As memset() can be optimized out by a compiler it should not be used in
privacy/security relevant code parts. OpenSSL provides the safe
OPENSSL_cleanse() function in crypto.h, which perfectly does the job of
clean and overwrite data.
For details see: http://www.viva64.com/en/b/0178/
- change memset() to OPENSSL_cleanse() where appropriate
- change a hard-coded number from netbase.cpp into a sizeof()
- ensure header inclusion guard is named after the header file
- add missing comments at the end of some inclusion guards
- add a small Qt5 compatibility fix in macdockiconhandler.h
CreateNewBlock was reading pindexBest at the start before taking the lock
so it was possible to have the the block content not match the prevheader.
(Partial of faff50d129)
- instead of "return false;" use "return QDialog::eventFilter(object,
event);" to harmonize this event filter with our default behaviour
(partial of 83a3fb81f3)
This allows fun stuff such as `bitcoin --help | less`, and more
easy piping to files.
Looking at other tools such as bash, gcc, they all send their help
text to stdout.
As the code was before, toHTML added empty elements to mapValue to check for their existance. Now first it check for their existance and then for their non-emptiness.
Removed a duplicated identical if
There are two equal ifs, one inside another. If the first one is true, then the second one is true.
Matt pointed out some time ago that there existed a minor DOS
attack where a node in its initial block download could be wedged
by an overwrite attack in a fork created between checkpoints before
a time where BIP30 was enforced. Now that the BIP30 timestamp
is irreversibly past the check can be more aggressive and apply to
all blocks except the two historic violations.
Hard-code a special nId=max int alert, to be broadcast if the
alert key is ever compromised. It applies to all versions, never
expires, cancels all previous alerts, and has a fixed message:
URGENT: Alert key compromised, upgrade required
Variations are not allowed (ignored), so an attacker with
the private key cannot broadcast empty-message nId=max alerts.
This fixes two alert system vulnerabilities found by
Sergio Lerner; you could send peers unlimited numbers
of invalid alert message to try to either fill up their
debug.log with messages and/or keep their CPU busy
checking signatures.
Fixed by disconnecting/banning peers if they send 10 or more
bad (invalid/expired/cancelled) alerts.
Windows & WindowsXP style have a problem with displaying the block progress.
Add a custom stylesheet as workaround, but only when one of those renderers is active,
otherwise leave the theme alone (issue #1071).
If 950 of the last 1,000 blocks are nVersion=2, reject nVersion=1
(or zero, but no bitcoin release has created block.nVersion=0) blocks
-- 75 of last 100 on testnet3.
This rule is being put in place now so that we don't have to go
through another "express support" process to get what we really
want, which is for every single new block to include the block height
in the coinbase.
"Version 2" blocks are blocks that have nVersion=2 and
have the block height as the first item in their coinbase.
Block-height-in-the-coinbase is strictly enforced when
version=2 blocks are a supermajority in the block chain
(750 of the last 1,000 blocks on main net, 51 of 100 for
testnet). This does not affect old clients/miners at all,
which will continue producing nVersion=1 blocks, and
which will continue to be valid.
