Update from https://crrev.com/311076

crypto/signature_verifier_unittest.cc

 // Copyright (c) 2011 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 "crypto/signature_verifier.h"
 
 #include "base/numerics/safe_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 TEST(SignatureVerifierTest, BasicTest) {
@@ skipping 982 matching lines @@
   while (in[0] != '\0') {
     if (!isxdigit(in[0]) || !isxdigit(in[1]) || in[2] != ' ')
       return false;
     uint8 octet = HexDigitValue(in[0]) * 16 + HexDigitValue(in[1]);
     out->push_back(octet);
     in += 3;
   }
   return true;
 }
 
+// PrependASN1Length prepends an ASN.1 serialized length to the beginning of
+// |out|.
+static void PrependASN1Length(std::vector<uint8>* out, size_t len) {
+  if (len < 128) {
+    out->insert(out->begin(), static_cast<uint8>(len));
+  } else if (len < 256) {
+    out->insert(out->begin(), static_cast<uint8>(len));
+    out->insert(out->begin(), 0x81);
+  } else if (len < 0x10000) {
+    out->insert(out->begin(), static_cast<uint8>(len));
+    out->insert(out->begin(), static_cast<uint8>(len >> 8));
+    out->insert(out->begin(), 0x82);
+  } else {
+    CHECK(false) << "ASN.1 length not handled: " << len;
+  }
+}
+
 static bool EncodeRSAPublicKey(const std::vector<uint8>& modulus_n,
                                const std::vector<uint8>& public_exponent_e,
                                std::vector<uint8>* public_key_info) {
   // The public key is specified as the following ASN.1 structure:
   //   SubjectPublicKeyInfo  ::=  SEQUENCE  {
   //       algorithm            AlgorithmIdentifier,
   //       subjectPublicKey     BIT STRING  }
   //
   // The signature algorithm is specified as the following ASN.1 structure:
   //    AlgorithmIdentifier  ::=  SEQUENCE  {
   //        algorithm               OBJECT IDENTIFIER,
   //        parameters              ANY DEFINED BY algorithm OPTIONAL  }
   //
   // An RSA public key is specified as the following ASN.1 structure:
   //    RSAPublicKey ::= SEQUENCE {
   //        modulus           INTEGER,  -- n
   //        publicExponent    INTEGER   -- e
   //    }
   static const uint8 kIntegerTag = 0x02;
   static const uint8 kBitStringTag = 0x03;
   static const uint8 kSequenceTag = 0x30;
   public_key_info->clear();
 
   // Encode the public exponent e as an INTEGER.
   public_key_info->insert(public_key_info->begin(),
                           public_exponent_e.begin(),
                           public_exponent_e.end());
-  uint8 exponent_size = base::checked_cast<uint8>(public_exponent_e.size());
-  public_key_info->insert(public_key_info->begin(), exponent_size);
+  PrependASN1Length(public_key_info, public_exponent_e.size());
   public_key_info->insert(public_key_info->begin(), kIntegerTag);
 
   // Encode the modulus n as an INTEGER.
   public_key_info->insert(public_key_info->begin(),
                           modulus_n.begin(), modulus_n.end());
-  uint16 modulus_size = base::checked_cast<uint16>(modulus_n.size());
+  size_t modulus_size = modulus_n.size();
   if (modulus_n[0] & 0x80) {
     public_key_info->insert(public_key_info->begin(), 0x00);
     modulus_size++;
   }
-  public_key_info->insert(public_key_info->begin(), modulus_size & 0xff);
-  public_key_info->insert(public_key_info->begin(), (modulus_size >> 8) & 0xff);
-  public_key_info->insert(public_key_info->begin(), 0x82);
+  PrependASN1Length(public_key_info, modulus_size);
   public_key_info->insert(public_key_info->begin(), kIntegerTag);
 
   // Encode the RSAPublicKey SEQUENCE.
-  uint16 info_size = base::checked_cast<uint16>(public_key_info->size());
-  public_key_info->insert(public_key_info->begin(), info_size & 0xff);
-  public_key_info->insert(public_key_info->begin(), (info_size >> 8) & 0xff);
-  public_key_info->insert(public_key_info->begin(), 0x82);
+  PrependASN1Length(public_key_info, public_key_info->size());
   public_key_info->insert(public_key_info->begin(), kSequenceTag);
 
   // Encode the BIT STRING.
   // Number of unused bits.
   public_key_info->insert(public_key_info->begin(), 0x00);
-  info_size = base::checked_cast<uint16>(public_key_info->size());
-  public_key_info->insert(public_key_info->begin(), info_size & 0xff);
-  public_key_info->insert(public_key_info->begin(), (info_size >> 8) & 0xff);
-  public_key_info->insert(public_key_info->begin(), 0x82);
+  PrependASN1Length(public_key_info, public_key_info->size());
   public_key_info->insert(public_key_info->begin(), kBitStringTag);
 
   // Encode the AlgorithmIdentifier.
   static const uint8 algorithm[] = {
     0x30, 0x0d,  // a SEQUENCE of length 13
       0x06, 0x09,  // an OBJECT IDENTIFIER of length 9
         0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x01,
       0x05, 0x00,
   };
   public_key_info->insert(public_key_info->begin(),
                           algorithm, algorithm + sizeof(algorithm));
 
   // Encode the outermost SEQUENCE.
-  info_size = base::checked_cast<uint16>(public_key_info->size());
-  public_key_info->insert(public_key_info->begin(), info_size & 0xff);
-  public_key_info->insert(public_key_info->begin(), (info_size >> 8) & 0xff);
-  public_key_info->insert(public_key_info->begin(), 0x82);
+  PrependASN1Length(public_key_info, public_key_info->size());
   public_key_info->insert(public_key_info->begin(), kSequenceTag);
 
   return true;
 }
 
 TEST(SignatureVerifierTest, VerifyRSAPSS) {
   for (unsigned int i = 0; i < arraysize(pss_test); i++) {
+    SCOPED_TRACE(i);
     std::vector<uint8> modulus_n;
     std::vector<uint8> public_exponent_e;
     ASSERT_TRUE(DecodeTestInput(pss_test[i].modulus_n, &modulus_n));
     ASSERT_TRUE(DecodeTestInput(pss_test[i].public_exponent_e,
                                 &public_exponent_e));
     std::vector<uint8> public_key_info;
     ASSERT_TRUE(EncodeRSAPublicKey(modulus_n, public_exponent_e,
                                    &public_key_info));
 
     for (unsigned int j = 0; j < arraysize(pss_test[i].example); j++) {
+      SCOPED_TRACE(j);
       std::vector<uint8> message;
       std::vector<uint8> salt;
       std::vector<uint8> signature;
       ASSERT_TRUE(DecodeTestInput(pss_test[i].example[j].message, &message));
       ASSERT_TRUE(DecodeTestInput(pss_test[i].example[j].salt, &salt));
       ASSERT_TRUE(DecodeTestInput(pss_test[i].example[j].signature,
                                   &signature));
 
       crypto::SignatureVerifier verifier;
       bool ok;
@@ skipping 46 matching lines @@
                                      &public_key_info[0],
                                      public_key_info.size());
       signature[0] -= 1;
       ASSERT_TRUE(ok);
       verifier.VerifyUpdate(&message[0], message.size());
       ok = verifier.VerifyFinal();
       EXPECT_FALSE(ok);
     }
   }
 }