When closing connections due to exiting, the IO service is
already gone, so the data exchange needed for a gracious SSL
shutdown cannot happen. We just close the socket in that case.
An override for the wallet to daemon connection is provided, but not for
other SSL contexts. The intent is to prevent users from supplying a
system CA as the "user" whitelisted certificate, which is less secure
since the key is controlled by a third party.
If the verification mode is `system_ca`, clients will now do hostname
verification. Thus, only certificates from expected hostnames are
allowed when SSL is enabled. This can be overridden by forcible setting
the SSL mode to autodetect.
Clients will also send the hostname even when `system_ca` is not being
performed. This leaks possible metadata, but allows servers providing
multiple hostnames to respond with the correct certificate. One example
is cloudflare, which getmonero.org is currently using.
If SSL is "enabled" via command line without specifying a fingerprint or
certificate, the system CA list is checked for server verification and
_now_ fails the handshake if that check fails. This change was made to
remain consistent with standard SSL/TLS client behavior. This can still
be overridden by using the allow any certificate flag.
If the SSL behavior is autodetect, the system CA list is still checked
but a warning is logged if this fails. The stream is not rejected
because a re-connect will be attempted - its better to have an
unverified encrypted stream than an unverified + unencrypted stream.
Specifying SSL certificates for peer verification does an exact match,
making it a not-so-obvious alias for the fingerprints option. This
changes the checks to OpenSSL which loads concatenated certificate(s)
from a single file and does a certificate-authority (chain of trust)
check instead. There is no drop in security - a compromised exact match
fingerprint has the same worse case failure. There is increased security
in allowing separate long-term CA key and short-term SSL server keys.
This also removes loading of the system-default CA files if a custom
CA file or certificate fingerprint is specified.
Manually initialize the array_entry_t iterator to ensure it points
to the correct m_array, thereby preventing a potential use-after-free
situation.
Signed-off-by: Guido Vranken <guidovranken@gmail.com>
This avoids the annoying case where the shell prints its prompt
after the last line from Monero output, causing line editing to
sometimes go wonky, for lack of a better term
RPC connections now have optional tranparent SSL.
An optional private key and certificate file can be passed,
using the --{rpc,daemon}-ssl-private-key and
--{rpc,daemon}-ssl-certificate options. Those have as
argument a path to a PEM format private private key and
certificate, respectively.
If not given, a temporary self signed certificate will be used.
SSL can be enabled or disabled using --{rpc}-ssl, which
accepts autodetect (default), disabled or enabled.
Access can be restricted to particular certificates using the
--rpc-ssl-allowed-certificates, which takes a list of
paths to PEM encoded certificates. This can allow a wallet to
connect to only the daemon they think they're connected to,
by forcing SSL and listing the paths to the known good
certificates.
To generate long term certificates:
openssl genrsa -out /tmp/KEY 4096
openssl req -new -key /tmp/KEY -out /tmp/REQ
openssl x509 -req -days 999999 -sha256 -in /tmp/REQ -signkey /tmp/KEY -out /tmp/CERT
/tmp/KEY is the private key, and /tmp/CERT is the certificate,
both in PEM format. /tmp/REQ can be removed. Adjust the last
command to set expiration date, etc, as needed. It doesn't
make a whole lot of sense for monero anyway, since most servers
will run with one time temporary self signed certificates anyway.
SSL support is transparent, so all communication is done on the
existing ports, with SSL autodetection. This means you can start
using an SSL daemon now, but you should not enforce SSL yet or
nothing will talk to you.
RPC connections now have optional tranparent SSL.
An optional private key and certificate file can be passed,
using the --{rpc,daemon}-ssl-private-key and
--{rpc,daemon}-ssl-certificate options. Those have as
argument a path to a PEM format private private key and
certificate, respectively.
If not given, a temporary self signed certificate will be used.
SSL can be enabled or disabled using --{rpc}-ssl, which
accepts autodetect (default), disabled or enabled.
Access can be restricted to particular certificates using the
--rpc-ssl-allowed-certificates, which takes a list of
paths to PEM encoded certificates. This can allow a wallet to
connect to only the daemon they think they're connected to,
by forcing SSL and listing the paths to the known good
certificates.
To generate long term certificates:
openssl genrsa -out /tmp/KEY 4096
openssl req -new -key /tmp/KEY -out /tmp/REQ
openssl x509 -req -days 999999 -sha256 -in /tmp/REQ -signkey /tmp/KEY -out /tmp/CERT
/tmp/KEY is the private key, and /tmp/CERT is the certificate,
both in PEM format. /tmp/REQ can be removed. Adjust the last
command to set expiration date, etc, as needed. It doesn't
make a whole lot of sense for monero anyway, since most servers
will run with one time temporary self signed certificates anyway.
SSL support is transparent, so all communication is done on the
existing ports, with SSL autodetection. This means you can start
using an SSL daemon now, but you should not enforce SSL yet or
nothing will talk to you.
- Support for ".onion" in --add-exclusive-node and --add-peer
- Add --anonymizing-proxy for outbound Tor connections
- Add --anonymous-inbounds for inbound Tor connections
- Support for sharing ".onion" addresses over Tor connections
- Support for broadcasting transactions received over RPC exclusively
over Tor (else broadcast over public IP when Tor not enabled).
The blockchain prunes seven eighths of prunable tx data.
This saves about two thirds of the blockchain size, while
keeping the node useful as a sync source for an eighth
of the blockchain.
No other data is currently pruned.
There are three ways to prune a blockchain:
- run monerod with --prune-blockchain
- run "prune_blockchain" in the monerod console
- run the monero-blockchain-prune utility
The first two will prune in place. Due to how LMDB works, this
will not reduce the blockchain size on disk. Instead, it will
mark parts of the file as free, so that future data will use
that free space, causing the file to not grow until free space
grows scarce.
The third way will create a second database, a pruned copy of
the original one. Since this is a new file, this one will be
smaller than the original one.
Once the database is pruned, it will stay pruned as it syncs.
That is, there is no need to use --prune-blockchain again, etc.
Number matching semantics are slightly changed: since this is used
as a filter to check whether a number is signed and/or floating
point, we can speed this up further. strto* functions are called
afterwards and will error out where necessary. We now also accept
numbers like .4 which were not accepted before.
The strto* calls on a boost::string_ref will not access unallocated
memory since the parsers always stop at the first bad character,
and the original string is zero terminated.
in arbitrary time measurement units for some arbitrary test case:
match_number2: 235 -> 70
match_word2: 330 -> 108
a13eb0a1 epee: speed up string matching a bit (moneromooo-monero)
3a3858dc epee: avoid string allocation when parsing a pod from string (moneromooo-monero)
b36353e2 unit_tests: add some hex parsing test for non hex input (xiphon)
6671110c unit_tests: add a test for parse_hexstr_to_binbuff (moneromooo-monero)
f6187cd8 epee: speed up parse_hexstr_to_binbuff a little (Howard Chu)
00901e9c epee: initialize a few data members where it seems to be appropriate (moneromooo-monero)
144a6c32 abstract_tcp_server2: move m_period to subclass (moneromooo-monero)
758d7684 connection_basic: remove unused floating time start time (moneromooo-monero)
e5108a29 Catch more exceptions in dtors (moneromooo-monero)
bcf3f6af fuzz_tests: catch unhandled exceptions (moneromooo-monero)
3ebd05d4 miner: restore stream flags after changing them (moneromooo-monero)
a093092e levin_protocol_handler_async: do not propagate exception through dtor (moneromooo-monero)
1eebb82b net_helper: do not propagate exceptions through dtor (moneromooo-monero)
fb6a3630 miner: do not propagate exceptions through dtor (moneromooo-monero)
2e2139ff epee: do not propagate exception through dtor (moneromooo-monero)
0749a8bd db_lmdb: do not propagate exceptions in dtor (moneromooo-monero)
1b0afeeb wallet_rpc_server: exit cleanly on unhandled exceptions (moneromooo-monero)
418a9936 unit_tests: catch unhandled exceptions (moneromooo-monero)
ea7f9543 threadpool: do not propagate exceptions through the dtor (moneromooo-monero)
6e855422 gen_multisig: nice exit on unhandled exception (moneromooo-monero)
53df2deb db_lmdb: catch error in mdb_stat calls during migration (moneromooo-monero)
e67016dd blockchain_blackball: catch failure to commit db transaction (moneromooo-monero)
661439f4 mlog: don't remove old logs if we failed to rename the current file (moneromooo-monero)
5fdcda50 easylogging++: test for NULL before dereference (moneromooo-monero)
7ece1550 performance_test: fix bad last argument calling add_arg (moneromooo-monero)
a085da32 unit_tests: add check for page size > 0 before dividing (moneromooo-monero)
d8b1ec8b unit_tests: use std::shared_ptr to shut coverity up about leaks (moneromooo-monero)
02563bf4 simplewallet: top level exception catcher to print nicer messages (moneromooo-monero)
c57a65b2 blockchain_blackball: fix shift range for 32 bit archs (moneromooo-monero)
26a42fe5 Added features to epee::span<T> : - Support for classes - Added `remove_prefix` function - Added `to_mut_span` and `as_mut_byte_span` (Lee Clagett)
56b50faa wallet: use wipeable_string in more places where a secret is used (moneromooo-monero)
07ec748c wipeable_string: add hex_to_pod function (moneromooo-monero)
42397359 Fixup 32bit arm build (TheCharlatan)
a06d2581 Fix Windows build (TheCharlatan)
ecaf5b3f Add libsodium to the packages, the arm build was complaining about it. (TheCharlatan)
cbbf4d24 Adapt translations to upstream changes (TheCharlatan)
db571546 Updated pcsc url (TheCharlatan)
f0ba19fd Add lrelease to the depends (TheCharlatan)
cfb30462 Add Miniupnp submodule (TheCharlatan)
5f7da005 Unbound is now a submodule. Adapt depends for this. (TheCharlatan)
d6b9bdd3 Update readmes to reflect the usage of depends (TheCharlatan)
56b6e41e Add support for apple and arm building (TheCharlatan)
29311fd1 Disable stack unwinding for mingw32 depends build. (TheCharlatan)
8db3d573 Modify depends for monero's dependencies (TheCharlatan)
0806a23a Initial depends addition (TheCharlatan)
4469b0c4 abstract_tcp_server2: fix binding to the wrong IP (moneromooo-monero)
8eab6147 epee: use the socket::bind variant which does not throw (moneromooo-monero)
Add readline, ldns, graphviz, unbound to depends packages
Add a cmake toolchain file to depends that is uniquely created for every build and placed in triple/share/toolchain.cmake
This file is then passed to cmake with -DCMAKE_TOOLCHAIN_FILE=/path/to/triple/share/toolchain.cmake
Add the boost locale package to depends
In the depends cmake toolchain file, a DEPENDS flag is added
to exclude, or change cmake checks done that are required for depends
Link miniupnpc and unwind from depends and not external
Add libiconv and icu4c to depends, required for mingw32 builds.
Headers (winsock) need to be lower case in order to compile on unix systems.
This should not affect building on windows.
29dea03 epee: resize vectors where possible in serialization (moneromooo-monero)
76affd9 epee: some speedup in parsing (moneromooo-monero)
dc6c069 db_lmdb: speedup the get_output_distribution common case (moneromooo-monero)
76ac5a8 wallet2: ask for a binary output distribution, for speed (moneromooo-monero)
This class will allow mlocking small objects, of which there
may be several per page. It adds refcounting so pages are only
munlocked when the last object on that page munlocks.
The secret spend key is kept encrypted in memory, and
decrypted on the fly when needed.
Both spend and view secret keys are kept encrypted in a JSON
field in the keys file. This avoids leaving the keys in
memory due to being manipulated by the JSON I/O API.
f8dd433 epee: fix detection of 172.16.0.0/172.31.255.255 local IP range (moneromooo-monero)
5db9e3c unit_tests: add tests for local IP range detection (moneromooo-monero)
a connection's timeout is halved for every extra connection
from the same host.
Also keep track of when we don't need to use a connection
anymore, so we can close it and free the resource for another
connection.
Also use the longer timeout for non routable local addresses.
In file included from src/cryptonote_basic/hardfork.cpp:33:
In file included from src/blockchain_db/blockchain_db.h:42:
In file included from src/cryptonote_basic/hardfork.h:31:
contrib/epee/include/syncobj.h:37:10: fatal error: 'boost/thread/v2/thread.hpp' file not found
#include <boost/thread/v2/thread.hpp>
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from src/rpc/daemon_handler.cpp:29:
In file included from src/rpc/daemon_handler.h:36:
In file included from src/p2p/net_node.h:41:
In file included from contrib/epee/include/net/levin_server_cp2.h:32:
In file included from contrib/epee/include/net/abstract_tcp_server2.h:324:
contrib/epee/include/net/abstract_tcp_server2.inl:44:10: fatal error: 'boost/thread/v2/thread.hpp' file not found
#include <boost/thread/v2/thread.hpp> // TODO
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
contrib/epee/include/math_helper.h: In member function 'bool epee::math_helper::average<val, default_base>::set_base()':
contrib/epee/include/syncobj.h:227:56: error: 'sleep_for' is not a member of 'boost::this_thread'
#define CRITICAL_REGION_LOCAL(x) {boost::this_thread::sleep_for(boost::chrono::milliseconds(epee::debug::g_test_dbg_lock_sleep()));} epee::critical_region_t<decltype(x)> critical_region_var(x)
^
contrib/epee/include/syncobj.h:227:56: note: in definition of macro 'CRITICAL_REGION_LOCAL'
#define CRITICAL_REGION_LOCAL(x) {boost::this_thread::sleep_for(boost::chrono::milliseconds(epee::debug::g_test_dbg_lock_sleep()));} epee::critical_region_t<decltype(x)> critical_region_var(x)
^~~~~~~~~
contrib/epee/include/syncobj.h:227:56: note: suggested alternative: 'sleep'
#define CRITICAL_REGION_LOCAL(x) {boost::this_thread::sleep_for(boost::chrono::milliseconds(epee::debug::g_test_dbg_lock_sleep()));} epee::critical_region_t<decltype(x)> critical_region_var(x)
^
contrib/epee/include/syncobj.h:227:56: note: in definition of macro 'CRITICAL_REGION_LOCAL'
#define CRITICAL_REGION_LOCAL(x) {boost::this_thread::sleep_for(boost::chrono::milliseconds(epee::debug::g_test_dbg_lock_sleep()));} epee::critical_region_t<decltype(x)> critical_region_var(x)
^~~~~~~~~
e4646379 keccak: fix mdlen bounds sanity checking (moneromooo-monero)
2e3e90ac pass large parameters by const ref, not value (moneromooo-monero)
61defd89 blockchain: sanity check number of precomputed hash of hash blocks (moneromooo-monero)
9af6b2d1 ringct: fix infinite loop in unused h2b function (moneromooo-monero)
8cea8d0c simplewallet: double check a new multisig wallet is multisig (moneromooo-monero)
9b98a6ac threadpool: catch exceptions in dtor, to avoid terminate (moneromooo-monero)
24803ed9 blockchain_export: fix buffer overflow in exporter (moneromooo-monero)
f3f7da62 perf_timer: rewrite to make it clear there is no division by zero (moneromooo-monero)
c6ea3df0 performance_tests: remove add_arg call stray extra param (moneromooo-monero)
fa6b4566 fuzz_tests: fix an uninitialized var in setup (moneromooo-monero)
03887f11 keccak: fix sanity check bounds test (moneromooo-monero)
ad11db91 blockchain_db: initialize m_open in base class ctor (moneromooo-monero)
bece67f9 miner: restore std::cout precision after modification (moneromooo-monero)
1aabd14c db_lmdb: check hard fork info drop succeeded (moneromooo-monero)
cb9aa23c levin_protocol_handler_async: another attempt at fixing at exception (moneromooo-monero)
64d23ce3 Revert "epee: keep a ref to a connection we're deleting" (moneromooo-monero)
bd5cce07 network_throttle: fix ineffective locking (moneromooo-monero)
e0a61299 network_throttle: remove unused xxx static member (moneromooo-monero)
24f584d9 cryptonote_core: remove unused functions with off by one bugs (moneromooo-monero)
b1634aa3 blockchain: don't leave dangling pointers in this (moneromooo-monero)
8e60b81c cryptonote_core: fix db leak on error (moneromooo-monero)
213e326c abstract_tcp_server2: log init_server errors as fatal (moneromooo-monero)
b51dc566 use const refs in for loops for non tiny types (moneromooo-monero)
f0568ca6 net_parse_helpers: fix regex error checking (moneromooo-monero)
b49ddc76 check accessing an element past the end of a container (moneromooo-monero)
2305bf26 check return value for generate_key_derivation and derive_public_key (moneromooo-monero)
a4240d9f catch const exceptions (moneromooo-monero)
45a1c4c0 add empty container sanity checks when using front() and back() (moneromooo-monero)
56fa6ce1 tests: fix a buffer overread in a unit test (moneromooo-monero)
b4524892 rpc: guard against json parsing a non object (moneromooo-monero)
c2ed8618 easylogging++: avoid buffer underflow (moneromooo-monero)
187a6ab2 epee: trap failure to parse URI from request (moneromooo-monero)
061789b5 checkpoints: trap failure to load JSON checkpoints (moneromooo-monero)
ba2fefb9 checkpoints: pass std::string by const ref, not const value (moneromooo-monero)
38c8f4e0 mlog: terminate a string at last char, just in case (moneromooo-monero)
d753d716 fix a few leaks by throwing objects, not newed pointers to objects (moneromooo-monero)
fe568db8 p2p: use size_t for arbitrary counters instead of uint8_t (moneromooo-monero)
46d6fa35 cryptonote_protocol: sanity check chain hashes from peer (moneromooo-monero)
25584f86 cryptonote_protocol: print peer versions when unexpected (moneromooo-monero)
490a5d41 rpc: do not try to use an invalid txid in relay_tx (moneromooo-monero)
43f5269f Wallets now do not depend on the daemon rpc lib (moneromooo-monero)
bb89ae8b move connection_basic and network_throttle from src/p2p to epee (moneromooo-monero)
4abf25f3 cryptonote_core does not depend on p2p anymore (moneromooo-monero)
Partially implements #74.
Securely erases keys from memory after they are no longer needed. Might have a
performance impact, which I haven't measured (perf measurements aren't
generally reliable on laptops).
Thanks to @stoffu for the suggestion to specialize the pod_to_hex/hex_to_pod
functions. Using overloads + SFINAE instead generalizes it so other types can
be marked as scrubbed without adding more boilerplate.
3dffe71b new wipeable_string class to replace std::string passphrases (moneromooo-monero)
7a2a5741 utils: initialize easylogging++ in on_startup (moneromooo-monero)
54950829 use memwipe in a few relevant places (moneromooo-monero)
000666ff add a memwipe function (moneromooo-monero)
27aa8ce9 net_utils_base: fix peer list parsing (moneromooo-monero)
fe5ab2c4 epee: fix kv_unserialize return value when a field is not found (moneromooo-monero)
Deleted 3 out of 4 calls to method connection_basic::sleep_before_packet
that were erroneous / superfluous, which enabled the elimination of a
"fudge" factor of 2.1 in connection_basic::set_rate_up_limit;
also ended the multiplying of limit values and numbers of bytes
transferred by 1024 before handing them over to the global throttle
objects
Fixes compile error when building with OpenSSL v1.1:
contrib/epee/include/net/net_helper.h: In member function ‘void epee::net_utils::blocked_mode_client::shutdown_ssl()’:
contrib/epee/include/net/net_helper.h:579:106: error: ‘SSL_R_SHORT_READ’ was not declared in this scope
if (ec.category() == boost::asio::error::get_ssl_category() && ec.value() != ERR_PACK(ERR_LIB_SSL, 0, SSL_R_SHORT_READ))
^
contrib/epee/include/net/net_helper.h:579:106: note: suggested alternative: ‘SSL_F_SSL_READ’
See boost/asio/ssl/error.hpp.
Boost handles differences between OpenSSL versions.
cmake: fail if Boost is too old for OpenSSL v1.1
The commands handler must not be destroyed before the config
object, or we'll be accessing freed memory.
An earlier attempt at using boost::shared_ptr to control object
lifetime turned out to be very invasive, though would be a
better solution in theory.
15e62581 connection_context: initialize m_callback_request_count to 0 (moneromooo-monero)
5fa199c6 copyable_atomic: add a ctor with initial value (moneromooo-monero)
- internal nullptr checks
- prevent modifications to network_address (shallow copy issues)
- automagically works with any type containing interface functions
- removed fnv1a hashing
- ipv4_network_address now flattened with no base class
792ba4f0 Log categories can now be added to and removed from (moneromooo-monero)
48f92eb6 easylogging++: add categories getter (moneromooo-monero)
f35afe62 epee: factor log level/categories setting (moneromooo-monero)
ef005f5e p2p: add a couple early outs when the stop signal is received (moneromooo-monero)
80d361c7 abstract_tcp_server2: improve tracking/cancelling of early connections (moneromooo-monero)
close might end up dropping a ref, ending up removing the
connection from m_connects, as the lock is recursive. This'd
cause an out of bounds exception and kill the idle connection
maker thread
df0cffed cryptonote_protocol: warn if we see a higher top version we expect (moneromooo-monero)
317ab21a cryptonote_protocol: less strict check on top version on connect (moneromooo-monero)
cc81a371 cryptonote_protocol: update target height when syncing too (moneromooo-monero)
e2ad372b cryptonote_protocol: simplify and remove unnecessary casts (moneromooo-monero)
727e67ca cryptonote_protocol: print peer top height along with its version (moneromooo-monero)
b5345ef4 crypto: use malloc instead of alloca (moneromooo-monero)
80794b31 thread_group: set thread size to THREAD_STACK_SIZE (moneromooo-monero)
5524bc31 print peer id in 0 padded hex for consistency (moneromooo-monero)
8f8cc09b contrib: add sync_info to rlwrap command set (moneromooo-monero)
70b8c6d7 cryptonote_protocol: misc fixes to the new sync algorithm (moneromooo-monero)
We don't actually need to keep them past the call to start, as this
adds them to the config object list, and so they'll then be cancelled
already when the stop signal arrives. This allows removing the periodic
call to cleanup connections.
b7d6ec83 simplewallet: add (out of sync) or (no daemon) markers in the prompt (moneromooo-monero)
fa23a500 wallet2: add a is_synced function (moneromooo-monero)
f1307bbd node_rpc_proxy: add a proxy for target height (moneromooo-monero)
5d4ef719 core: speed up output index unique set calculation (moneromooo-monero)
19d7f568 perf_timer: allow profiling more granular than millisecond (moneromooo-monero)
bda8c598 epee: add nanosecond timer and pause/restart profiling macros (moneromooo-monero)
dc0b312f wallet_rpc_server: optionally return tx blobs on transfer calls (moneromooo-monero)
5eb79983 epee: add a KV_SERIALIZE variant for optional parameters (moneromooo-monero)
A block queue is now placed between block download and
block processing. Blocks are now requested only from one
peer (unless starved).
Includes a new sync_info coommand.
Nanosecond timer precision won't work on Windows, but we don't
care since I'm using that just for profiling incremental code
paths, but a Windows coder is welcome to add it if there's a way.
This was the case for monero-wallet-cli already, but not for
monerod, which was making it pretty spammy as it was duplicating
intended output. Since my original intent was to ensure logs
included command output for debugging, this achieves both.
07c4276c Don't issue a new timedsync while one is already in progress (Howard Chu)
cf3a376c Don't timeout a slow operation that's making progress (Howard Chu)
340830de Fix PR#2039 (Howard Chu)
This PR adds readline support to the daemon and monero-wallet-cli. Only
GNU readline is supported (e.g. not libedit) and there are cmake checks
to ensure this.
There is a cmake variable, Readline_ROOT_DIR that can specify a
directory to find readline, otherwise some default paths are searched.
There is also a cmake option, USE_READLINE, that defaults to ON. If set
to ON, if readline is not found, the build continues but without
readline support.
One negative side effect of using readline is that the color prompt in
the wallet-cli now has no color and just uses terminal default. I know
how to fix this but it's quite a big change so will tackle another time.
A timedsync is issued every minute on a connection, but the input
tineout is 2 minutes. This means a new sync request could be issued
while a slow sync request was already in progress. The additional
request will further clog the network on a slow connection, and
cause a premature timeout.
All code which was using ip and port now uses a new IPv4 object,
subclass of a new network_address class. This will allow easy
addition of I2P addresses later (and also IPv6, etc).
Both old style and new style peer lists are now sent in the P2P
protocol, which is inefficient but allows peers using both
codebases to talk to each other. This will be removed in the
future. No other subclasses than IPv4 exist yet.
- Performance improvements
- Added `span` for zero-copy pointer+length arguments
- Added `std::ostream` overload for direct writing to output buffers
- Removal of unused `string_tools::buff_to_hex`
