initial commit

2 files changed, 103 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..12f2a77
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,9 @@
+pam_propperpwnam.so: pam_propperpwnam.c
+	$(CC) -shared -fPIC -o pam_propperpwnam.so pam_propperpwnam.c -lpam
+
+
+.PHONY: clean
+
+clean:
+	rm *.o *.so
+
diff --git a/pam_propperpwnam.c b/pam_propperpwnam.c
new file mode 100644
index 0000000..49b9769
--- /dev/null
+++ b/pam_propperpwnam.c
@@ -0,0 +1,94 @@
+/*
+* pam_propperpwnam 
+*
+* 2011-06-09
+*
+* Wolfgang Draxinger
+* Wolfgang.Draxinger@physik.uni-muenchen.de
+*
+* a PAM module that sets the user loginname to the username
+* stored in the user databased using the loginname passed
+* as access key.
+*
+* Example usage scenario is adjusting the usernames' characters
+* case in  environments where case sensitive and case insensitive
+* services are mixed (the module was initially developed for
+* this very usage scenario).
+*/
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <pwd.h>
+
+#if DEBUG
+#include <stdio.h>
+#endif
+
+#define PAM_SM_AUTH
+
+#include <security/pam_modules.h>
+#include <security/_pam_macros.h>
+
+PAM_EXTERN int
+pam_sm_setcred(pam_handle_t *pamh, int flags, int argc, const char **argv)
+{
+	return PAM_SUCCESS;
+}
+
+PAM_EXTERN int pam_sm_authenticate(
+	pam_handle_t *pamh,
+	int flags,
+	int argc,
+	char const *argv[] )
+{
+	int error;
+	char *entered_username;
+
+	struct passwd pwd;
+	struct passwd *pwd_result;
+	char *pwd_buf;
+	size_t pwd_bufsize;
+
+#if DEBUG
+	fprintf(stderr, "pam_propperpwnam called\n");
+#endif
+
+	error = pam_get_user(pamh, (char const **)&entered_username, 0);
+	if(PAM_SUCCESS != error)
+		return PAM_USER_UNKNOWN;
+
+#if DEBUG	
+	fprintf(stderr, "pam_propperpwnam entered username is %s\n", entered_username);
+#endif
+
+	pwd_bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
+	if( -1 == pwd_bufsize )          /* Value was indeterminate */
+		pwd_bufsize = 16384;        /* Should be more than enough */
+
+	pwd_buf = malloc( pwd_bufsize );
+	if( !pwd_buf ) {
+		return PAM_AUTH_ERR;
+	}
+
+	error = getpwnam_r(entered_username, &pwd, pwd_buf, pwd_bufsize, &pwd_result);
+	if( !pwd_result ) {
+		free(pwd_buf);
+		if( !error )
+			return PAM_USER_UNKNOWN;
+		return PAM_AUTH_ERR;
+	}
+
+#if DEBUG
+	fprintf(stderr, "pam_propperpwnam propper username is %s\n", pwd_result->pw_name);
+#endif
+
+	error = pam_set_item(pamh, PAM_USER, pwd_result->pw_name);
+	free( pwd_buf );
+	if( PAM_SUCCESS != error ) {
+		return PAM_AUTH_ERR;
+	}
+
+	return PAM_SUCCESS;
+}
+