Disallow identical names for the Encryption and Crypto-Key headers

components/gcm_driver/crypto/encryption_header_parsers.cc

 // Copyright 2015 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 "components/gcm_driver/crypto/encryption_header_parsers.h"
 
 #include "base/base64url.h"
 #include "base/strings/string_number_conversions.h"
 
 #include "base/strings/string_util.h"
@@ skipping 57 matching lines @@
   rs_ = kDefaultRecordSizeBytes;
 
   if (!iterator_.GetNext())
     return false;
 
   net::HttpUtil::NameValuePairsIterator name_value_pairs(
       iterator_.value_begin(), iterator_.value_end(), ';',
       net::HttpUtil::NameValuePairsIterator::Values::REQUIRED,
       net::HttpUtil::NameValuePairsIterator::Quotes::NOT_STRICT);
 
+  bool found_keyid = false;
+  bool found_salt = false;
+  bool found_rs = false;
+
   while (name_value_pairs.GetNext()) {
     const base::StringPiece name(name_value_pairs.name_begin(),
                                  name_value_pairs.name_end());
     const base::StringPiece value(name_value_pairs.value_begin(),
                                   name_value_pairs.value_end());
 
     if (base::LowerCaseEqualsASCII(name, "keyid")) {
+      if (found_keyid)
+        return false;
       value.CopyToString(&keyid_);
+      found_keyid = true;
     } else if (base::LowerCaseEqualsASCII(name, "salt")) {
-      if (!ValueToDecodedString(value, &salt_))
+      if (found_salt || !ValueToDecodedString(value, &salt_))
         return false;
+      found_salt = true;
     } else if (base::LowerCaseEqualsASCII(name, "rs")) {
-      if (!RecordSizeToInt(value, &rs_))
+      if (found_rs || !RecordSizeToInt(value, &rs_))
         return false;
+      found_rs = true;
     } else {
       // Silently ignore unknown directives for forward compatibility.
     }
   }
 
   return name_value_pairs.valid();
 }
 
 CryptoKeyHeaderIterator::CryptoKeyHeaderIterator(
     std::string::const_iterator header_begin,
     std::string::const_iterator header_end)
     : iterator_(header_begin, header_end, ',') {}
 
 CryptoKeyHeaderIterator::~CryptoKeyHeaderIterator() {}
 
 bool CryptoKeyHeaderIterator::GetNext() {
   keyid_.clear();
   aesgcm128_.clear();
   dh_.clear();
 
   if (!iterator_.GetNext())
     return false;
 
   net::HttpUtil::NameValuePairsIterator name_value_pairs(
       iterator_.value_begin(), iterator_.value_end(), ';',
       net::HttpUtil::NameValuePairsIterator::Values::REQUIRED,
       net::HttpUtil::NameValuePairsIterator::Quotes::NOT_STRICT);
 
+  bool found_keyid = false;
+  bool found_aesgcm128 = false;
+  bool found_dh = false;
+
   while (name_value_pairs.GetNext()) {
     const base::StringPiece name(name_value_pairs.name_begin(),
                                  name_value_pairs.name_end());
     const base::StringPiece value(name_value_pairs.value_begin(),
                                   name_value_pairs.value_end());
 
     if (base::LowerCaseEqualsASCII(name, "keyid")) {
+      if (found_keyid)
+        return false;
       value.CopyToString(&keyid_);
+      found_keyid = true;
     } else if (base::LowerCaseEqualsASCII(name, "aesgcm128")) {
-      if (!ValueToDecodedString(value, &aesgcm128_))
+      if (found_aesgcm128 || !ValueToDecodedString(value, &aesgcm128_))
         return false;
+      found_aesgcm128 = true;
     } else if (base::LowerCaseEqualsASCII(name, "dh")) {
-      if (!ValueToDecodedString(value, &dh_))
+      if (found_dh || !ValueToDecodedString(value, &dh_))
         return false;
+      found_dh = true;
     } else {
       // Silently ignore unknown directives for forward compatibility.
     }
   }
 
   return name_value_pairs.valid();
 }
 
 }  // namespace gcm