Odd-length lists should be rejected everywhere upon parsing. Nevertheless,
be extra careful and add guards against off-by-one reads.

Also, drive-by replace inexplicable double-negation with an explicit comparison.
Reviewed-by: NMatt Caswell <matt@openssl.org>

The Supported Elliptic Curves extension contains a vector of NamedCurves
of 2 bytes each, so the total length must be even. Accepting odd-length
lists was observed to lead to a non-exploitable one-byte out-of-bounds
read in the latest development branches (1.0.2 and master). Released
versions of OpenSSL are not affected.

Thanks to Felix Groebert of the Google Security Team for reporting this issue.
Reviewed-by: NMatt Caswell <matt@openssl.org>

Add includes missing from commit 33eab3f6Reviewed-by: NGeoff Thorpe <geoff@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Signed-off-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Always use goto err on failure and call ssl_cert_free() on the error path so all
fields and "ret" itself are freed
Signed-off-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Signed-off-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Signed-off-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Signed-off-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Signed-off-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Signed-off-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Signed-off-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Signed-off-by: NKurt Roeckx <kurt@roeckx.be>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NTim Hudson <tjh@openssl.org>

The only support for SSLv2 left is receiving a SSLv2 compatible client hello.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NBodo Moeller <bodo@openssl.org>

Reviewed-by: NTim Hudson <tjh@openssl.org>

than the mtu we are already using
Reviewed-by: NTim Hudson <tjh@openssl.org>

and UDP header) when setting an mtu. This constant is not always correct (e.g.
if using IPv6). Use the new DTLS_CTRL functions instead.
Reviewed-by: NTim Hudson <tjh@openssl.org>

we will support then dtls1_do_write can go into an infinite loop. This commit
fixes that.
Reviewed-by: NTim Hudson <tjh@openssl.org>

at least the minimum or it will fail.
There were some instances in dtls1_query_mtu where the final mtu can end up
being less than the minimum, i.e. where the user has set an mtu manually. This
shouldn't be allowed. Also remove dtls1_guess_mtu that, despite having
logic for guessing an mtu, was actually only ever used to work out the minimum
mtu to use.
Reviewed-by: NTim Hudson <tjh@openssl.org>

and instead use the value provided by the underlying BIO. Also provide some
new DTLS_CTRLs so that the library user can set the mtu without needing to
know this constant. These new DTLS_CTRLs provide the capability to set the
link level mtu to be used (i.e. including this IP/UDP overhead). The previous
DTLS_CTRLs required the library user to subtract this overhead first.
Reviewed-by: NTim Hudson <tjh@openssl.org>

used with no explanation. Some of this was introduced as part of RT#1929. The
value 28 is the length of the IP header (20 bytes) plus the UDP header (8
bytes). However use of this constant is incorrect because there may be
instances where a different value is needed, e.g. an IPv4 header is 20 bytes
but an IPv6 header is 40. Similarly you may not be using UDP (e.g. SCTP).
This commit introduces a new BIO_CTRL that provides the value to be used for
this mtu "overhead". It will be used by subsequent commits.
Reviewed-by: NTim Hudson <tjh@openssl.org>

mtu that we have received is not less than the minimum. If its less it uses the
minimum instead. The second call to query the mtu does not do that, but
instead uses whatever comes back. We have seen an instance in RT#3592 where we
have got an unreasonably small mtu come back. This commit makes both query
checks consistent.
Reviewed-by: NTim Hudson <tjh@openssl.org>

automatically updated, and we should use the one provided instead.
Unfortunately there are a couple of locations where this is not respected.
Reviewed-by: NTim Hudson <tjh@openssl.org>

RT#3592 provides an instance where the OPENSSL_assert that this commit
replaces can be hit. I was able to recreate this issue by forcing the
underlying BIO to misbehave and come back with very small mtu values. This
happens the second time around the while loop after we have detected that the
MTU has been exceeded following the call to dtls1_write_bytes.
Reviewed-by: NTim Hudson <tjh@openssl.org>

If SSLv2 and SSLv3 are both disabled we still support SSL/TLS.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NTim Hudson <tjh@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

Previously, state variant was not advanced, which resulted in state
being stuck in the st1 variant (usually "_A").

This broke certificate callback retry logic when accepting connections
that were using SSLv2 ClientHello (hence reusing the message), because
their state never advanced to SSL3_ST_SR_CLNT_HELLO_C variant required
for the retry code path.

Reported by Yichun Zhang (agentzh).
Signed-off-by: NPiotr Sikora <piotr@cloudflare.com>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

The current documentation contains a bunch of spelling and grammar mistakes. I also
found it hard to understand some paragraphs, so here is my attempt to improve its
readability.
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

PR#1767
Reviewed-by: NRichard Levitte <levitte@openssl.org>