dash/src/net_permissions.cpp
Wladimir J. van der Laan 058c9f729f Merge #17754: net: Don't allow resolving of std::string with embedded NUL characters. Add tests.
7a046cdc1423963bdcbcf9bb98560af61fa90b37 tests: Avoid using C-style NUL-terminated strings as arguments (practicalswift)
fefb9165f23fe9d10ad092ec31715f906e0d2ee7 tests: Add tests to make sure lookup methods fail on std::string parameters with embedded NUL characters (practicalswift)
9574de86ad703ad942cdd0eca79f48c0d42b102b net: Avoid using C-style NUL-terminated strings as arguments in the netbase interface (practicalswift)

Pull request description:

  Don't allow resolving of `std::string`:s with embedded `NUL` characters.

  Avoid using C-style `NUL`-terminated strings as arguments in the `netbase` interface

  Add tests.

  The only place in where C-style `NUL`-terminated strings are actually needed is here:

  ```diff
  +    if (!ValidAsCString(name)) {
  +        return false;
  +    }
  ...
  -    int nErr = getaddrinfo(pszName, nullptr, &aiHint, &aiRes);
  +    int nErr = getaddrinfo(name.c_str(), nullptr, &aiHint, &aiRes);
       if (nErr)
           return false;
  ```

  Interface changes:

  ```diff
  -bool LookupHost(const char *pszName, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup);
  +bool LookupHost(const std::string& name, std::vector<CNetAddr>& vIP, unsigned int nMaxSolutions, bool fAllowLookup);

  -bool LookupHost(const char *pszName, CNetAddr& addr, bool fAllowLookup);
  +bool LookupHost(const std::string& name, CNetAddr& addr, bool fAllowLookup);

  -bool Lookup(const char *pszName, CService& addr, int portDefault, bool fAllowLookup);
  +bool Lookup(const std::string& name, CService& addr, int portDefault, bool fAllowLookup);

  -bool Lookup(const char *pszName, std::vector<CService>& vAddr, int portDefault, bool fAllowLookup, unsigned int nMaxSolutions);
  +bool Lookup(const std::string& name, std::vector<CService>& vAddr, int portDefault, bool fAllowLookup, unsigned int nMaxSolutions);

  -bool LookupSubNet(const char *pszName, CSubNet& subnet);
  +bool LookupSubNet(const std::string& strSubnet, CSubNet& subnet);

  -CService LookupNumeric(const char *pszName, int portDefault = 0);
  +CService LookupNumeric(const std::string& name, int portDefault = 0);

  -bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, const SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed);
  +bool ConnectThroughProxy(const proxyType &proxy, const std::string& strDest, int port, const SOCKET& hSocketRet, int nTimeout, bool& outProxyConnectionFailed);
  ```

  It should be noted that the `ConnectThroughProxy` change (from `bool *outProxyConnectionFailed` to `bool& outProxyConnectionFailed`) has nothing to do with `NUL` handling but I thought it was worth doing when touching this file :)

ACKs for top commit:
  EthanHeilman:
    ACK 7a046cdc1423963bdcbcf9bb98560af61fa90b37
  laanwj:
    ACK 7a046cdc1423963bdcbcf9bb98560af61fa90b37

Tree-SHA512: 66556e290db996917b54091acd591df221f72230f6b9f6b167b9195ee870ebef6e26f4cda2f6f54d00e1c362e1743bf56785d0de7cae854e6bf7d26f6caccaba
2022-10-03 16:08:31 -04:00

112 lines
4.2 KiB
C++

// Copyright (c) 2009-2018 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <net_permissions.h>
#include <netbase.h>
#include <util/error.h>
#include <util/system.h>
#include <util/translation.h>
namespace {
// Parse the following format: "perm1,perm2@xxxxxx"
bool TryParsePermissionFlags(const std::string& str, NetPermissionFlags& output, size_t& readen, bilingual_str& error)
{
NetPermissionFlags flags = PF_NONE;
const auto atSeparator = str.find('@');
// if '@' is not found (ie, "xxxxx"), the caller should apply implicit permissions
if (atSeparator == std::string::npos) {
NetPermissions::AddFlag(flags, PF_ISIMPLICIT);
readen = 0;
}
// else (ie, "perm1,perm2@xxxxx"), let's enumerate the permissions by splitting by ',' and calculate the flags
else {
readen = 0;
// permissions == perm1,perm2
const auto permissions = str.substr(0, atSeparator);
while (readen < permissions.length()) {
const auto commaSeparator = permissions.find(',', readen);
const auto len = commaSeparator == std::string::npos ? permissions.length() - readen : commaSeparator - readen;
// permission == perm1
const auto permission = permissions.substr(readen, len);
readen += len; // We read "perm1"
if (commaSeparator != std::string::npos) readen++; // We read ","
if (permission == "bloomfilter" || permission == "bloom") NetPermissions::AddFlag(flags, PF_BLOOMFILTER);
else if (permission == "noban") NetPermissions::AddFlag(flags, PF_NOBAN);
else if (permission == "forcerelay") NetPermissions::AddFlag(flags, PF_FORCERELAY);
else if (permission == "mempool") NetPermissions::AddFlag(flags, PF_MEMPOOL);
else if (permission == "all") NetPermissions::AddFlag(flags, PF_ALL);
else if (permission == "relay") NetPermissions::AddFlag(flags, PF_RELAY);
else if (permission.length() == 0); // Allow empty entries
else {
error = strprintf(_("Invalid P2P permission: '%s'"), permission);
return false;
}
}
readen++;
}
output = flags;
error = Untranslated("");
return true;
}
}
std::vector<std::string> NetPermissions::ToStrings(NetPermissionFlags flags)
{
std::vector<std::string> strings;
if (NetPermissions::HasFlag(flags, PF_BLOOMFILTER)) strings.push_back("bloomfilter");
if (NetPermissions::HasFlag(flags, PF_NOBAN)) strings.push_back("noban");
if (NetPermissions::HasFlag(flags, PF_FORCERELAY)) strings.push_back("forcerelay");
if (NetPermissions::HasFlag(flags, PF_RELAY)) strings.push_back("relay");
if (NetPermissions::HasFlag(flags, PF_MEMPOOL)) strings.push_back("mempool");
return strings;
}
bool NetWhitebindPermissions::TryParse(const std::string& str, NetWhitebindPermissions& output, bilingual_str& error)
{
NetPermissionFlags flags;
size_t offset;
if (!TryParsePermissionFlags(str, flags, offset, error)) return false;
const std::string strBind = str.substr(offset);
CService addrBind;
if (!Lookup(strBind, addrBind, 0, false)) {
error = ResolveErrMsg("whitebind", strBind);
return false;
}
if (addrBind.GetPort() == 0) {
error = strprintf(_("Need to specify a port with -whitebind: '%s'"), strBind);
return false;
}
output.m_flags = flags;
output.m_service = addrBind;
error = Untranslated("");
return true;
}
bool NetWhitelistPermissions::TryParse(const std::string& str, NetWhitelistPermissions& output, bilingual_str& error)
{
NetPermissionFlags flags;
size_t offset;
if (!TryParsePermissionFlags(str, flags, offset, error)) return false;
const std::string net = str.substr(offset);
CSubNet subnet;
LookupSubNet(net, subnet);
if (!subnet.IsValid()) {
error = strprintf(_("Invalid netmask specified in -whitelist: '%s'"), net);
return false;
}
output.m_flags = flags;
output.m_subnet = subnet;
error = Untranslated("");
return true;
}