From 6f6d04fadee9fdd6763f01cbbfc5ed2cef360b05 Mon Sep 17 00:00:00 2001
From: Martin Mirchev <mmirchev@comp.nus.edu.sg>
Date: Thu, 22 Oct 2026 23:41:48 +0800
Subject: [PATCH 1/2] Fix GOST and Snefru digests of 512 MiB or more

The bit counter update in PHP_GOSTUpdate() and PHP_SNEFRUUpdate() set the
low word one too high when it wrapped, and added at most one carry to the
high word per update. Snefru also computed the bit length of a single
update in 32 bits. The encoded message length, and thus the digest, was
wrong for inputs of 2^29 bytes or more. Compute the counter with 64-bit
arithmetic.
---
 ext/hash/hash_gost.c                   | 13 ++++-------
 ext/hash/hash_snefru.c                 | 13 ++++-------
 ext/hash/tests/gost_snefru_512mib.phpt | 30 ++++++++++++++++++++++++++
 3 files changed, 38 insertions(+), 18 deletions(-)
 create mode 100644 ext/hash/tests/gost_snefru_512mib.phpt

diff --git a/ext/hash/hash_gost.c b/ext/hash/hash_gost.c
index ee2f3c89381c..8f23e8dcc097 100644
--- a/ext/hash/hash_gost.c
+++ b/ext/hash/hash_gost.c
@@ -247,17 +247,12 @@ PHP_HASH_API void PHP_GOSTInitCrypto(PHP_GOST_CTX *context, ZEND_ATTRIBUTE_UNUSE
 	context->tables = &tables_crypto;
 }
 
-static const uint32_t MAX32 = 0xffffffffLU;
-
 PHP_HASH_API void PHP_GOSTUpdate(PHP_GOST_CTX *context, const unsigned char *input, size_t len)
 {
-	if ((MAX32 - context->count[0]) < (len * 8)) {
-		context->count[1]++;
-		context->count[0] = MAX32 - context->count[0];
-		context->count[0] = (len * 8) - context->count[0];
-	} else {
-		context->count[0] += len * 8;
-	}
+	uint64_t count = ((uint64_t) context->count[1] << 32) + context->count[0] + (uint64_t) len * 8;
+
+	context->count[0] = (uint32_t) count;
+	context->count[1] = (uint32_t) (count >> 32);
 
 	if (context->length + len < 32) {
 		memcpy(&context->buffer[context->length], input, len);
diff --git a/ext/hash/hash_snefru.c b/ext/hash/hash_snefru.c
index fd2ee28c80e7..3b6ff10f3096 100644
--- a/ext/hash/hash_snefru.c
+++ b/ext/hash/hash_snefru.c
@@ -133,17 +133,12 @@ PHP_HASH_API void PHP_SNEFRUInit(PHP_SNEFRU_CTX *context, ZEND_ATTRIBUTE_UNUSED
 	memset(context, 0, sizeof(*context));
 }
 
-static const uint32_t MAX32 = 0xffffffffLU;
-
 PHP_HASH_API void PHP_SNEFRUUpdate(PHP_SNEFRU_CTX *context, const unsigned char *input, size_t len)
 {
-	if ((MAX32 - context->count[1]) < (len * 8)) {
-		context->count[0]++;
-		context->count[1] = MAX32 - context->count[1];
-		context->count[1] = ((uint32_t) len * 8) - context->count[1];
-	} else {
-		context->count[1] += (uint32_t) len * 8;
-	}
+	uint64_t count = ((uint64_t) context->count[0] << 32) + context->count[1] + (uint64_t) len * 8;
+
+	context->count[0] = (uint32_t) (count >> 32);
+	context->count[1] = (uint32_t) count;
 
 	if (context->length + len < 32) {
 		memcpy(&context->buffer[context->length], input, len);
diff --git a/ext/hash/tests/gost_snefru_512mib.phpt b/ext/hash/tests/gost_snefru_512mib.phpt
new file mode 100644
index 000000000000..0304f2bfc9a5
--- /dev/null
+++ b/ext/hash/tests/gost_snefru_512mib.phpt
@@ -0,0 +1,30 @@
+--TEST--
+Hash: gost and snefru with 512 MiB of input (bit counter carry)
+--SKIPIF--
+<?php
+if (!getenv('RUN_RESOURCE_HEAVY_TESTS')) die('skip resource-heavy test');
+if (PHP_INT_SIZE != 8) die('skip this test is for 64bit platforms only');
+if (getenv('SKIP_SLOW_TESTS')) die('skip slow tests excluded by request');
+?>
+--INI--
+memory_limit=-1
+--FILE--
+<?php
+/* 2^29 bytes are 2^32 bits, so the low word of the bit counter wraps. */
+$chunk = str_repeat('a', 1 << 20);
+foreach (['gost', 'snefru'] as $algo) {
+    $ctx = hash_init($algo);
+    for ($i = 0; $i < 512; $i++) {
+        hash_update($ctx, $chunk);
+    }
+    echo $algo, ': ', hash_final($ctx), "\n";
+}
+unset($chunk);
+
+/* A single update of 2^29 bytes. */
+echo 'snefru: ', hash('snefru', str_repeat('a', 1 << 29)), "\n";
+?>
+--EXPECT--
+gost: 6c30acc180f544a79c22fa763593a812aec721dd61658b1a5e9a6f3a7955146d
+snefru: 0842a8e735ab08a30149e7e6e34833f365291978ee68c37a5135253b70afa486
+snefru: 0842a8e735ab08a30149e7e6e34833f365291978ee68c37a5135253b70afa486

From e2c8c6554992f67448973dcbf461e6a092afab9a Mon Sep 17 00:00:00 2001
From: Martin Mirchev <mmirchev@comp.nus.edu.sg>
Date: Sat, 24 Oct 2026 09:37:25 +0800
Subject: [PATCH 2/2] Address review: combine the counter words with OR, run
 the test on 32-bit

Use a bitwise OR to combine the two 32-bit words of the bit counter so
that compilers emit a single 64-bit addition, and drop the 64-bit-only
SKIPIF from the resource-heavy test.
---
 ext/hash/hash_gost.c                   | 2 +-
 ext/hash/hash_snefru.c                 | 2 +-
 ext/hash/tests/gost_snefru_512mib.phpt | 1 -
 3 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/ext/hash/hash_gost.c b/ext/hash/hash_gost.c
index 8f23e8dcc097..56ef9bfaa67d 100644
--- a/ext/hash/hash_gost.c
+++ b/ext/hash/hash_gost.c
@@ -249,7 +249,7 @@ PHP_HASH_API void PHP_GOSTInitCrypto(PHP_GOST_CTX *context, ZEND_ATTRIBUTE_UNUSE
 
 PHP_HASH_API void PHP_GOSTUpdate(PHP_GOST_CTX *context, const unsigned char *input, size_t len)
 {
-	uint64_t count = ((uint64_t) context->count[1] << 32) + context->count[0] + (uint64_t) len * 8;
+	uint64_t count = (((uint64_t) context->count[1] << 32) | context->count[0]) + (uint64_t) len * 8;
 
 	context->count[0] = (uint32_t) count;
 	context->count[1] = (uint32_t) (count >> 32);
diff --git a/ext/hash/hash_snefru.c b/ext/hash/hash_snefru.c
index 3b6ff10f3096..98d4601d14e2 100644
--- a/ext/hash/hash_snefru.c
+++ b/ext/hash/hash_snefru.c
@@ -135,7 +135,7 @@ PHP_HASH_API void PHP_SNEFRUInit(PHP_SNEFRU_CTX *context, ZEND_ATTRIBUTE_UNUSED
 
 PHP_HASH_API void PHP_SNEFRUUpdate(PHP_SNEFRU_CTX *context, const unsigned char *input, size_t len)
 {
-	uint64_t count = ((uint64_t) context->count[0] << 32) + context->count[1] + (uint64_t) len * 8;
+	uint64_t count = (((uint64_t) context->count[0] << 32) | context->count[1]) + (uint64_t) len * 8;
 
 	context->count[0] = (uint32_t) (count >> 32);
 	context->count[1] = (uint32_t) count;
diff --git a/ext/hash/tests/gost_snefru_512mib.phpt b/ext/hash/tests/gost_snefru_512mib.phpt
index 0304f2bfc9a5..6649140b2722 100644
--- a/ext/hash/tests/gost_snefru_512mib.phpt
+++ b/ext/hash/tests/gost_snefru_512mib.phpt
@@ -3,7 +3,6 @@ Hash: gost and snefru with 512 MiB of input (bit counter carry)
 --SKIPIF--
 <?php
 if (!getenv('RUN_RESOURCE_HEAVY_TESTS')) die('skip resource-heavy test');
-if (PHP_INT_SIZE != 8) die('skip this test is for 64bit platforms only');
 if (getenv('SKIP_SLOW_TESTS')) die('skip slow tests excluded by request');
 ?>
 --INI--