add nfc pam module

Change-Id: Icc42361f64948e2c2ab082fa973793f19737df2d
Signed-off-by: Loïc Collignon <loic.collignon@iot.bzh>

1 files changed, 152 insertions, 0 deletions

diff --git a/pam_agl/pam_agl_nfc.c b/pam_agl/pam_agl_nfc.c
new file mode 100644
index 0000000..b25ba5c
--- /dev/null
+++ b/pam_agl/pam_agl_nfc.c
@@ -0,0 +1,152 @@
+#include <fcntl.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <uuid/uuid.h>
+#include <json-c/json.h>
+
+#define PAM_SM_AUTH
+#define PAM_SM_ACCOUNT
+#define PAM_SM_SESSION
+#define PAM_SM_PASSWORD
+#include <security/pam_modules.h>
+#include <security/pam_appl.h>
+
+#include <security/pam_client.h>
+#include <security/pam_ext.h>
+#include <security/pam_filter.h>
+#include <security/pam_misc.h>
+#include <security/pam_modutil.h>
+
+#define DATABASE_FILE "/etc/agl/keys.json"
+
+int authenticate(pam_handle_t* pamh, const char* uid)
+{
+	struct json_object* database;
+	struct json_object* nfc;
+	struct json_object* key;
+
+	database = json_object_from_file(DATABASE_FILE);
+	if (!database)
+	{
+		printf("[PAM DEBUG] Failed to parse the database\n");
+		return PAM_SERVICE_ERR;
+	}
+	
+	if (json_object_object_get_ex(database, "nfc", &nfc))
+	{	
+		if (json_object_object_get_ex(nfc, uid, &key))
+		{
+			printf("[PAM] Key found!\n");
+			printf("[PAM DEBUG] pam_set_item(\"%s\")\n", uid);
+			pam_set_item(pamh, PAM_USER, uid);
+				
+			const char* pam_authtok;
+			if (pam_get_item(pamh, PAM_AUTHTOK, (const void**)&pam_authtok) == PAM_SUCCESS && !pam_authtok)
+				pam_set_item(pamh, PAM_AUTHTOK, uid);
+			
+			json_object_put(database);
+			return PAM_SUCCESS;
+		}
+	}
+	
+	printf("[PAM] Key not found!\n");
+	if (database) json_object_put(database);
+	return PAM_AUTH_ERR;
+}
+
+int check_device(pam_handle_t* pamh, const char* device)
+{
+	char* idkey;
+	int ret;
+	
+	ret = read_device(device, &idkey);
+	if (ret != PAM_SUCCESS) return ret;
+	
+	printf("[PAM DEBUG] Data read:\n%s\n", idkey);
+	
+	json_object* idkey_json = json_tokener_parse(idkey);
+	if (!idkey_json)
+	{
+		free(idkey);
+		printf("[PAM DEBUG] Failed to parse json data!\n");
+		return PAM_SERVICE_ERR;
+	}
+
+	json_object* uuid_json;
+	if(!json_object_object_get_ex(idkey_json, "uuid", &uuid_json))
+	{
+		free(idkey);
+		printf("[PAM DEBUG] The json does not contains a valid uuid\n");
+		return PAM_SERVICE_ERR;
+	}
+
+	const char* uuid = json_object_get_string(uuid_json);
+	printf("[PAM DEBUG] uuid: %s\n", uuid);
+	
+	ret = authenticate(pamh, uuid);
+	free(idkey);
+	json_object_put(idkey_json);
+	return ret;
+}
+
+void log_pam(const char* fname, int flags, int argc, const char** argv, const char* device)
+{
+	printf("[PAM DEBUG] ---------- %s ----------\n", fname);
+	printf("[PAM DEBUG] flags: %d\n", flags);
+	for(int i = 0; i < argc; ++i)
+	{
+		printf("[PAM DEBUG] argv[%d]: %s\n", i, argv[i]);
+	}
+	printf("[PAM DEBUG] device: %s\n", device);
+	printf("[PAM DEBUG] ----------------------------------------\n");
+}
+
+/*!
+	@brief The pam_sm_authenticate function is the service module's implementation
+	of the pam_authenticate(3) interface.
+	This function performs the task of authenticating the user.
+
+	@param[in] pamh Unknown.
+	@param[in] flags PAM_SILENT and/or PAM_DISALLOW_NULL_AUTHTOK.
+	@return PAM_SUCCESS if ok.
+*/
+PAM_EXTERN int pam_sm_authenticate(pam_handle_t* pamh, int flags, int argc, const char** argv)
+{
+	const char* uid = pam_getenv(pamh, "UID");
+	log_pam("pam_sm_authenticate", flags, argc, argv, uid);
+	return authenticate(pamh, uid);
+}
+
+PAM_EXTERN int pam_sm_setcred(pam_handle_t* pamh, int flags, int argc, const char** argv)
+{
+	log_pam("pam_sm_setcred", flags, argc, argv, pam_getenv(pamh, "DEVICE"));
+	return PAM_SUCCESS;
+}
+
+PAM_EXTERN int pam_sm_acct_mgmt(pam_handle_t* pamh, int flags, int argc, const char** argv)
+{
+	log_pam("pam_sm_acct_mgmt", flags, argc, argv, pam_getenv(pamh, "DEVICE"));
+	return PAM_SUCCESS;
+}
+
+PAM_EXTERN int pam_sm_open_session(pam_handle_t* pamh, int flags, int argc, const char** argv)
+{
+	log_pam("pam_sm_open_session", flags, argc, argv, pam_getenv(pamh, "DEVICE"));
+	return PAM_SUCCESS;
+}
+
+PAM_EXTERN int pam_sm_close_session(pam_handle_t* pamh, int flags, int argc, const char** argv)
+{
+	log_pam("pam_sm_close_session", flags, argc, argv, pam_getenv(pamh, "DEVICE"));
+	return PAM_SUCCESS;
+}
+
+PAM_EXTERN int pam_sm_chauthtok(pam_handle_t* pamh, int flags, int argc, const char** argv)
+{
+	log_pam("pam_sm_chauthtok", flags, argc, argv, pam_getenv(pamh, "DEVICE"));
+	return PAM_SUCCESS;
+}