diff -up openssh-7.4p1/entropy.c.entropy openssh-7.4p1/entropy.c
--- openssh-7.4p1/entropy.c.entropy	2016-12-19 05:59:41.000000000 +0100
+++ openssh-7.4p1/entropy.c	2016-12-23 18:34:27.769753570 +0100
@@ -229,6 +229,9 @@ seed_rng(void)
 	memset(buf, '\0', sizeof(buf));
 
 #endif /* OPENSSL_PRNG_ONLY */
+#ifdef __linux__
+	linux_seed();
+#endif /* __linux__ */
 	if (RAND_status() != 1)
 		fatal("PRNG is not seeded");
 }
diff -up openssh-7.4p1/openbsd-compat/Makefile.in.entropy openssh-7.4p1/openbsd-compat/Makefile.in
--- openssh-7.4p1/openbsd-compat/Makefile.in.entropy	2016-12-23 18:34:53.715762155 +0100
+++ openssh-7.4p1/openbsd-compat/Makefile.in	2016-12-23 18:35:15.890769493 +0100
@@ -20,7 +20,8 @@ OPENBSD=base64.o basename.o bcrypt_pbkdf
 	port-solaris.o \
 	port-net.o \
 	port-uw.o \
-	port-linux-sshd.o
+	port-linux-sshd.o \
+	port-linux-prng.o
 
 .c.o:
 	$(CC) $(CFLAGS) $(CPPFLAGS) -c $<
diff -up openssh-7.4p1/openbsd-compat/port-linux.h.entropy openssh-7.4p1/openbsd-compat/port-linux.h
--- openssh-7.4p1/openbsd-compat/port-linux.h.entropy	2016-12-23 18:34:27.747753563 +0100
+++ openssh-7.4p1/openbsd-compat/port-linux.h	2016-12-23 18:34:27.769753570 +0100
@@ -34,4 +34,6 @@ void oom_adjust_restore(void);
 void oom_adjust_setup(void);
 #endif
 
+void linux_seed(void);
+
 #endif /* ! _PORT_LINUX_H */
diff -up openssh-7.4p1/openbsd-compat/port-linux-prng.c.entropy openssh-7.4p1/openbsd-compat/port-linux-prng.c
--- openssh-7.4p1/openbsd-compat/port-linux-prng.c.entropy	2016-12-23 18:34:27.769753570 +0100
+++ openssh-7.4p1/openbsd-compat/port-linux-prng.c	2016-12-23 18:34:27.769753570 +0100
@@ -0,0 +1,59 @@
+/* $Id: port-linux.c,v 1.11.4.2 2011/02/04 00:43:08 djm Exp $ */
+
+/*
+ * Copyright (c) 2011 Jan F. Chadima <jchadima@redhat.com>
+ *
+ * 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.
+ */
+
+/*
+ * Linux-specific portability code - prng support
+ */
+
+#include "includes.h"
+
+#include <errno.h>
+#include <stdarg.h>
+#include <string.h>
+#include <stdio.h>
+#include <openssl/rand.h>
+
+#include "log.h"
+#include "xmalloc.h"
+#include "misc.h"      /* servconf.h needs misc.h for struct ForwardOptions */
+#include "servconf.h"
+#include "port-linux.h"
+#include "key.h"
+#include "hostfile.h"
+#include "auth.h"
+
+void
+linux_seed(void)
+{
+	char *env = getenv("SSH_USE_STRONG_RNG");
+	char *random = "/dev/random";
+	size_t len, ienv, randlen = 14;
+
+	if (!env || !strcmp(env, "0"))
+		random = "/dev/urandom";
+	else if ((ienv = atoi(env)) > randlen)
+		randlen = ienv;
+
+	errno = 0;
+	if ((len = RAND_load_file(random, randlen)) != randlen) {
+		if (errno)
+			fatal ("cannot read from %s, %s", random, strerror(errno));
+		else
+			fatal ("EOF reading %s", random);
+	}
+}
diff -up openssh-7.4p1/ssh.1.entropy openssh-7.4p1/ssh.1
--- openssh-7.4p1/ssh.1.entropy	2016-12-23 18:34:27.754753565 +0100
+++ openssh-7.4p1/ssh.1	2016-12-23 18:34:27.770753571 +0100
@@ -1441,6 +1441,23 @@ For more information, see the
 .Cm PermitUserEnvironment
 option in
 .Xr sshd_config 5 .
+.Sh ENVIRONMENT
+.Bl -tag -width Ds -compact
+.It Ev SSH_USE_STRONG_RNG
+The reseeding of the OpenSSL random generator is usually done from
+.Cm /dev/urandom .
+If the 
+.Cm SSH_USE_STRONG_RNG
+environment variable is set to value other than
+.Cm 0
+the OpenSSL random generator is reseeded from
+.Cm /dev/random .
+The number of bytes read is defined by the SSH_USE_STRONG_RNG value. 
+Minimum is 14 bytes.
+This setting is not recommended on the computers without the hardware
+random generator because insufficient entropy causes the connection to 
+be blocked until enough entropy is available.
+.El
 .Sh FILES
 .Bl -tag -width Ds -compact
 .It Pa ~/.rhosts
diff -up openssh-7.4p1/ssh-add.1.entropy openssh-7.4p1/ssh-add.1
--- openssh-7.4p1/ssh-add.1.entropy	2016-12-19 05:59:41.000000000 +0100
+++ openssh-7.4p1/ssh-add.1	2016-12-23 18:34:27.770753571 +0100
@@ -171,6 +171,20 @@ to make this work.)
 Identifies the path of a
 .Ux Ns -domain
 socket used to communicate with the agent.
+.It Ev SSH_USE_STRONG_RNG
+The reseeding of the OpenSSL random generator is usually done from
+.Cm /dev/urandom .
+If the 
+.Cm SSH_USE_STRONG_RNG
+environment variable is set to value other than
+.Cm 0
+the OpenSSL random generator is reseeded from
+.Cm /dev/random .
+The number of bytes read is defined by the SSH_USE_STRONG_RNG value. 
+Minimum is 14 bytes.
+This setting is not recommended on the computers without the hardware
+random generator because insufficient entropy causes the connection to 
+be blocked until enough entropy is available.
 .El
 .Sh FILES
 .Bl -tag -width Ds
diff -up openssh-7.4p1/ssh-agent.1.entropy openssh-7.4p1/ssh-agent.1
--- openssh-7.4p1/ssh-agent.1.entropy	2016-12-19 05:59:41.000000000 +0100
+++ openssh-7.4p1/ssh-agent.1	2016-12-23 18:34:27.770753571 +0100
@@ -214,6 +214,24 @@ sockets used to contain the connection t
 These sockets should only be readable by the owner.
 The sockets should get automatically removed when the agent exits.
 .El
+.Sh ENVIRONMENT
+.Bl -tag -width Ds -compact
+.Pp
+.It Pa SSH_USE_STRONG_RNG
+The reseeding of the OpenSSL random generator is usually done from
+.Cm /dev/urandom .
+If the 
+.Cm SSH_USE_STRONG_RNG
+environment variable is set to value other than
+.Cm 0
+the OpenSSL random generator is reseeded from
+.Cm /dev/random .
+The number of bytes read is defined by the SSH_USE_STRONG_RNG value. 
+Minimum is 14 bytes.
+This setting is not recommended on the computers without the hardware
+random generator because insufficient entropy causes the connection to 
+be blocked until enough entropy is available.
+.El
 .Sh SEE ALSO
 .Xr ssh 1 ,
 .Xr ssh-add 1 ,
diff -up openssh-7.4p1/sshd.8.entropy openssh-7.4p1/sshd.8
--- openssh-7.4p1/sshd.8.entropy	2016-12-23 18:34:27.755753566 +0100
+++ openssh-7.4p1/sshd.8	2016-12-23 18:34:27.770753571 +0100
@@ -920,6 +920,24 @@ concurrently for different ports, this c
 started last).
 The content of this file is not sensitive; it can be world-readable.
 .El
+.Sh ENVIRONMENT
+.Bl -tag -width Ds -compact
+.Pp
+.It Pa SSH_USE_STRONG_RNG
+The reseeding of the OpenSSL random generator is usually done from
+.Cm /dev/urandom .
+If the 
+.Cm SSH_USE_STRONG_RNG
+environment variable is set to value other than
+.Cm 0
+the OpenSSL random generator is reseeded from
+.Cm /dev/random .
+The number of bytes read is defined by the SSH_USE_STRONG_RNG value. 
+Minimum is 14 bytes.
+This setting is not recommended on the computers without the hardware
+random generator because insufficient entropy causes the connection to 
+be blocked until enough entropy is available.
+.El
 .Sh IPV6
 IPv6 address can be used everywhere where IPv4 address. In all entries must be the IPv6 address enclosed in square brackets. Note: The square brackets are metacharacters for the shell and must be escaped in shell.
 .Sh SEE ALSO
diff -up openssh-7.4p1/ssh-keygen.1.entropy openssh-7.4p1/ssh-keygen.1
--- openssh-7.4p1/ssh-keygen.1.entropy	2016-12-19 05:59:41.000000000 +0100
+++ openssh-7.4p1/ssh-keygen.1	2016-12-23 18:34:27.770753571 +0100
@@ -848,6 +848,24 @@ Contains Diffie-Hellman groups used for
 The file format is described in
 .Xr moduli 5 .
 .El
+.Sh ENVIRONMENT
+.Bl -tag -width Ds -compact
+.Pp
+.It Pa SSH_USE_STRONG_RNG
+The reseeding of the OpenSSL random generator is usually done from
+.Cm /dev/urandom .
+If the 
+.Cm SSH_USE_STRONG_RNG
+environment variable is set to value other than
+.Cm 0
+the OpenSSL random generator is reseeded from
+.Cm /dev/random .
+The number of bytes read is defined by the SSH_USE_STRONG_RNG value. 
+Minimum is 14 bytes.
+This setting is not recommended on the computers without the hardware
+random generator because insufficient entropy causes the connection to 
+be blocked until enough entropy is available.
+.El
 .Sh SEE ALSO
 .Xr ssh 1 ,
 .Xr ssh-add 1 ,
diff -up openssh-7.4p1/ssh-keysign.8.entropy openssh-7.4p1/ssh-keysign.8
--- openssh-7.4p1/ssh-keysign.8.entropy	2016-12-19 05:59:41.000000000 +0100
+++ openssh-7.4p1/ssh-keysign.8	2016-12-23 18:34:27.770753571 +0100
@@ -80,6 +80,24 @@ must be set-uid root if host-based authe
 If these files exist they are assumed to contain public certificate
 information corresponding with the private keys above.
 .El
+.Sh ENVIRONMENT
+.Bl -tag -width Ds -compact
+.Pp
+.It Pa SSH_USE_STRONG_RNG
+The reseeding of the OpenSSL random generator is usually done from
+.Cm /dev/urandom .
+If the 
+.Cm SSH_USE_STRONG_RNG
+environment variable is set to value other than
+.Cm 0
+the OpenSSL random generator is reseeded from
+.Cm /dev/random .
+The number of bytes read is defined by the SSH_USE_STRONG_RNG value. 
+Minimum is 14 bytes.
+This setting is not recommended on the computers without the hardware
+random generator because insufficient entropy causes the connection to 
+be blocked until enough entropy is available.
+.El
 .Sh SEE ALSO
 .Xr ssh 1 ,
 .Xr ssh-keygen 1 ,