1 files changed, 230 insertions, 0 deletions
diff --git a/third_party/boringssl/src/crypto/rand/rand.c b/third_party/boringssl/src/crypto/rand/rand.c
new file mode 100644
index 0000000000..924b54bccb
--- /dev/null
+++ b/third_party/boringssl/src/crypto/rand/rand.c
@@ -0,0 +1,230 @@
+/* Copyright (c) 2014, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <openssl/rand.h>
+
+#include <assert.h>
+#include <limits.h>
+#include <string.h>
+
+#include <openssl/chacha.h>
+#include <openssl/cpu.h>
+#include <openssl/mem.h>
+
+#include "internal.h"
+#include "../internal.h"
+
+
+/* It's assumed that the operating system always has an unfailing source of
+ * entropy which is accessed via |CRYPTO_sysrand|. (If the operating system
+ * entropy source fails, it's up to |CRYPTO_sysrand| to abort the process—we
+ * don't try to handle it.)
+ *
+ * In addition, the hardware may provide a low-latency RNG. Intel's rdrand
+ * instruction is the canonical example of this. When a hardware RNG is
+ * available we don't need to worry about an RNG failure arising from fork()ing
+ * the process or moving a VM, so we can keep thread-local RNG state and XOR
+ * the hardware entropy in.
+ *
+ * (We assume that the OS entropy is safe from fork()ing and VM duplication.
+ * This might be a bit of a leap of faith, esp on Windows, but there's nothing
+ * that we can do about it.) */
+
+/* rand_thread_state contains the per-thread state for the RNG. This is only
+ * used if the system has support for a hardware RNG. */
+struct rand_thread_state {
+  uint8_t key[32];
+  uint64_t calls_used;
+  size_t bytes_used;
+  uint8_t partial_block[64];
+  unsigned partial_block_used;
+};
+
+/* kMaxCallsPerRefresh is the maximum number of |RAND_bytes| calls that we'll
+ * serve before reading a new key from the operating system. This only applies
+ * if we have a hardware RNG. */
+static const unsigned kMaxCallsPerRefresh = 1024;
+
+/* kMaxBytesPerRefresh is the maximum number of bytes that we'll return from
+ * |RAND_bytes| before reading a new key from the operating system. This only
+ * applies if we have a hardware RNG. */
+static const uint64_t kMaxBytesPerRefresh = 1024 * 1024;
+
+/* rand_thread_state_free frees a |rand_thread_state|. This is called when a
+ * thread exits. */
+static void rand_thread_state_free(void *state) {
+  if (state == NULL) {
+    return;
+  }
+
+  OPENSSL_cleanse(state, sizeof(struct rand_thread_state));
+  OPENSSL_free(state);
+}
+
+#if defined(OPENSSL_X86_64) && !defined(OPENSSL_NO_ASM)
+
+/* These functions are defined in asm/rdrand-x86_64.pl */
+extern int CRYPTO_rdrand(uint8_t out[8]);
+extern int CRYPTO_rdrand_multiple8_buf(uint8_t *buf, size_t len);
+
+static int have_rdrand(void) {
+  return (OPENSSL_ia32cap_P[1] & (1u << 30)) != 0;
+}
+
+static int hwrand(uint8_t *buf, size_t len) {
+  if (!have_rdrand()) {
+    return 0;
+  }
+
+  const size_t len_multiple8 = len & ~7;
+  if (!CRYPTO_rdrand_multiple8_buf(buf, len_multiple8)) {
+    return 0;
+  }
+  len -= len_multiple8;
+
+  if (len != 0) {
+    assert(len < 8);
+
+    uint8_t rand_buf[8];
+    if (!CRYPTO_rdrand(rand_buf)) {
+      return 0;
+    }
+    memcpy(buf + len_multiple8, rand_buf, len);
+  }
+
+  return 1;
+}
+
+#else
+
+static int hwrand(uint8_t *buf, size_t len) {
+  return 0;
+}
+
+#endif
+
+int RAND_bytes(uint8_t *buf, size_t len) {
+  if (len == 0) {
+    return 1;
+  }
+
+  if (!hwrand(buf, len)) {
+    /* Without a hardware RNG to save us from address-space duplication, the OS
+     * entropy is used directly. */
+    CRYPTO_sysrand(buf, len);
+    return 1;
+  }
+
+  struct rand_thread_state *state =
+      CRYPTO_get_thread_local(OPENSSL_THREAD_LOCAL_RAND);
+  if (state == NULL) {
+    state = OPENSSL_malloc(sizeof(struct rand_thread_state));
+    if (state == NULL ||
+        !CRYPTO_set_thread_local(OPENSSL_THREAD_LOCAL_RAND, state,
+                                 rand_thread_state_free)) {
+      CRYPTO_sysrand(buf, len);
+      return 1;
+    }
+
+    memset(state->partial_block, 0, sizeof(state->partial_block));
+    state->calls_used = kMaxCallsPerRefresh;
+  }
+
+  if (state->calls_used >= kMaxCallsPerRefresh ||
+      state->bytes_used >= kMaxBytesPerRefresh) {
+    CRYPTO_sysrand(state->key, sizeof(state->key));
+    state->calls_used = 0;
+    state->bytes_used = 0;
+    state->partial_block_used = sizeof(state->partial_block);
+  }
+
+  if (len >= sizeof(state->partial_block)) {
+    size_t remaining = len;
+    while (remaining > 0) {
+      // kMaxBytesPerCall is only 2GB, while ChaCha can handle 256GB. But this
+      // is sufficient and easier on 32-bit.
+      static const size_t kMaxBytesPerCall = 0x80000000;
+      size_t todo = remaining;
+      if (todo > kMaxBytesPerCall) {
+        todo = kMaxBytesPerCall;
+      }
+      CRYPTO_chacha_20(buf, buf, todo, state->key,
+                       (uint8_t *)&state->calls_used, 0);
+      buf += todo;
+      remaining -= todo;
+      state->calls_used++;
+    }
+  } else {
+    if (sizeof(state->partial_block) - state->partial_block_used < len) {
+      CRYPTO_chacha_20(state->partial_block, state->partial_block,
+                       sizeof(state->partial_block), state->key,
+                       (uint8_t *)&state->calls_used, 0);
+      state->partial_block_used = 0;
+    }
+
+    unsigned i;
+    for (i = 0; i < len; i++) {
+      buf[i] ^= state->partial_block[state->partial_block_used++];
+    }
+    state->calls_used++;
+  }
+  state->bytes_used += len;
+
+  return 1;
+}
+
+int RAND_pseudo_bytes(uint8_t *buf, size_t len) {
+  return RAND_bytes(buf, len);
+}
+
+void RAND_seed(const void *buf, int num) {}
+
+int RAND_load_file(const char *path, long num) {
+  if (num < 0) {  /* read the "whole file" */
+    return 1;
+  } else if (num <= INT_MAX) {
+    return (int) num;
+  } else {
+    return INT_MAX;
+  }
+}
+
+void RAND_add(const void *buf, int num, double entropy) {}
+
+int RAND_egd(const char *path) {
+  return 255;
+}
+
+int RAND_poll(void) {
+  return 1;
+}
+
+int RAND_status(void) {
+  return 1;
+}
+
+static const struct rand_meth_st kSSLeayMethod = {
+  RAND_seed,
+  RAND_bytes,
+  RAND_cleanup,
+  RAND_add,
+  RAND_pseudo_bytes,
+  RAND_status,
+};
+
+RAND_METHOD *RAND_SSLeay(void) {
+  return (RAND_METHOD*) &kSSLeayMethod;
+}
+
+void RAND_set_rand_method(const RAND_METHOD *method) {}