This change disables SSLv2/SSLv3 use by default, and introduces a
command line flag to opt into using SSLv2/SSLv3.
SSLv2 and SSLv3 are considered unsafe, and should only be used in
situations where compatibility with other components is required and
they cannot be upgrade to support newer forms of TLS.
ClientHelloParser used to contain an 18k buffer that was kept around
for the life of the connection, even though it was not needed in many
situations. I changed it to be deallocated when it's determined to
be no longer needed.
Signed-off-by: Fedor Indutny <fedor@indutny.com>
The default entropy source is /dev/urandom on UNIX platforms, which is
okay but we can do better by seeding it from OpenSSL's entropy pool.
On Windows we can certainly do better; on that platform, V8 seeds the
random number generator using only the current system time.
Fixes#6250.
NB: This is a back-port of commit 7ac2391 from the master branch that
for some reason never got back-ported to the v0.10 branch.
The default on UNIX platforms in v0.10 is different and arguably worse
than it is with master: if no entropy source is provided, V8 3.14 calls
srandom() with a xor of the PID and the current time in microseconds.
That means that on systems with a coarse system clock, the initial
state of the PRNG may be easily guessable.
The situation on Windows is even more dire because there the PRNG is
seeded with only the current time... in milliseconds.
NOTE: Also removed `.receivedShutdown` method of `Connection` it wasn't
documented anywhere, and was rewritten with `true` after receiving
`close_notify`.
fix#6638
Quote from SSL_shutdown man page:
The output of SSL_get_error(3) may be misleading,
as an erroneous SSL_ERROR_SYSCALL may be flagged even though
no error occurred.
Also, handle all other errors to prevent assertion in `ClearError()`.
The TLS protocol allows (and sometimes requires) clients to renegotiate the
session. However, renegotiation requires a disproportional amount of server-side
resources, particularly CPU time, which makes it a potential vector for
denial-of-service attacks.
To mitigate this issue, we keep track of and limit the number of renegotiation
requests over time, emitting an error if the threshold is exceeded.
SecureContext.setOptions() is backed by SSL_CTX_set_options() which, contrary to
what the name suggests, is additive: it doesn't set options, it adds them to the
already active options.
Hence the need for SecureContext.clearOptions(), which lets you unset active
options.
Also, secureOptions flag was added (and passed through) and allows
the context to have all supported SSL_OP_* set via createCredentials.
All SSL_OP_ flags (outside of ALL) have been added to constants.
node::SecureStream is definitely not a "stream" in the Node sense. Renaming
it to avoid ambiguity. (Adding namespace to not confuse with some other
Connection object.)
Timothy J Fontaine