Add OpenSSL BIO method that writes to a std::string.

crypto/openssl_bio_string_unittest.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "crypto/openssl_bio_string.h"
+
+#include <openssl/bio.h>
+
+#include "crypto/openssl_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+TEST(OpenSSLBIOString, TestWrite) {
+  std::string s;
+  const std::string expected1("a one\nb 2\n");
+  const std::string expected2("c d e f");
+  {
+    crypto::ScopedOpenSSL<BIO, BIO_free_all> bio(crypto::BIO_new_string(&s));
+    ASSERT_TRUE(bio.get());
+
+    EXPECT_EQ(static_cast<int>(expected1.size()),
+              BIO_printf(bio.get(), "a %s\nb %i\n", "one", 2));
+    EXPECT_EQ(expected1, s);
+    EXPECT_EQ(static_cast<int>(expected1.size()), BIO_tell(bio.get()));
+
+    EXPECT_EQ(1, BIO_flush(bio.get()));
+    EXPECT_EQ(-1, BIO_seek(bio.get(), 0));
+    EXPECT_EQ(expected1, s);
+
+    EXPECT_EQ(static_cast<int>(expected2.size()),
+              BIO_write(bio.get(), expected2.data(), expected2.size()));
+    EXPECT_EQ(expected1 + expected2, s);
+    EXPECT_EQ(static_cast<int>(expected1.size() + expected2.size()),
+              BIO_tell(bio.get()));
+  }
+  EXPECT_EQ(expected1 + expected2, s);
+}
+
+TEST(OpenSSLBIOString, TestReset) {
+  std::string s;
+  const std::string expected1("a b c\n");
+  const std::string expected2("d e f g\n");
+  {
+    crypto::ScopedOpenSSL<BIO, BIO_free_all> bio(crypto::BIO_new_string(&s));
+    ASSERT_TRUE(bio.get());
+
+    EXPECT_EQ(static_cast<int>(expected1.size()),
+              BIO_write(bio.get(), expected1.data(), expected1.size()));
+    EXPECT_EQ(expected1, s);
+
+    EXPECT_EQ(1, BIO_reset(bio.get()));
+    EXPECT_EQ(std::string(), s);
+
+    EXPECT_EQ(static_cast<int>(expected2.size()),
+              BIO_write(bio.get(), expected2.data(), expected2.size()));
+    EXPECT_EQ(expected2, s);
+  }
+  EXPECT_EQ(expected2, s);
+}