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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 20:46:53 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 20:46:53 +0000 |
commit | 19da58be2d9359a9641381feb559be0b918ef710 (patch) | |
tree | 109724175f07436696f51b14b5abbd3f4d704d6d /lib/sgetpwent.c | |
parent | Initial commit. (diff) | |
download | shadow-19da58be2d9359a9641381feb559be0b918ef710.tar.xz shadow-19da58be2d9359a9641381feb559be0b918ef710.zip |
Adding upstream version 1:4.13+dfsg1.upstream/1%4.13+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/sgetpwent.c')
-rw-r--r-- | lib/sgetpwent.c | 109 |
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; +} + |