common: add OpenSSL Intel SHA ext hook

common/platform/openssl.c

@@ -0,0 +1,106 @@
+#include <windows.h>
+
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <intrin.h>
+
+#include "hook/table.h"
+
+#include "hooklib/config.h"
+
+#include "platform/openssl.h"
+
+#include "util/dprintf.h"
+
+/* API hooks */
+
+static char * __cdecl hook_getenv(const char *name);
+
+/* Link pointers */
+
+static char * (__cdecl *next_getenv)(const char *name);
+
+static bool openssl_hook_initted;
+static struct openssl_config openssl_config;
+
+static const struct hook_symbol openssl_hooks[] = {
+    {
+        .name  = "getenv",
+        .patch = hook_getenv,
+        .link  = (void **) &next_getenv
+    },
+};
+
+int check_intel_sha_extension() {
+    int cpui[4] = {0};
+
+    __cpuid(cpui, 0);
+    int nIds_ = cpui[0];
+
+    char vendor[0x20] = {0};
+    *((int*)vendor) = cpui[1];
+    *((int*)(vendor + 4)) = cpui[3];
+    *((int*)(vendor + 8)) = cpui[2];
+
+    // Intel CPU
+    int isIntel = (strcmp(vendor, "GenuineIntel") == 0);
+
+    if (isIntel && nIds_ >= 7) {
+        __cpuidex(cpui, 7, 0);
+        // SHA extension
+        return (cpui[1] & (1 << 29)) != 0; 
+    }
+
+    return 0;
+}
+
+HRESULT openssl_hook_init(const struct openssl_config *cfg)
+{
+    assert(cfg != NULL);
+
+    if (!cfg->enable) {
+        return S_FALSE;
+    }
+
+    if (openssl_hook_initted) {
+        return S_FALSE;
+    }
+
+    if (cfg->override) {
+        dprintf("OpenSSL: hook enabled.\n");
+    } else if (check_intel_sha_extension()) {
+        dprintf("OpenSSL: Intel CPU SHA extension detected, hook enabled.\n");
+    } else {
+        return S_FALSE;
+    }
+
+    openssl_hook_initted = true;
+
+    memcpy(&openssl_config, cfg, sizeof(*cfg));
+    hook_table_apply(
+        NULL,
+        "msvcr110.dll",
+        openssl_hooks,
+        _countof(openssl_hooks)
+    );
+
+    return S_OK;
+}
+
+static char * __cdecl hook_getenv(const char *name)
+{
+    /* Intercept OpenSSL CPU-cap override */
+    if (name && strcmp(name, "OPENSSL_ia32cap") == 0) {
+        static char override[] = "~0x20000000";
+
+        dprintf("OpenSSL: Overriding OPENSSL_ia32cap -> %s\n", override);
+        
+        return override;
+    }
+
+    char *real_val = next_getenv(name);
+
+    return real_val;
+}