Add WARN_UNUSED_RESULT to crypto/hmac.h

BUG=none
TEST=none


Review URL: http://codereview.chromium.org/7522014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@94826 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 58 insertions, 30 deletions

diff --git a/net/http/http_mac_signature.cc b/net/http/http_mac_signature.cc
index 32f1e0c..1e3ea95 100644
--- a/net/http/http_mac_signature.cc
+++ b/net/http/http_mac_signature.cc
@@ -95,28 +95,38 @@ bool HttpMacSignature::AddHttpInfo(const std::string& method,
   return true;
 }
 
-std::string HttpMacSignature::GenerateAuthorizationHeader() {
-  DCHECK(!id_.empty()) << "Call AddStateInfo first.";
-  DCHECK(!method_.empty()) << "Call AddHttpInfo first.";
+bool HttpMacSignature::GenerateAuthorizationHeader(std::string* header) {
+  if (id_.empty()) {
+    NOTREACHED() << "Call AddStateInfo first.";
+    return false;
+  }
+  if (method_.empty()) {
+    NOTREACHED() << "Call AddHttpInfo first.";
+    return false;
+  }
 
   std::string age = base::Int64ToString(
       (base::Time::Now() - creation_date_).InSeconds());
   std::string nonce = GenerateNonce();
 
-  return GenerateHeaderString(age, nonce);
+  return GenerateHeaderString(age, nonce, header);
 }
 
-std::string HttpMacSignature::GenerateHeaderString(const std::string& age,
-                                                   const std::string& nonce) {
-  std::string mac = GenerateMAC(age, nonce);
+bool HttpMacSignature::GenerateHeaderString(const std::string& age,
+                                            const std::string& nonce,
+                                            std::string* header) {
+  std::string mac;
+  if (!GenerateMAC(age, nonce, &mac))
+    return false;
 
   DCHECK(IsPlainString(age));
   DCHECK(IsPlainString(nonce));
   DCHECK(IsPlainString(mac));
 
-  return "MAC id=\"" + id_ +
+  *header = "MAC id=\"" + id_ +
       "\", nonce=\"" + age + ":" + nonce +
       "\", mac=\"" + mac + "\"";
+  return true;
 }
 
 std::string HttpMacSignature::GenerateNormalizedRequest(
@@ -135,25 +145,34 @@ std::string HttpMacSignature::GenerateNormalizedRequest(
   return normalized_request;
 }
 
-std::string HttpMacSignature::GenerateMAC(const std::string& age,
-                                          const std::string& nonce) {
+bool HttpMacSignature::GenerateMAC(const std::string& age,
+                                   const std::string& nonce,
+                                   std::string* mac) {
   std::string request = GenerateNormalizedRequest(age, nonce);
 
   crypto::HMAC hmac(mac_algorithm_);
-  hmac.Init(mac_key_);
+  if (!hmac.Init(mac_key_)) {
+    NOTREACHED();
+    return false;
+  }
 
   std::string signature;
   size_t length = hmac.DigestLength();
   char* buffer = WriteInto(&signature, length);
-  bool result = hmac.Sign(request,
-                          reinterpret_cast<unsigned char*>(buffer),
-                          length);
-  DCHECK(result);
+  if (!hmac.Sign(request, reinterpret_cast<unsigned char*>(buffer),
+                 length)) {
+    NOTREACHED();
+    return false;
+  }
 
   std::string encoded_signature;
-  result = base::Base64Encode(signature, &encoded_signature);
-  DCHECK(result);
-  return encoded_signature;
+  if (!base::Base64Encode(signature, &encoded_signature)) {
+    NOTREACHED();
+    return false;
+  }
+
+  mac->swap(encoded_signature);
+  return true;
 }
 
 }  // namespace net
diff --git a/net/http/http_mac_signature.h b/net/http/http_mac_signature.h
index 00191e1..7a1e971 100644
--- a/net/http/http_mac_signature.h
+++ b/net/http/http_mac_signature.h
@@ -39,20 +39,24 @@ class NET_TEST HttpMacSignature {
                    const std::string& host,
                    int port);
 
-  // Returns the value of the Authorization header for use in an HTTP request.
-  std::string GenerateAuthorizationHeader();
+  // Generates the Authorization header for use in an HTTP request. If
+  // successfully generated, returns true and stores the resultant header in
+  // |*header|.
+  bool GenerateAuthorizationHeader(std::string* header);
 
  private:
   FRIEND_TEST_ALL_PREFIXES(HttpMacSignatureTest, GenerateHeaderString);
   FRIEND_TEST_ALL_PREFIXES(HttpMacSignatureTest, GenerateNormalizedRequest);
   FRIEND_TEST_ALL_PREFIXES(HttpMacSignatureTest, GenerateMAC);
 
-  std::string GenerateHeaderString(const std::string& age,
-                                   const std::string& nonce);
+  bool GenerateHeaderString(const std::string& age,
+                            const std::string& nonce,
+                            std::string* header);
   std::string GenerateNormalizedRequest(const std::string& age,
                                         const std::string& nonce);
-  std::string GenerateMAC(const std::string& age,
-                          const std::string& nonce);
+  bool GenerateMAC(const std::string& age,
+                   const std::string& nonce,
+                   std::string* mac);
 
   std::string id_;
   base::Time creation_date_;
diff --git a/net/http/http_mac_signature_unittest.cc b/net/http/http_mac_signature_unittest.cc
index e0c6be2..74064dd 100644
--- a/net/http/http_mac_signature_unittest.cc
+++ b/net/http/http_mac_signature_unittest.cc
@@ -55,10 +55,12 @@ TEST(HttpMacSignatureTest, GenerateHeaderString) {
   std::string age = "239034";
   std::string nonce = "mn4302j0n+32r2/f3r=";
 
+  std::string header_string;
+  EXPECT_TRUE(signature.GenerateHeaderString(age, nonce, &header_string));
   EXPECT_EQ("MAC id=\"dfoi30j0qnf\", "
             "nonce=\"239034:mn4302j0n+32r2/f3r=\", "
             "mac=\"GrkHtPKzB1m1dCHfa7OCWOw6EQ==\"",
-            signature.GenerateHeaderString(age, nonce));
+            header_string);
 }
 
 
@@ -100,7 +102,8 @@ TEST(HttpMacSignatureTest, GenerateMAC) {
   std::string age = "239034";
   std::string nonce = "mn4302j0n+32r2/f3r=";
 
-  EXPECT_EQ("GrkHtPKzB1m1dCHfa7OCWOw6EQ==",
-            signature.GenerateMAC(age, nonce));
+  std::string mac;
+  EXPECT_TRUE(signature.GenerateMAC(age, nonce, &mac));
+  EXPECT_EQ("GrkHtPKzB1m1dCHfa7OCWOw6EQ==", mac);
 }
 }
diff --git a/net/url_request/url_request_http_job.cc b/net/url_request/url_request_http_job.cc
index 7e989a8..1315472 100644
--- a/net/url_request/url_request_http_job.cc
+++ b/net/url_request/url_request_http_job.cc
@@ -75,9 +75,11 @@ void AddAuthorizationHeader(
     }
     if (!signature.AddHttpInfo(method, request_uri, host, port))
       continue;
-    request_info->extra_headers.SetHeader(
-        HttpRequestHeaders::kAuthorization,
-        signature.GenerateAuthorizationHeader());
+    std::string authorization_header;
+    if (!signature.GenerateAuthorizationHeader(&authorization_header))
+      continue;
+    request_info->extra_headers.SetHeader(HttpRequestHeaders::kAuthorization,
+                                          authorization_header);
     return;  // Only add the first valid header.
   }
 }