Use vector_as_array() consistently throughout WebCrypto code.

In some cases this simplifies code by not explicitly handling the empty case.

Before the code was inconsistently using either:
  * vector_as_array()
  * ternery operator
  * &v[0]
  * v->front().

Once we have C++11 library support these will simply become v.data().

BUG=None

Review URL: https://codereview.chromium.org/974183006

Cr-Commit-Position: refs/heads/master@{#319285}

9 files changed, 31 insertions, 31 deletions

diff --git a/content/child/webcrypto/crypto_data.cc b/content/child/webcrypto/crypto_data.cc
index 73bfc18..c80503c 100644
--- a/content/child/webcrypto/crypto_data.cc
+++ b/content/child/webcrypto/crypto_data.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "content/child/webcrypto/crypto_data.h"
+#include "base/stl_util.h"
 
 namespace content {
 
@@ -16,7 +17,7 @@ CryptoData::CryptoData(const unsigned char* bytes, unsigned int byte_length)
 }
 
 CryptoData::CryptoData(const std::vector<unsigned char>& bytes)
-    : bytes_(bytes.size() ? &bytes[0] : NULL), byte_length_(bytes.size()) {
+    : bytes_(vector_as_array(&bytes)), byte_length_(bytes.size()) {
 }
 
 CryptoData::CryptoData(const std::string& bytes)
diff --git a/content/child/webcrypto/openssl/aes_ctr_openssl.cc b/content/child/webcrypto/openssl/aes_ctr_openssl.cc
index 43a1837..89e99ee 100644
--- a/content/child/webcrypto/openssl/aes_ctr_openssl.cc
+++ b/content/child/webcrypto/openssl/aes_ctr_openssl.cc
@@ -108,7 +108,7 @@ crypto::ScopedBIGNUM GetCounter(const CryptoData& counter_block,
   counter[0] &= ~(0xFF << counter_length_remainder_bits);
 
   return crypto::ScopedBIGNUM(
-      BN_bin2bn(&counter.front(), counter.size(), NULL));
+      BN_bin2bn(vector_as_array(&counter), counter.size(), NULL));
 }
 
 // Returns a counter block with the counter bits all set all zero.
diff --git a/content/child/webcrypto/openssl/ec_algorithm_openssl.cc b/content/child/webcrypto/openssl/ec_algorithm_openssl.cc
index b248235..7909fd9 100644
--- a/content/child/webcrypto/openssl/ec_algorithm_openssl.cc
+++ b/content/child/webcrypto/openssl/ec_algorithm_openssl.cc
@@ -161,8 +161,10 @@ Status WritePaddedBIGNUM(const std::string& member_name,
                          size_t padded_length,
                          JwkWriter* jwk) {
   std::vector<uint8_t> padded_bytes(padded_length);
-  if (!BN_bn2bin_padded(&padded_bytes.front(), padded_bytes.size(), value))
+  if (!BN_bn2bin_padded(vector_as_array(&padded_bytes), padded_bytes.size(),
+                        value)) {
     return Status::OperationError();
+  }
   jwk->SetBytes(member_name, CryptoData(padded_bytes));
   return Status::Success();
 }
diff --git a/content/child/webcrypto/openssl/ecdh_openssl.cc b/content/child/webcrypto/openssl/ecdh_openssl.cc
index 9499a25..e4fa01b 100644
--- a/content/child/webcrypto/openssl/ecdh_openssl.cc
+++ b/content/child/webcrypto/openssl/ecdh_openssl.cc
@@ -7,6 +7,7 @@
 #include <openssl/evp.h>
 
 #include "base/logging.h"
+#include "base/stl_util.h"
 #include "content/child/webcrypto/algorithm_implementation.h"
 #include "content/child/webcrypto/crypto_data.h"
 #include "content/child/webcrypto/generate_key_result.h"
@@ -99,8 +100,9 @@ class EcdhImplementation : public EcAlgorithm {
     unsigned int length_bits =
         has_optional_length_bits ? optional_length_bits : field_size_bytes * 8;
 
-    // Handle the empty length case now to avoid calling an undefined
-    // |&derived_bytes->front()| later.
+    // Short-circuit when deriving an empty key.
+    // TODO(eroman): ECDH_compute_key() is not happy when given a NULL output.
+    //               http://crbug.com/464194.
     if (length_bits == 0) {
       derived_bytes->clear();
       return Status::Success();
@@ -114,7 +116,7 @@ class EcdhImplementation : public EcAlgorithm {
     derived_bytes->resize(NumBitsToBytes(length_bits));
 
     int result =
-        ECDH_compute_key(&derived_bytes->front(), derived_bytes->size(),
+        ECDH_compute_key(vector_as_array(derived_bytes), derived_bytes->size(),
                          public_key_point, private_key_ec.get(), 0);
     if (result < 0 || static_cast<size_t>(result) != derived_bytes->size())
       return Status::OperationError();
diff --git a/content/child/webcrypto/openssl/ecdsa_openssl.cc b/content/child/webcrypto/openssl/ecdsa_openssl.cc
index a42b211..49585ee 100644
--- a/content/child/webcrypto/openssl/ecdsa_openssl.cc
+++ b/content/child/webcrypto/openssl/ecdsa_openssl.cc
@@ -7,6 +7,7 @@
 #include <openssl/evp.h>
 
 #include "base/logging.h"
+#include "base/stl_util.h"
 #include "content/child/webcrypto/algorithm_implementation.h"
 #include "content/child/webcrypto/crypto_data.h"
 #include "content/child/webcrypto/generate_key_result.h"
@@ -68,14 +69,14 @@ Status ConvertDerSignatureToWebCryptoSignature(
     std::vector<uint8_t>* signature) {
   crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE);
 
-  const unsigned char* der_data = &signature->front();
+  const unsigned char* der_data = vector_as_array(signature);
   crypto::ScopedECDSA_SIG ecdsa_sig(
       d2i_ECDSA_SIG(NULL, &der_data, static_cast<long>(signature->size())));
   if (!ecdsa_sig.get())
     return Status::ErrorUnexpected();
 
   // |der_data| is updated to point to past the end of the DER structure.
-  if (der_data != (&signature->front()) + signature->size())
+  if (der_data != vector_as_array(signature) + signature->size())
     return Status::ErrorUnexpected();
 
   // Determine the maximum length of r and s.
@@ -86,7 +87,7 @@ Status ConvertDerSignatureToWebCryptoSignature(
 
   signature->resize(order_size_bytes * 2);
 
-  if (!BN_bn2bin_padded(&signature->front(), order_size_bytes,
+  if (!BN_bn2bin_padded(vector_as_array(signature), order_size_bytes,
                         ecdsa_sig.get()->r)) {
     return Status::ErrorUnexpected();
   }
@@ -151,7 +152,7 @@ Status ConvertWebCryptoSignatureToDerSignature(
 
   // DER-encode the signature.
   der_signature->resize(der_encoding_size);
-  uint8_t* result = &der_signature->front();
+  uint8_t* result = vector_as_array(der_signature);
   if (0 > i2d_ECDSA_SIG(ecdsa_sig.get(), &result))
     return Status::OperationError();
 
@@ -207,7 +208,7 @@ class EcdsaImplementation : public EcAlgorithm {
     }
 
     buffer->resize(sig_len);
-    if (!EVP_DigestSignFinal(ctx.get(), &buffer->front(), &sig_len))
+    if (!EVP_DigestSignFinal(ctx.get(), vector_as_array(buffer), &sig_len))
       return Status::OperationError();
     buffer->resize(sig_len);
 
@@ -252,7 +253,7 @@ class EcdsaImplementation : public EcAlgorithm {
     }
 
     *signature_match =
-        1 == EVP_DigestVerifyFinal(ctx.get(), &der_signature.front(),
+        1 == EVP_DigestVerifyFinal(ctx.get(), vector_as_array(&der_signature),
                                    der_signature.size());
     return Status::Success();
   }
diff --git a/content/child/webcrypto/openssl/hkdf_openssl.cc b/content/child/webcrypto/openssl/hkdf_openssl.cc
index 7a33b96..13005ba 100644
--- a/content/child/webcrypto/openssl/hkdf_openssl.cc
+++ b/content/child/webcrypto/openssl/hkdf_openssl.cc
@@ -72,13 +72,10 @@ class HkdfImplementation : public AlgorithmImplementation {
     // |algorithm|.
     const std::vector<uint8_t>& raw_key =
         SymKeyOpenSsl::Cast(base_key)->raw_key_data();
-    const uint8_t* raw_key_ptr = raw_key.empty() ? NULL : &raw_key.front();
-    uint8_t* derived_bytes_ptr =
-        derived_bytes->empty() ? NULL : &derived_bytes->front();
-    if (!HKDF(derived_bytes_ptr, derived_bytes_len, digest_algorithm,
-              raw_key_ptr, raw_key.size(), params->salt().data(),
-              params->salt().size(), params->info().data(),
-              params->info().size())) {
+    if (!HKDF(vector_as_array(derived_bytes), derived_bytes_len,
+              digest_algorithm, vector_as_array(&raw_key), raw_key.size(),
+              params->salt().data(), params->salt().size(),
+              params->info().data(), params->info().size())) {
       uint32_t error = ERR_get_error();
       if (ERR_GET_LIB(error) == ERR_LIB_HKDF &&
           ERR_GET_REASON(error) == HKDF_R_OUTPUT_TOO_LARGE) {
diff --git a/content/child/webcrypto/openssl/pbkdf2_openssl.cc b/content/child/webcrypto/openssl/pbkdf2_openssl.cc
index d7ce485..5c7bf1a 100644
--- a/content/child/webcrypto/openssl/pbkdf2_openssl.cc
+++ b/content/child/webcrypto/openssl/pbkdf2_openssl.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/stl_util.h"
 #include "content/child/webcrypto/algorithm_implementation.h"
 #include "content/child/webcrypto/crypto_data.h"
 #include "content/child/webcrypto/openssl/key_openssl.h"
@@ -75,16 +76,11 @@ class Pbkdf2Implementation : public AlgorithmImplementation {
     const std::vector<uint8_t>& password =
         SymKeyOpenSsl::Cast(base_key)->raw_key_data();
 
-    if (keylen_bytes == 0)
-      return Status::Success();
-
-    const char* password_ptr =
-        password.empty() ? NULL : reinterpret_cast<const char*>(&password[0]);
-
-    if (!PKCS5_PBKDF2_HMAC(password_ptr, password.size(), params->salt().data(),
-                           params->salt().size(), params->iterations(),
-                           digest_algorithm, keylen_bytes,
-                           &derived_bytes->front())) {
+    if (!PKCS5_PBKDF2_HMAC(
+            reinterpret_cast<const char*>(vector_as_array(&password)),
+            password.size(), params->salt().data(), params->salt().size(),
+            params->iterations(), digest_algorithm, keylen_bytes,
+            vector_as_array(derived_bytes))) {
       return Status::OperationError();
     }
     return Status::Success();
diff --git a/content/child/webcrypto/openssl/rsa_sign_openssl.cc b/content/child/webcrypto/openssl/rsa_sign_openssl.cc
index f24432e..be4449c 100644
--- a/content/child/webcrypto/openssl/rsa_sign_openssl.cc
+++ b/content/child/webcrypto/openssl/rsa_sign_openssl.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/numerics/safe_math.h"
+#include "base/stl_util.h"
 #include "content/child/webcrypto/crypto_data.h"
 #include "content/child/webcrypto/openssl/key_openssl.h"
 #include "content/child/webcrypto/openssl/rsa_sign_openssl.h"
@@ -103,7 +104,7 @@ Status RsaSign(const blink::WebCryptoKey& key,
   }
 
   buffer->resize(sig_len);
-  if (!EVP_DigestSignFinal(ctx.get(), &buffer->front(), &sig_len))
+  if (!EVP_DigestSignFinal(ctx.get(), vector_as_array(buffer), &sig_len))
     return Status::OperationError();
 
   buffer->resize(sig_len);
diff --git a/content/child/webcrypto/test/sha_unittest.cc b/content/child/webcrypto/test/sha_unittest.cc
index 65c19c0..50d58fc 100644
--- a/content/child/webcrypto/test/sha_unittest.cc
+++ b/content/child/webcrypto/test/sha_unittest.cc
@@ -69,7 +69,7 @@ TEST(WebCryptoShaTest, DigestSampleSetsInChunks) {
       size_t chunk_length = std::min(kChunkSizeBytes, length - chunk_index);
       std::vector<uint8_t> chunk(begin, begin + chunk_length);
       ASSERT_TRUE(chunk.size() > 0);
-      EXPECT_TRUE(digestor->consume(&chunk.front(), chunk.size()));
+      EXPECT_TRUE(digestor->consume(vector_as_array(&chunk), chunk.size()));
       chunk_index = chunk_index + chunk_length;
       begin = begin + chunk_length;
     }