Private API for extensions like ssh-client that need access to TCP.

crypto/symmetric_key_mac.cc

Index: crypto/symmetric_key_mac.cc
diff --git a/crypto/symmetric_key_mac.cc b/crypto/symmetric_key_mac.cc
index 47193a0883311a9ee376721d8fee084734db8734..7c339de03eb034d0935b6bea06d4c89a91cd746d 100644
--- a/crypto/symmetric_key_mac.cc
+++ b/crypto/symmetric_key_mac.cc
@@ -32,14 +32,14 @@ CSSM_KEY_TYPE CheckKeyParams(crypto::SymmetricKey::Algorithm algorithm,
   }
 }
 
-void* CreateRandomBytes(size_t size) {
+uint8_t* CreateRandomBytes(size_t size) {
   CSSM_RETURN err;
   CSSM_CC_HANDLE ctx;
   err = CSSM_CSP_CreateRandomGenContext(crypto::GetSharedCSPHandle(),
                                         CSSM_ALGID_APPLE_YARROW,
                                         NULL,
                                         size, &ctx);
-  if (err) {
+  if (err != CSSM_OK) {

[wtc, 2011/05/17 23:37:52]

Although I prefer this form, it's more important to be
consistent.  So I prefer we not change this, or we should
change all instances of
  if (err)
in this file.

[Denis Lagno, 2011/05/18 11:53:32]

Done.

     crypto::LogCSSMError("CSSM_CSP_CreateRandomGenContext", err);
     return NULL;
   }
@@ -50,7 +50,7 @@ void* CreateRandomBytes(size_t size) {
     random_data.Data = NULL;
   }
   CSSM_DeleteContext(ctx);
-  return random_data.Data;  // Caller responsible for freeing this
+  return random_data.Data;  // Caller responsible for freeing this.
 }
 
 inline CSSM_DATA StringToData(const std::string& str) {
@@ -65,16 +65,20 @@ inline CSSM_DATA StringToData(const std::string& str) {
 
 namespace crypto {
 
-SymmetricKey::~SymmetricKey() {}
+SymmetricKey::~SymmetricKey() {
+  std::fill(key_.begin(), key_.end(), 0);
+}
 
 // static
 SymmetricKey* SymmetricKey::GenerateRandomKey(Algorithm algorithm,
                                               size_t key_size_in_bits) {
   CheckKeyParams(algorithm, key_size_in_bits);
-  void* random_bytes = CreateRandomBytes((key_size_in_bits + 7) / 8);
+  size_t key_size_in_bytes = (key_size_in_bits + 7) / 8;
+  uint8_t* random_bytes = CreateRandomBytes(key_size_in_bytes);
   if (!random_bytes)
     return NULL;
   SymmetricKey *key = new SymmetricKey(random_bytes, key_size_in_bits);
+  std::fill(random_bytes, random_bytes + key_size_in_bytes, 0);

[wtc, 2011/05/17 23:37:52]

You can use
  memset(random_bytes, 0, key_size_in_bytes);
here instead.  Then you don't need to change CreateRandomBytes
to return uint8_t*.

[Denis Lagno, 2011/05/18 11:53:32]

better leave std::fill for consistency

   free(random_bytes);
   return key;
 }
@@ -139,9 +143,9 @@ SymmetricKey* SymmetricKey::Import(Algorithm algorithm,
   return new SymmetricKey(raw_key.data(), raw_key.size() * 8);
 }
 
-SymmetricKey::SymmetricKey(const void *key_data, size_t key_size_in_bits)
-  : key_(reinterpret_cast<const char*>(key_data),
-         key_size_in_bits / 8) {}
+SymmetricKey::SymmetricKey(const void* key_data, size_t key_size_in_bits)
+    : key_(static_cast<const char*>(key_data), key_size_in_bits / 8) {

[wtc, 2011/05/17 23:37:52]

I was told to use reinterpret_cast to cast void* to foo*.
I don't remember why, but it may be the recommendations
of the Style Guide:
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Casting

So I prefer that we not change this cast.

[Denis Lagno, 2011/05/18 11:53:32]

Done.

+}
 
 bool SymmetricKey::GetRawKey(std::string* raw_key) {
   *raw_key = key_;