Disallow identical names for the Encryption and Crypto-Key headers

This is to be enforced per the following spec change:
https://github.com/martinthomson/http-encryption/commit/d11c8263ef3a9fa9cec261898b5d462162045099

BUG=538576

Review-Url: https://codereview.chromium.org/2106333003
Cr-Commit-Position: refs/heads/master@{#403352}

components/gcm_driver/crypto/encryption_header_parsers.cc

@@ -75,6 +75,10 @@ bool EncryptionHeaderIterator::GetNext() {
       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());
@@ -82,13 +86,18 @@ bool EncryptionHeaderIterator::GetNext() {
                                   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.
     }
@@ -117,6 +126,10 @@ bool CryptoKeyHeaderIterator::GetNext() {
       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());
@@ -124,13 +137,18 @@ bool CryptoKeyHeaderIterator::GetNext() {
                                   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.
     }

components/gcm_driver/crypto/encryption_header_parsers_unittest.cc

@@ -42,7 +42,6 @@ TEST(EncryptionHeaderParsersTest, ParseValidEncryptionHeaders) {
       "", "sixteencoolbytes", kDefaultRecordSize },
     { "rs=2048", "", "", 2048 },
     { "keyid=foo;someothervalue=1;rs=42", "foo", "", 42 },
-    { "keyid=foo;keyid=bar", "bar", "", kDefaultRecordSize },
   };
 
   for (size_t i = 0; i < arraysize(expected_results); i++) {
@@ -116,6 +115,10 @@ TEST(EncryptionHeaderParsersTest, ParseInvalidEncryptionHeaders) {
     "rs",
     "rs=",
 
+    // Supplying the same name multiple times in the same value is invalid.
+    "keyid=foo;keyid=bar",
+    "keyid=foo;bar=baz;keyid=qux",
+
     // The salt must be a URL-safe base64 decodable string.
     "salt=YmV/2ZXJ-sMDA",
     "salt=dHdlbHZlY29vbGJ5dGVz=====",
@@ -187,7 +190,6 @@ TEST(EncryptionHeaderParsersTest, ParseValidCryptoKeyHeaders) {
     { "dh=dHdlbHZlY29vbGJ5dGVz", "", "", "twelvecoolbytes" },
     { "keyid=foo;someothervalue=bar;aesgcm128=dHdlbHZlY29vbGJ5dGVz",
       "foo", "twelvecoolbytes", "" },
-    { "keyid=foo;keyid=bar", "bar", "", "" },
   };
 
   for (size_t i = 0; i < arraysize(expected_results); i++) {
@@ -262,6 +264,10 @@ TEST(EncryptionHeaderParsersTest, ParseInvalidCryptoKeyHeaders) {
     "dh",
     "dh=",
 
+    // Supplying the same name multiple times in the same value is invalid.
+    "keyid=foo;keyid=bar",
+    "keyid=foo;bar=baz;keyid=qux",
+
     // The "aesgcm128" parameter must be a URL-safe base64 decodable string.
     "aesgcm128=123$xyz",
     "aesgcm128=foobar;aesgcm128=123$xyz",