upstream commit

refuse to generate or accept RSA keys smaller than 1024
 bits; feedback and ok dtucker@

Upstream-ID: 7ea3d31271366ba264f06e34a3539bf1ac30f0ba

6 files changed, 21 insertions, 24 deletions

diff --git a/ssh-keygen.1 b/ssh-keygen.1
index 9b93666c..8c3317be 100644
--- a/ssh-keygen.1
+++ b/ssh-keygen.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: ssh-keygen.1,v 1.125 2015/02/24 15:24:05 naddy Exp $
+.\"	$OpenBSD: ssh-keygen.1,v 1.126 2015/07/03 03:49:45 djm Exp $
 .\"
 .\" Author: Tatu Ylonen <ylo@cs.hut.fi>
 .\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -35,7 +35,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: February 24 2015 $
+.Dd $Mdocdate: July 3 2015 $
 .Dt SSH-KEYGEN 1
 .Os
 .Sh NAME
@@ -244,7 +244,7 @@ This option specifies the number of primality tests to perform.
 Show the bubblebabble digest of specified private or public key file.
 .It Fl b Ar bits
 Specifies the number of bits in the key to create.
-For RSA keys, the minimum size is 768 bits and the default is 2048 bits.
+For RSA keys, the minimum size is 1024 bits and the default is 2048 bits.
 Generally, 2048 bits is considered sufficient.
 DSA keys must be exactly 1024 bits as specified by FIPS 186-2.
 For ECDSA keys, the
diff --git a/ssh-keygen.c b/ssh-keygen.c
index b546366f..ea5f1e49 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.275 2015/07/03 03:43:18 djm Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.276 2015/07/03 03:49:45 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -217,8 +217,8 @@ type_bits_valid(int type, const char *name, u_int32_t *bitsp)
 		fatal("key bits exceeds maximum %d", maxbits);
 	if (type == KEY_DSA && *bitsp != 1024)
 		fatal("DSA keys must be 1024 bits");
-	else if (type != KEY_ECDSA && type != KEY_ED25519 && *bitsp < 768)
-		fatal("Key must at least be 768 bits");
+	else if (type != KEY_ECDSA && type != KEY_ED25519 && *bitsp < 1024)
+		fatal("Key must at least be 1024 bits");
 	else if (type == KEY_ECDSA && sshkey_ecdsa_bits_to_nid(*bitsp) == -1)
 		fatal("Invalid ECDSA key length - valid lengths are "
 		    "256, 384 or 521 bits");
diff --git a/ssh.h b/ssh.h
index c94633bd..4f8da5c1 100644
--- a/ssh.h
+++ b/ssh.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.h,v 1.79 2010/06/25 07:14:46 djm Exp $ */
+/* $OpenBSD: ssh.h,v 1.80 2015/07/03 03:49:45 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -93,7 +93,7 @@
 #endif
 
 /* Minimum modulus size (n) for RSA keys. */
-#define SSH_RSA_MINIMUM_MODULUS_SIZE	768
+#define SSH_RSA_MINIMUM_MODULUS_SIZE	1024
 
 /* Listen backlog for sshd, ssh-agent and forwarding sockets */
 #define SSH_LISTEN_BACKLOG		128
diff --git a/sshd.8 b/sshd.8
index dcf20f0e..213b5fc4 100644
--- a/sshd.8
+++ b/sshd.8
@@ -33,8 +33,8 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.\" $OpenBSD: sshd.8,v 1.279 2015/05/01 07:11:47 djm Exp $
-.Dd $Mdocdate: May 1 2015 $
+.\" $OpenBSD: sshd.8,v 1.280 2015/07/03 03:49:45 djm Exp $
+.Dd $Mdocdate: July 3 2015 $
 .Dt SSHD 8
 .Os
 .Sh NAME
@@ -184,15 +184,12 @@ Specifies that
 .Nm
 is being run from
 .Xr inetd 8 .
+If SSH protocol 1 is enabled,
 .Nm
-is normally not run
+should not  normally be run
 from inetd because it needs to generate the server key before it can
-respond to the client, and this may take tens of seconds.
-Clients would have to wait too long if the key was regenerated every time.
-However, with small key sizes (e.g. 512) using
-.Nm
-from inetd may
-be feasible.
+respond to the client, and this may take some time.
+Clients may have to wait too long if the key was regenerated every time.
 .It Fl k Ar key_gen_time
 Specifies how often the ephemeral protocol version 1 server key is
 regenerated (default 3600 seconds, or one hour).
@@ -287,7 +284,7 @@ used to identify the host.
 .Pp
 Forward security for protocol 1 is provided through
 an additional server key,
-normally 768 bits,
+normally 1024 bits,
 generated when the server starts.
 This key is normally regenerated every hour if it has been used, and
 is never stored on disk.
diff --git a/sshd.c b/sshd.c
index 80105001..86b3c643 100644
--- a/sshd.c
+++ b/sshd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshd.c,v 1.452 2015/07/03 03:47:00 djm Exp $ */
+/* $OpenBSD: sshd.c,v 1.453 2015/07/03 03:49:45 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1874,8 +1874,8 @@ main(int ac, char **av)
 #ifdef WITH_SSH1
 	/* Check certain values for sanity. */
 	if (options.protocol & SSH_PROTO_1) {
-		if (options.server_key_bits < 512 ||
-		    options.server_key_bits > 32768) {
+		if (options.server_key_bits < SSH_RSA_MINIMUM_MODULUS_SIZE ||
+		    options.server_key_bits > OPENSSL_RSA_MAX_MODULUS_BITS) {
 			fprintf(stderr, "Bad server key size.\n");
 			exit(1);
 		}
diff --git a/sshd_config.5 b/sshd_config.5
index 5ab43189..edd4cc9b 100644
--- a/sshd_config.5
+++ b/sshd_config.5
@@ -33,8 +33,8 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.\" $OpenBSD: sshd_config.5,v 1.204 2015/06/05 03:44:14 djm Exp $
-.Dd $Mdocdate: June 5 2015 $
+.\" $OpenBSD: sshd_config.5,v 1.205 2015/07/03 03:49:45 djm Exp $
+.Dd $Mdocdate: July 3 2015 $
 .Dt SSHD_CONFIG 5
 .Os
 .Sh NAME
@@ -1343,7 +1343,7 @@ The default is
 This option applies to protocol version 1 only.
 .It Cm ServerKeyBits
 Defines the number of bits in the ephemeral protocol version 1 server key.
-The minimum value is 512, and the default is 1024.
+The default and minimum value is 1024.
 .It Cm StreamLocalBindMask
 Sets the octal file creation mode mask
 .Pq umask