Update dropbear
authorRISCi_ATOM <bob@bobcall.me>
Tue, 4 Sep 2018 13:20:06 +0000 (09:20 -0400)
committerRISCi_ATOM <bob@bobcall.me>
Tue, 4 Sep 2018 18:22:38 +0000 (14:22 -0400)
package/network/services/dropbear/Config.in
package/network/services/dropbear/Makefile
package/network/services/dropbear/files/dropbear.init
package/network/services/dropbear/patches/010-runtime-maxauthtries.patch [new file with mode: 0644]
package/network/services/dropbear/patches/020-Wait-to-fail-invalid-usernames.patch [new file with mode: 0644]
package/network/services/dropbear/patches/100-pubkey_path.patch
package/network/services/dropbear/patches/610-skip-default-keys-in-custom-runs.patch

index 7c2edd79f23708f9ef01c6a62a54073b0c7a33ed..ca0af9d5e078f3a4d0d9e02e034cd1e03ce40a2e 100644 (file)
@@ -32,6 +32,15 @@ config DROPBEAR_ECC
 
                Increases binary size by about 23 kB (MIPS).
 
+config DROPBEAR_ZLIB
+       bool "Enable compression"
+       default n
+       help
+               Enables compression using shared zlib library.
+
+               Increases binary size by about 0.1 kB (MIPS) and requires additional 62 kB (MIPS)
+               for a shared zlib library.
+
 config DROPBEAR_UTMP
        bool "Utmp support"
        default n
index 05df1bc6ac9665dca2321ce2bd92b7e8f60402a0..c1fa3c93ca55920946763e9f479bf73302da73f5 100644 (file)
@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=dropbear
 PKG_VERSION:=2017.75
-PKG_RELEASE:=2
+PKG_RELEASE:=5
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.bz2
 PKG_SOURCE_URL:= \
@@ -23,7 +23,10 @@ PKG_LICENSE_FILES:=LICENSE libtomcrypt/LICENSE libtommath/LICENSE
 PKG_BUILD_PARALLEL:=1
 PKG_USE_MIPS16:=0
 
-PKG_CONFIG_DEPENDS:=CONFIG_TARGET_INIT_PATH CONFIG_DROPBEAR_ECC CONFIG_DROPBEAR_CURVE25519
+PKG_CONFIG_DEPENDS:= \
+       CONFIG_TARGET_INIT_PATH CONFIG_DROPBEAR_ECC \
+       CONFIG_DROPBEAR_CURVE25519 CONFIG_DROPBEAR_ZLIB \
+       CONFIG_DROPBEAR_UTMP CONFIG_DROPBEAR_PUTUTLINE
 
 include $(INCLUDE_DIR)/package.mk
 
@@ -44,6 +47,7 @@ define Package/dropbear
   SECTION:=net
   CATEGORY:=Base system
   TITLE:=Small SSH2 client/server
+  DEPENDS:= +DROPBEAR_ZLIB:zlib
 endef
 
 define Package/dropbear/description
@@ -74,7 +78,7 @@ CONFIGURE_ARGS += \
        --disable-loginfunc \
        $(if $(CONFIG_DROPBEAR_PUTUTLINE),,--disable-pututline) \
        --disable-pututxline \
-       --disable-zlib \
+       $(if $(CONFIG_DROPBEAR_ZLIB),,--disable-zlib) \
        --enable-bundled-libtom
 
 TARGET_CFLAGS += -DARGTYPE=3 -ffunction-sections -fdata-sections
index 5c21359cbf449d777a9219118cf6170374f288d5..3d8cb2ca5e372121e3f1c29fa5aca3d49e6c5a10 100755 (executable)
@@ -41,6 +41,7 @@ validate_section_dropbear()
                'Port:list(port):22' \
                'SSHKeepAlive:uinteger:300' \
                'IdleTimeout:uinteger:0' \
+               'MaxAuthTries:uinteger:3' \
                'mdns:bool:1'
 }
 
@@ -49,7 +50,7 @@ dropbear_instance()
        local PasswordAuth enable Interface GatewayPorts \
                RootPasswordAuth RootLogin rsakeyfile \
                BannerFile Port SSHKeepAlive IdleTimeout \
-               mdns ipaddrs
+               MaxAuthTries mdns ipaddrs
 
        validate_section_dropbear "${1}" || {
                echo "validation failed"
@@ -78,6 +79,7 @@ dropbear_instance()
        append_ports "${ipaddrs}" "${Port}"
        [ "${IdleTimeout}" -ne 0 ] && procd_append_param command -I "${IdleTimeout}"
        [ "${SSHKeepAlive}" -ne 0 ] && procd_append_param command -K "${SSHKeepAlive}"
+       [ "${MaxAuthTries}" -ne 0 ] && procd_append_param command -T "${MaxAuthTries}"
        [ "${mdns}" -ne 0 ] && procd_add_mdns "ssh" "tcp" "$Port" "daemon=dropbear"
        procd_set_param respawn
        procd_close_instance
@@ -109,7 +111,9 @@ keygen()
 load_interfaces()
 {
        config_get interface "$1" Interface
-       interfaces=" ${interface} ${interfaces}"
+       config_get enable "$1" enable 1
+
+       [ "${enable}" = "1" ] && interfaces=" ${interface} ${interfaces}"
 }
 
 start_service()
diff --git a/package/network/services/dropbear/patches/010-runtime-maxauthtries.patch b/package/network/services/dropbear/patches/010-runtime-maxauthtries.patch
new file mode 100644 (file)
index 0000000..26db318
--- /dev/null
@@ -0,0 +1,130 @@
+From 46b22e57d91e33a591d0fba97da52672af4d6ed2 Mon Sep 17 00:00:00 2001
+From: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
+Date: Mon, 29 May 2017 10:25:09 +0100
+Subject: [PATCH] dropbear server: support -T max auth tries
+
+Add support for '-T n' for a run-time specification for maximum number
+of authentication attempts where 'n' is between 1 and compile time
+option MAX_AUTH_TRIES.
+
+A default number of tries can be specified at compile time using
+'DEFAULT_AUTH_TRIES' which itself defaults to MAX_AUTH_TRIES for
+backwards compatibility.
+
+Signed-off-by: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>
+---
+ options.h     |  7 +++++++
+ runopts.h     |  1 +
+ svr-auth.c    |  2 +-
+ svr-runopts.c | 17 +++++++++++++++++
+ 4 files changed, 26 insertions(+), 1 deletion(-)
+
+diff --git a/options.h b/options.h
+index 0c51bb1..4d22704 100644
+--- a/options.h
++++ b/options.h
+@@ -284,6 +284,13 @@ Homedir is prepended unless path begins with / */
+ #define MAX_AUTH_TRIES 10
+ #endif
++/* Default maximum number of failed authentication tries.
++ * defaults to MAX_AUTH_TRIES */
++
++#ifndef DEFAULT_AUTH_TRIES
++#define DEFAULT_AUTH_TRIES MAX_AUTH_TRIES
++#endif
++
+ /* The default file to store the daemon's process ID, for shutdown
+    scripts etc. This can be overridden with the -P flag */
+ #ifndef DROPBEAR_PIDFILE
+diff --git a/runopts.h b/runopts.h
+index f7c869d..2f7da63 100644
+--- a/runopts.h
++++ b/runopts.h
+@@ -96,6 +96,7 @@ typedef struct svr_runopts {
+       int noauthpass;
+       int norootpass;
+       int allowblankpass;
++      unsigned int maxauthtries;
+ #ifdef ENABLE_SVR_REMOTETCPFWD
+       int noremotetcp;
+diff --git a/svr-auth.c b/svr-auth.c
+index 577ea88..6a7ce0b 100644
+--- a/svr-auth.c
++++ b/svr-auth.c
+@@ -362,7 +362,7 @@ void send_msg_userauth_failure(int partial, int incrfail) {
+               ses.authstate.failcount++;
+       }
+-      if (ses.authstate.failcount >= MAX_AUTH_TRIES) {
++      if (ses.authstate.failcount >= svr_opts.maxauthtries) {
+               char * userstr;
+               /* XXX - send disconnect ? */
+               TRACE(("Max auth tries reached, exiting"))
+diff --git a/svr-runopts.c b/svr-runopts.c
+index 8f60059..1e7440f 100644
+--- a/svr-runopts.c
++++ b/svr-runopts.c
+@@ -73,6 +73,7 @@ static void printhelp(const char * progname) {
+                                       "-g             Disable password logins for root\n"
+                                       "-B             Allow blank password logins\n"
+ #endif
++                                      "-T <1 to %d>   Maximum authentication tries (default %d)\n"
+ #ifdef ENABLE_SVR_LOCALTCPFWD
+                                       "-j             Disable local port forwarding\n"
+ #endif
+@@ -106,6 +107,7 @@ static void printhelp(const char * progname) {
+ #ifdef DROPBEAR_ECDSA
+                                       ECDSA_PRIV_FILENAME,
+ #endif
++                                      MAX_AUTH_TRIES, DEFAULT_AUTH_TRIES,
+                                       DROPBEAR_MAX_PORTS, DROPBEAR_DEFPORT, DROPBEAR_PIDFILE,
+                                       DEFAULT_RECV_WINDOW, DEFAULT_KEEPALIVE, DEFAULT_IDLE_TIMEOUT);
+ }
+@@ -118,6 +120,7 @@ void svr_getopts(int argc, char ** argv) {
+       char* recv_window_arg = NULL;
+       char* keepalive_arg = NULL;
+       char* idle_timeout_arg = NULL;
++      char* maxauthtries_arg = NULL;
+       char* keyfile = NULL;
+       char c;
+@@ -130,6 +133,7 @@ void svr_getopts(int argc, char ** argv) {
+       svr_opts.noauthpass = 0;
+       svr_opts.norootpass = 0;
+       svr_opts.allowblankpass = 0;
++      svr_opts.maxauthtries = DEFAULT_AUTH_TRIES;
+       svr_opts.inetdmode = 0;
+       svr_opts.portcount = 0;
+       svr_opts.hostkey = NULL;
+@@ -234,6 +238,9 @@ void svr_getopts(int argc, char ** argv) {
+                               case 'I':
+                                       next = &idle_timeout_arg;
+                                       break;
++                              case 'T':
++                                      next = &maxauthtries_arg;
++                                      break;
+ #if defined(ENABLE_SVR_PASSWORD_AUTH) || defined(ENABLE_SVR_PAM_AUTH)
+                               case 's':
+                                       svr_opts.noauthpass = 1;
+@@ -330,6 +337,16 @@ void svr_getopts(int argc, char ** argv) {
+                       dropbear_exit("Bad recv window '%s'", recv_window_arg);
+               }
+       }
++
++      if (maxauthtries_arg) {
++              unsigned int val = 0;
++              if (m_str_to_uint(maxauthtries_arg, &val) == DROPBEAR_FAILURE ||
++                      val == 0 || val > MAX_AUTH_TRIES) {
++                      dropbear_exit("Bad maxauthtries '%s'", maxauthtries_arg);
++              }
++              svr_opts.maxauthtries = val;
++      }
++
+       
+       if (keepalive_arg) {
+               unsigned int val;
+-- 
+2.7.4
+
diff --git a/package/network/services/dropbear/patches/020-Wait-to-fail-invalid-usernames.patch b/package/network/services/dropbear/patches/020-Wait-to-fail-invalid-usernames.patch
new file mode 100644 (file)
index 0000000..593dca9
--- /dev/null
@@ -0,0 +1,221 @@
+From 52adbb34c32d3e2e1bcdb941e20a6f81138b8248 Mon Sep 17 00:00:00 2001
+From: Matt Johnston <matt@ucc.asn.au>
+Date: Thu, 23 Aug 2018 23:43:12 +0800
+Subject: [PATCH 2/2] Wait to fail invalid usernames
+
+---
+ auth.h           |  6 +++---
+ svr-auth.c       | 19 +++++--------------
+ svr-authpam.c    | 26 ++++++++++++++++++++++----
+ svr-authpasswd.c | 27 ++++++++++++++-------------
+ svr-authpubkey.c | 11 ++++++++++-
+ 5 files changed, 54 insertions(+), 35 deletions(-)
+
+--- a/auth.h
++++ b/auth.h
+@@ -37,9 +37,9 @@ void recv_msg_userauth_request(void);
+ void send_msg_userauth_failure(int partial, int incrfail);
+ void send_msg_userauth_success(void);
+ void send_msg_userauth_banner(buffer *msg);
+-void svr_auth_password(void);
+-void svr_auth_pubkey(void);
+-void svr_auth_pam(void);
++void svr_auth_password(int valid_user);
++void svr_auth_pubkey(int valid_user);
++void svr_auth_pam(int valid_user);
+ #ifdef ENABLE_SVR_PUBKEY_OPTIONS
+ int svr_pubkey_allows_agentfwd(void);
+--- a/svr-auth.c
++++ b/svr-auth.c
+@@ -176,10 +176,8 @@ void recv_msg_userauth_request() {
+               if (methodlen == AUTH_METHOD_PASSWORD_LEN &&
+                               strncmp(methodname, AUTH_METHOD_PASSWORD,
+                                       AUTH_METHOD_PASSWORD_LEN) == 0) {
+-                      if (valid_user) {
+-                              svr_auth_password();
+-                              goto out;
+-                      }
++                      svr_auth_password(valid_user);
++                      goto out;
+               }
+       }
+ #endif
+@@ -191,10 +189,8 @@ void recv_msg_userauth_request() {
+               if (methodlen == AUTH_METHOD_PASSWORD_LEN &&
+                               strncmp(methodname, AUTH_METHOD_PASSWORD,
+                                       AUTH_METHOD_PASSWORD_LEN) == 0) {
+-                      if (valid_user) {
+-                              svr_auth_pam();
+-                              goto out;
+-                      }
++                      svr_auth_pam(valid_user);
++                      goto out;
+               }
+       }
+ #endif
+@@ -204,12 +200,7 @@ void recv_msg_userauth_request() {
+       if (methodlen == AUTH_METHOD_PUBKEY_LEN &&
+                       strncmp(methodname, AUTH_METHOD_PUBKEY,
+                               AUTH_METHOD_PUBKEY_LEN) == 0) {
+-              if (valid_user) {
+-                      svr_auth_pubkey();
+-              } else {
+-                      /* pubkey has no failure delay */
+-                      send_msg_userauth_failure(0, 0);
+-              }
++              svr_auth_pubkey(valid_user);
+               goto out;
+       }
+ #endif
+--- a/svr-authpam.c
++++ b/svr-authpam.c
+@@ -178,13 +178,14 @@ pamConvFunc(int num_msg,
+  * Keyboard interactive would be a lot nicer, but since PAM is synchronous, it
+  * gets very messy trying to send the interactive challenges, and read the
+  * interactive responses, over the network. */
+-void svr_auth_pam() {
++void svr_auth_pam(int valid_user) {
+       struct UserDataS userData = {NULL, NULL};
+       struct pam_conv pamConv = {
+               pamConvFunc,
+               &userData /* submitted to pamvConvFunc as appdata_ptr */ 
+       };
++      const char* printable_user = NULL;
+       pam_handle_t* pamHandlep = NULL;
+@@ -204,12 +205,23 @@ void svr_auth_pam() {
+       password = buf_getstring(ses.payload, &passwordlen);
++      /* We run the PAM conversation regardless of whether the username is valid
++      in case the conversation function has an inherent delay.
++      Use ses.authstate.username rather than ses.authstate.pw_name.
++      After PAM succeeds we then check the valid_user flag too */
++
+       /* used to pass data to the PAM conversation function - don't bother with
+        * strdup() etc since these are touched only by our own conversation
+        * function (above) which takes care of it */
+-      userData.user = ses.authstate.pw_name;
++      userData.user = ses.authstate.username;
+       userData.passwd = password;
++      if (ses.authstate.pw_name) {
++              printable_user = ses.authstate.pw_name;
++      } else {
++              printable_user = "<invalid username>";
++      }
++
+       /* Init pam */
+       if ((rc = pam_start("sshd", NULL, &pamConv, &pamHandlep)) != PAM_SUCCESS) {
+               dropbear_log(LOG_WARNING, "pam_start() failed, rc=%d, %s", 
+@@ -236,7 +248,7 @@ void svr_auth_pam() {
+                               rc, pam_strerror(pamHandlep, rc));
+               dropbear_log(LOG_WARNING,
+                               "Bad PAM password attempt for '%s' from %s",
+-                              ses.authstate.pw_name,
++                              printable_user,
+                               svr_ses.addrstring);
+               send_msg_userauth_failure(0, 1);
+               goto cleanup;
+@@ -247,12 +259,18 @@ void svr_auth_pam() {
+                               rc, pam_strerror(pamHandlep, rc));
+               dropbear_log(LOG_WARNING,
+                               "Bad PAM password attempt for '%s' from %s",
+-                              ses.authstate.pw_name,
++                              printable_user,
+                               svr_ses.addrstring);
+               send_msg_userauth_failure(0, 1);
+               goto cleanup;
+       }
++      if (!valid_user) {
++              /* PAM auth succeeded but the username isn't allowed in for another reason
++              (checkusername() failed) */
++              send_msg_userauth_failure(0, 1);
++      }
++
+       /* successful authentication */
+       dropbear_log(LOG_NOTICE, "PAM password auth succeeded for '%s' from %s",
+                       ses.authstate.pw_name,
+--- a/svr-authpasswd.c
++++ b/svr-authpasswd.c
+@@ -48,22 +48,14 @@ static int constant_time_strcmp(const ch
+ /* Process a password auth request, sending success or failure messages as
+  * appropriate */
+-void svr_auth_password() {
++void svr_auth_password(int valid_user) {
+       
+       char * passwdcrypt = NULL; /* the crypt from /etc/passwd or /etc/shadow */
+       char * testcrypt = NULL; /* crypt generated from the user's password sent */
+-      char * password;
++      char * password = NULL;
+       unsigned int passwordlen;
+-
+       unsigned int changepw;
+-      passwdcrypt = ses.authstate.pw_passwd;
+-
+-#ifdef DEBUG_HACKCRYPT
+-      /* debugging crypt for non-root testing with shadows */
+-      passwdcrypt = DEBUG_HACKCRYPT;
+-#endif
+-
+       /* check if client wants to change password */
+       changepw = buf_getbool(ses.payload);
+       if (changepw) {
+@@ -73,12 +65,21 @@ void svr_auth_password() {
+       }
+       password = buf_getstring(ses.payload, &passwordlen);
+-
+-      /* the first bytes of passwdcrypt are the salt */
+-      testcrypt = crypt(password, passwdcrypt);
++      if (valid_user) {
++              /* the first bytes of passwdcrypt are the salt */
++              passwdcrypt = ses.authstate.pw_passwd;
++              testcrypt = crypt(password, passwdcrypt);
++      }
+       m_burn(password, passwordlen);
+       m_free(password);
++      /* After we have got the payload contents we can exit if the username
++      is invalid. Invalid users have already been logged. */
++      if (!valid_user) {
++              send_msg_userauth_failure(0, 1);
++              return;
++      }
++
+       if (testcrypt == NULL) {
+               /* crypt() with an invalid salt like "!!" */
+               dropbear_log(LOG_WARNING, "User account '%s' is locked",
+--- a/svr-authpubkey.c
++++ b/svr-authpubkey.c
+@@ -79,7 +79,7 @@ static int checkfileperm(char * filename
+ /* process a pubkey auth request, sending success or failure message as
+  * appropriate */
+-void svr_auth_pubkey() {
++void svr_auth_pubkey(int valid_user) {
+       unsigned char testkey; /* whether we're just checking if a key is usable */
+       char* algo = NULL; /* pubkey algo */
+@@ -102,6 +102,15 @@ void svr_auth_pubkey() {
+       keybloblen = buf_getint(ses.payload);
+       keyblob = buf_getptr(ses.payload, keybloblen);
++      if (!valid_user) {
++              /* Return failure once we have read the contents of the packet
++              required to validate a public key. 
++              Avoids blind user enumeration though it isn't possible to prevent
++              testing for user existence if the public key is known */
++              send_msg_userauth_failure(0, 0);
++              goto out;
++      }
++
+       /* check if the key is valid */
+       if (checkpubkey(algo, algolen, keyblob, keybloblen) == DROPBEAR_FAILURE) {
+               send_msg_userauth_failure(0, 0);
index 401c7e1ba56443560a89c2e0dd571afce9cf0838..274d3af46a68961d076cd838c38951311d0d1340 100644 (file)
@@ -1,6 +1,6 @@
 --- a/svr-authpubkey.c
 +++ b/svr-authpubkey.c
-@@ -220,14 +220,20 @@ static int checkpubkey(char* algo, unsig
+@@ -229,14 +229,20 @@ static int checkpubkey(char* algo, unsig
                goto out;
        }
  
@@ -29,7 +29,7 @@
  
        /* open the file as the authenticating user. */
        origuid = getuid();
-@@ -396,26 +402,35 @@ static int checkpubkeyperms() {
+@@ -405,26 +411,35 @@ static int checkpubkeyperms() {
                goto out;
        }
  
index f6453a4626ed0bed12d6f60621e2d47362df4510..a555a9e49856dd4466d6893a61b907fba341292d 100644 (file)
@@ -1,6 +1,6 @@
 --- a/svr-runopts.c
 +++ b/svr-runopts.c
-@@ -488,6 +488,7 @@ void load_all_hostkeys() {
+@@ -505,6 +505,7 @@ void load_all_hostkeys() {
                m_free(hostkey_file);
        }
  
@@ -8,7 +8,7 @@
  #ifdef DROPBEAR_RSA
        loadhostkey(RSA_PRIV_FILENAME, 0);
  #endif
-@@ -499,6 +500,7 @@ void load_all_hostkeys() {
+@@ -516,6 +517,7 @@ void load_all_hostkeys() {
  #ifdef DROPBEAR_ECDSA
        loadhostkey(ECDSA_PRIV_FILENAME, 0);
  #endif