- Aug 22, 2016
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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: Matt Caswell <matt@openssl.org>
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Andy Polyakov authored
Originally PKCS#12 subroutines treated password strings as ASCII. It worked as long as they were pure ASCII, but if there were some none-ASCII characters result was non-interoperable. But fixing it poses problem accessing data protected with broken password. In order to make asscess to old data possible add retry with old-style password. Reviewed-by: Richard Levitte <levitte@openssl.org>
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Andy Polyakov authored
Reviewed-by: Richard Levitte <levitte@openssl.org>
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Andy Polyakov authored
Reviewed-by: Richard Levitte <levitte@openssl.org>
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Andy Polyakov authored
Reviewed-by: Richard Levitte <levitte@openssl.org>
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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 a...
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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: Richard Levitte <levitte@openssl.org>
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Matt Caswell authored
The enable-zlib option was broken by the recent "const" changes. Reviewed-by: Stephen Henson <steve@openssl.org>
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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. Reviewed-by: Rich Salz <rsalz@openssl.org>
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- Aug 21, 2016
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Andy Polyakov authored
RT#4628 Reviewed-by: Rich Salz <rsalz@openssl.org>
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Andy Polyakov authored
RT#4628 Reviewed-by: Rich Salz <rsalz@openssl.org>
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Andy Polyakov authored
Thanks to Brian Smith for reporting this. Reviewed-by: Rich Salz <rsalz@openssl.org>
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Rich Salz authored
Reviewed-by: Richard Levitte <levitte@openssl.org>
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Dr. Stephen Henson authored
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
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Dr. Stephen Henson authored
Add mutable versions of X509_get0_notBefore and X509_get0_notAfter. Rename X509_SIG_get0_mutable to X509_SIG_getm. Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
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- Aug 20, 2016
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FdaSilvaYY authored
Reviewed-by: Richard Levitte <levitte@openssl.org> Reviewed-by: Rich Salz <rsalz@openssl.org> (Merged from https://github.com/openssl/openssl/pull/1475)
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Kurt Roeckx authored
Reviewed-by: Rich Salz <rsalz@openssl.org> MR: #3176
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Rich Salz authored
Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
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- Aug 19, 2016
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Dr. Stephen Henson authored
Reviewed-by: Rich Salz <rsalz@openssl.org>
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Dr. Stephen Henson authored
Reviewed-by: Rich Salz <rsalz@openssl.org>
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Dr. Stephen Henson authored
Reviewed-by: Rich Salz <rsalz@openssl.org>
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Dr. Stephen Henson authored
Update certificate and CRL time routines to match new standard. Reviewed-by: Rich Salz <rsalz@openssl.org>
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Viktor Dukhovni authored
The DANE API supports a DANE_FLAG_NO_DANE_EE_NAMECHECKS option, but there was no way to exercise/enable it via s_client. This commit addresses that gap. Reviewed-by: Rich Salz <rsalz@openssl.org>
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Dr. Stephen Henson authored
Reviewed-by: Rich Salz <rsalz@openssl.org>
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Dr. Stephen Henson authored
The certificate and CRL time setting functions used similar code, combine into a single utility function. Reviewed-by: Rich Salz <rsalz@openssl.org>
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Rich Salz authored
Reviewed-by: Richard Levitte <levitte@openssl.org>
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Richard Levitte authored
Reviewed-by: Rich Salz <rsalz@openssl.org>
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FdaSilvaYY authored
... without any interruption. Reviewed-by: Matt Caswell <matt@openssl.org> Reviewed-by: Rich Salz <rsalz@openssl.org> (Merged from https://github.com/openssl/openssl/pull/1468)
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Dr. Stephen Henson authored
Reviewed-by: Richard Levitte <levitte@openssl.org>
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Matt Caswell authored
Reviewed-by: Richard Levitte <levitte@openssl.org> Reviewed-by: Stephen Henson <steve@openssl.org>
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Matt Caswell authored
A function error code needed updating due to merge issues. Reviewed-by: Richard Levitte <levitte@openssl.org>
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Matt Caswell authored
Clang was complaining about some unused functions. Moving the stack declaration to the header seems to sort it. Also the certstatus variable in dtlstest needed to be declared static. Reviewed-by: Richard Levitte <levitte@openssl.org>
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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: Richard Levitte <levitte@openssl.org>
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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: Richard Levitte <levitte@openssl.org>
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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: Richard Levitte <levitte@openssl.org>
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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: Richard Levitte <levitte@openssl.org>
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Matt Caswell authored
Split the create_ssl_connection() helper function into two steps: one to create the SSL objects, and one to actually create the connection. This provides the ability to make changes to the SSL object before the connection is actually made. Reviewed-by: Richard Levitte <levitte@openssl.org>
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Matt Caswell authored
This adds a BIO similar to a normal mem BIO but with datagram awareness. It also has the capability to inject additional packets at arbitrary locations into the BIO, for testing purposes. Reviewed-by: Richard Levitte <levitte@openssl.org>
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Matt Caswell authored
Dump out the records passed over the BIO. Only works for DTLS at the moment but could easily be extended to TLS. Reviewed-by: Richard Levitte <levitte@openssl.org>
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Emilia Kasper authored
Reviewed-by: Stephen Henson <steve@openssl.org>
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