OpenSSL CHANGES

---

The following example JOSE Header declares that the encoded object is a JWT, and the JWT is a JWS that is MACed using the HMAC SHA-256 algorithm:

{"typ":"JWT",
"alg":"HS256"}

To remove potential ambiguities in the representation of the JSON object above, the octet sequence for the actual UTF-8 representation used in this example for the JOSE Header above is also included below. (Note that ambiguities can arise due to differing platform representations of line breaks (CRLF versus LF), differing spacing at the beginning and ends of lines, whether the last line has a terminating line break or not, and other causes. In the representation used in this example, the first line has no leading or trailing spaces, a CRLF line break (13, 10) occurs between the first and second lines, the second line has one leading space (32) and no trailing spaces, and the last line does not have a terminating line break.) The octets representing the UTF-8 representation of the JOSE Header in this example (using JSON array notation) are:

[123, 34, 116, 121, 112, 34, 58, 34, 74, 87, 84, 34, 44, 13, 10, 32, 34, 97, 108, 103, 34, 58, 34, 72, 83, 50, 53, 54, 34, 125]

Base64url encoding the octets of the UTF-8 representation of the JOSE Header yields this encoded JOSE Header value:

eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9

The following is an example of a JWT Claims Set:

{"iss":"joe",
"exp":1300819380,
"http://example.com/is_root":true}

The following octet sequence, which is the UTF-8 representation used in this example for the JWT Claims Set above, is the JWS Payload:

[123, 34, 105, 115, 115, 34, 58, 34, 106, 111, 101, 34, 44, 13, 10, 32, 34, 101, 120, 112, 34, 58, 49, 51, 48, 48, 56, 49, 57, 51, 56, 48, 44, 13, 10, 32, 34, 104, 116, 116, 112, 58, 47, 47, 101, 120, 97, 109, 112, 108, 101, 46, 99, 111, 109, 47, 105, 115, 95, 114, 111, 111, 116, 34, 58, 116, 114, 117, 101, 125]

Base64url encoding the JWS Payload yields this encoded JWS Payload (with line breaks for display purposes only):

eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly
9leGFtcGxlLmNvbS9pc19yb290Ijp0cnVlfQ

Computing the MAC of the encoded JOSE Header and encoded JWS Payload with the HMAC SHA-256 algorithm and base64url encoding the HMAC value in the manner specified in [JWS] yields this encoded JWS Signature:

dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk

Concatenating these encoded parts in this order with period ('.') characters between the parts yields this complete JWT (with line breaks for display purposes only):

eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9
.
eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt
cGxlLmNvbS9pc19yb290Ijp0cnVlfQ
.
dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk

This computation is illustrated in more detail in Appendix A.1 of [JWS]. See Appendix A.1 for an example of an encrypted JWT.
Subscription Control Center 10.1 for Dr.Web AV-Desk released

May 24, 2016

Doctor Web has released Subscription Control Center (SCC) 10.1 for its Internet service Dr.Web AV-Desk. The updated version offers new features for resellers and Dr.Web anti-virus service subscribers and delivers fixes for known defects.

A new trial subscription policy has been introduced for business customers. Now a reseller can define the duration of the trial period (up to 60 days) during which a subscriber (a legal person) is entitled to use the Dr.Web Anti-virus service. A trial period starts as soon as the user creates their first subscription.

Now the SCC offers more options for viewing customer account balances and provides more detailed information.

New features are also available to service providers who offer hardware maintenance services. They can now use the SCC to create new subscriptions; view information about existing ones; suspend, block or unblock subscriptions; and change subscription packages.

Now it’s also possible to configure security policies for subscriber passwords.

The update also provides a fix for a problem that caused errors when group administrators installed the software.

To ensure that the SCC works properly, the libraries that facilitate third-party software integration (php-avd and libdwavdapi) must be updated. If you have any questions, please contact Doctor Web’s specialists.
Changes between 1.0.1t and 1.0.1u [xx XXX xxxx]

*)

Changes between 1.0.1s and 1.0.1t [3 May 2016]

*) Prevent padding oracle in AES-NI CBC MAC check

 A MITM attacker can use a padding oracle attack to decrypt traffic
 when the connection uses an AES CBC cipher and the server support
 AES-NI.

 This issue was introduced as part of the fix for Lucky 13 padding
 attack (CVE-2013-0169). The padding check was rewritten to be in
 constant time by making sure that always the same bytes are read and
 compared against either the MAC or padding bytes. But it no longer
 checked that there was enough data to have both the MAC and padding
 bytes.

 This issue was reported by Juraj Somorovsky using TLS-Attacker.
 (CVE-2016-2107)
 [Kurt Roeckx]

*) Fix EVP_EncodeUpdate overflow

 An overflow can occur in the EVP_EncodeUpdate() function which is used for
 Base64 encoding of binary data. If an attacker is able to supply very large
 amounts of input data then a length check can overflow resulting in a heap
 corruption.

 Internally to OpenSSL the EVP_EncodeUpdate() function is primarly used by
 the PEM_write_bio* family of functions. These are mainly used within the
 OpenSSL command line applications, so any application which processes data
 from an untrusted source and outputs it as a PEM file should be considered
 vulnerable to this issue. User applications that call these APIs directly
 with large amounts of untrusted data may also be vulnerable.

 This issue was reported by Guido Vranken.
 (CVE-2016-2105)
 [Matt Caswell]

*) Fix EVP_EncryptUpdate overflow

 An overflow can occur in the EVP_EncryptUpdate() function. If an attacker
 is able to supply very large amounts of input data after a previous call to
 EVP_EncryptUpdate() with a partial block then a length check can overflow
 resulting in a heap corruption. Following an analysis of all OpenSSL
 internal usage of the EVP_EncryptUpdate() function all usage is one of two
 forms. The first form is where the EVP_EncryptUpdate() call is known to be
 the first called function after an EVP_EncryptInit(), and therefore that
 specific call must be safe. The second form is where the length passed to
 EVP_EncryptUpdate() can be seen from the code to be some small value and
 therefore there is no possibility of an overflow. Since all instances are
 one of these two forms, it is believed that there can be no overflows in
 internal code due to this problem. It should be noted that
 EVP_DecryptUpdate() can call EVP_EncryptUpdate() in certain code paths.
 Also EVP_CipherUpdate() is a synonym for EVP_EncryptUpdate(). All instances
 of these calls have also been analysed too and it is believed there are no
 instances in internal usage where an overflow could occur.

 This issue was reported by Guido Vranken.
 (CVE-2016-2106)
 [Matt Caswell]

*) Prevent ASN.1 BIO excessive memory allocation

 When ASN.1 data is read from a BIO using functions such as d2i_CMS_bio()
 a short invalid encoding can casuse allocation of large amounts of memory
 potentially consuming excessive resources or exhausting memory.

 Any application parsing untrusted data through d2i BIO functions is
 affected. The memory based functions such as d2i_X509() are *not* affected.
 Since the memory based functions are used by the TLS library, TLS
 applications are not affected.

 This issue was reported by Brian Carpenter.
 (CVE-2016-2109)
 [Stephen Henson]

*) EBCDIC overread

 ASN1 Strings that are over 1024 bytes can cause an overread in applications
 using the X509_NAME_oneline() function on EBCDIC systems. This could result
 in arbitrary stack data being returned in the buffer.

 This issue was reported by Guido Vranken.
 (CVE-2016-2176)
 [Matt Caswell]

*) Modify behavior of ALPN to invoke callback after SNI/servername
callback, such that updates to the SSL_CTX affect ALPN.
[Todd Short]

*) Remove LOW from the DEFAULT cipher list. This removes singles DES from the
default.
[Kurt Roeckx]

*) Only remove the SSLv2 methods with the no-ssl2-method option. When the
methods are enabled and ssl2 is disabled the methods return NULL.
[Kurt Roeckx]

Changes between 1.0.1r and 1.0.1s [1 Mar 2016]

• Disable weak ciphers in SSLv3 and up in default builds of OpenSSL.
  Builds that are not configured with "enable-weak-ssl-ciphers" will not
  provide any "EXPORT" or "LOW" strength ciphers.
  [Viktor Dukhovni]

• Disable SSLv2 default build, default negotiation and weak ciphers. SSLv2
  is by default disabled at build-time. Builds that are not configured with
  "enable-ssl2" will not support SSLv2. Even if "enable-ssl2" is used,
  users who want to negotiate SSLv2 via the version-flexible SSLv23_method()
  will need to explicitly call either of:

  SSL_CTX_clear_options(ctx, SSL_OP_NO_SSLv2);
  

  or
  SSL_clear_options(ssl, SSL_OP_NO_SSLv2);

  as appropriate. Even if either of those is used, or the application
  explicitly uses the version-specific SSLv2_method() or its client and
  server variants, SSLv2 ciphers vulnerable to exhaustive search key
  recovery have been removed. Specifically, the SSLv2 40-bit EXPORT
  ciphers, and SSLv2 56-bit DES are no longer available.
  (CVE-2016-0800)
  [Viktor Dukhovni]

*) Fix a double-free in DSA code

 A double free bug was discovered when OpenSSL parses malformed DSA private
 keys and could lead to a DoS attack or memory corruption for applications
 that receive DSA private keys from untrusted sources.  This scenario is
 considered rare.

 This issue was reported to OpenSSL by Adam Langley(Google/BoringSSL) using
 libFuzzer.
 (CVE-2016-0705)
 [Stephen Henson]

*) Disable SRP fake user seed to address a server memory leak.

 Add a new method SRP_VBASE_get1_by_user that handles the seed properly.

 SRP_VBASE_get_by_user had inconsistent memory management behaviour.
 In order to fix an unavoidable memory leak, SRP_VBASE_get_by_user
 was changed to ignore the "fake user" SRP seed, even if the seed
 is configured.

 Users should use SRP_VBASE_get1_by_user instead. Note that in
 SRP_VBASE_get1_by_user, caller must free the returned value. Note
 also that even though configuring the SRP seed attempts to hide
 invalid usernames by continuing the handshake with fake
 credentials, this behaviour is not constant time and no strong
 guarantees are made that the handshake is indistinguishable from
 that of a valid user.
 (CVE-2016-0798)
 [Emilia Käsper]

*) Fix BN_hex2bn/BN_dec2bn NULL pointer deref/heap corruption

 In the BN_hex2bn function the number of hex digits is calculated using an
 int value |i|. Later |bn_expand| is called with a value of |i * 4|. For
 large values of |i| this can result in |bn_expand| not allocating any
 memory because |i * 4| is negative. This can leave the internal BIGNUM data
 field as NULL leading to a subsequent NULL ptr deref. For very large values
 of |i|, the calculation |i * 4| could be a positive value smaller than |i|.
 In this case memory is allocated to the internal BIGNUM data field, but it
 is insufficiently sized leading to heap corruption. A similar issue exists
 in BN_dec2bn. This could have security consequences if BN_hex2bn/BN_dec2bn
 is ever called by user applications with very large untrusted hex/dec data.
 This is anticipated to be a rare occurrence.

 All OpenSSL internal usage of these functions use data that is not expected
 to be untrusted, e.g. config file data or application command line
 arguments. If user developed applications generate config file data based
 on untrusted data then it is possible that this could also lead to security
 consequences. This is also anticipated to be rare.

 This issue was reported to OpenSSL by Guido Vranken.
 (CVE-2016-0797)
 [Matt Caswell]

*) Fix memory issues in BIO_*printf functions

 The internal |fmtstr| function used in processing a "%s" format string in
 the BIO_*printf functions could overflow while calculating the length of a
 string and cause an OOB read when printing very long strings.

 Additionally the internal |doapr_outch| function can attempt to write to an
 OOB memory location (at an offset from the NULL pointer) in the event of a
 memory allocation failure. In 1.0.2 and below this could be caused where
 the size of a buffer to be allocated is greater than INT_MAX. E.g. this
 could be in processing a very long "%s" format string. Memory leaks can
 also occur.

 The first issue may mask the second issue dependent on compiler behaviour.
 These problems could enable attacks where large amounts of untrusted data
 is passed to the BIO_*printf functions. If applications use these functions
 in this way then they could be vulnerable. OpenSSL itself uses these
 functions when printing out human-readable dumps of ASN.1 data. Therefore
 applications that print this data could be vulnerable if the data is from
 untrusted sources. OpenSSL command line applications could also be
 vulnerable where they print out ASN.1 data, or if untrusted data is passed
 as command line arguments.

 Libssl is not considered directly vulnerable. Additionally certificates etc
 received via remote connections via libssl are also unlikely to be able to
 trigger these issues because of message size limits enforced within libssl.

 This issue was reported to OpenSSL Guido Vranken.
 (CVE-2016-0799)
 [Matt Caswell]

*) Side channel attack on modular exponentiation

 A side-channel attack was found which makes use of cache-bank conflicts on
 the Intel Sandy-Bridge microarchitecture which could lead to the recovery
 of RSA keys.  The ability to exploit this issue is limited as it relies on
 an attacker who has control of code in a thread running on the same
 hyper-threaded core as the victim thread which is performing decryptions.

 This issue was reported to OpenSSL by Yuval Yarom, The University of
 Adelaide and NICTA, Daniel Genkin, Technion and Tel Aviv University, and
 Nadia Heninger, University of Pennsylvania with more information at
 http://cachebleed.info.
 (CVE-2016-0702)
 [Andy Polyakov]

*) Change the req app to generate a 2048-bit RSA/DSA key by default,
if no keysize is specified with default_bits. This fixes an
omission in an earlier change that changed all RSA/DSA key generation
apps to use 2048 bits by default.
[Emilia Käsper]

Changes between 1.0.1q and 1.0.1r [28 Jan 2016]

*) Protection for DH small subgroup attacks

 As a precautionary measure the SSL_OP_SINGLE_DH_USE option has been
 switched on by default and cannot be disabled. This could have some
 performance impact.
 [Matt Caswell]

*) SSLv2 doesn't block disabled ciphers

 A malicious client can negotiate SSLv2 ciphers that have been disabled on
 the server and complete SSLv2 handshakes even if all SSLv2 ciphers have
 been disabled, provided that the SSLv2 protocol was not also disabled via
 SSL_OP_NO_SSLv2.

 This issue was reported to OpenSSL on 26th December 2015 by Nimrod Aviram
 and Sebastian Schinzel.
 (CVE-2015-3197)
 [Viktor Dukhovni]

*) Reject DH handshakes with parameters shorter than 1024 bits.
[Kurt Roeckx]

Changes between 1.0.1p and 1.0.1q [3 Dec 2015]

*) Certificate verify crash with missing PSS parameter

 The signature verification routines will crash with a NULL pointer
 dereference if presented with an ASN.1 signature using the RSA PSS
 algorithm and absent mask generation function parameter. Since these
 routines are used to verify certificate signature algorithms this can be
 used to crash any certificate verification operation and exploited in a
 DoS attack. Any application which performs certificate verification is
 vulnerable including OpenSSL clients and servers which enable client
 authentication.

 This issue was reported to OpenSSL by Loïc Jonas Etienne (Qnective AG).
 (CVE-2015-3194)
 [Stephen Henson]

*) X509_ATTRIBUTE memory leak

 When presented with a malformed X509_ATTRIBUTE structure OpenSSL will leak
 memory. This structure is used by the PKCS#7 and CMS routines so any
 application which reads PKCS#7 or CMS data from untrusted sources is
 affected. SSL/TLS is not affected.

 This issue was reported to OpenSSL by Adam Langley (Google/BoringSSL) using
 libFuzzer.
 (CVE-2015-3195)
 [Stephen Henson]

*) Rewrite EVP_DecodeUpdate (base64 decoding) to fix several bugs.
This changes the decoding behaviour for some invalid messages,
though the change is mostly in the more lenient direction, and
legacy behaviour is preserved as much as possible.
[Emilia Käsper]

*) In DSA_generate_parameters_ex, if the provided seed is too short,
use a random seed, as already documented.
[Rich Salz and Ismo Puustinen ismo.puustinen@intel.com]