Disallow use of DES encryption functions in new programs.

The functions encrypt, setkey, encrypt_r, setkey_r, cbc_crypt,
ecb_crypt, and des_setparity should not be used in new programs,
because they use the DES block cipher, which is unacceptably weak by
modern standards.  Demote all of them to compatibility symbols, and
remove their prototypes from installed headers.  cbc_crypt, ecb_crypt,
and des_setparity were already compat symbols when glibc was
configured with --disable-obsolete-rpc.

POSIX requires encrypt and setkey to be available when _XOPEN_CRYPT
is defined, so this change also removes the definition of X_OPEN_CRYPT
from <unistd.h>.

The entire "DES Encryption" section is dropped from the manual, as is
the mention of AUTH_DES and FIPS 140-2 in the introduction to
crypt.texi.  The documentation of 'memfrob' cross-referenced the DES
Encryption section, which is replaced by a hyperlink to libgcrypt, and
while I was in there I spruced up the actual documentation of
'memfrob' and 'strfry' a little.  It's still fairly jokey, because
those functions _are_ jokes, but they do also have real use cases, so
people trying to use them for real should have all the information
they need.

DES-based authentication for Sun RPC is also insecure and should be
deprecated or even removed, but maybe that can be left as TI-RPC's
problem.

1 files changed, 33 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 55d4f3a3c5..d3c4c423e1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,36 @@
+2018-06-29  Zack Weinberg  <zackw@panix.com>
+	    Florian Weimer <fweimer@redhat.com>
+
+	* posix/unistd.h: Do not declare encrypt.
+	(_XOPEN_CRYPT): Remove macro definition.
+	(crypt): Declare only for _USE_MISC.
+	* stdlib/stdlib.h: Do not declare setkey.
+	* crypt/crypt.h: Do not declare encrypt, setkey, encrypt_r, setkey_r.
+	* sunrpc/Makefile: Do not install des_crypt.h nor rpc_des.h.
+
+	* crypt/crypt-entry.c: Make fcrypt a compat symbol.
+	* crypt/crypt_util.c: Make encrypt, encrypt_r, setkey, setkey_r
+	into compat symbols.  Don't define initial_perm if it's not
+	going to be used.
+	* crypt/cert.c: Link explicitly with the expected versions for
+	setkey and encrypt.  If they are not available at all, mark
+	the test as unsupported.
+
+	* sunrpc/des_crypt.c: Unconditionally block linkage with
+	cbc_crypt and ecb_crypt for new binaries.
+	* sunrpc/des_soft.c: Unconditionally block linkage with
+	des_setparity for new binaries.
+
+	* manual/crypt.texi: Remove the entire "DES Encryption"
+	section.  Also remove the paragraph talking about FIPS 140-2
+	from the introduction.
+	* manual/string.texi (strfry, memfrob): Revise.	 Recommend use
+	of libgcrypt for "real" encryption, not DES.
+	* manual/conf.texi (Constants for Sysconf): Mention that
+	_XOPEN_CRYPT is no longer impelemented.
+
+	* conform/data/unistd.h-data: Remove crypt function declaration.
+
 2018-06-29  Florian Weimer  <fweimer@redhat.com>
 
 	[BZ #23351]