Mailing List Archive

Remove missing AES CTR compatibility hacks
Hi all.

Similar to the previous diff about GCM mode, we have some compatibility
poo that was added to support OpenSSL versions that do not support
AES CTR. Since that time, however, the minimum OpenSSL version that
we support has moved to 1.0.1 which *does* have GCM, so this compat poo
is now useless and this diff removes it. I've test-built this against
OpenSSL 1.0.1 and LibreSSL 2.1.8.

ok?

diff --git a/.depend b/.depend
index cd38d15f..0661aba3 100644
--- a/.depend
+++ b/.depend
@@ -39,7 +39,6 @@ cipher-aes.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-co
cipher-aesctr.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/fnmatch.h openbsd-compat/getopt.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h cipher-aesctr.h rijndael.h
cipher-chachapoly-libcrypto.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/fnmatch.h openbsd-compat/getopt.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h
cipher-chachapoly.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/fnmatch.h openbsd-compat/getopt.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h log.h ssherr.h sshbuf.h cipher-chachapoly.h chacha.h poly1305.h
-cipher-ctr.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/fnmatch.h openbsd-compat/getopt.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h
cipher.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/fnmatch.h openbsd-compat/getopt.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h cipher.h cipher-chachapoly.h chacha.h poly1305.h cipher-aesctr.h rijndael.h misc.h sshbuf.h ssherr.h digest.h openbsd-compat/openssl-compat.h
cleanup.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/fnmatch.h openbsd-compat/getopt.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h log.h ssherr.h
clientloop.o: includes.h config.h defines.h platform.h openbsd-compat/openbsd-compat.h openbsd-compat/base64.h openbsd-compat/sigact.h openbsd-compat/readpassphrase.h openbsd-compat/vis.h openbsd-compat/getrrsetbyname.h openbsd-compat/sha1.h openbsd-compat/sha2.h openbsd-compat/md5.h openbsd-compat/blf.h openbsd-compat/fnmatch.h openbsd-compat/getopt.h openbsd-compat/bsd-signal.h openbsd-compat/bsd-misc.h openbsd-compat/bsd-setres_id.h openbsd-compat/bsd-statvfs.h openbsd-compat/bsd-waitpid.h openbsd-compat/bsd-poll.h openbsd-compat/fake-rfc2553.h openbsd-compat/bsd-cygwin_util.h openbsd-compat/port-aix.h openbsd-compat/port-irix.h openbsd-compat/port-linux.h openbsd-compat/port-solaris.h openbsd-compat/port-net.h openbsd-compat/port-uw.h openbsd-compat/bsd-nextstep.h entropy.h openbsd-compat/sys-queue.h xmalloc.h ssh.h ssh2.h packet.h dispatch.h sshbuf.h compat.h channels.h sshkey.h cipher.h cipher-chachapoly.h chacha.h poly1305.h cipher-aesctr.h rijndael.h kex.h mac.h cry!
pto_api.h
diff --git a/Makefile.in b/Makefile.in
index 3c285682..a5c292bd 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -94,7 +94,7 @@ LIBOPENSSH_OBJS=\
LIBSSH_OBJS=${LIBOPENSSH_OBJS} \
authfd.o authfile.o \
canohost.o channels.o cipher.o cipher-aes.o cipher-aesctr.o \
- cipher-ctr.o cleanup.o \
+ cleanup.o \
compat.o fatal.o hostfile.o \
log.o match.o moduli.o nchan.o packet.o \
readpass.o ttymodes.o xmalloc.o addr.o addrmatch.o \
diff --git a/cipher-ctr.c b/cipher-ctr.c
deleted file mode 100644
index 32771f28..00000000
--- a/cipher-ctr.c
+++ /dev/null
@@ -1,146 +0,0 @@
-/* $OpenBSD: cipher-ctr.c,v 1.11 2010/10/01 23:05:32 djm Exp $ */
-/*
- * Copyright (c) 2003 Markus Friedl <markus@openbsd.org>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-#include "includes.h"
-
-#if defined(WITH_OPENSSL) && !defined(OPENSSL_HAVE_EVPCTR)
-#include <sys/types.h>
-
-#include <stdarg.h>
-#include <string.h>
-
-#include <openssl/evp.h>
-
-#include "xmalloc.h"
-#include "log.h"
-
-/* compatibility with old or broken OpenSSL versions */
-#include "openbsd-compat/openssl-compat.h"
-
-#ifndef USE_BUILTIN_RIJNDAEL
-#include <openssl/aes.h>
-#endif
-
-struct ssh_aes_ctr_ctx
-{
- AES_KEY aes_ctx;
- u_char aes_counter[AES_BLOCK_SIZE];
-};
-
-/*
- * increment counter 'ctr',
- * the counter is of size 'len' bytes and stored in network-byte-order.
- * (LSB at ctr[len-1], MSB at ctr[0])
- */
-static void
-ssh_ctr_inc(u_char *ctr, size_t len)
-{
- int i;
-
- for (i = len - 1; i >= 0; i--)
- if (++ctr[i]) /* continue on overflow */
- return;
-}
-
-static int
-ssh_aes_ctr(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src,
- LIBCRYPTO_EVP_INL_TYPE len)
-{
- struct ssh_aes_ctr_ctx *c;
- size_t n = 0;
- u_char buf[AES_BLOCK_SIZE];
-
- if (len == 0)
- return (1);
- if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL)
- return (0);
-
- while ((len--) > 0) {
- if (n == 0) {
- AES_encrypt(c->aes_counter, buf, &c->aes_ctx);
- ssh_ctr_inc(c->aes_counter, AES_BLOCK_SIZE);
- }
- *(dest++) = *(src++) ^ buf[n];
- n = (n + 1) % AES_BLOCK_SIZE;
- }
- return (1);
-}
-
-static int
-ssh_aes_ctr_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv,
- int enc)
-{
- struct ssh_aes_ctr_ctx *c;
-
- if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) {
- c = xmalloc(sizeof(*c));
- EVP_CIPHER_CTX_set_app_data(ctx, c);
- }
- if (key != NULL)
- AES_set_encrypt_key(key, EVP_CIPHER_CTX_key_length(ctx) * 8,
- &c->aes_ctx);
- if (iv != NULL)
- memcpy(c->aes_counter, iv, AES_BLOCK_SIZE);
- return (1);
-}
-
-static int
-ssh_aes_ctr_cleanup(EVP_CIPHER_CTX *ctx)
-{
- struct ssh_aes_ctr_ctx *c;
-
- if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) {
- memset(c, 0, sizeof(*c));
- free(c);
- EVP_CIPHER_CTX_set_app_data(ctx, NULL);
- }
- return (1);
-}
-
-void
-ssh_aes_ctr_iv(EVP_CIPHER_CTX *evp, int doset, u_char * iv, size_t len)
-{
- struct ssh_aes_ctr_ctx *c;
-
- if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL)
- fatal("ssh_aes_ctr_iv: no context");
- if (doset)
- memcpy(c->aes_counter, iv, len);
- else
- memcpy(iv, c->aes_counter, len);
-}
-
-const EVP_CIPHER *
-evp_aes_128_ctr(void)
-{
- static EVP_CIPHER aes_ctr;
-
- memset(&aes_ctr, 0, sizeof(EVP_CIPHER));
- aes_ctr.nid = NID_undef;
- aes_ctr.block_size = AES_BLOCK_SIZE;
- aes_ctr.iv_len = AES_BLOCK_SIZE;
- aes_ctr.key_len = 16;
- aes_ctr.init = ssh_aes_ctr_init;
- aes_ctr.cleanup = ssh_aes_ctr_cleanup;
- aes_ctr.do_cipher = ssh_aes_ctr;
-#ifndef SSH_OLD_EVP
- aes_ctr.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH |
- EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV;
-#endif
- return (&aes_ctr);
-}
-
-#endif /* defined(WITH_OPENSSL) && !defined(OPENSSL_HAVE_EVPCTR) */
diff --git a/cipher.c b/cipher.c
index 5b3a86d6..40ecf20b 100644
--- a/cipher.c
+++ b/cipher.c
@@ -487,11 +487,6 @@ cipher_get_keyiv(struct sshcipher_ctx *cc, u_char *iv, size_t len)
return SSH_ERR_LIBCRYPTO_ERROR;
if ((size_t)evplen != len)
return SSH_ERR_INVALID_ARGUMENT;
-#ifndef OPENSSL_HAVE_EVPCTR
- if (c->evptype == evp_aes_128_ctr)
- ssh_aes_ctr_iv(cc->evp, 0, iv, len);
- else
-#endif
if (cipher_authlen(c)) {
if (!EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_IV_GEN,
len, iv))
@@ -521,12 +516,6 @@ cipher_set_keyiv(struct sshcipher_ctx *cc, const u_char *iv, size_t len)
return SSH_ERR_LIBCRYPTO_ERROR;
if ((size_t)evplen != len)
return SSH_ERR_INVALID_ARGUMENT;
-#ifndef OPENSSL_HAVE_EVPCTR
- /* XXX iv arg is const, but ssh_aes_ctr_iv isn't */
- if (c->evptype == evp_aes_128_ctr)
- ssh_aes_ctr_iv(cc->evp, 1, (u_char *)iv, evplen);
- else
-#endif
if (cipher_authlen(c)) {
/* XXX iv arg is const, but EVP_CIPHER_CTX_ctrl isn't */
if (!EVP_CIPHER_CTX_ctrl(cc->evp,
diff --git a/configure.ac b/configure.ac
index 3e9fd700..713ee24c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2987,28 +2987,6 @@ if test "x$openssl" = "xyes" ; then
]
)

- # Check for OpenSSL with EVP_aes_*ctr
- AC_MSG_CHECKING([whether OpenSSL has AES CTR via EVP])
- AC_LINK_IFELSE(
- [.AC_LANG_PROGRAM([.[.
- #include <stdlib.h>
- #include <string.h>
- #include <openssl/evp.h>
- ]], [.[.
- exit(EVP_aes_128_ctr() == NULL ||
- EVP_aes_192_cbc() == NULL ||
- EVP_aes_256_cbc() == NULL);
- ]])],
- [
- AC_MSG_RESULT([yes])
- AC_DEFINE([OPENSSL_HAVE_EVPCTR], [1],
- [libcrypto has EVP AES CTR])
- ],
- [
- AC_MSG_RESULT([no])
- ]
- )
-
# Check for OpenSSL with EVP_aes_*gcm
AC_MSG_CHECKING([whether OpenSSL has AES GCM via EVP])
AC_LINK_IFELSE(
diff --git a/openbsd-compat/openssl-compat.h b/openbsd-compat/openssl-compat.h
index 8ca50b5a..40e24cae 100644
--- a/openbsd-compat/openssl-compat.h
+++ b/openbsd-compat/openssl-compat.h
@@ -68,14 +68,6 @@ void ssh_libcrypto_init(void);
# endif
#endif

-#ifndef OPENSSL_HAVE_EVPCTR
-# define EVP_aes_128_ctr evp_aes_128_ctr
-# define EVP_aes_192_ctr evp_aes_128_ctr
-# define EVP_aes_256_ctr evp_aes_128_ctr
-const EVP_CIPHER *evp_aes_128_ctr(void);
-void ssh_aes_ctr_iv(EVP_CIPHER_CTX *, int, u_char *, size_t);
-#endif
-
/* Avoid some #ifdef. Code that uses these is unreachable without GCM */
#if !defined(OPENSSL_HAVE_EVPGCM) && !defined(EVP_CTRL_GCM_SET_IV_FIXED)
# define EVP_CTRL_GCM_SET_IV_FIXED -1

--
Darren Tucker (dtucker at dtucker.net)
GPG key 11EAA6FA / A86E 3E07 5B19 5880 E860 37F4 9357 ECEF 11EA A6FA (new)
Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.
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Re: Remove missing AES CTR compatibility hacks [ In reply to ]
Darren Tucker wrote:
> diff --git a/cipher-ctr.c b/cipher-ctr.c
> deleted file mode 100644

I can't really protest removing this file but I am sad to see it go;
that code helped me achieve compliance in another SSH implementation
for an environment only supporting CBC.

It was very helpful to have a reference for that exact case in OpenSSH,
and if there's a way to keep that around in some meaningful way I would
like that a lot, but I understand that OpenSSH itself no longer needs it.

It will remain in the repo history, but that can only really be found
by someone who already knows about it, it isn't really discoverable if
facing that problem the first time...


Thanks

//Peter
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