first version of LOCAL pam backend

1 files changed, 295 insertions, 0 deletions

diff --git a/server/responder/pam/pam_LOCAL_domain.c b/server/responder/pam/pam_LOCAL_domain.c
new file mode 100644
index 000000000..54b68307e
--- /dev/null
+++ b/server/responder/pam/pam_LOCAL_domain.c
@@ -0,0 +1,295 @@
+#include <security/pam_modules.h>
+
+#include "util/util.h"
+#include "responder/pam/pamsrv.h"
+#include "db/sysdb.h"
+#include "util/nss_sha512crypt.h"
+
+
+#define NULL_CHECK_OR_JUMP(var, msg, ret, err, label) do { \
+    if (var == NULL) { \
+        DEBUG(1, (msg)); \
+        ret = (err); \
+        goto label; \
+    } \
+} while(0)
+
+#define NEQ_CHECK_OR_JUMP(var, val, msg, ret, err, label) do { \
+    if (var != (val)) { \
+        DEBUG(1, (msg)); \
+        ret = (err); \
+        goto label; \
+    } \
+} while(0)
+
+
+struct LOCAL_request {
+    struct cli_ctx *cctx;
+    struct pam_data *pd;
+    pam_dp_callback_t callback;
+
+};
+
+struct callback_ctx {
+    struct cli_ctx *cctx;
+    pam_dp_callback_t callback;
+    int pam_status;
+    char *domain;
+};
+
+static int authtok2str(const void *mem_ctx, uint8_t *src, const int src_size, char **dest)
+{
+    if ((src == NULL && src_size != 0) ||
+        (src != NULL && *src != '\0' && src_size == 0)) {
+        return EINVAL;
+    }
+
+    *dest = talloc_size(mem_ctx, src_size + 1);
+    if (dest == NULL) {
+        return ENOMEM;
+    }
+    memcpy(*dest, src, src_size);
+    (*dest)[src_size]='\0';
+
+    return EOK;
+}
+
+static void LOCAL_call_callback(struct tevent_context *ev,
+                                struct tevent_timer *te,
+                                struct timeval tv, void *pvt) {
+
+    struct callback_ctx *callback_ctx;
+    struct cli_ctx *cctx;
+    pam_dp_callback_t callback;
+    int pam_status;
+    char *domain;
+
+    callback_ctx = talloc_get_type(pvt, struct callback_ctx);
+    cctx = callback_ctx->cctx;
+    callback = callback_ctx->callback;
+    pam_status = callback_ctx->pam_status;
+    domain = callback_ctx->domain;
+
+    talloc_free(callback_ctx);
+
+    callback(cctx, pam_status, domain);
+}
+
+static void LOCAL_pam_handler(struct tevent_context *ev,
+                              struct tevent_timer *te,
+                              struct timeval tv, void *pvt)
+{
+    int ret;
+    int pam_status = PAM_SUCCESS;
+    struct LOCAL_request *lreq;
+    struct sysdb_ctx *dbctx=NULL;
+    struct ldb_result *res=NULL;
+    struct ldb_context *ldb_ctx;
+    struct ldb_dn *user_base_dn=NULL;
+    struct ldb_message *msg;
+    const char *attrs[] = {SYSDB_PW_NAME, SYSDB_PW_PWD, SYSDB_PW_DISABLED,
+                           NULL};
+    char *authtok=NULL;
+    char *newauthtok=NULL;
+    const char *username=NULL;
+    const char *password=NULL;
+    char *new_hash=NULL;
+    const char *disabled=NULL;
+    char *salt=NULL;
+    struct callback_ctx *callback_ctx;
+    int callback_delay;
+
+    DEBUG(4, ("LOCAL pam handler.\n"));
+    lreq = talloc_get_type(pvt, struct LOCAL_request);
+
+    ret = sysdb_init(lreq, lreq->cctx->ev, lreq->cctx->nctx->cdb, NULL, &dbctx);
+    NEQ_CHECK_OR_JUMP(ret, EOK, ("Could not set up LOCAL db"),
+                      pam_status, PAM_SYSTEM_ERR, done);
+
+    ldb_ctx = sysdb_ctx_get_ldb(dbctx);
+
+/* FIXME: replace with proper sysdb calls */
+    user_base_dn = ldb_dn_new_fmt(lreq, ldb_ctx, SYSDB_TMPL_USER_BASE,
+                                  "LOCAL");
+    NULL_CHECK_OR_JUMP(user_base_dn, ("Could not set up user base dn"),
+                       pam_status, PAM_SYSTEM_ERR, done);
+
+    ret = ldb_search(ldb_ctx, lreq, &res, user_base_dn, LDB_SCOPE_SUBTREE,
+                     attrs, SYSDB_PWNAM_FILTER, lreq->pd->user);
+    NEQ_CHECK_OR_JUMP(ret, LDB_SUCCESS, ("ldb_search failed"),
+                      pam_status, PAM_SYSTEM_ERR, done);
+
+    if (res->count < 1) {
+        DEBUG(4, ("No user found with filter ["SYSDB_PWNAM_FILTER"]\n", lreq->pd->user));
+        pam_status = PAM_USER_UNKNOWN;
+        goto done;
+    } else if (res->count > 1) {
+        DEBUG(4, ("More than one object found with filter ["SYSDB_PWNAM_FILTER"]\n", lreq->pd->user));
+        pam_status = PAM_SYSTEM_ERR;
+        goto done;
+    }
+
+    username = ldb_msg_find_attr_as_string(res->msgs[0], SYSDB_PW_NAME, NULL);
+    if (strcmp(username, lreq->pd->user) != 0) {
+        DEBUG(1, ("Expected username [%s] get [%s].\n", lreq->pd->user, username));
+        pam_status = PAM_SYSTEM_ERR;
+        goto done;
+    }
+
+    switch (lreq->pd->cmd) {
+        case SSS_PAM_AUTHENTICATE:
+        case SSS_PAM_CHAUTHTOK:
+            ret = authtok2str(lreq, lreq->pd->authtok,
+                              lreq->pd->authtok_size, &authtok);
+            NEQ_CHECK_OR_JUMP(ret, EOK, ("authtok2str failed.\n"),
+                              pam_status, PAM_SYSTEM_ERR, done);
+
+            ret = authtok2str(lreq, lreq->pd->newauthtok,
+                              lreq->pd->newauthtok_size, &newauthtok);
+            NEQ_CHECK_OR_JUMP(ret, EOK, ("authtok2str failed.\n"),
+                              pam_status, PAM_SYSTEM_ERR, done);
+
+            password = ldb_msg_find_attr_as_string(res->msgs[0], SYSDB_PW_PWD, NULL);
+            NULL_CHECK_OR_JUMP(password, ("No password stored.\n"),
+                               pam_status, PAM_SYSTEM_ERR, done);
+            DEBUG(4, ("user: [%s], password hash: [%s]\n", username, password));
+
+            new_hash = nss_sha512_crypt(authtok, password);
+            if (strcmp(new_hash, password) != 0) {
+                DEBUG(1, ("Passwords do not match.\n"));
+                pam_status = PAM_AUTH_ERR;
+/* TODO: maybe add more inteligent delay calculation */
+                callback_delay = 3;
+                goto done;
+            }
+            pam_status = PAM_SUCCESS;
+            break;
+    }
+
+    switch (lreq->pd->cmd) {
+        case SSS_PAM_AUTHENTICATE:
+            /* already done */
+            break;
+        case SSS_PAM_CHAUTHTOK:
+            salt = gen_salt();
+            NULL_CHECK_OR_JUMP(salt, ("Salt generation failed.\n"),
+                               pam_status, PAM_SYSTEM_ERR, done);
+            DEBUG(4, ("Using salt [%s]\n", salt));
+
+            new_hash = nss_sha512_crypt(newauthtok, salt);
+            NULL_CHECK_OR_JUMP(new_hash, ("Hash generation failed.\n"),
+                               pam_status, PAM_SYSTEM_ERR, done);
+            DEBUG(4, ("New hash [%s]\n", new_hash));
+
+            msg = ldb_msg_new(lreq);
+            msg->dn = res->msgs[0]->dn;
+            NULL_CHECK_OR_JUMP(msg, ("ldb_msg_new failed.\n"),
+                               pam_status, PAM_SYSTEM_ERR, done);
+
+            ret = ldb_msg_add_empty(msg, SYSDB_PW_PWD, LDB_FLAG_MOD_REPLACE,
+                                    NULL);
+            NEQ_CHECK_OR_JUMP(ret, LDB_SUCCESS, ("ldb_msg_add_empty failed.\n"),
+                              pam_status, PAM_SYSTEM_ERR, done);
+
+            ret = ldb_msg_add_string(msg, SYSDB_PW_PWD, new_hash);
+            NEQ_CHECK_OR_JUMP(ret, LDB_SUCCESS, ("ldb_msg_add_string failed.\n"),
+                              pam_status, PAM_SYSTEM_ERR, done);
+
+            ret = ldb_modify(ldb_ctx, msg);
+            NEQ_CHECK_OR_JUMP(ret, LDB_SUCCESS, ("ldb_modify failed.\n"),
+                              pam_status, PAM_SYSTEM_ERR, done);
+
+            pam_status = PAM_SUCCESS;
+            break;
+        case SSS_PAM_ACCT_MGMT:
+            disabled = ldb_msg_find_attr_as_string(res->msgs[0],
+                                                   SYSDB_PW_DISABLED, NULL);
+            if (disabled == NULL ||
+                strncasecmp(disabled, "false",5)==0 ||
+                strncasecmp(disabled, "no",2)==0 ) {
+                pam_status = PAM_SUCCESS;
+            } else {
+                pam_status = PAM_PERM_DENIED;
+            }
+            break;
+        case SSS_PAM_SETCRED:
+            pam_status = PAM_SUCCESS;
+            break;
+        case SSS_PAM_OPEN_SESSION:
+            pam_status = PAM_SUCCESS;
+            break;
+        case SSS_PAM_CLOSE_SESSION:
+            pam_status = PAM_SUCCESS;
+            break;
+        default:
+            pam_status = PAM_SYSTEM_ERR;
+            DEBUG(1, ("Unknown PAM task [%d].\n"));
+    }
+
+done:
+    if (lreq->pd->authtok != NULL)
+        memset(lreq->pd->authtok, 0, lreq->pd->authtok_size);
+    if (authtok != NULL)
+        memset(authtok, 0, lreq->pd->authtok_size);
+    if (lreq->pd->newauthtok != NULL)
+        memset(lreq->pd->newauthtok, 0, lreq->pd->newauthtok_size);
+    if (newauthtok != NULL)
+        memset(newauthtok, 0, lreq->pd->newauthtok_size);
+    talloc_free(res);
+    talloc_free(user_base_dn);
+    talloc_free(dbctx);
+
+    callback_ctx = talloc(lreq->cctx, struct callback_ctx);
+    if (callback_ctx == NULL) {
+        DEBUG(1, ("Cannot prepare callback data.\n"));
+        return;
+    }
+
+    callback_ctx->cctx = lreq->cctx;
+    callback_ctx->callback = lreq->callback;
+    callback_ctx->pam_status = pam_status;
+    callback_ctx->domain = "LOCAL";
+
+    talloc_free(lreq);
+
+    ret = gettimeofday(&tv, NULL);
+    if (ret != 0) {
+        DEBUG(1, ("gettimeofday failed, continuing.\n"));
+    }
+    tv.tv_sec += callback_delay;
+    tv.tv_usec = 0;
+
+    te = tevent_add_timer(ev, callback_ctx->cctx, tv, LOCAL_call_callback,
+                          callback_ctx);
+    if (te == NULL) {
+        DEBUG(1, ("Cannot add callback to event loop.\n"));
+        return;
+    }
+}
+
+int LOCAL_schedule_request(struct cli_ctx *cctx, pam_dp_callback_t callback,
+                           struct pam_data *pd)
+{
+    struct LOCAL_request *lreq;
+    struct tevent_timer *te;
+    struct timeval tv;
+
+    lreq = talloc(cctx, struct LOCAL_request);
+    if (!lreq) {
+        return ENOMEM;
+    }
+    lreq->cctx = cctx;
+    lreq->pd = pd;
+    lreq->callback = callback;
+
+    /* fire immediately */
+    tv.tv_sec = 0;
+    tv.tv_usec = 0;
+
+    te = tevent_add_timer(cctx->ev, cctx, tv, LOCAL_pam_handler, lreq);
+    if (te == NULL) {
+        return EIO;
+    }
+
+    return EOK;
+}