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 like this:
EVP_EncryptInit()
EVP_EncryptUpdate()
i.e. 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, I believe 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(). Therefore I have checked all instances of these
calls too, and came to the same conclusion, i.e. there are no instances
in internal usage where an overflow could occur.
This could still represent a security issue for end user code that calls
this function directly.
CVE-2016-2106
Issue reported by Guido Vranken.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Don't have #error statements in header files, but instead wrap
the contents of that file in #ifndef OPENSSL_NO_xxx
This means it is now always safe to include the header file.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Simplifies calling code. Also fixed up any !ptr tests that were
nearby, turning them into NULL tests.
Reviewed-by: Richard Levitte <levitte@openssl.org>
This was done by the following
find . -name '*.[ch]' | /tmp/pl
where /tmp/pl is the following three-line script:
print unless $. == 1 && m@/\* .*\.[ch] \*/@;
close ARGV if eof; # Close file to reset $.
And then some hand-editing of other files.
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
EVP_CIPHER_CTX_flags was returning the flags of its associated
EVP_CIPHER. However, EVP_CIPHER_CTX has flags of its own, so this
function is quite confusing and therefore error prone.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Following the method used for EVP_MD_CTX and HMAC_CTX,
EVP_CIPHER_CTX_init and EVP_CIPHER_CTX_cleanup are joined together
into one function, EVP_CIPHER_CTX_reset, with EVP_CIPHER_CTX_init kept
as an alias.
EVP_CIPHER_CTX_cleanup fills no purpose of its own any more and is
therefore removed.
Reviewed-by: Rich Salz <rsalz@openssl.org>
There are many places (nearly 50) where we malloc and then memset.
Add an OPENSSL_zalloc routine to encapsulate that.
(Missed one conversion; thanks Richard)
Also fixes GH328
Reviewed-by: Richard Levitte <levitte@openssl.org>
There are header files in crypto/ that are used by a number of crypto/
submodules. Move those to crypto/include/internal and adapt the
affected source code and Makefiles.
The header files that got moved are:
crypto/cryptolib.h
crypto/md32_common.h
Reviewed-by: Rich Salz <rsalz@openssl.org>
If an EVP implementation (such as an engine) fails out early, it's
possible to call EVP_CIPHER_CTX_cleanup() which will call
ctx->cipher->cleanup() before the cipher_data has been initialized
via ctx->cipher->init(). Guarantee it's all-bytes-zero as soon as
it is allocated.
Reviewed-by: Matt Caswell <matt@openssl.org>
Just as with the OPENSSL_malloc calls, consistently use sizeof(*ptr)
for memset and memcpy. Remove needless casts for those functions.
For memset, replace alternative forms of zero with 0.
Reviewed-by: Richard Levitte <levitte@openssl.org>
For a local variable:
TYPE *p;
Allocations like this are "risky":
p = OPENSSL_malloc(sizeof(TYPE));
if the type of p changes, and the malloc call isn't updated, you
could get memory corruption. Instead do this:
p = OPENSSL_malloc(sizeof(*p));
Also fixed a few memset() calls that I noticed while doing this.
Reviewed-by: Richard Levitte <levitte@openssl.org>
EVP_.*free; this gets:
EVP_CIPHER_CTX_free EVP_PKEY_CTX_free EVP_PKEY_asn1_free
EVP_PKEY_asn1_set_free EVP_PKEY_free EVP_PKEY_free_it
EVP_PKEY_meth_free; and also EVP_CIPHER_CTX_cleanup
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Causes more problems than it fixes: even though error codes
are not part of the stable API, several users rely on the
specific error code, and the change breaks them. Conversely,
we don't have any concrete use-cases for constant-time behaviour here.
This reverts commit 4aac102f75.
Reviewed-by: Andy Polyakov <appro@openssl.org>
The different -I compiler parameters will take care of the rest...
Reviewed-by: Tim Hudson <tjh@openssl.org>
Conflicts:
crypto/evp/evp_enc.c
crypto/rsa/rsa_oaep.c
crypto/rsa/rsa_pk1.c
Do the final padding check in EVP_DecryptFinal_ex in constant time to
avoid a timing leak from padding failure.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Add support for key wrap algorithms via EVP interface.
Generalise AES wrap algorithm and add to modes, making existing
AES wrap algorithm a special case.
Move test code to evptests.txt
knock-on work than expected - they've been extracted into a patch
series that can be completed elsewhere, or in a different branch,
before merging back to HEAD.
changes are the fallout). As this could break source code that doesn't
directly include headers for interfaces it uses, changes to recursive
includes are covered by the OPENSSL_NO_DEPRECATED symbol. It's better to
define this when building and using openssl, and then adapt code where
necessary - this is how to stay current. However the mechanism exists for
the lethargic.
I have tried to convert 'len' type variable declarations to unsigned as a
means to address these warnings when appropriate, but when in doubt I have
used casts in the comparisons instead. The better solution (that would get
us all lynched by API users) would be to go through and convert all the
function prototypes and structure definitions to use unsigned variables
except when signed is necessary. The proliferation of (signed) "int" for
strictly non-negative uses is unfortunate.
