shim: move |SettingsWriter| into its own file.

This helps with creating a separate binary to perform split
handshakes.

Change-Id: Ie4bab40bebf39e79a90d45fabb566b7ce90945bb
Reviewed-on: https://boringssl-review.googlesource.com/29344
Commit-Queue: Matt Braithwaite <mab@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: David Benjamin <davidben@google.com>
diff --git a/ssl/test/CMakeLists.txt b/ssl/test/CMakeLists.txt
index 3b07903..5a73319 100644
--- a/ssl/test/CMakeLists.txt
+++ b/ssl/test/CMakeLists.txt
@@ -6,6 +6,7 @@
   async_bio.cc
   bssl_shim.cc
   packeted_bio.cc
+  settings_writer.cc
   test_config.cc
 
   $<TARGET_OBJECTS:test_support>
diff --git a/ssl/test/bssl_shim.cc b/ssl/test/bssl_shim.cc
index 4010f62..d12cd18 100644
--- a/ssl/test/bssl_shim.cc
+++ b/ssl/test/bssl_shim.cc
@@ -64,8 +64,8 @@
 #include "../../crypto/internal.h"
 #include "../internal.h"
 #include "async_bio.h"
-#include "fuzzer_tags.h"
 #include "packeted_bio.h"
+#include "settings_writer.h"
 #include "test_config.h"
 
 
@@ -1943,116 +1943,6 @@
   return true;
 }
 
-// SettingsWriter writes fuzzing inputs to a file if |write_settings| is set.
-struct SettingsWriter {
- public:
-  SettingsWriter() {}
-
-  // Init initializes the writer for a new connection, given by |i|.  Each
-  // connection gets a unique output file.
-  bool Init(int i, const TestConfig *config, SSL_SESSION *session) {
-    if (config->write_settings.empty()) {
-      return true;
-    }
-    // Treat write_settings as a path prefix for each connection in the run.
-    char buf[DECIMAL_SIZE(int)];
-    snprintf(buf, sizeof(buf), "%d", i);
-    path_ = config->write_settings + buf;
-
-    if (!CBB_init(cbb_.get(), 64)) {
-      return false;
-    }
-
-    if (session != nullptr) {
-      uint8_t *data;
-      size_t len;
-      if (!SSL_SESSION_to_bytes(session, &data, &len)) {
-        return false;
-      }
-      bssl::UniquePtr<uint8_t> free_data(data);
-      CBB child;
-      if (!CBB_add_u16(cbb_.get(), kSessionTag) ||
-          !CBB_add_u24_length_prefixed(cbb_.get(), &child) ||
-          !CBB_add_bytes(&child, data, len) ||
-          !CBB_flush(cbb_.get())) {
-        return false;
-      }
-    }
-
-    if (config->is_server &&
-        (config->require_any_client_certificate || config->verify_peer) &&
-        !CBB_add_u16(cbb_.get(), kRequestClientCert)) {
-      return false;
-    }
-
-    if (config->tls13_variant != 0 &&
-        (!CBB_add_u16(cbb_.get(), kTLS13Variant) ||
-         !CBB_add_u8(cbb_.get(),
-                     static_cast<uint8_t>(config->tls13_variant)))) {
-      return false;
-    }
-
-    return true;
-  }
-
-  // Commit writes the buffered data to disk.
-  bool Commit() {
-    if (path_.empty()) {
-      return true;
-    }
-
-    uint8_t *settings;
-    size_t settings_len;
-    if (!CBB_add_u16(cbb_.get(), kDataTag) ||
-        !CBB_finish(cbb_.get(), &settings, &settings_len)) {
-      return false;
-    }
-    bssl::UniquePtr<uint8_t> free_settings(settings);
-
-    using ScopedFILE = std::unique_ptr<FILE, decltype(&fclose)>;
-    ScopedFILE file(fopen(path_.c_str(), "w"), fclose);
-    if (!file) {
-      return false;
-    }
-
-    return fwrite(settings, settings_len, 1, file.get()) == 1;
-  }
-
-  bool WriteHandoff(const bssl::Array<uint8_t> &handoff) {
-    if (path_.empty()) {
-      return true;
-    }
-
-    CBB child;
-    if (!CBB_add_u16(cbb_.get(), kHandoffTag) ||
-        !CBB_add_u24_length_prefixed(cbb_.get(), &child) ||
-        !CBB_add_bytes(&child, handoff.data(), handoff.size()) ||
-        !CBB_flush(cbb_.get())) {
-      return false;
-    }
-    return true;
-  }
-
-  bool WriteHandback(const bssl::Array<uint8_t> &handback) {
-    if (path_.empty()) {
-      return true;
-    }
-
-    CBB child;
-    if (!CBB_add_u16(cbb_.get(), kHandbackTag) ||
-        !CBB_add_u24_length_prefixed(cbb_.get(), &child) ||
-        !CBB_add_bytes(&child, handback.data(), handback.size()) ||
-        !CBB_flush(cbb_.get())) {
-      return false;
-    }
-    return true;
-  }
-
- private:
-  std::string path_;
-  bssl::ScopedCBB cbb_;
-};
-
 static bssl::UniquePtr<SSL> NewSSL(SSL_CTX *ssl_ctx, const TestConfig *config,
                                    SSL_SESSION *session, bool is_resume,
                                    std::unique_ptr<TestState> test_state) {
diff --git a/ssl/test/settings_writer.cc b/ssl/test/settings_writer.cc
new file mode 100644
index 0000000..66025f6
--- /dev/null
+++ b/ssl/test/settings_writer.cc
@@ -0,0 +1,121 @@
+/* Copyright (c) 2018, 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 "settings_writer.h"
+
+#include <stdio.h>
+
+#include <openssl/ssl.h>
+
+#include "fuzzer_tags.h"
+#include "test_config.h"
+
+
+SettingsWriter::SettingsWriter() {}
+
+bool SettingsWriter::Init(int i, const TestConfig *config,
+                          SSL_SESSION *session) {
+  if (config->write_settings.empty()) {
+    return true;
+  }
+  // Treat write_settings as a path prefix for each connection in the run.
+  char buf[DECIMAL_SIZE(int)];
+  snprintf(buf, sizeof(buf), "%d", i);
+  path_ = config->write_settings + buf;
+
+  if (!CBB_init(cbb_.get(), 64)) {
+    return false;
+  }
+
+  if (session != nullptr) {
+    uint8_t *data;
+    size_t len;
+    if (!SSL_SESSION_to_bytes(session, &data, &len)) {
+      return false;
+    }
+    bssl::UniquePtr<uint8_t> free_data(data);
+    CBB child;
+    if (!CBB_add_u16(cbb_.get(), kSessionTag) ||
+        !CBB_add_u24_length_prefixed(cbb_.get(), &child) ||
+        !CBB_add_bytes(&child, data, len) || !CBB_flush(cbb_.get())) {
+      return false;
+    }
+  }
+
+  if (config->is_server &&
+      (config->require_any_client_certificate || config->verify_peer) &&
+      !CBB_add_u16(cbb_.get(), kRequestClientCert)) {
+    return false;
+  }
+
+  if (config->tls13_variant != 0 &&
+      (!CBB_add_u16(cbb_.get(), kTLS13Variant) ||
+       !CBB_add_u8(cbb_.get(), static_cast<uint8_t>(config->tls13_variant)))) {
+    return false;
+  }
+
+  return true;
+}
+
+bool SettingsWriter::Commit() {
+  if (path_.empty()) {
+    return true;
+  }
+
+  uint8_t *settings;
+  size_t settings_len;
+  if (!CBB_add_u16(cbb_.get(), kDataTag) ||
+      !CBB_finish(cbb_.get(), &settings, &settings_len)) {
+    return false;
+  }
+  bssl::UniquePtr<uint8_t> free_settings(settings);
+
+  using ScopedFILE = std::unique_ptr<FILE, decltype(&fclose)>;
+  ScopedFILE file(fopen(path_.c_str(), "w"), fclose);
+  if (!file) {
+    return false;
+  }
+
+  return fwrite(settings, settings_len, 1, file.get()) == 1;
+}
+
+bool SettingsWriter::WriteHandoff(bssl::Span<const uint8_t> handoff) {
+  if (path_.empty()) {
+    return true;
+  }
+
+  CBB child;
+  if (!CBB_add_u16(cbb_.get(), kHandoffTag) ||
+      !CBB_add_u24_length_prefixed(cbb_.get(), &child) ||
+      !CBB_add_bytes(&child, handoff.data(), handoff.size()) ||
+      !CBB_flush(cbb_.get())) {
+    return false;
+  }
+  return true;
+}
+
+bool SettingsWriter::WriteHandback(bssl::Span<const uint8_t> handback) {
+  if (path_.empty()) {
+    return true;
+  }
+
+  CBB child;
+  if (!CBB_add_u16(cbb_.get(), kHandbackTag) ||
+      !CBB_add_u24_length_prefixed(cbb_.get(), &child) ||
+      !CBB_add_bytes(&child, handback.data(), handback.size()) ||
+      !CBB_flush(cbb_.get())) {
+    return false;
+  }
+  return true;
+}
diff --git a/ssl/test/settings_writer.h b/ssl/test/settings_writer.h
new file mode 100644
index 0000000..322850d
--- /dev/null
+++ b/ssl/test/settings_writer.h
@@ -0,0 +1,46 @@
+/* Copyright (c) 2018, 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. */
+
+#ifndef HEADER_SETTINGS_WRITER
+#define HEADER_SETTINGS_WRITER
+
+#include <string>
+
+#include <openssl/bytestring.h>
+#include <openssl/ssl.h>
+
+#include "../internal.h"
+#include "test_config.h"
+
+struct SettingsWriter {
+ public:
+  SettingsWriter();
+
+  // Init initializes the writer for a new connection, given by |i|.  Each
+  // connection gets a unique output file.
+  bool Init(int i, const TestConfig *config, SSL_SESSION *session);
+
+  // Commit writes the buffered data to disk.
+  bool Commit();
+
+  bool WriteHandoff(bssl::Span<const uint8_t> handoff);
+
+  bool WriteHandback(bssl::Span<const uint8_t> handback);
+
+ private:
+  std::string path_;
+  bssl::ScopedCBB cbb_;
+};
+
+#endif  // HEADER_SETTINGS_WRITER