OpenSSL 1.1.1-pre2

crypto/rand/rand_win.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -10,15 +10,19 @@
 #include "internal/cryptlib.h"
 #include <openssl/rand.h>
 #include "rand_lcl.h"
-
 #if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
-# include <windows.h>
-/* On Windows 7 or higher use BCrypt instead of the legacy CryptoAPI */
-# if defined(_MSC_VER) && defined(_WIN32_WINNT) && _WIN32_WINNT>=0x0601
-#  define RAND_WINDOWS_USE_BCRYPT
+
+# ifndef OPENSSL_RAND_SEED_OS
+#  error "Unsupported seeding method configured; must be os"
 # endif
 
-# ifdef RAND_WINDOWS_USE_BCRYPT
+# include <windows.h>
+/* On Windows 7 or higher use BCrypt instead of the legacy CryptoAPI */
+# if defined(_MSC_VER) && defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x0601
+#  define USE_BCRYPTGENRANDOM
+# endif
+
+# ifdef USE_BCRYPTGENRANDOM
 #  include <bcrypt.h>
 #  pragma comment(lib, "bcrypt.lib")
 #  ifndef STATUS_SUCCESS
@@ -34,55 +38,83 @@
 #  define INTEL_DEF_PROV L"Intel Hardware Cryptographic Service Provider"
 # endif
 
-static void readtimer(void);
-
-int RAND_poll(void)
+size_t RAND_POOL_acquire_entropy(RAND_POOL *pool)
 {
-    MEMORYSTATUS mst;
-# ifndef RAND_WINDOWS_USE_BCRYPT
+# ifndef USE_BCRYPTGENRANDOM
     HCRYPTPROV hProvider;
 # endif
-    DWORD w;
-    BYTE buf[64];
+    unsigned char *buffer;
+    size_t bytes_needed;
+    size_t entropy_available = 0;
 
-# ifdef RAND_WINDOWS_USE_BCRYPT
-    if (BCryptGenRandom(NULL, buf, (ULONG)sizeof(buf), BCRYPT_USE_SYSTEM_PREFERRED_RNG) == STATUS_SUCCESS) {
-        RAND_add(buf, sizeof(buf), sizeof(buf));
-    }
-# else
-    /* poll the CryptoAPI PRNG */
-    /* The CryptoAPI returns sizeof(buf) bytes of randomness */
-    if (CryptAcquireContextW(&hProvider, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT | CRYPT_SILENT)) {
-        if (CryptGenRandom(hProvider, (DWORD)sizeof(buf), buf) != 0) {
-            RAND_add(buf, sizeof(buf), sizeof(buf));
-        }
-        CryptReleaseContext(hProvider, 0);
-    }
 
-    /* poll the Pentium PRG with CryptoAPI */
-    if (CryptAcquireContextW(&hProvider, NULL, INTEL_DEF_PROV, PROV_INTEL_SEC, CRYPT_VERIFYCONTEXT | CRYPT_SILENT)) {
-        if (CryptGenRandom(hProvider, (DWORD)sizeof(buf), buf) != 0) {
-            RAND_add(buf, sizeof(buf), sizeof(buf));
-        }
-        CryptReleaseContext(hProvider, 0);
-    }
+# ifdef OPENSSL_RAND_SEED_RDTSC
+    entropy_available = rand_acquire_entropy_from_tsc(pool);
+    if (entropy_available > 0)
+        return entropy_available;
 # endif
 
-    /* timer data */
-    readtimer();
+# ifdef OPENSSL_RAND_SEED_RDCPU
+    entropy_available = rand_acquire_entropy_from_cpu(pool);
+    if (entropy_available > 0)
+        return entropy_available;
+# endif
 
-    /* memory usage statistics */
-    GlobalMemoryStatus(&mst);
-    RAND_add(&mst, sizeof(mst), 1);
+# ifdef USE_BCRYPTGENRANDOM
+    bytes_needed = RAND_POOL_bytes_needed(pool, 8 /*entropy_per_byte*/);
+    buffer = RAND_POOL_add_begin(pool, bytes_needed);
+    if (buffer != NULL) {
+        size_t bytes = 0;
+        if (BCryptGenRandom(NULL, buffer, bytes_needed,
+            BCRYPT_USE_SYSTEM_PREFERRED_RNG) == STATUS_SUCCESS)
+            bytes = bytes_needed;
 
-    /* process ID */
-    w = GetCurrentProcessId();
-    RAND_add(&w, sizeof(w), 1);
+        entropy_available = RAND_POOL_add_end(pool, bytes, 8 * bytes);
+    }
+    if (entropy_available > 0)
+        return entropy_available;
+# else
+    bytes_needed = RAND_POOL_bytes_needed(pool, 8 /*entropy_per_byte*/);
+    buffer = RAND_POOL_add_begin(pool, bytes_needed);
+    if (buffer != NULL) {
+        size_t bytes = 0;
+        /* poll the CryptoAPI PRNG */
+        if (CryptAcquireContextW(&hProvider, NULL, NULL, PROV_RSA_FULL,
+            CRYPT_VERIFYCONTEXT | CRYPT_SILENT) != 0) {
+            if (CryptGenRandom(hProvider, bytes_needed, buffer) != 0)
+                bytes = bytes_needed;
 
-    return (1);
+            CryptReleaseContext(hProvider, 0);
+        }
+
+        entropy_available = RAND_POOL_add_end(pool, bytes, 8 * bytes);
+    }
+    if (entropy_available > 0)
+        return entropy_available;
+
+    bytes_needed = RAND_POOL_bytes_needed(pool, 8 /*entropy_per_byte*/);
+    buffer = RAND_POOL_add_begin(pool, bytes_needed);
+    if (buffer != NULL) {
+        size_t bytes = 0;
+        /* poll the Pentium PRG with CryptoAPI */
+        if (CryptAcquireContextW(&hProvider, NULL,
+                                 INTEL_DEF_PROV, PROV_INTEL_SEC,
+                                 CRYPT_VERIFYCONTEXT | CRYPT_SILENT) != 0) {
+            if (CryptGenRandom(hProvider, bytes_needed, buffer) != 0)
+                bytes = bytes_needed;
+
+            CryptReleaseContext(hProvider, 0);
+        }
+        entropy_available = RAND_POOL_add_end(pool, bytes, 8 * bytes);
+    }
+    if (entropy_available > 0)
+        return entropy_available;
+# endif
+
+    return RAND_POOL_entropy_available(pool);
 }
 
-#if OPENSSL_API_COMPAT < 0x10100000L
+# if OPENSSL_API_COMPAT < 0x10100000L
 int RAND_event(UINT iMsg, WPARAM wParam, LPARAM lParam)
 {
     RAND_poll();
@@ -93,43 +125,6 @@ void RAND_screen(void)
 {
     RAND_poll();
 }
-#endif
-
-/* feed timing information to the PRNG */
-static void readtimer(void)
-{
-    DWORD w;
-    LARGE_INTEGER l;
-    static int have_perfc = 1;
-# if defined(_MSC_VER) && defined(_M_X86)
-    static int have_tsc = 1;
-    DWORD cyclecount;
-
-    if (have_tsc) {
-        __try {
-            __asm {
-            _emit 0x0f _emit 0x31 mov cyclecount, eax}
-            RAND_add(&cyclecount, sizeof(cyclecount), 1);
-        }
-        __except(EXCEPTION_EXECUTE_HANDLER) {
-            have_tsc = 0;
-        }
-    }
-# else
-#  define have_tsc 0
 # endif
 
-    if (have_perfc) {
-        if (QueryPerformanceCounter(&l) == 0)
-            have_perfc = 0;
-        else
-            RAND_add(&l, sizeof(l), 0);
-    }
-
-    if (!have_tsc && !have_perfc) {
-        w = GetTickCount();
-        RAND_add(&w, sizeof(w), 0);
-    }
-}
-
 #endif