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| author | imp <imp@FreeBSD.org> | 1998-02-13 02:13:24 +0000 |
|---|---|---|
| committer | imp <imp@FreeBSD.org> | 1998-02-13 02:13:24 +0000 |
| commit | 9461b07207276f197a45e7ed0bc94bda8106f779 (patch) | |
| tree | bf29f53d22853e188a325419db4e6bdeecab1744 /lib/libc/stdio/mktemp.3 | |
| parent | b31dde27bfeaed94b1026c0788c4e98b1af47f3c (diff) | |
| download | FreeBSD-src-9461b07207276f197a45e7ed0bc94bda8106f779.zip FreeBSD-src-9461b07207276f197a45e7ed0bc94bda8106f779.tar.gz | |
Many security improvements from OpenBSD:
implement mkdtemp
improve man page for mk*temp
use arc4random to seed extra XXX's randomly
Optionally warn of unsafe mktemp uses
From various commits by theo de raadt and Todd Miller.
Obtained from: OpenBSD
This should go into 2.2 after a testing period.
Diffstat (limited to 'lib/libc/stdio/mktemp.3')
| -rw-r--r-- | lib/libc/stdio/mktemp.3 | 52 |
1 files changed, 41 insertions, 11 deletions
diff --git a/lib/libc/stdio/mktemp.3 b/lib/libc/stdio/mktemp.3 index 28a662d..50d7de4 100644 --- a/lib/libc/stdio/mktemp.3 +++ b/lib/libc/stdio/mktemp.3 @@ -31,7 +31,7 @@ .\" .\" @(#)mktemp.3 8.1 (Berkeley) 6/4/93 .\" -.Dd June 4, 1993 +.Dd February 11, 1998 .Dt MKTEMP 3 .Os .Sh NAME @@ -43,6 +43,8 @@ .Fn mktemp "char *template" .Ft int .Fn mkstemp "char *template" +.Ft char * +.Fn mkdtemp "char *template" .Sh DESCRIPTION The .Fn mktemp @@ -78,11 +80,18 @@ makes the same replacement to the template and creates the template file, mode 0600, returning a file descriptor opened for reading and writing. This avoids the race between testing for a file's existence and opening it for use. +.Pp +The +.Fn mkdtemp +function makes the same replacement to the template as in +.Xr mktemp 3 +and creates the template directory, mode 0700. .Sh RETURN VALUES The .Fn mktemp -function -returns a pointer to the template on success and +and +.Fn mkdtemp +functions return a pointer to the template on success and .Dv NULL on failure. The @@ -93,9 +102,9 @@ If either call fails an error code is placed in the global variable .Va errno . .Sh ERRORS The -.Fn mktemp -and .Fn mkstemp +and +.Fn mkdtemp functions may set .Va errno @@ -106,9 +115,9 @@ The pathname portion of the template is not an existing directory. .El .Pp The -.Fn mktemp -and .Fn mkstemp +and +.Fn mkdtemp functions may also set .Va errno @@ -124,12 +133,22 @@ may also set to any value specified by the .Xr open 2 function. +.Pp +The +.Fn mkdtemp +function +may also set +.Va errno +to any value specified by the +.Xr mkdir 2 +function. .Sh NOTES A common problem that results in a core dump is that the programmer passes in a read-only string to -.Fn mktemp -or -.Fn mkstemp . +.Fn mktemp , +.Fn mkstemp +or +.Fn mkdtemp . This is common with programs that were developed before .St -ansiC compilers were common. @@ -146,13 +165,24 @@ so that it will store string constants in a writable segment of memory. See .Xr gcc 1 for more information. +.Sh BUGS +An attacker can guess the filenames produced by +.Fn mktemp . +Whenever it is possible +.Fn mkstemp +should be used instead. .Sh SEE ALSO .Xr chmod 2 , .Xr getpid 2 , +.Xr mkdir 2 , .Xr open 2 , .Xr stat 2 .Sh HISTORY A -.Nm mktemp +.Fn mktemp function appeared in .At v7 . +The +.Fn mkdtemp +function first appeared in +.Ox 2.2 . |
