blob: 3363ff499de395f41d94e34798c797e6502cfcff [file] [log] [blame]
// Copyright 2016 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 "net/tools/cert_verify_tool/verify_using_path_builder.h"
#include <iostream>
#include <memory>
#include "base/logging.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "crypto/sha2.h"
#include "net/cert/cert_net_fetcher.h"
#include "net/cert/internal/cert_issuer_source_aia.h"
#include "net/cert/internal/cert_issuer_source_static.h"
#include "net/cert/internal/parse_name.h"
#include "net/cert/internal/parsed_certificate.h"
#include "net/cert/internal/path_builder.h"
#include "net/cert/internal/simple_path_builder_delegate.h"
#include "net/cert/internal/system_trust_store.h"
#include "net/cert/x509_certificate.h"
#include "net/cert/x509_util.h"
#include "net/tools/cert_verify_tool/cert_verify_tool_util.h"
namespace {
// Converts a base::Time::Exploded to a net::der::GeneralizedTime.
// TODO(mattm): This function exists in cast_cert_validator.cc also. Dedupe it?
net::der::GeneralizedTime ConvertExplodedTime(
const base::Time::Exploded& exploded) {
net::der::GeneralizedTime result;
result.year = exploded.year;
result.month = exploded.month;
result.day = exploded.day_of_month;
result.hours = exploded.hour;
result.minutes = exploded.minute;
result.seconds = exploded.second;
return result;
}
bool AddPemEncodedCert(const net::ParsedCertificate* cert,
std::vector<std::string>* pem_encoded_chain) {
std::string der_cert;
cert->der_cert().AsStringPiece().CopyToString(&der_cert);
std::string pem;
if (!net::X509Certificate::GetPEMEncodedFromDER(der_cert, &pem)) {
std::cerr << "ERROR: GetPEMEncodedFromDER failed\n";
return false;
}
pem_encoded_chain->push_back(pem);
return true;
}
// Dumps a chain of ParsedCertificate objects to a PEM file.
bool DumpParsedCertificateChain(const base::FilePath& file_path,
const net::CertPathBuilderResultPath& path) {
std::vector<std::string> pem_encoded_chain;
for (const auto& cert : path.certs) {
if (!AddPemEncodedCert(cert.get(), &pem_encoded_chain))
return false;
}
return WriteToFile(file_path, base::JoinString(pem_encoded_chain, ""));
}
// Returns a hex-encoded sha256 of the DER-encoding of |cert|.
std::string FingerPrintParsedCertificate(const net::ParsedCertificate* cert) {
std::string hash = crypto::SHA256HashString(cert->der_cert().AsStringPiece());
return base::HexEncode(hash.data(), hash.size());
}
std::string SubjectToString(const net::RDNSequence& parsed_subject) {
std::string subject_str;
if (!net::ConvertToRFC2253(parsed_subject, &subject_str))
return std::string();
return subject_str;
}
// Returns a textual representation of the Subject of |cert|.
std::string SubjectFromParsedCertificate(const net::ParsedCertificate* cert) {
net::RDNSequence parsed_subject;
if (!net::ParseName(cert->tbs().subject_tlv, &parsed_subject))
return std::string();
return SubjectToString(parsed_subject);
}
// Dumps a ResultPath to std::cout.
void PrintResultPath(const net::CertPathBuilderResultPath* result_path,
size_t index,
bool is_best) {
std::cout << "path " << index << " "
<< (result_path->IsValid() ? "valid" : "invalid")
<< (is_best ? " (best)" : "") << "\n";
// Print the certificate chain.
for (const auto& cert : result_path->certs) {
std::cout << " " << FingerPrintParsedCertificate(cert.get()) << " "
<< SubjectFromParsedCertificate(cert.get()) << "\n";
}
// Print the errors/warnings if there were any.
std::string errors_str =
result_path->errors.ToDebugString(result_path->certs);
if (!errors_str.empty()) {
std::cout << "Errors:\n";
std::cout << errors_str << "\n";
}
}
scoped_refptr<net::ParsedCertificate> ParseCertificate(const CertInput& input) {
net::CertErrors errors;
scoped_refptr<net::ParsedCertificate> cert = net::ParsedCertificate::Create(
net::x509_util::CreateCryptoBuffer(input.der_cert), {}, &errors);
if (!cert) {
PrintCertError("ERROR: ParsedCertificate failed:", input);
std::cout << errors.ToDebugString() << "\n";
}
// TODO(crbug.com/634443): Print errors if there are any on success too (i.e.
// warnings).
return cert;
}
} // namespace
// Verifies |target_der_cert| using CertPathBuilder.
bool VerifyUsingPathBuilder(
const CertInput& target_der_cert,
const std::vector<CertInput>& intermediate_der_certs,
const std::vector<CertInput>& root_der_certs,
const base::Time at_time,
const base::FilePath& dump_prefix_path,
scoped_refptr<net::CertNetFetcher> cert_net_fetcher) {
base::Time::Exploded exploded_time;
at_time.UTCExplode(&exploded_time);
net::der::GeneralizedTime time = ConvertExplodedTime(exploded_time);
std::unique_ptr<net::SystemTrustStore> ssl_trust_store =
net::CreateSslSystemTrustStore();
for (const auto& der_cert : root_der_certs) {
scoped_refptr<net::ParsedCertificate> cert = ParseCertificate(der_cert);
if (cert) {
ssl_trust_store->AddTrustAnchor(cert);
}
}
if (!ssl_trust_store->UsesSystemTrustStore() && root_der_certs.empty()) {
std::cerr << "NOTE: CertPathBuilder does not currently use OS trust "
"settings (--roots must be specified).\n";
}
net::CertIssuerSourceStatic intermediate_cert_issuer_source;
for (const auto& der_cert : intermediate_der_certs) {
scoped_refptr<net::ParsedCertificate> cert = ParseCertificate(der_cert);
if (cert)
intermediate_cert_issuer_source.AddCert(cert);
}
scoped_refptr<net::ParsedCertificate> target_cert =
ParseCertificate(target_der_cert);
if (!target_cert)
return false;
// Verify the chain.
net::SimplePathBuilderDelegate delegate(
2048, net::SimplePathBuilderDelegate::DigestPolicy::kWeakAllowSha1);
net::CertPathBuilder::Result result;
net::CertPathBuilder path_builder(
target_cert, ssl_trust_store->GetTrustStore(), &delegate, time,
net::KeyPurpose::SERVER_AUTH, net::InitialExplicitPolicy::kFalse,
{net::AnyPolicy()}, net::InitialPolicyMappingInhibit::kFalse,
net::InitialAnyPolicyInhibit::kFalse, &result);
path_builder.AddCertIssuerSource(&intermediate_cert_issuer_source);
std::unique_ptr<net::CertIssuerSourceAia> aia_cert_issuer_source;
if (cert_net_fetcher.get()) {
aia_cert_issuer_source =
std::make_unique<net::CertIssuerSourceAia>(std::move(cert_net_fetcher));
path_builder.AddCertIssuerSource(aia_cert_issuer_source.get());
}
// Run the path builder.
path_builder.Run();
// TODO(crbug.com/634443): Display any errors/warnings associated with path
// building that were not part of a particular
// PathResult.
std::cout << "CertPathBuilder result: "
<< (result.HasValidPath() ? "SUCCESS" : "FAILURE") << "\n";
for (size_t i = 0; i < result.paths.size(); ++i) {
PrintResultPath(result.paths[i].get(), i, i == result.best_result_index);
}
// TODO(mattm): add flag to dump all paths, not just the final one?
if (!dump_prefix_path.empty() && !result.paths.empty()) {
if (!DumpParsedCertificateChain(
dump_prefix_path.AddExtension(
FILE_PATH_LITERAL(".CertPathBuilder.pem")),
*result.GetBestPathPossiblyInvalid())) {
return false;
}
}
return result.HasValidPath();
}