Zend: Add new zend APIs for bin2hex to remove ext/hash usage in various extensions (#21724)

There are various extensions in the php code base that includes
ext/hash/php_hash for the php_hash_bin2hex method. While these method is
actually simple, we can make them as APIs in the zend engine to remove the
dependence on ext/hash/

This commit added the needed APIs (zend_bin2hex and zend_bin2hex_str).

A follow-up PR will be made in the future to replace the usage of ext/hash
with the added APIs.

Author: LamentXU123

UPGRADING.INTERNALS

@@ -68,6 +68,8 @@ PHP 8.6 INTERNALS UPGRADE NOTES
   . Added Z_PARAM_ENUM().
   . Added zend_enum_fetch_case_id().
   . Added zend_enum_get_case_by_id().
+  . Added zend_bin2hex() and zend_bin2hex_str() as helper functions to remove
+    dependencies on /ext/hash in various extensions.
   . ZEND_INI_GET_ADDR() is now a void* pointer instead of a char* pointer. This
     more correctly represents the generic nature of the returned pointer and
     allows to remove explicit casts, but possibly breaks pointer arithmetic

Zend/zend_string.c

@@ -52,6 +52,17 @@ ZEND_API zend_string  *zend_empty_string = NULL;
 ZEND_API zend_string  *zend_one_char_string[256];
 ZEND_API zend_string **zend_known_strings = NULL;
 
+/* this is read-only, so it's ok */
+ZEND_SET_ALIGNED(16, static const char zend_hexconvtab[]) = "0123456789abcdef";
+
+static zend_always_inline void zend_bin2hex_impl(char *out, const unsigned char *in, size_t in_len, const char *hexconvtab)
+{
+	for (size_t i = 0; i < in_len; i++) {
+		out[i * 2] = hexconvtab[in[i] >> 4];
+		out[i * 2 + 1] = hexconvtab[in[i] & 0x0f];
+	}
+}
+
 ZEND_API zend_ulong ZEND_FASTCALL zend_string_hash_func(zend_string *str)
 {
 	return ZSTR_H(str) = zend_hash_func(ZSTR_VAL(str), ZSTR_LEN(str));
@@ -62,6 +73,21 @@ ZEND_API zend_ulong ZEND_FASTCALL zend_hash_func(const char *str, size_t len)
 	return zend_inline_hash_func(str, len);
 }
 
+ZEND_API void ZEND_FASTCALL zend_bin2hex(char *out, const unsigned char *in, size_t in_len)
+{
+	zend_bin2hex_impl(out, in, in_len, zend_hexconvtab);
+}
+
+ZEND_API zend_string *zend_bin2hex_str(const unsigned char *in, size_t in_len)
+{
+	zend_string *result = zend_string_safe_alloc(in_len, 2 * sizeof(char), 0, 0);
+
+	zend_bin2hex(ZSTR_VAL(result), in, in_len);
+	ZSTR_VAL(result)[in_len * 2] = '\0';
+
+	return result;
+}
+
 static void _str_dtor(zval *zv)
 {
 	zend_string *str = Z_STR_P(zv);

Zend/zend_string.h

@@ -43,6 +43,8 @@ ZEND_API extern zend_string_init_existing_interned_func_t zend_string_init_exist
 ZEND_API zend_ulong ZEND_FASTCALL zend_string_hash_func(zend_string *str);
 ZEND_API zend_ulong ZEND_FASTCALL zend_hash_func(const char *str, size_t len);
 ZEND_API zend_string* ZEND_FASTCALL zend_interned_string_find_permanent(zend_string *str);
+ZEND_API void ZEND_FASTCALL zend_bin2hex(char *out, const unsigned char *in, size_t in_len);
+ZEND_API zend_string *zend_bin2hex_str(const unsigned char *in, size_t in_len);
 
 ZEND_API zend_string *zend_string_concat2(
 	const char *str1, size_t str1_len,