+/*
+ * auth.c -- system-level password checking for autologin
+ * by Nathan Bryant, March 1999
+ *
+ * $Id$
+ */
+
+#ifdef linux
+#define _XOPEN_SOURCE /* needed for crypt() */
+#define _XOPEN_SOURCE_EXTENDED /* needed for strdup() */
+#endif
+
+#include <pwd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+
+#include "auth.h"
+#include "sysdep.h"
+
+#ifdef HAVE_GETSPNAM
+#include <shadow.h>
+#endif
+
+#ifdef HAVE_PAM_START
+#include <security/pam_appl.h>
+
+/*
+ * struct appdata: passed to the conversation function
+ */
+
+struct appdata
+{
+ const char *name;
+ const char *pw;
+};
+
+/*
+ * conv(): the PAM conversation function. this assumes that a
+ * PAM_PROMPT_ECHO_ON is asking for a username, and a PAM_PROMPT_ECHO_OFF is
+ * asking for a password. esoteric authentication modules will fail with this
+ * code, but we can't really support them with the existing client protocol
+ * anyway. the failure mode should be to deny access, in any case.
+ */
+
+static int conv(int num_msg, const struct pam_message **msg,
+ struct pam_response **resp, void *appdata_ptr)
+{
+ struct pam_response *temp_resp;
+ struct appdata *data = appdata_ptr;
+
+ if ((temp_resp = malloc(sizeof(struct pam_response[num_msg]))) == NULL)
+ return PAM_CONV_ERR;
+
+ while (num_msg--)
+ {
+ switch ((*msg)[num_msg].msg_style)
+ {
+ case PAM_PROMPT_ECHO_ON:
+ temp_resp[num_msg].resp = strdup(data->name);
+ break;
+ case PAM_PROMPT_ECHO_OFF:
+ temp_resp[num_msg].resp = strdup(data->pw);
+ break;
+ default:
+ temp_resp[num_msg].resp = NULL;
+ }
+ temp_resp[num_msg].resp_retcode = 0;
+ }
+
+ *resp = temp_resp;
+ return PAM_SUCCESS;
+}
+#endif /* HAVE_PAM_START */
+
+/*
+ * validpw(): check that `pass' is the correct password for `uid'
+ * returns zero if no, nonzero if yes
+ */
+
+int validpw(uid_t uid, const char *pass)
+{
+#ifdef HAVE_PAM_START
+ struct pam_conv pc;
+ struct appdata data;
+ pam_handle_t *ph;
+ int i;
+#else
+ char *crypted_pwd;
+#ifdef HAVE_GETSPNAM
+ struct spwd *sp;
+#endif
+#endif
+ struct passwd *pw;
+ int retval = 0;
+
+ if ((pw = getpwuid(uid)) == NULL)
+ return retval;
+
+#ifdef HAVE_PAM_START
+ pc.conv = conv;
+ pc.appdata_ptr = &data;
+ data.name = pw->pw_name;
+ data.pw = pass;
+ if (pam_start("citadel", pw->pw_name, &pc, &ph) != PAM_SUCCESS)
+ return retval;
+
+ if ((i = pam_authenticate(ph, PAM_SILENT)) == PAM_SUCCESS)
+ if ((i = pam_acct_mgmt(ph, PAM_SILENT)) == PAM_SUCCESS)
+ retval = -1;
+
+ pam_end(ph, i | PAM_DATA_SILENT);
+#else
+ crypted_pwd = pw->pw_passwd;
+
+#ifdef HAVE_GETSPNAM
+ if ((sp = getspnam(pw->pw_name)) != NULL)
+ crypted_pwd = sp->sp_pwdp;
+#endif
+
+ if (!strcmp(crypt(pass, crypted_pwd), crypted_pwd))
+ retval = -1;
+#endif /* HAVE_PAM_START */
+
+ return retval;
+}
projects / citadel.git / commitdiff