openssh/SOURCES/openssh-8.0p1-entropy.patch

diff --git a/entropy.c b/entropy.c
index 2d483b3..b361a04 100644
--- a/entropy.c
+++ b/entropy.c
@@ -234,6 +234,9 @@ seed_rng(void)
 	}
 #endif /* OPENSSL_PRNG_ONLY */
 
+#ifdef __linux__
+	linux_seed();
+#endif /* __linux__ */
 	if (RAND_status() != 1)
 		fatal("PRNG is not seeded");
 
diff --git a/openbsd-compat/Makefile.in b/openbsd-compat/Makefile.in
index b912dbe..9206337 100644
--- a/openbsd-compat/Makefile.in
+++ b/openbsd-compat/Makefile.in
@@ -20,6 +20,7 @@ OPENBSD=base64.o basename.o bcrypt_pbkdf.o bindresvport.o blowfish.o daemon.o di
 	port-solaris.o \
 	port-net.o \
 	port-uw.o \
+	port-linux-prng.o \
 	port-linux-sshd.o
 
 .c.o:
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 --git a/openbsd-compat/port-linux-prng.c b/openbsd-compat/port-linux-prng.c
new file mode 100644
index 0000000..92a617c
--- /dev/null
+++ b/openbsd-compat/port-linux-prng.c
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2011 - 2020 Red Hat, Inc.
+ *
+ * Authors:
+ *  Jan F. Chadima <jchadima@redhat.com>
+ *  Jakub Jelen <jjelen@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 <string.h>
+#include <openssl/rand.h>
+#include <sys/random.h>
+
+#include "log.h"
+
+void
+linux_seed(void)
+{
+	char *env = NULL;
+	size_t randlen = 14, left;
+	unsigned int flags = 0;
+	unsigned char buf[256], *p;
+
+	env = getenv("SSH_USE_STRONG_RNG");
+	if (env && strcmp(env, "0") != 0) {
+		size_t ienv = atoi(env);
+
+		/* Max on buffer length */
+		if (ienv > sizeof(buf))
+			ienv = sizeof(buf);
+		/* Minimum is always 14 B */
+		if (ienv > randlen)
+			randlen = ienv;
+		flags = GRND_RANDOM;
+	}
+
+	errno = 0;
+	left = randlen;
+	p = buf;
+	do {
+		ssize_t len = getrandom(p, left, flags);
+		if (len == -1) {
+			if (errno != EINTR) {
+				if (flags) {
+					/* With the variable present, this is fatal error */
+					fatal("Failed to seed from getrandom: %s", strerror(errno));
+				} else {
+					/* Otherwise we log the issue drop out from here */
+					debug("Failed to seed from getrandom: %s", strerror(errno));
+					return;
+				}
+			}
+		} else if (len > 0) {
+			left -= len;
+			p += len;
+		}
+	} while (left > 0);
+
+	RAND_seed(buf, randlen);
+}
diff --git a/ssh-add.1 b/ssh-add.1
index 4812448..16305bf 100644
--- a/ssh-add.1
+++ b/ssh-add.1
@@ -161,6 +161,22 @@ 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 getrandom(1)
+without any specific flags.
+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 getrandom(1)
+with GRND_RANDOM flag specified.
+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 --git a/ssh-agent.1 b/ssh-agent.1
index 281ecbd..1a9a635 100644
--- a/ssh-agent.1
+++ b/ssh-agent.1
@@ -201,6 +201,26 @@ sockets used to contain the connection to the authentication agent.
 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 getrandom(1)
+without any specific flags.
+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 getrandom(1)
+with GRND_RANDOM flag specified.
+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 --git a/ssh-keygen.1 b/ssh-keygen.1
index 12e00d4..1b51a4a 100644
--- a/ssh-keygen.1
+++ b/ssh-keygen.1
@@ -832,6 +832,26 @@ Contains Diffie-Hellman groups used for DH-GEX.
 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 getrandom(1)
+without any specific flags.
+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 getrandom(1)
+with GRND_RANDOM flag specified.
+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 --git a/ssh-keysign.8 b/ssh-keysign.8
index 69d0829..02d79f8 100644
--- a/ssh-keysign.8
+++ b/ssh-keysign.8
@@ -80,6 +80,26 @@ must be set-uid root if host-based authentication is used.
 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 getrandom(1)
+without any specific flags.
+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 getrandom(1)
+with GRND_RANDOM flag specified.
+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 ,
diff --git a/ssh.1 b/ssh.1
index 929904b..f65e42f 100644
--- a/ssh.1
+++ b/ssh.1
@@ -1309,6 +1309,25 @@ For more information, see the
 .Cm PermitUserEnvironment
 option in
 .Xr sshd_config 5 .
+.Bl -tag -width "SSH_ORIGINAL_COMMAND"
+.Pp
+.It Ev SSH_USE_STRONG_RNG
+The reseeding of the OpenSSL random generator is usually done from
+.Cm getrandom(1)
+without any specific flags.
+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 getrandom(1)
+with GRND_RANDOM flag specified.
+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 --git a/sshd.8 b/sshd.8
index c2c237f..058d37a 100644
--- a/sshd.8
+++ b/sshd.8
@@ -951,6 +951,26 @@ concurrently for different ports, this contains the process ID of the one
 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 Ev SSH_USE_STRONG_RNG
+The reseeding of the OpenSSL random generator is usually done from
+.Cm getrandom(1)
+without any specific flags.
+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 getrandom(1)
+with GRND_RANDOM flag specified.
+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