common-channel.c

@@ -38,18 +38,18 @@
 static void send_msg_channel_open_failure(unsigned int remotechan, int reason,
 		const char *text, const char *lang);
-static void send_msg_channel_open_confirmation(struct Channel* channel,
+static void send_msg_channel_open_confirmation(const struct Channel* channel,
 		unsigned int recvwindow, 
 		unsigned int recvmaxpacket);
 static int writechannel(struct Channel* channel, int fd, circbuffer *cbuf,
 	const unsigned char *moredata, unsigned int *morelen);
-static void send_msg_channel_window_adjust(struct Channel *channel, 
+static void send_msg_channel_window_adjust(const struct Channel *channel,
 		unsigned int incr);
 static void send_msg_channel_data(struct Channel *channel, int isextended);
 static void send_msg_channel_eof(struct Channel *channel);
 static void send_msg_channel_close(struct Channel *channel);
 static void remove_channel(struct Channel *channel);
-static unsigned int write_pending(struct Channel * channel);
+static unsigned int write_pending(const struct Channel * channel);
 static void check_close(struct Channel *channel);
 static void close_chan_fd(struct Channel *channel, int fd, int how);
@@ -198,7 +198,7 @@ struct Channel* getchannel() {
 }
 /* Iterate through the channels, performing IO if available */
-void channelio(fd_set *readfds, fd_set *writefds) {
+void channelio(const fd_set *readfds, const fd_set *writefds) {
 	/* Listeners such as TCP, X11, agent-auth */
 	struct Channel *channel;
@@ -262,7 +262,7 @@ void channelio(fd_set *readfds, fd_set *writefds) {
 /* Returns true if there is data remaining to be written to stdin or
  * stderr of a channel's endpoint. */
-static unsigned int write_pending(struct Channel * channel) {
+static unsigned int write_pending(const struct Channel * channel) {
 	if (channel->writefd >= 0 && cbuf_getused(channel->writebuf) > 0) {
 		return 1;
@@ -903,7 +903,7 @@ void recv_msg_channel_window_adjust() {
 /* Increment the incoming data window for a channel, and let the remote
  * end know */
-static void send_msg_channel_window_adjust(struct Channel* channel, 
+static void send_msg_channel_window_adjust(const struct Channel* channel,
 		unsigned int incr) {
 	TRACE(("sending window adjust %d", incr))
@@ -1008,7 +1008,7 @@ cleanup:
 }
 /* Send a failure message */
-void send_msg_channel_failure(struct Channel *channel) {
+void send_msg_channel_failure(const struct Channel *channel) {
 	TRACE(("enter send_msg_channel_failure"))
 	CHECKCLEARTOWRITE();
@@ -1021,7 +1021,7 @@ void send_msg_channel_failure(struct Channel *channel) {
 }
 /* Send a success message */
-void send_msg_channel_success(struct Channel *channel) {
+void send_msg_channel_success(const struct Channel *channel) {
 	TRACE(("enter send_msg_channel_success"))
 	CHECKCLEARTOWRITE();
@@ -1053,7 +1053,7 @@ static void send_msg_channel_open_failure(unsigned int remotechan,
 /* Confirm a channel open, and let the remote end know what number we've
  * allocated and the receive parameters */
-static void send_msg_channel_open_confirmation(struct Channel* channel,
+static void send_msg_channel_open_confirmation(const struct Channel* channel,
 		unsigned int recvwindow, 
 		unsigned int recvmaxpacket) {
@@ -1239,8 +1239,8 @@ struct Channel* get_any_ready_channel() {
 	return NULL;
 }
-void start_send_channel_request(struct Channel *channel, 
-		char *type) {
+void start_send_channel_request(const struct Channel *channel,
+		const char *type) {
 	CHECKCLEARTOWRITE();
 	buf_putbyte(ses.writepayload, SSH_MSG_CHANNEL_REQUEST);

common-kex.c

@@ -714,7 +714,7 @@ void free_kexcurve25519_param(struct kex_curve25519_param *param)
 	m_free(param);
 }
-void kexcurve25519_comb_key(struct kex_curve25519_param *param, buffer *buf_pub_them,
+void kexcurve25519_comb_key(const struct kex_curve25519_param *param, const buffer *buf_pub_them,
 	sign_key *hostkey) {
 	unsigned char out[CURVE25519_LEN];
 	const unsigned char* Q_C = NULL;

configure.ac

@@ -9,7 +9,6 @@ AC_PREREQ(2.59)
 AC_INIT
 AC_CONFIG_SRCDIR(buffer.c)
-OLDCFLAGS="$CFLAGS"
 # Checks for programs.
 AC_PROG_CC
 AC_PROG_MAKE_SET
@@ -19,23 +18,43 @@ if test -z "$LD" ; then
 fi
 AC_SUBST(LD)	
+AC_DEFUN(DB_TRYADDCFLAGS, 
+[{
+		OLDFLAGS="$CFLAGS"
+		TESTFLAGS="$1"
+		CFLAGS="$CFLAGS $TESTFLAGS"
+		AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])], 
+			[AC_MSG_NOTICE([Setting $TESTFLAGS])], 
+			[AC_MSG_NOTICE([Not setting $TESTFLAGS]); CFLAGS="$OLDFLAGS" ]
+			)
+}])
+
 # set compile flags prior to other tests
 if test -z "$OLDCFLAGS" && test "$GCC" = "yes"; then
 	AC_MSG_NOTICE(No \$CFLAGS set... using "-Os -W -Wall" for GCC)
-	CFLAGS="-Os -W -Wall -Wno-pointer-sign"
+	CFLAGS="-Os -W -Wall"
 fi
-AC_MSG_CHECKING([if compiler '$CC' supports -fno-strict-overflow])
-OLDCFLAGS="$CFLAGS"
-CFLAGS="$CFLAGS -fno-strict-overflow"
-AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])], 
-    [AC_MSG_RESULT(yes)], 
-    [AC_MSG_RESULT(no); CFLAGS="$OLDCFLAGS" ]
-    )
+AC_MSG_NOTICE([Checking if compiler '$CC' supports -Wno-pointer-sign])
+DB_TRYADDCFLAGS([-Wno-pointer-sign])
+
+AC_MSG_NOTICE([Checking if compiler '$CC' supports -fno-strict-overflow])
+DB_TRYADDCFLAGS([-fno-strict-overflow])
+
+STATIC=0
+AC_ARG_ENABLE(static,
+	[  --enable-static         Build static binaries],
+	[
+		if test "x$enableval" = "xyes"; then
+			STATIC=1
+			AC_MSG_NOTICE(Static Build)
+		fi
+	], [])
+AC_SUBST(STATIC)
 hardenbuild=1
 AC_ARG_ENABLE(harden,
-	[  --disable-harden          Don't set hardened build flags],
+	[  --disable-harden        Don't set hardened build flags],
 	[
 		if test "x$enableval" = "xno"; then
 			hardenbuild=0
@@ -45,37 +64,35 @@ AC_ARG_ENABLE(harden,
 if test "$hardenbuild" -eq 1; then
 	AC_MSG_NOTICE(Checking for available hardened build flags:)
-	# pie
-	OLDCFLAGS="$CFLAGS"
-	TESTFLAGS="-fPIE"
-	CFLAGS="$CFLAGS $TESTFLAGS"
-	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])], 
-	    [AC_MSG_NOTICE([Setting $TESTFLAGS])], 
-	    [AC_MSG_NOTICE([Not setting $TESTFLAGS]); CFLAGS="$OLDCFLAGS" ]
-	    )
-	OLDLDFLAGS="$LDFLAGS"
-	TESTFLAGS="-Wl,-pie"
-	LDFLAGS="$LDFLAGS $TESTFLAGS"
-	AC_LINK_IFELSE([AC_LANG_PROGRAM([])], 
-	    [AC_MSG_NOTICE([Setting $TESTFLAGS])], 
-		[
-			LDFLAGS="$OLDLDFLAGS"
-			TESTFLAGS="-pie"
-			LDFLAGS="$LDFLAGS $TESTFLAGS"
-			AC_LINK_IFELSE([AC_LANG_PROGRAM([])], 
-				[AC_MSG_NOTICE([Setting $TESTFLAGS])], 
-				[AC_MSG_NOTICE([Not setting $TESTFLAGS]); LDFLAGS="$OLDLDFLAGS" ]
-				)
-		]
-	    )
-	# readonly elf relocation sections (relro)
-	OLDLDFLAGS="$LDFLAGS"
-	TESTFLAGS="-Wl,-z,now -Wl,-z,relro"
-	LDFLAGS="$LDFLAGS $TESTFLAGS"
-	AC_LINK_IFELSE([AC_LANG_PROGRAM([])], 
-	    [AC_MSG_NOTICE([Setting $TESTFLAGS])], 
-	    [AC_MSG_NOTICE([Not setting $TESTFLAGS]); LDFLAGS="$OLDLDFLAGS" ]
-	    )
+	# relocation flags don't make sense for static builds
+	if test "$STATIC" -ne 1; then
+		# pie
+		DB_TRYADDCFLAGS([-fPIE])
+
+		OLDLDFLAGS="$LDFLAGS"
+		TESTFLAGS="-Wl,-pie"
+		LDFLAGS="$LDFLAGS $TESTFLAGS"
+		AC_LINK_IFELSE([AC_LANG_PROGRAM([])], 
+			[AC_MSG_NOTICE([Setting $TESTFLAGS])], 
+			[
+				LDFLAGS="$OLDLDFLAGS"
+				TESTFLAGS="-pie"
+				LDFLAGS="$LDFLAGS $TESTFLAGS"
+				AC_LINK_IFELSE([AC_LANG_PROGRAM([])], 
+					[AC_MSG_NOTICE([Setting $TESTFLAGS])], 
+					[AC_MSG_NOTICE([Not setting $TESTFLAGS]); LDFLAGS="$OLDLDFLAGS" ]
+					)
+			]
+			)
+		# readonly elf relocation sections (relro)
+		OLDLDFLAGS="$LDFLAGS"
+		TESTFLAGS="-Wl,-z,now -Wl,-z,relro"
+		LDFLAGS="$LDFLAGS $TESTFLAGS"
+		AC_LINK_IFELSE([AC_LANG_PROGRAM([])], 
+			[AC_MSG_NOTICE([Setting $TESTFLAGS])], 
+			[AC_MSG_NOTICE([Not setting $TESTFLAGS]); LDFLAGS="$OLDLDFLAGS" ]
+			)
+	fi # non-static
 	# stack protector. -strong is good but only in gcc 4.9 or later
 	OLDCFLAGS="$CFLAGS"
 	TESTFLAGS="-fstack-protector-strong"
@@ -93,13 +110,7 @@ if test "$hardenbuild" -eq 1; then
 	    ]
 	    )
 	# FORTIFY_SOURCE
-	OLDCFLAGS="$CFLAGS"
-	TESTFLAGS="-D_FORTIFY_SOURCE=2"
-	CFLAGS="$CFLAGS $TESTFLAGS"
-	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])], 
-	    [AC_MSG_NOTICE([Setting $TESTFLAGS])], 
-	    [AC_MSG_NOTICE([Not setting $TESTFLAGS]); CFLAGS="$OLDCFLAGS" ]
-	    )
+	DB_TRYADDCFLAGS([-D_FORTIFY_SOURCE=2])
 fi
 # large file support is useful for scp
@@ -230,7 +241,7 @@ AC_ARG_WITH(pam,
 AC_ARG_ENABLE(pam,
-	[  --enable-pam          Try to include PAM support],
+	[  --enable-pam            Try to include PAM support],
 	[
 		if test "x$enableval" = "xyes"; then
 			AC_CHECK_LIB(pam, pam_authenticate, , AC_MSG_ERROR([*** PAM missing - install first or check config.log ***]))
@@ -255,15 +266,20 @@ AC_ARG_ENABLE(openpty,
 			AC_MSG_NOTICE(Not using openpty)
 		else
 			AC_MSG_NOTICE(Using openpty if available)
-			AC_SEARCH_LIBS(openpty, util, [AC_DEFINE(HAVE_OPENPTY,1,[Have openpty() function])])
+			AC_SEARCH_LIBS(openpty, util, [dropbear_cv_func_have_openpty=yes])
 		fi
 	],
 	[
 		AC_MSG_NOTICE(Using openpty if available)
-		AC_SEARCH_LIBS(openpty, util, [AC_DEFINE(HAVE_OPENPTY)])
+		AC_SEARCH_LIBS(openpty, util, [dropbear_cv_func_have_openpty=yes])
 	]
 )
-		
+
+if test "x$dropbear_cv_func_have_openpty" = "xyes"; then
+	AC_DEFINE(HAVE_OPENPTY,,Have openpty() function)
+	no_ptc_check=yes
+	no_ptmx_check=yes
+fi
 AC_ARG_ENABLE(syslog,
 	[  --disable-syslog        Don't include syslog support],
@@ -782,60 +798,11 @@ fi
 AC_EXEEXT
-# XXX there must be a nicer way to do this
 if test $BUNDLED_LIBTOM = 1 ; then
-AS_MKDIR_P(libtomcrypt/src/ciphers/aes)
-AS_MKDIR_P(libtomcrypt/src/ciphers/safer)
-AS_MKDIR_P(libtomcrypt/src/ciphers/twofish)
-AS_MKDIR_P(libtomcrypt/src/encauth/ccm)
-AS_MKDIR_P(libtomcrypt/src/encauth/eax)
-AS_MKDIR_P(libtomcrypt/src/encauth/gcm)
-AS_MKDIR_P(libtomcrypt/src/encauth/ocb)
-AS_MKDIR_P(libtomcrypt/src/hashes)
-AS_MKDIR_P(libtomcrypt/src/hashes/chc)
-AS_MKDIR_P(libtomcrypt/src/hashes/helper)
-AS_MKDIR_P(libtomcrypt/src/hashes/sha2)
-AS_MKDIR_P(libtomcrypt/src/hashes/whirl)
-AS_MKDIR_P(libtomcrypt/src/mac/hmac)
-AS_MKDIR_P(libtomcrypt/src/mac/omac)
-AS_MKDIR_P(libtomcrypt/src/mac/pelican)
-AS_MKDIR_P(libtomcrypt/src/mac/pmac)
-AS_MKDIR_P(libtomcrypt/src/mac/f9)
-AS_MKDIR_P(libtomcrypt/src/mac/xcbc)
-AS_MKDIR_P(libtomcrypt/src/math/fp)
-AS_MKDIR_P(libtomcrypt/src/misc/base64)
-AS_MKDIR_P(libtomcrypt/src/misc/crypt)
-AS_MKDIR_P(libtomcrypt/src/misc/mpi)
-AS_MKDIR_P(libtomcrypt/src/misc/pkcs5)
-AS_MKDIR_P(libtomcrypt/src/modes/cbc)
-AS_MKDIR_P(libtomcrypt/src/modes/cfb)
-AS_MKDIR_P(libtomcrypt/src/modes/ctr)
-AS_MKDIR_P(libtomcrypt/src/modes/ecb)
-AS_MKDIR_P(libtomcrypt/src/modes/ofb)
-AS_MKDIR_P(libtomcrypt/src/modes/f8)
-AS_MKDIR_P(libtomcrypt/src/modes/lrw)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/bit)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/boolean)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/choice)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/ia5)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/integer)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/object_identifier)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/octet)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/printable_string)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/sequence)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/set)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/short_integer)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/utctime)
-AS_MKDIR_P(libtomcrypt/src/pk/asn1/der/utf8)
-AS_MKDIR_P(libtomcrypt/src/pk/dh)
-AS_MKDIR_P(libtomcrypt/src/pk/dsa)
-AS_MKDIR_P(libtomcrypt/src/pk/ecc)
-AS_MKDIR_P(libtomcrypt/src/pk/katja)
-AS_MKDIR_P(libtomcrypt/src/pk/pkcs1)
-AS_MKDIR_P(libtomcrypt/src/pk/rsa)
-AS_MKDIR_P(libtomcrypt/src/prngs)
+(cd $srcdir; find libtomcrypt -type d) | xargs mkdir -pv 
 LIBTOM_FILES="libtomcrypt/Makefile libtommath/Makefile"
 fi
+
 AC_CONFIG_HEADER(config.h)
 AC_CONFIG_FILES(Makefile $LIBTOM_FILES)
 AC_OUTPUT

dbclient.1

@@ -133,8 +133,8 @@ Can be used to give options in the format used by OpenSSH config file. This is
 useful for specifying options for which there is no separate command-line flag.
 For full details of the options listed below, and their possible values, see
 ssh_config(5).
-For now following options have been implemented:
+The following options have currently been implemented:
 .RS
 .TP
 .B ExitOnForwardFailure
@@ -147,6 +147,10 @@ Send dbclient log messages to syslog in addition to stderr.
 .B \-s 
 The specified command will be requested as a subsystem, used for sftp. Dropbear doesn't implement sftp itself but the OpenSSH sftp client can be used eg \fIsftp -S dbclient user@host\fR
 .TP
+.B \-b \fI[address][:port]
+Bind to a specific local address when connecting to the remote host. This can be used to choose from
+multiple outgoing interfaces. Either address or port (or both) can be given.
+.TP
 .B \-V
 Print the version

dbrandom.c

@@ -141,7 +141,7 @@ out:
 	return ret;
 }
-void addrandom(unsigned char * buf, unsigned int len)
+void addrandom(const unsigned char * buf, unsigned int len)
 {
 	hash_state hs;

dbrandom.h

@@ -29,7 +29,7 @@
 void seedrandom(void);
 void genrandom(unsigned char* buf, unsigned int len);
-void addrandom(unsigned char * buf, unsigned int len);
+void addrandom(const unsigned char * buf, unsigned int len);
 void gen_random_mpint(mp_int *max, mp_int *rand);
 #endif /* DROPBEAR_RANDOM_H_ */

dbutil.c

@@ -241,7 +241,7 @@ int connect_unix(const char* path) {
  * it will be run after the child has fork()ed, and is passed exec_data.
  * If ret_errfd == NULL then stderr will not be captured.
  * ret_pid can be passed as  NULL to discard the pid. */
-int spawn_command(void(*exec_fn)(void *user_data), void *exec_data,
+int spawn_command(void(*exec_fn)(const void *user_data), const void *exec_data,
 		int *ret_writefd, int *ret_readfd, int *ret_errfd, pid_t *ret_pid) {
 	int infds[2];
 	int outfds[2];
@@ -506,7 +506,7 @@ out:
 void m_close(int fd) {
 	int val;
-	if (fd == -1) {
+	if (fd < 0) {
 		return;
 	}
@@ -634,6 +634,10 @@ reach userspace include headers */
 #ifndef CLOCK_MONOTONIC_COARSE
 #define CLOCK_MONOTONIC_COARSE 6
 #endif
+/* Some old toolchains know SYS_clock_gettime but not CLOCK_MONOTONIC */
+#ifndef CLOCK_MONOTONIC
+#define CLOCK_MONOTONIC 1
+#endif
 static clockid_t get_linux_clock_source() {
 	struct timespec ts;
 	if (syscall(SYS_clock_gettime, CLOCK_MONOTONIC_COARSE, &ts) == 0) {

dbutil.h

@@ -56,7 +56,7 @@ extern int debug_trace;
 char * stripcontrol(const char * text);
-int spawn_command(void(*exec_fn)(void *user_data), void *exec_data,
+int spawn_command(void(*exec_fn)(const void *user_data), const void *exec_data,
 		int *writefd, int *readfd, int *errfd, pid_t *pid);
 void run_shell_command(const char* cmd, unsigned int maxfd, char* usershell);
 #ifdef ENABLE_CONNECT_UNIX

default_options.h

@@ -380,7 +380,8 @@ Homedir is prepended unless path begins with / */
 #define MAX_UNAUTH_CLIENTS 30
 #endif
-/* Maximum number of failed authentication tries (server option) */
+/* Default maximum number of failed authentication tries (server option) */
+/* -T runtime option overrides */
 #ifndef MAX_AUTH_TRIES
 #define MAX_AUTH_TRIES 10
 #endif

default_options.h.in

@@ -258,7 +258,8 @@ Homedir is prepended unless path begins with / */
  * come from many IPs */
 #define MAX_UNAUTH_CLIENTS 30
-/* Maximum number of failed authentication tries (server option) */
+/* Default maximum number of failed authentication tries (server option) */
+/* -T server option overrides */
 #define MAX_AUTH_TRIES 10
 /* The default file to store the daemon's process ID, for shutdown

dropbear.8

@@ -91,6 +91,9 @@ if 0 disables keepalives. If no response is received for 3 consecutive keepalive
 .B \-I \fIidle_timeout
 Disconnect the session if no traffic is transmitted or received for \fIidle_timeout\fR seconds.
 .TP
+.B \-T \fImax_authentication_attempts
+Set the number of authentication attempts allowed per connection. If unspecified the default is 10 (MAX_AUTH_TRIES)
+.TP
 .B \-c \fIforced_command
 Disregard the command provided by the user and always run \fIforced_command\fR. This also
 overrides any authorized_keys command= option.

dropbearkey.c

@@ -241,7 +241,7 @@ int main(int argc, char ** argv) {
 	}
 	genbits = signkey_generate_get_bits(keytype, bits);
-	fprintf(stderr, "Generating %d bit %s key, this may take a while...\n", genbits, typetext);
+	fprintf(stderr, "Generating %u bit %s key, this may take a while...\n", genbits, typetext);
 	if (signkey_generate(keytype, bits, filename, 0) == DROPBEAR_FAILURE)
 	{
 		dropbear_exit("Failed to generate key.\n");

dss.c

@@ -127,7 +127,7 @@ void dss_key_free(dropbear_dss_key *key) {
  * mpint	g
  * mpint	y
  */
-void buf_put_dss_pub_key(buffer* buf, dropbear_dss_key *key) {
+void buf_put_dss_pub_key(buffer* buf, const dropbear_dss_key *key) {
 	dropbear_assert(key != NULL);
 	buf_putstring(buf, SSH_SIGNKEY_DSS, SSH_SIGNKEY_DSS_LEN);
@@ -139,7 +139,7 @@ void buf_put_dss_pub_key(buffer* buf, dropbear_dss_key *key) {
 }
 /* Same as buf_put_dss_pub_key, but with the private "x" key appended */
-void buf_put_dss_priv_key(buffer* buf, dropbear_dss_key *key) {
+void buf_put_dss_priv_key(buffer* buf, const dropbear_dss_key *key) {
 	dropbear_assert(key != NULL);
 	buf_put_dss_pub_key(buf, key);
@@ -150,7 +150,7 @@ void buf_put_dss_priv_key(buffer* buf, dropbear_dss_key *key) {
 #if DROPBEAR_SIGNKEY_VERIFY
 /* Verify a DSS signature (in buf) made on data by the key given. 
  * returns DROPBEAR_SUCCESS or DROPBEAR_FAILURE */
-int buf_dss_verify(buffer* buf, dropbear_dss_key *key, buffer *data_buf) {
+int buf_dss_verify(buffer* buf, const dropbear_dss_key *key, const buffer *data_buf) {
 	unsigned char msghash[SHA1_HASH_SIZE];
 	hash_state hs;
 	int ret = DROPBEAR_FAILURE;
@@ -255,7 +255,7 @@ out:
 /* Sign the data presented with key, writing the signature contents
  * to the buffer */
-void buf_put_dss_sign(buffer* buf, dropbear_dss_key *key, buffer *data_buf) {
+void buf_put_dss_sign(buffer* buf, const dropbear_dss_key *key, const buffer *data_buf) {
 	unsigned char msghash[SHA1_HASH_SIZE];
 	unsigned int writelen;
 	unsigned int i;

dss.h

@@ -44,14 +44,14 @@ typedef struct {
 #define DSS_P_BITS 1024
 #define DSS_Q_BITS 160
-void buf_put_dss_sign(buffer* buf, dropbear_dss_key *key, buffer *data_buf);
+void buf_put_dss_sign(buffer* buf, const dropbear_dss_key *key, const buffer *data_buf);
 #if DROPBEAR_SIGNKEY_VERIFY
-int buf_dss_verify(buffer* buf, dropbear_dss_key *key, buffer *data_buf);
+int buf_dss_verify(buffer* buf, const dropbear_dss_key *key, const buffer *data_buf);
 #endif
 int buf_get_dss_pub_key(buffer* buf, dropbear_dss_key *key);
 int buf_get_dss_priv_key(buffer* buf, dropbear_dss_key *key);
-void buf_put_dss_pub_key(buffer* buf, dropbear_dss_key *key);
-void buf_put_dss_priv_key(buffer* buf, dropbear_dss_key *key);
+void buf_put_dss_pub_key(buffer* buf, const dropbear_dss_key *key);
+void buf_put_dss_priv_key(buffer* buf, const dropbear_dss_key *key);
 void dss_key_free(dropbear_dss_key *key);
 #endif /* DROPBEAR_DSS */

ecc.c

@@ -82,7 +82,7 @@ ecc_key * new_ecc_key(void) {
 /* Copied from libtomcrypt ecc_import.c (version there is static), modified
    for different mp_int pointer without LTC_SOURCE */
-static int ecc_is_point(ecc_key *key)
+static int ecc_is_point(const ecc_key *key)
 {
 	mp_int *prime, *b, *t1, *t2;
 	int err;
@@ -213,7 +213,7 @@ ecc_key * buf_get_ecc_raw_pubkey(buffer *buf, const struct dropbear_ecc_curve *c
 /* a modified version of libtomcrypt's "ecc_shared_secret" to output
    a mp_int instead. */
-mp_int * dropbear_ecc_shared_secret(ecc_key *public_key, ecc_key *private_key)
+mp_int * dropbear_ecc_shared_secret(ecc_key *public_key, const ecc_key *private_key)
 {
 	ecc_point *result = NULL;
 	mp_int *prime = NULL, *shared_secret = NULL;

ecc.h

@@ -29,7 +29,7 @@ void buf_put_ecc_raw_pubkey_string(buffer *buf, ecc_key *key);
 ecc_key * buf_get_ecc_raw_pubkey(buffer *buf, const struct dropbear_ecc_curve *curve);
 int buf_get_ecc_privkey_string(buffer *buf, ecc_key *key);
-mp_int * dropbear_ecc_shared_secret(ecc_key *pub_key, ecc_key *priv_key);
+mp_int * dropbear_ecc_shared_secret(ecc_key *pub_key, const ecc_key *priv_key);
 #endif

ecdsa.c

@@ -15,7 +15,7 @@ int signkey_is_ecdsa(enum signkey_type type)
 		|| type == DROPBEAR_SIGNKEY_ECDSA_NISTP521;
 }
-enum signkey_type ecdsa_signkey_type(ecc_key * key) {
+enum signkey_type ecdsa_signkey_type(const ecc_key * key) {
 #if DROPBEAR_ECC_256
 	if (key->dp == ecc_curve_nistp256.dp) {
 		return DROPBEAR_SIGNKEY_ECDSA_NISTP256;
@@ -154,7 +154,7 @@ void buf_put_ecdsa_priv_key(buffer *buf, ecc_key *key) {
 	buf_putmpint(buf, key->k);
 }
-void buf_put_ecdsa_sign(buffer *buf, ecc_key *key, buffer *data_buf) {
+void buf_put_ecdsa_sign(buffer *buf, const ecc_key *key, const buffer *data_buf) {
 	/* Based on libtomcrypt's ecc_sign_hash but without the asn1 */
 	int err = DROPBEAR_FAILURE;
 	struct dropbear_ecc_curve *curve = NULL;
@@ -272,7 +272,7 @@ out:
 }
-int buf_ecdsa_verify(buffer *buf, ecc_key *key, buffer *data_buf) {
+int buf_ecdsa_verify(buffer *buf, const ecc_key *key, const buffer *data_buf) {
 	/* Based on libtomcrypt's ecc_verify_hash but without the asn1 */
 	int ret = DROPBEAR_FAILURE;
 	hash_state hs;

ecdsa.h

@@ -23,10 +23,10 @@ ecc_key *buf_get_ecdsa_pub_key(buffer* buf);
 ecc_key *buf_get_ecdsa_priv_key(buffer *buf);
 void buf_put_ecdsa_pub_key(buffer *buf, ecc_key *key);
 void buf_put_ecdsa_priv_key(buffer *buf, ecc_key *key);
-enum signkey_type ecdsa_signkey_type(ecc_key * key);
-void buf_put_ecdsa_sign(buffer *buf, ecc_key *key, buffer *data_buf);
-int buf_ecdsa_verify(buffer *buf, ecc_key *key, buffer *data_buf);
+enum signkey_type ecdsa_signkey_type(const ecc_key * key);
+void buf_put_ecdsa_sign(buffer *buf, const ecc_key *key, const buffer *data_buf);
+int buf_ecdsa_verify(buffer *buf, const ecc_key *key, const buffer *data_buf);
 /* Returns 1 on success */
 int signkey_is_ecdsa(enum signkey_type type);

gendss.c

@@ -37,11 +37,11 @@
 #if DROPBEAR_DSS
-static void getq(dropbear_dss_key *key);
-static void getp(dropbear_dss_key *key, unsigned int size);
-static void getg(dropbear_dss_key *key);
-static void getx(dropbear_dss_key *key);
-static void gety(dropbear_dss_key *key);
+static void getq(const dropbear_dss_key *key);
+static void getp(const dropbear_dss_key *key, unsigned int size);
+static void getg(const dropbear_dss_key *key);
+static void getx(const dropbear_dss_key *key);
+static void gety(const dropbear_dss_key *key);
 dropbear_dss_key * gen_dss_priv_key(unsigned int size) {
@@ -65,7 +65,7 @@ dropbear_dss_key * gen_dss_priv_key(unsigned int size) {
 	
 }
-static void getq(dropbear_dss_key *key) {
+static void getq(const dropbear_dss_key *key) {
 	unsigned char buf[QSIZE];
@@ -83,7 +83,7 @@ static void getq(dropbear_dss_key *key) {
 	}
 }
-static void getp(dropbear_dss_key *key, unsigned int size) {
+static void getp(const dropbear_dss_key *key, unsigned int size) {
 	DEF_MP_INT(tempX);
 	DEF_MP_INT(tempC);
@@ -142,7 +142,7 @@ static void getp(dropbear_dss_key *key, unsigned int size) {
 	m_free(buf);
 }
-static void getg(dropbear_dss_key * key) {
+static void getg(const dropbear_dss_key * key) {
 	DEF_MP_INT(div);
 	DEF_MP_INT(h);
@@ -179,12 +179,12 @@ static void getg(dropbear_dss_key * key) {
 	mp_clear_multi(&div, &h, &val, NULL);
 }
-static void getx(dropbear_dss_key *key) {
+static void getx(const dropbear_dss_key *key) {
 	gen_random_mpint(key->q, key->x);
 }
-static void gety(dropbear_dss_key *key) {
+static void gety(const dropbear_dss_key *key) {
 	if (mp_exptmod(key->g, key->x, key->p, key->y) != MP_OKAY) {
 		fprintf(stderr, "DSS key generation failed\n");

kex.h

@@ -50,7 +50,7 @@ void kexecdh_comb_key(struct kex_ecdh_param *param, buffer *pub_them,
 #if DROPBEAR_CURVE25519
 struct kex_curve25519_param *gen_kexcurve25519_param(void);
 void free_kexcurve25519_param(struct kex_curve25519_param *param);
-void kexcurve25519_comb_key(struct kex_curve25519_param *param, buffer *pub_them,
+void kexcurve25519_comb_key(const struct kex_curve25519_param *param, const buffer *pub_them,
 		sign_key *hostkey);
 #endif