zeek/src/Hash.cc
2025-05-16 10:14:37 -07:00

577 lines
17 KiB
C++

// See the file "COPYING" in the main distribution directory for copyright.
#include "zeek/Hash.h"
#include <highwayhash/highwayhash_target.h>
#include <highwayhash/instruction_sets.h>
#include <highwayhash/sip_hash.h>
#include <cinttypes>
#include "zeek/DebugLogger.h"
#include "zeek/Desc.h"
#include "zeek/Reporter.h"
#include "zeek/Val.h" // needed for const.bif
#include "zeek/ZeekString.h"
#include "zeek/digest.h"
#include "const.bif.netvar_h"
#include "zeek/3rdparty/doctest.h"
namespace zeek::detail {
alignas(32) uint64_t KeyedHash::shared_highwayhash_key[4];
alignas(32) uint64_t KeyedHash::cluster_highwayhash_key[4];
alignas(16) unsigned long long KeyedHash::shared_siphash_key[2];
// we use the following lines to not pull in the highwayhash headers in Hash.h - but to check the
// types did not change underneath us.
static_assert(std::is_same_v<hash64_t, highwayhash::HHResult64>, "Highwayhash return values must match hash_x_t");
static_assert(std::is_same_v<hash128_t, highwayhash::HHResult128>, "Highwayhash return values must match hash_x_t");
static_assert(std::is_same_v<hash256_t, highwayhash::HHResult256>, "Highwayhash return values must match hash_x_t");
void KeyedHash::InitializeSeeds(const std::array<uint32_t, SEED_INIT_SIZE>& seed_data) {
static_assert(std::is_same_v<decltype(KeyedHash::shared_siphash_key), highwayhash::SipHashState::Key>,
"Highwayhash Key is not unsigned long long[2]");
static_assert(std::is_same_v<decltype(KeyedHash::shared_highwayhash_key), highwayhash::HHKey>,
"Highwayhash HHKey is not uint64_t[4]");
if ( seeds_initialized )
return;
// leaving this at being generated by md5, allowing user scripts that use hmac_md5 functionality
// to get the same hash values as before. For now.
internal_md5((const u_char*)seed_data.data(), sizeof(seed_data) - 16,
shared_hmac_md5_key); // The last 128 bits of buf are for siphash
// yes, we use the same buffer twice to initialize two different keys. This should not really be
// a security problem of any kind: hmac-md5 is not really used anymore - and even if it was, the
// hashes should not reveal any information about their initialization vector.
static_assert(sizeof(shared_highwayhash_key) == ZEEK_SHA256_DIGEST_LENGTH);
calculate_digest(Hash_SHA256, (const u_char*)seed_data.data(), sizeof(seed_data) - 16,
reinterpret_cast<unsigned char*>(shared_highwayhash_key));
memcpy(shared_siphash_key, reinterpret_cast<const char*>(seed_data.data()) + 64, 16);
seeds_initialized = true;
}
void KeyedHash::InitOptions() {
calculate_digest(Hash_SHA256, BifConst::digest_salt->Bytes(), BifConst::digest_salt->Len(),
reinterpret_cast<unsigned char*>(cluster_highwayhash_key));
}
hash64_t KeyedHash::Hash64(const void* bytes, uint64_t size) {
return highwayhash::SipHash(shared_siphash_key, static_cast<const char*>(bytes), size);
}
void KeyedHash::Hash128(const void* bytes, uint64_t size, hash128_t* result) {
highwayhash::InstructionSets::Run<highwayhash::HighwayHash>(shared_highwayhash_key, static_cast<const char*>(bytes),
size, result);
}
void KeyedHash::Hash256(const void* bytes, uint64_t size, hash256_t* result) {
highwayhash::InstructionSets::Run<highwayhash::HighwayHash>(shared_highwayhash_key, static_cast<const char*>(bytes),
size, result);
}
hash64_t KeyedHash::StaticHash64(const void* bytes, uint64_t size) {
hash64_t result = 0;
highwayhash::InstructionSets::Run<highwayhash::HighwayHash>(cluster_highwayhash_key,
static_cast<const char*>(bytes), size, &result);
return result;
}
void KeyedHash::StaticHash128(const void* bytes, uint64_t size, hash128_t* result) {
highwayhash::InstructionSets::Run<highwayhash::HighwayHash>(cluster_highwayhash_key,
static_cast<const char*>(bytes), size, result);
}
void KeyedHash::StaticHash256(const void* bytes, uint64_t size, hash256_t* result) {
highwayhash::InstructionSets::Run<highwayhash::HighwayHash>(cluster_highwayhash_key,
static_cast<const char*>(bytes), size, result);
}
void init_hash_function() {
// Make sure we have already called init_random_seed().
if ( ! KeyedHash::IsInitialized() )
reporter->InternalError("Zeek's hash functions aren't fully initialized");
}
HashKey::HashKey(bool b) { Set(b); }
HashKey::HashKey(int i) { Set(i); }
HashKey::HashKey(zeek_int_t bi) { Set(bi); }
HashKey::HashKey(zeek_uint_t bu) { Set(bu); }
HashKey::HashKey(uint32_t u) { Set(u); }
HashKey::HashKey(const uint32_t u[], size_t n) {
size = write_size = n * sizeof(u[0]);
key = (char*)u;
}
HashKey::HashKey(double d) { Set(d); }
HashKey::HashKey(const void* p) { Set(p); }
HashKey::HashKey(const char* s) {
size = write_size = strlen(s); // note - skip final \0
key = (char*)s;
}
HashKey::HashKey(const String* s) {
size = write_size = s->Len();
key = (char*)s->Bytes();
}
HashKey::HashKey(const void* bytes, size_t arg_size) {
size = write_size = arg_size;
key = CopyKey((char*)bytes, size);
is_our_dynamic = true;
}
HashKey::HashKey(const void* arg_key, size_t arg_size, hash_t arg_hash) {
size = write_size = arg_size;
hash = arg_hash;
key = CopyKey((char*)arg_key, size);
is_our_dynamic = true;
}
HashKey::HashKey(const void* arg_key, size_t arg_size, hash_t arg_hash, bool /* dont_copy */) {
size = write_size = arg_size;
hash = arg_hash;
key = (char*)arg_key;
}
HashKey::HashKey(const HashKey& other) : HashKey(other.key, other.size, other.hash) {}
HashKey::HashKey(HashKey&& other) noexcept {
hash = other.hash;
size = other.size;
write_size = other.write_size;
read_size = other.read_size;
is_our_dynamic = other.is_our_dynamic;
key = other.key;
other.size = 0;
other.is_our_dynamic = false;
other.key = nullptr;
}
HashKey::~HashKey() {
if ( is_our_dynamic )
delete[] reinterpret_cast<char*>(key);
}
hash_t HashKey::Hash() const {
if ( hash == 0 )
hash = HashBytes(key, size);
#ifdef DEBUG
if ( zeek::detail::debug_logger.IsEnabled(DBG_HASHKEY) ) {
ODesc d;
Describe(&d);
DBG_LOG(DBG_HASHKEY, "HashKey %p %s", this, d.Description());
}
#endif
return hash;
}
void* HashKey::TakeKey() {
if ( is_our_dynamic ) {
is_our_dynamic = false;
return key;
}
else
return CopyKey(key, size);
}
void HashKey::Describe(ODesc* d) const {
char buf[64];
snprintf(buf, 16, "%0" PRIx64, hash);
d->Add(buf);
d->SP();
if ( size > 0 ) {
d->Add(IsAllocated() ? "(" : "[");
for ( size_t i = 0; i < size; i++ ) {
if ( i > 0 ) {
d->SP();
// Extra spacing every 8 bytes, for readability.
if ( i % 8 == 0 )
d->SP();
}
// Don't display unwritten content, only say how much there is.
if ( i > write_size ) {
d->Add("<+");
d->Add(static_cast<uint64_t>(size - write_size - 1));
d->Add(" of ");
d->Add(static_cast<uint64_t>(size));
d->Add(" available>");
break;
}
snprintf(buf, 3, "%02x", key[i]);
d->Add(buf);
}
d->Add(IsAllocated() ? ")" : "]");
}
}
char* HashKey::CopyKey(const char* k, size_t s) const {
char* k_copy = new char[s]; // s == 0 is okay, returns non-nil
memcpy(k_copy, k, s);
return k_copy;
}
hash_t HashKey::HashBytes(const void* bytes, size_t size) { return KeyedHash::Hash64(bytes, size); }
void HashKey::Set(bool b) {
key_u.b = b;
key = reinterpret_cast<char*>(&key_u);
size = write_size = sizeof(b);
}
void HashKey::Set(int i) {
key_u.i = i;
key = reinterpret_cast<char*>(&key_u);
size = write_size = sizeof(i);
}
void HashKey::Set(zeek_int_t bi) {
key_u.bi = bi;
key = reinterpret_cast<char*>(&key_u);
size = write_size = sizeof(bi);
}
void HashKey::Set(zeek_uint_t bu) {
key_u.bi = zeek_int_t(bu);
key = reinterpret_cast<char*>(&key_u);
size = write_size = sizeof(bu);
}
void HashKey::Set(uint32_t u) {
key_u.u32 = u;
key = reinterpret_cast<char*>(&key_u);
size = write_size = sizeof(u);
}
void HashKey::Set(double d) {
key_u.d = d;
key = reinterpret_cast<char*>(&key_u);
size = write_size = sizeof(d);
}
void HashKey::Set(const void* p) {
key_u.p = p;
key = reinterpret_cast<char*>(&key_u);
size = write_size = sizeof(p);
}
void HashKey::Reserve(const char* tag, size_t addl_size, size_t alignment) {
ASSERT(! IsAllocated());
size_t s0 = size;
size_t s1 = util::memory_size_align(size, alignment);
size = s1 + addl_size;
DBG_LOG(DBG_HASHKEY, "HashKey %p reserving %lu/%lu: %lu -> %lu -> %lu [%s]", this, addl_size, alignment, s0, s1,
size, tag);
}
void HashKey::Allocate() {
if ( key != nullptr && key != reinterpret_cast<char*>(&key_u) ) {
reporter->InternalWarning("usage error in HashKey::Allocate(): already allocated");
return;
}
is_our_dynamic = true;
key = reinterpret_cast<char*>(new double[size / sizeof(double) + 1]);
read_size = 0;
write_size = 0;
}
void HashKey::Write(const char* tag, bool b) { Write(tag, &b, sizeof(b), 0); }
void HashKey::Write(const char* tag, int i, bool align) {
if ( ! IsAllocated() ) {
Set(i);
return;
}
Write(tag, &i, sizeof(i), align ? sizeof(i) : 0);
}
void HashKey::Write(const char* tag, zeek_int_t bi, bool align) {
if ( ! IsAllocated() ) {
Set(bi);
return;
}
Write(tag, &bi, sizeof(bi), align ? sizeof(bi) : 0);
}
void HashKey::Write(const char* tag, zeek_uint_t bu, bool align) {
if ( ! IsAllocated() ) {
Set(bu);
return;
}
Write(tag, &bu, sizeof(bu), align ? sizeof(bu) : 0);
}
void HashKey::Write(const char* tag, uint32_t u, bool align) {
if ( ! IsAllocated() ) {
Set(u);
return;
}
Write(tag, &u, sizeof(u), align ? sizeof(u) : 0);
}
void HashKey::Write(const char* tag, double d, bool align) {
if ( ! IsAllocated() ) {
Set(d);
return;
}
Write(tag, &d, sizeof(d), align ? sizeof(d) : 0);
}
void HashKey::Write(const char* tag, const void* bytes, size_t n, size_t alignment) {
size_t s0 = write_size;
AlignWrite(alignment);
size_t s1 = write_size;
EnsureWriteSpace(n);
memcpy(key + write_size, bytes, n);
write_size += n;
DBG_LOG(DBG_HASHKEY, "HashKey %p writing %lu/%lu: %lu -> %lu -> %lu [%s]", this, n, alignment, s0, s1, write_size,
tag);
}
void HashKey::SkipWrite(const char* tag, size_t n) {
DBG_LOG(DBG_HASHKEY, "HashKey %p skip-writing %lu: %lu -> %lu [%s]", this, n, write_size, write_size + n, tag);
EnsureWriteSpace(n);
write_size += n;
}
void HashKey::AlignWrite(size_t alignment) {
ASSERT(IsAllocated());
if ( alignment == 0 )
return;
size_t old_size = write_size;
write_size = util::memory_size_align(write_size, alignment);
if ( write_size > size )
reporter->InternalError(
"buffer overflow in HashKey::AlignWrite(): "
"after alignment, %lu bytes used of %lu allocated",
write_size, size);
while ( old_size < write_size )
key[old_size++] = '\0';
}
void HashKey::AlignRead(size_t alignment) const {
ASSERT(IsAllocated());
if ( alignment == 0 )
return;
int old_size = read_size;
read_size = util::memory_size_align(read_size, alignment);
if ( read_size > size )
reporter->InternalError(
"buffer overflow in HashKey::AlignRead(): "
"after alignment, %lu bytes used of %lu allocated",
read_size, size);
}
void HashKey::Read(const char* tag, bool& b) const { Read(tag, &b, sizeof(b), 0); }
void HashKey::Read(const char* tag, int& i, bool align) const { Read(tag, &i, sizeof(i), align ? sizeof(i) : 0); }
void HashKey::Read(const char* tag, zeek_int_t& i, bool align) const {
Read(tag, &i, sizeof(i), align ? sizeof(i) : 0);
}
void HashKey::Read(const char* tag, zeek_uint_t& u, bool align) const {
Read(tag, &u, sizeof(u), align ? sizeof(u) : 0);
}
void HashKey::Read(const char* tag, uint32_t& u, bool align) const { Read(tag, &u, sizeof(u), align ? sizeof(u) : 0); }
void HashKey::Read(const char* tag, double& d, bool align) const { Read(tag, &d, sizeof(d), align ? sizeof(d) : 0); }
void HashKey::Read(const char* tag, void* out, size_t n, size_t alignment) const {
size_t s0 = read_size;
AlignRead(alignment);
size_t s1 = read_size;
EnsureReadSpace(n);
// In case out is nil, make sure nothing is to be read, and only memcpy
// when there is a non-zero amount. Memory checkers don't nullpointers
// in memcpy even if the size is 0.
ASSERT(out != nullptr || (out == nullptr && n == 0));
if ( n > 0 ) {
memcpy(out, key + read_size, n);
read_size += n;
}
DBG_LOG(DBG_HASHKEY, "HashKey %p reading %lu/%lu: %lu -> %lu -> %lu [%s]", this, n, alignment, s0, s1, read_size,
tag);
}
void HashKey::SkipRead(const char* tag, size_t n) const {
DBG_LOG(DBG_HASHKEY, "HashKey %p skip-reading %lu: %lu -> %lu [%s]", this, n, read_size, read_size + n, tag);
EnsureReadSpace(n);
read_size += n;
}
void HashKey::EnsureWriteSpace(size_t n) const {
if ( n == 0 )
return;
if ( ! IsAllocated() )
reporter->InternalError(
"usage error in HashKey::EnsureWriteSpace(): "
"size-checking unreserved buffer");
if ( write_size + n > size )
reporter->InternalError(
"buffer overflow in HashKey::Write(): writing %lu "
"bytes with %lu remaining",
n, size - write_size);
}
void HashKey::EnsureReadSpace(size_t n) const {
if ( n == 0 )
return;
if ( ! IsAllocated() )
reporter->InternalError(
"usage error in HashKey::EnsureReadSpace(): "
"size-checking unreserved buffer");
if ( read_size + n > size )
reporter->InternalError(
"buffer overflow in HashKey::EnsureReadSpace(): reading %lu "
"bytes with %lu remaining",
n, size - read_size);
}
bool HashKey::operator==(const HashKey& other) const {
// Quick exit for the same object.
if ( this == &other )
return true;
return Equal(other.key, other.size, other.hash);
}
bool HashKey::operator!=(const HashKey& other) const {
// Quick exit for different objects.
if ( this != &other )
return true;
return ! Equal(other.key, other.size, other.hash);
}
bool HashKey::Equal(const void* other_key, size_t other_size, hash_t other_hash) const {
// If the key memory is the same just return true.
if ( key == other_key && size == other_size )
return true;
// If either key is nullptr, return false. If they were both nullptr, it
// would have fallen into the above block already.
if ( key == nullptr || other_key == nullptr )
return false;
return (hash == other_hash) && (size == other_size) && (memcmp(key, other_key, size) == 0);
}
HashKey& HashKey::operator=(const HashKey& other) {
if ( this == &other )
return *this;
if ( is_our_dynamic && IsAllocated() )
delete[] key;
hash = other.hash;
size = other.size;
is_our_dynamic = true;
write_size = other.write_size;
read_size = other.read_size;
key = CopyKey(other.key, other.size);
return *this;
}
HashKey& HashKey::operator=(HashKey&& other) noexcept {
if ( this == &other )
return *this;
hash = other.hash;
size = other.size;
write_size = other.write_size;
read_size = other.read_size;
if ( is_our_dynamic && IsAllocated() )
delete[] key;
is_our_dynamic = other.is_our_dynamic;
key = other.key;
other.size = 0;
other.is_our_dynamic = false;
other.key = nullptr;
return *this;
}
TEST_SUITE_BEGIN("Hash");
TEST_CASE("equality") {
HashKey h1(12345);
HashKey h2(12345);
HashKey h3(67890);
CHECK(h1 == h2);
CHECK(h1 != h3);
}
TEST_CASE("copy assignment") {
HashKey h1(12345);
HashKey h2 = h1;
HashKey h3{h1};
CHECK(h1 == h2);
CHECK(h1 == h3);
}
TEST_CASE("move assignment") {
HashKey h1(12345);
HashKey h2(12345);
HashKey h3(12345);
HashKey h4 = std::move(h2);
HashKey h5{h3};
CHECK(h1 == h4);
CHECK(h1 == h5);
}
TEST_SUITE_END();
} // namespace zeek::detail