
+        /* if password is unspecified, set it to the fixed string "password" to
+         * be compatible with the behaviour of mod_ssl.
+         */
+        if (!pass) {
+            pass = "password";
+        }
+
+        conf->fakeuser =
+                ap_expr_parse_cmd(cmd, user, AP_EXPR_FLAG_STRING_RESULT,
+                        &err, NULL);
+        if (err) {
+            return apr_psprintf(cmd->pool,
+                    "Could not parse fake username expression '%s': %s", user,
+                    err);
+        }
+        conf->fakepass =
+                ap_expr_parse_cmd(cmd, pass, AP_EXPR_FLAG_STRING_RESULT,
+                        &err, NULL);
+        if (err) {
+            return apr_psprintf(cmd->pool,
+                    "Could not parse fake password expression associated to user '%s': %s",
+                    user, err);
+        }
+        conf->fake_set = 1;
+    }
+
+    return NULL;
+}
+
+static const char *set_use_digest_algorithm(cmd_parms *cmd, void *config,
+                                            const char *alg)
+{
+    auth_basic_config_rec *conf = (auth_basic_config_rec *)config;
+
+    if (strcasecmp(alg, "Off") && strcasecmp(alg, "MD5")) {
+        return apr_pstrcat(cmd->pool,
+                           "Invalid algorithm in "
+                           "AuthBasicUseDigestAlgorithm: ", alg, NULL);
+    }
+
+    conf->use_digest_algorithm = alg;
+    conf->use_digest_algorithm_set = 1;
+
+    return NULL;
+}
+
+static const command_rec auth_basic_cmds[] =
+{
+    AP_INIT_ITERATE("AuthBasicProvider", add_authn_provider, NULL, OR_AUTHCFG,
+                    "specify the auth providers for a directory or location"),
+    AP_INIT_FLAG("AuthBasicAuthoritative", set_authoritative, NULL, OR_AUTHCFG,
+                 "Set to 'Off' to allow access control to be passed along to "
+                 "lower modules if the UserID is not known to this module"),
+    AP_INIT_TAKE12("AuthBasicFake", add_basic_fake, NULL, OR_AUTHCFG,
+                  "Fake basic authentication using the given expressions for "
+                  "username and password, 'off' to disable. Password defaults "
+                  "to 'password' if missing."),
+    AP_INIT_TAKE1("AuthBasicUseDigestAlgorithm", set_use_digest_algorithm,
+                  NULL, OR_AUTHCFG,
+                  "Set to 'MD5' to use the auth provider's authentication "
+                  "check for digest auth, using a hash of 'user:realm:pass'"),
+    {NULL}
+};
+
+module AP_MODULE_DECLARE_DATA auth_basic_module;
+
+/* These functions return 0 if client is OK, and proper error status
+ * if not... either HTTP_UNAUTHORIZED, if we made a check, and it failed, or
+ * HTTP_INTERNAL_SERVER_ERROR, if things are so totally confused that we
+ * couldn't figure out how to tell if the client is authorized or not.
+ *
+ * If they return DECLINED, and all other modules also decline, that's
+ * treated by the server core as a configuration error, logged and
+ * reported as such.
+ */
+
+static void note_basic_auth_failure(request_rec *r)
+{
+    apr_table_setn(r->err_headers_out,
+                   (PROXYREQ_PROXY == r->proxyreq) ? "Proxy-Authenticate"
+                                                   : "WWW-Authenticate",
+                   apr_pstrcat(r->pool, "Basic realm=\"", ap_auth_name(r),
+                               "\"", NULL));
+}
+
+static int hook_note_basic_auth_failure(request_rec *r, const char *auth_type)
+{
+    if (strcasecmp(auth_type, "Basic"))
+        return DECLINED;
+
+    note_basic_auth_failure(r);
+    return OK;
+}
+
+static int get_basic_auth(request_rec *r, const char **user,
+                          const char **pw)
+{
+    const char *auth_line;
+    char *decoded_line;
+
+    /* Get the appropriate header */
+    auth_line = apr_table_get(r->headers_in, (PROXYREQ_PROXY == r->proxyreq)
+                                              ? "Proxy-Authorization"
+                                              : "Authorization");
+
+    if (!auth_line) {
+        note_basic_auth_failure(r);
+        return HTTP_UNAUTHORIZED;
+    }
+
+    if (strcasecmp(ap_getword(r->pool, &auth_line, ' '), "Basic")) {
+        /* Client tried to authenticate using wrong auth scheme */
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01614)
+                      "client used wrong authentication scheme: %s", r->uri);
+        note_basic_auth_failure(r);
+        return HTTP_UNAUTHORIZED;
+    }
+
+    /* Skip leading spaces. */
+    while (*auth_line == ' ' || *auth_line == '\t') {
+        auth_line++;
+    }
+
+    decoded_line = ap_pbase64decode(r->pool, auth_line);
+
+    *user = ap_getword_nulls(r->pool, (const char**)&decoded_line, ':');
+    *pw = decoded_line;
+
+    /* set the user, even though the user is unauthenticated at this point */
+    r->user = (char *) *user;
+
+    return OK;
+}
+
+/* Determine user ID, and check if it really is that user, for HTTP
+ * basic authentication...
+ */
+static int authenticate_basic_user(request_rec *r)
+{
+    auth_basic_config_rec *conf = ap_get_module_config(r->per_dir_config,
+                                                       &auth_basic_module);
+    const char *sent_user, *sent_pw, *current_auth;
+    const char *realm = NULL;
+    const char *digest = NULL;
+    int res;
+    authn_status auth_result;
+    authn_provider_list *current_provider;
+
+    /* Are we configured to be Basic auth? */
+    current_auth = ap_auth_type(r);
+    if (!current_auth || strcasecmp(current_auth, "Basic")) {
+        return DECLINED;
+    }
+
+    /* We need an authentication realm. */
+    if (!ap_auth_name(r)) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01615)
+                      "need AuthName: %s", r->uri);
+        return HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    r->ap_auth_type = (char*)current_auth;
+
+    res = get_basic_auth(r, &sent_user, &sent_pw);
+    if (res) {
+        return res;
+    }
+
+    if (conf->use_digest_algorithm
+        && !strcasecmp(conf->use_digest_algorithm, "MD5")) {
+        realm = ap_auth_name(r);
+        digest = ap_md5(r->pool,
+                        (unsigned char *)apr_pstrcat(r->pool, sent_user, ":",
+                                                     realm, ":",
+                                                     sent_pw, NULL));
+    }
+
+    current_provider = conf->providers;
+    do {
+        const authn_provider *provider;
+
+        /* For now, if a provider isn't set, we'll be nice and use the file
+         * provider.
+         */
+        if (!current_provider) {
+            provider = ap_lookup_provider(AUTHN_PROVIDER_GROUP,
+                                          AUTHN_DEFAULT_PROVIDER,
+                                          AUTHN_PROVIDER_VERSION);
+
+            if (!provider || !provider->check_password) {
+                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01616)
+                              "No Authn provider configured");
+                auth_result = AUTH_GENERAL_ERROR;
+                break;
+            }
+            apr_table_setn(r->notes, AUTHN_PROVIDER_NAME_NOTE, AUTHN_DEFAULT_PROVIDER);
+        }
+        else {
+            provider = current_provider->provider;
+            apr_table_setn(r->notes, AUTHN_PROVIDER_NAME_NOTE, current_provider->provider_name);
+        }
+
+        if (digest) {
+            char *password;
+
+            if (!provider->get_realm_hash) {
+                ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02493)
+                              "Authn provider does not support "
+                              "AuthBasicUseDigestAlgorithm");
+                auth_result = AUTH_GENERAL_ERROR;
+                break;
+            }
+            /* We expect the password to be hash of user:realm:password */
+            auth_result = provider->get_realm_hash(r, sent_user, realm,
+                                                   &password);
+            if (auth_result == AUTH_USER_FOUND) {
+                auth_result = strcmp(digest, password) ? AUTH_DENIED
+                                                       : AUTH_GRANTED;
+            }
+        }
+        else {
+            auth_result = provider->check_password(r, sent_user, sent_pw);
+        }
+
+        apr_table_unset(r->notes, AUTHN_PROVIDER_NAME_NOTE);
+
+        /* Something occurred. Stop checking. */
+        if (auth_result != AUTH_USER_NOT_FOUND) {
+            break;
+        }
+
+        /* If we're not really configured for providers, stop now. */
+        if (!conf->providers) {
+            break;
+        }
+
+        current_provider = current_provider->next;
+    } while (current_provider);
+
+    if (auth_result != AUTH_GRANTED) {
+        int return_code;
+
+        /* If we're not authoritative, then any error is ignored. */
+        if (!(conf->authoritative) && auth_result != AUTH_DENIED) {
+            return DECLINED;
+        }
+
+        switch (auth_result) {
+        case AUTH_DENIED:
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01617)
+                      "user %s: authentication failure for \"%s\": "
+                      "Password Mismatch",
+                      sent_user, r->uri);
+            return_code = HTTP_UNAUTHORIZED;
+            break;
+        case AUTH_USER_NOT_FOUND:
+            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01618)
+                      "user %s not found: %s", sent_user, r->uri);
+            return_code = HTTP_UNAUTHORIZED;
+            break;
+        case AUTH_GENERAL_ERROR:
+        default:
+            /* We'll assume that the module has already said what its error
+             * was in the logs.
+             */
+            return_code = HTTP_INTERNAL_SERVER_ERROR;
+            break;
+        }
+
+        /* If we're returning 401, tell them to try again. */
+        if (return_code == HTTP_UNAUTHORIZED) {
+            note_basic_auth_failure(r);
+        }
+        return return_code;
+    }
+
+    return OK;
+}
+
+/* If requested, create a fake basic authentication header for the benefit
+ * of a proxy or application running behind this server.
+ */
+static int authenticate_basic_fake(request_rec *r)
+{
+    const char *auth_line, *user, *pass, *err;
+    auth_basic_config_rec *conf = ap_get_module_config(r->per_dir_config,
+                                                       &auth_basic_module);
+
+    if (!conf->fakeuser) {
+        return DECLINED;
+    }
+
+    user = ap_expr_str_exec(r, conf->fakeuser, &err);
+    if (err) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02455)
+                      "AuthBasicFake: could not evaluate user expression for URI '%s': %s", r->uri, err);
+        return HTTP_INTERNAL_SERVER_ERROR;
+    }
+    if (!user || !*user) {
+        ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02458)
+                      "AuthBasicFake: empty username expression for URI '%s', ignoring", r->uri);
+
+        apr_table_unset(r->headers_in, "Authorization");
+
+        return DECLINED;
+    }
+
+    pass = ap_expr_str_exec(r, conf->fakepass, &err);
+    if (err) {
+        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02456)
+                      "AuthBasicFake: could not evaluate password expression for URI '%s': %s", r->uri, err);
+        return HTTP_INTERNAL_SERVER_ERROR;
+    }
+    if (!pass || !*pass) {
+        ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02459)
+                      "AuthBasicFake: empty password expression for URI '%s', ignoring", r->uri);
+
+        apr_table_unset(r->headers_in, "Authorization");
+
+        return DECLINED;
+    }
+
+    auth_line = apr_pstrcat(r->pool, "Basic ",
+                            ap_pbase64encode(r->pool,
+                                             apr_pstrcat(r->pool, user,
+                                                         ":", pass, NULL)),
+                            NULL);
+    apr_table_setn(r->headers_in, "Authorization", auth_line);
+
+    ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(02457)
+                  "AuthBasicFake: \"Authorization: %s\"",
+                  auth_line);
+
+    return OK;
+}
+
+static void register_hooks(apr_pool_t *p)
+{
+    ap_hook_check_authn(authenticate_basic_user, NULL, NULL, APR_HOOK_MIDDLE,
+                        AP_AUTH_INTERNAL_PER_CONF);
+    ap_hook_fixups(authenticate_basic_fake, NULL, NULL, APR_HOOK_LAST);
+    ap_hook_note_auth_failure(hook_note_basic_auth_failure, NULL, NULL,
+                              APR_HOOK_MIDDLE);
+}
+
+AP_DECLARE_MODULE(auth_basic) =
+{
+    STANDARD20_MODULE_STUFF,
+    create_auth_basic_dir_config,  /* dir config creater */
+    merge_auth_basic_dir_config,   /* dir merger --- default is to override */
+    NULL,                          /* server config */
+    NULL,                          /* merge server config */
+    auth_basic_cmds,               /* command apr_table_t */
+    register_hooks                 /* register hooks */
+};