1 files changed, 109 insertions, 0 deletions
diff --git a/lib/sgetpwent.c b/lib/sgetpwent.c
new file mode 100644
index 0000000..1c8c63e
--- /dev/null
+++ b/lib/sgetpwent.c
@@ -0,0 +1,109 @@
+/*
+ * SPDX-FileCopyrightText: 1989 - 1994, Julianne Frances Haugh
+ * SPDX-FileCopyrightText: 1996 - 1998, Marek Michałkiewicz
+ * SPDX-FileCopyrightText: 2003 - 2005, Tomasz Kłoczko
+ * SPDX-FileCopyrightText: 2008       , Nicolas François
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <config.h>
+
+#ident "$Id$"
+
+#include <sys/types.h>
+#include "defines.h"
+#include <stdio.h>
+#include <pwd.h>
+#include "prototypes.h"
+#include "shadowlog_internal.h"
+
+#define	NFIELDS	7
+
+/*
+ * sgetpwent - convert a string to a (struct passwd)
+ *
+ * sgetpwent() parses a string into the parts required for a password
+ * structure.  Strict checking is made for the UID and GID fields and
+ * presence of the correct number of colons.  Any failing tests result
+ * in a NULL pointer being returned.
+ *
+ * NOTE: This function uses hard-coded string scanning functions for
+ *	performance reasons.  I am going to come up with some conditional
+ *	compilation glarp to improve on this in the future.
+ */
+struct passwd *sgetpwent (const char *buf)
+{
+	static struct passwd pwent;
+	static char pwdbuf[PASSWD_ENTRY_MAX_LENGTH];
+	int i;
+	char *cp;
+	char *fields[NFIELDS];
+
+	/*
+	 * Copy the string to a static buffer so the pointers into
+	 * the password structure remain valid.
+	 */
+
+	if (strlen (buf) >= sizeof pwdbuf) {
+		fprintf (shadow_logfd,
+		         "%s: Too long passwd entry encountered, file corruption?\n",
+		         shadow_progname);
+		return 0;	/* fail if too long */
+	}
+	strcpy (pwdbuf, buf);
+
+	/*
+	 * Save a pointer to the start of each colon separated
+	 * field.  The fields are converted into NUL terminated strings.
+	 */
+
+	for (cp = pwdbuf, i = 0; (i < NFIELDS) && (NULL != cp); i++) {
+		fields[i] = cp;
+		while (('\0' != *cp) && (':' != *cp)) {
+			cp++;
+		}
+
+		if ('\0' != *cp) {
+			*cp = '\0';
+			cp++;
+		} else {
+			cp = NULL;
+		}
+	}
+
+	/* something at the end, columns over shot */
+	if ( cp != NULL ) {
+		return( NULL );
+	}
+
+	/*
+	 * There must be exactly NFIELDS colon separated fields or
+	 * the entry is invalid.  Also, the UID and GID must be non-blank.
+	 */
+
+	if (i != NFIELDS || *fields[2] == '\0' || *fields[3] == '\0')
+		return NULL;
+
+	/*
+	 * Each of the fields is converted the appropriate data type
+	 * and the result assigned to the password structure.  If the
+	 * UID or GID does not convert to an integer value, a NULL
+	 * pointer is returned.
+	 */
+
+	pwent.pw_name = fields[0];
+	pwent.pw_passwd = fields[1];
+	if (get_uid (fields[2], &pwent.pw_uid) == 0) {
+		return NULL;
+	}
+	if (get_gid (fields[3], &pwent.pw_gid) == 0) {
+		return NULL;
+	}
+	pwent.pw_gecos = fields[4];
+	pwent.pw_dir = fields[5];
+	pwent.pw_shell = fields[6];
+
+	return &pwent;
+}
+