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  1. Aug 22, 2016
    • Richard Levitte's avatar
      mk1mf: dtlstest needs ssltestlib, include it with a hack · 3cb28d18
      Richard Levitte authored
      
      
      We don't really have a mechanism to include other object files into a given
      test program.  For now, a simple hack in mk1mf.pl will do.
      
      RT#4653
      
      Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
      3cb28d18
    • David Benjamin's avatar
      Don't check for malloc failure twice. · 01f879d3
      David Benjamin authored
      a03f81f4
      
       added a malloc failure check to
      EVP_PKEY_keygen, but there already was one.
      
      Signed-off-by: default avatarKurt Roeckx <kurt@roeckx.be>
      Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
      
      GH: #1473
      01f879d3
    • Kazuki Yamaguchi's avatar
      Fix overflow check in BN_bn2dec() · 67e11f1d
      Kazuki Yamaguchi authored
      Fix an off by one error in the overflow check added by 07bed46f
      
      
      ("Check for errors in BN_bn2dec()").
      
      Reviewed-by: default avatarStephen Henson <steve@openssl.org>
      Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
      (cherry picked from commit 099e2968)
      67e11f1d
    • Rich Salz's avatar
      RT2676: Reject RSA eponent if even or 1 · 561530da
      Rich Salz authored
      
      
      Also, re-organize RSA check to use goto err.
      Try all checks, not just stopping at first (via Richard Levitte)
      
      Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
      Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
      (cherry picked from commit 464d59a5)
      561530da
    • Richard Levitte's avatar
      VMS: Use strict refdef extern model when building library object files · 51690fb8
      Richard Levitte authored
      
      
      Most of the time, this isn't strictly needed.  However, in the default
      extern model (called relaxed refdef), symbols are treated as weak
      common objects unless they are initialised.  The librarian doesn't
      include weak symbols in the (static) libraries, which renders them
      invisible when linking a program with said those libraries, which is a
      problem at times.
      
      Using the strict refdef model is much more like standard C on all
      other platforms, and thereby avoid the issues that come with the
      relaxed refdef model.
      
      Note: this doesn't apply to VAX C.  It's possible that this will make
      OpenSSL building with VAX C difficult some time in the future if it
      isn't already.  However, VAX C is a very old compiler that we don't
      expect to see too often, as DEC C (a.k.a VMS C) should have replaced
      it a long time ago.
      
      Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
      51690fb8
    • Richard Levitte's avatar
      GOST: rearrange code so it's more like C rather than C++ · 93c616d6
      Richard Levitte authored
      
      
      Some builds fail otherwise.
      
      Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
      93c616d6
    • Richard Levitte's avatar
      Make 'openssl req -x509' more equivalent to 'openssl req -new' · fd7ca746
      Richard Levitte authored
      
      
      The following would fail, or rather, freeze:
      
          openssl genrsa -out rsa2048.pem 2048
          openssl req -x509 -key rsa2048.pem -keyform PEM -out cert.pem
      
      In that case, the second command wants to read a certificate request
      from stdin, because -x509 wasn't fully flagged as being for creating
      something new.  This changes makes it fully flagged.
      
      RT#4655
      
      Reviewed-by: default avatarAndy Polyakov <appro@openssl.org>
      fd7ca746
    • Andy Polyakov's avatar
      bn/asm/x86[_64]-mont*.pl: implement slightly alternative page-walking. · 9c8bca1c
      Andy Polyakov authored
      
      
      Original strategy for page-walking was adjust stack pointer and then
      touch pages in order. This kind of asks for double-fault, because
      if touch fails, then signal will be delivered to frame above adjusted
      stack pointer. But touching pages prior adjusting stack pointer would
      upset valgrind. As compromise let's adjust stack pointer in pages,
      touching top of the stack. This still asks for double-fault, but at
      least prevents corruption of neighbour stack if allocation is to
      overstep the guard page.
      
      Also omit predict-non-taken hints as they reportedly trigger illegal
      instructions in some VM setups.
      
      Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
      (cherry picked from commit 3ba1ef82)
      9c8bca1c
    • Richard Levitte's avatar
      ssltestlib: Tell compiler we don't care about the value when we don't · 91dc6054
      Richard Levitte authored
      
      
      In mempacket_test_read(), we've already fetched the top value of the
      stack, so when we shift the stack, we don't care for the value.  The
      compiler needs to be told, or it will complain harshly when we tell it
      to be picky.
      
      Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
      (cherry picked from commit 1c288878)
      91dc6054
    • Matt Caswell's avatar
      Prevent DTLS Finished message injection · 20200681
      Matt Caswell authored
      
      
      Follow on from CVE-2016-2179
      
      The investigation and analysis of CVE-2016-2179 highlighted a related flaw.
      
      This commit fixes a security "near miss" in the buffered message handling
      code. Ultimately this is not currently believed to be exploitable due to
      the reasons outlined below, and therefore there is no CVE for this on its
      own.
      
      The issue this commit fixes is a MITM attack where the attacker can inject
      a Finished message into the handshake. In the description below it is
      assumed that the attacker injects the Finished message for the server to
      receive it. The attack could work equally well the other way around (i.e
      where the client receives the injected Finished message).
      
      The MITM requires the following capabilities:
      - The ability to manipulate the MTU that the client selects such that it
      is small enough for the client to fragment Finished messages.
      - The ability to selectively drop and modify records sent from the client
      - The ability to inject its own records and send them to the server
      
      The MITM forces the client to select a small MTU such that the client
      will fragment the Finished message. Ideally for the attacker the first
      fragment will contain all but the last byte of the Finished message,
      with the second fragment containing the final byte.
      
      During the handshake and prior to the client sending the CCS the MITM
      injects a plaintext Finished message fragment to the server containing
      all but the final byte of the Finished message. The message sequence
      number should be the one expected to be used for the real Finished message.
      
      OpenSSL will recognise that the received fragment is for the future and
      will buffer it for later use.
      
      After the client sends the CCS it then sends its own Finished message in
      two fragments. The MITM causes the first of these fragments to be
      dropped. The OpenSSL server will then receive the second of the fragments
      and reassemble the complete Finished message consisting of the MITM
      fragment and the final byte from the real client.
      
      The advantage to the attacker in injecting a Finished message is that
      this provides the capability to modify other handshake messages (e.g.
      the ClientHello) undetected. A difficulty for the attacker is knowing in
      advance what impact any of those changes might have on the final byte of
      the handshake hash that is going to be sent in the "real" Finished
      message. In the worst case for the attacker this means that only 1 in
      256 of such injection attempts will succeed.
      
      It may be possible in some situations for the attacker to improve this such
      that all attempts succeed. For example if the handshake includes client
      authentication then the final message flight sent by the client will
      include a Certificate. Certificates are ASN.1 objects where the signed
      portion is DER encoded. The non-signed portion could be BER encoded and so
      the attacker could re-encode the certificate such that the hash for the
      whole handshake comes to a different value. The certificate re-encoding
      would not be detectable because only the non-signed portion is changed. As
      this is the final flight of messages sent from the client the attacker
      knows what the complete hanshake hash value will be that the client will
      send - and therefore knows what the final byte will be. Through a process
      of trial and error the attacker can re-encode the certificate until the
      modified handhshake also has a hash with the same final byte. This means
      that when the Finished message is verified by the server it will be
      correct in all cases.
      
      In practice the MITM would need to be able to perform the same attack
      against both the client and the server. If the attack is only performed
      against the server (say) then the server will not detect the modified
      handshake, but the client will and will abort the connection.
      Fortunately, although OpenSSL is vulnerable to Finished message
      injection, it is not vulnerable if *both* client and server are OpenSSL.
      The reason is that OpenSSL has a hard "floor" for a minimum MTU size
      that it will never go below. This minimum means that a Finished message
      will never be sent in a fragmented form and therefore the MITM does not
      have one of its pre-requisites. Therefore this could only be exploited
      if using OpenSSL and some other DTLS peer that had its own and separate
      Finished message injection flaw.
      
      The fix is to ensure buffered messages are cleared on epoch change.
      
      Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
      20200681
    • Matt Caswell's avatar
      Fix DTLS buffered message DoS attack · 26f2c577
      Matt Caswell authored
      
      
      DTLS can handle out of order record delivery. Additionally since
      handshake messages can be bigger than will fit into a single packet, the
      messages can be fragmented across multiple records (as with normal TLS).
      That means that the messages can arrive mixed up, and we have to
      reassemble them. We keep a queue of buffered messages that are "from the
      future", i.e. messages we're not ready to deal with yet but have arrived
      early. The messages held there may not be full yet - they could be one
      or more fragments that are still in the process of being reassembled.
      
      The code assumes that we will eventually complete the reassembly and
      when that occurs the complete message is removed from the queue at the
      point that we need to use it.
      
      However, DTLS is also tolerant of packet loss. To get around that DTLS
      messages can be retransmitted. If we receive a full (non-fragmented)
      message from the peer after previously having received a fragment of
      that message, then we ignore the message in the queue and just use the
      non-fragmented version. At that point the queued message will never get
      removed.
      
      Additionally the peer could send "future" messages that we never get to
      in order to complete the handshake. Each message has a sequence number
      (starting from 0). We will accept a message fragment for the current
      message sequence number, or for any sequence up to 10 into the future.
      However if the Finished message has a sequence number of 2, anything
      greater than that in the queue is just left there.
      
      So, in those two ways we can end up with "orphaned" data in the queue
      that will never get removed - except when the connection is closed. At
      that point all the queues are flushed.
      
      An attacker could seek to exploit this by filling up the queues with
      lots of large messages that are never going to be used in order to
      attempt a DoS by memory exhaustion.
      
      I will assume that we are only concerned with servers here. It does not
      seem reasonable to be concerned about a memory exhaustion attack on a
      client. They are unlikely to process enough connections for this to be
      an issue.
      
      A "long" handshake with many messages might be 5 messages long (in the
      incoming direction), e.g. ClientHello, Certificate, ClientKeyExchange,
      CertificateVerify, Finished. So this would be message sequence numbers 0
      to 4. Additionally we can buffer up to 10 messages in the future.
      Therefore the maximum number of messages that an attacker could send
      that could get orphaned would typically be 15.
      
      The maximum size that a DTLS message is allowed to be is defined by
      max_cert_list, which by default is 100k. Therefore the maximum amount of
      "orphaned" memory per connection is 1500k.
      
      Message sequence numbers get reset after the Finished message, so
      renegotiation will not extend the maximum number of messages that can be
      orphaned per connection.
      
      As noted above, the queues do get cleared when the connection is closed.
      Therefore in order to mount an effective attack, an attacker would have
      to open many simultaneous connections.
      
      Issue reported by Quan Luo.
      
      CVE-2016-2179
      
      Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
      26f2c577
    • Matt Caswell's avatar
  2. Aug 21, 2016
  3. Aug 20, 2016
  4. Aug 19, 2016
    • Rich Salz's avatar
      RT3940: For now, just document the issue. · ff5537c2
      Rich Salz authored
      
      
      Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
      (cherry picked from commit 2a9afa40)
      ff5537c2
    • Rich Salz's avatar
      Fix NULL-return checks in 1.0.2 · a03f81f4
      Rich Salz authored
      
      
      RT4386: Add sanity checks for BN_new()
      RT4384: Missing Sanity Checks for RSA_new_method()
      RT4384: Missing Sanity Check plus potential NULL pointer deref
      RT4382: Missing Sanity Check(s) for BUF_strdup()
      RT4380: Missing Sanity Checks for EVP_PKEY_new()
      RT4377: Prevent potential NULL pointer dereference
      RT4375: Missing sanity checks for OPENSSL_malloc()
      RT4374: Potential for NULL pointer dereferences
      RT4371: Missing Sanity Check for malloc()
      RT4370: Potential for NULL pointer dereferences
      
      Also expand tabs, make update, typo fix (rsalz)
      Minor tweak by Paul Dale.
      Some minor internal review feedback.
      
      Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
      a03f81f4
    • Richard Levitte's avatar
      Have dtlstest run on VMS as well · 66e70832
      Richard Levitte authored
      
      
      Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
      66e70832
    • Matt Caswell's avatar
      Update function error code · 26aebca7
      Matt Caswell authored
      
      
      A function error code needed updating due to merge issues.
      
      Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
      26aebca7
    • Matt Caswell's avatar
      Fix DTLS replay protection · 3884b47b
      Matt Caswell authored
      
      
      The DTLS implementation provides some protection against replay attacks
      in accordance with RFC6347 section 4.1.2.6.
      
      A sliding "window" of valid record sequence numbers is maintained with
      the "right" hand edge of the window set to the highest sequence number we
      have received so far. Records that arrive that are off the "left" hand
      edge of the window are rejected. Records within the window are checked
      against a list of records received so far. If we already received it then
      we also reject the new record.
      
      If we have not already received the record, or the sequence number is off
      the right hand edge of the window then we verify the MAC of the record.
      If MAC verification fails then we discard the record. Otherwise we mark
      the record as received. If the sequence number was off the right hand edge
      of the window, then we slide the window along so that the right hand edge
      is in line with the newly received sequence number.
      
      Records may arrive for future epochs, i.e. a record from after a CCS being
      sent, can arrive before the CCS does if the packets get re-ordered. As we
      have not yet received the CCS we are not yet in a position to decrypt or
      validate the MAC of those records. OpenSSL places those records on an
      unprocessed records queue. It additionally updates the window immediately,
      even though we have not yet verified the MAC. This will only occur if
      currently in a handshake/renegotiation.
      
      This could be exploited by an attacker by sending a record for the next
      epoch (which does not have to decrypt or have a valid MAC), with a very
      large sequence number. This means the right hand edge of the window is
      moved very far to the right, and all subsequent legitimate packets are
      dropped causing a denial of service.
      
      A similar effect can be achieved during the initial handshake. In this
      case there is no MAC key negotiated yet. Therefore an attacker can send a
      message for the current epoch with a very large sequence number. The code
      will process the record as normal. If the hanshake message sequence number
      (as opposed to the record sequence number that we have been talking about
      so far) is in the future then the injected message is bufferred to be
      handled later, but the window is still updated. Therefore all subsequent
      legitimate handshake records are dropped. This aspect is not considered a
      security issue because there are many ways for an attacker to disrupt the
      initial handshake and prevent it from completing successfully (e.g.
      injection of a handshake message will cause the Finished MAC to fail and
      the handshake to be aborted). This issue comes about as a result of trying
      to do replay protection, but having no integrity mechanism in place yet.
      Does it even make sense to have replay protection in epoch 0? That
      issue isn't addressed here though.
      
      This addressed an OCAP Audit issue.
      
      CVE-2016-2181
      
      Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
      3884b47b
    • Matt Caswell's avatar
      Add DTLS replay protection test · 30ea36e6
      Matt Caswell authored
      
      
      Injects a record from epoch 1 during epoch 0 handshake, with a record
      sequence number in the future, to test that the record replay protection
      feature works as expected. This is described more fully in the next commit.
      
      Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
      30ea36e6
    • Matt Caswell's avatar
      Fix DTLS unprocessed records bug · 20744f6b
      Matt Caswell authored
      
      
      During a DTLS handshake we may get records destined for the next epoch
      arrive before we have processed the CCS. In that case we can't decrypt or
      verify the record yet, so we buffer it for later use. When we do receive
      the CCS we work through the queue of unprocessed records and process them.
      
      Unfortunately the act of processing wipes out any existing packet data
      that we were still working through. This includes any records from the new
      epoch that were in the same packet as the CCS. We should only process the
      buffered records if we've not got any data left.
      
      Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
      20744f6b
    • Matt Caswell's avatar
      Add a DTLS unprocesed records test · bc4d7e12
      Matt Caswell authored
      
      
      Add a test to inject a record from the next epoch during the handshake and
      make sure it doesn't get processed immediately.
      
      Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
      bc4d7e12
    • Matt Caswell's avatar
      Back port ssltestlib code to 1.0.2 · 48e8df6e
      Matt Caswell authored
      
      
      Enables the testing of DTLS code in 1.0.2
      
      Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
      48e8df6e
    • Richard Levitte's avatar
      VSI submission: RAND fixups · 7b415b0e
      Richard Levitte authored
      
      
      - make the VMS version of RAND_poll() faster and more secure
      - avoid pointer size warnings with setvbuf()
      
      Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
      7b415b0e
    • Richard Levitte's avatar
    • Richard Levitte's avatar
    • Richard Levitte's avatar
  5. Aug 18, 2016
  6. Aug 16, 2016
  7. Aug 15, 2016
  8. Aug 11, 2016
  9. Aug 05, 2016
  10. Aug 04, 2016