// 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 <algorithm>
#include "net/cert/internal/certificate_policies.h"
#include "net/cert/internal/cert_error_params.h"
#include "net/cert/internal/cert_errors.h"
#include "net/der/input.h"
#include "net/der/parse_values.h"
#include "net/der/parser.h"
#include "net/der/tag.h"
namespace net {
namespace {
// ---------------------------------------------------------------
// Errors
// ---------------------------------------------------------------
DEFINE_CERT_ERROR_ID(kPolicyQualifiersEmptySequence,
"The policy qualifiers SEQUENCE is empty");
DEFINE_CERT_ERROR_ID(kUnknownPolicyQualifierOid,
"Unknown policy qualifier OID (not CPS or User Notice)");
DEFINE_CERT_ERROR_ID(kPoliciesEmptySequence, "Policies is an empty SEQUENCE");
DEFINE_CERT_ERROR_ID(kPoliciesDuplicateOid, "Policies contains duplicate OIDs");
DEFINE_CERT_ERROR_ID(kPolicyInformationTrailingData,
"PolicyInformation has trailing data");
DEFINE_CERT_ERROR_ID(kFailedParsingPolicyQualifiers,
"Failed parsing policy qualifiers");
DEFINE_CERT_ERROR_ID(kMissingQualifier,
"PolicyQualifierInfo is missing qualifier");
DEFINE_CERT_ERROR_ID(kPolicyQualifierInfoTrailingData,
"PolicyQualifierInfo has trailing data");
// -- policyQualifierIds for Internet policy qualifiers
//
// id-qt OBJECT IDENTIFIER ::= { id-pkix 2 }
// id-qt-cps OBJECT IDENTIFIER ::= { id-qt 1 }
//
// In dotted decimal form: 1.3.6.1.5.5.7.2.1
const der::Input CpsPointerId() {
static const uint8_t cps_pointer_id[] = {0x2b, 0x06, 0x01, 0x05,
0x05, 0x07, 0x02, 0x01};
return der::Input(cps_pointer_id);
}
// id-qt-unotice OBJECT IDENTIFIER ::= { id-qt 2 }
//
// In dotted decimal form: 1.3.6.1.5.5.7.2.2
const der::Input UserNoticeId() {
static const uint8_t user_notice_id[] = {0x2b, 0x06, 0x01, 0x05,
0x05, 0x07, 0x02, 0x02};
return der::Input(user_notice_id);
}
// Ignores the policyQualifiers, but does some minimal correctness checking.
// TODO(mattm): parse and return the policyQualifiers, since the cert viewer
// still needs to display them.
bool ParsePolicyQualifiers(bool restrict_to_known_qualifiers,
der::Parser* policy_qualifiers_sequence_parser,
CertErrors* errors) {
DCHECK(errors);
// If it is present, the policyQualifiers sequence should have at least 1
// element.
//
// policyQualifiers SEQUENCE SIZE (1..MAX) OF
// PolicyQualifierInfo OPTIONAL }
if (!policy_qualifiers_sequence_parser->HasMore()) {
errors->AddError(kPolicyQualifiersEmptySequence);
return false;
}
while (policy_qualifiers_sequence_parser->HasMore()) {
// PolicyQualifierInfo ::= SEQUENCE {
der::Parser policy_information_parser;
if (!policy_qualifiers_sequence_parser->ReadSequence(
&policy_information_parser)) {
return false;
}
// policyQualifierId PolicyQualifierId,
der::Input qualifier_oid;
if (!policy_information_parser.ReadTag(der::kOid, &qualifier_oid))
return false;
if (restrict_to_known_qualifiers && qualifier_oid != CpsPointerId() &&
qualifier_oid != UserNoticeId()) {
errors->AddError(kUnknownPolicyQualifierOid,
CreateCertErrorParams1Der("oid", qualifier_oid));
return false;
}
// qualifier ANY DEFINED BY policyQualifierId }
der::Tag tag;
der::Input value;
if (!policy_information_parser.ReadTagAndValue(&tag, &value)) {
errors->AddError(kMissingQualifier);
return false;
}
// Should not have trailing data after qualifier.
if (policy_information_parser.HasMore()) {
errors->AddError(kPolicyQualifierInfoTrailingData);
return false;
}
}
return true;
}
} // namespace
const der::Input AnyPolicy() {
// id-ce OBJECT IDENTIFIER ::= {joint-iso-ccitt(2) ds(5) 29}
//
// id-ce-certificatePolicies OBJECT IDENTIFIER ::= { id-ce 32 }
//
// anyPolicy OBJECT IDENTIFIER ::= { id-ce-certificatePolicies 0 }
//
// In dotted decimal form: 2.5.29.32.0
static const uint8_t any_policy[] = {0x55, 0x1D, 0x20, 0x00};
return der::Input(any_policy);
}
der::Input InhibitAnyPolicyOid() {
// From RFC 5280:
//
// id-ce-inhibitAnyPolicy OBJECT IDENTIFIER ::= { id-ce 54 }
//
// In dotted notation: 2.5.29.54
static const uint8_t oid[] = {0x55, 0x1d, 0x36};
return der::Input(oid);
}
der::Input PolicyMappingsOid() {
// From RFC 5280:
//
// id-ce-policyMappings OBJECT IDENTIFIER ::= { id-ce 33 }
//
// In dotted notation: 2.5.29.33
static const uint8_t oid[] = {0x55, 0x1d, 0x21};
return der::Input(oid);
}
// RFC 5280 section 4.2.1.4. Certificate Policies:
//
// certificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation
//
// PolicyInformation ::= SEQUENCE {
// policyIdentifier CertPolicyId,
// policyQualifiers SEQUENCE SIZE (1..MAX) OF
// PolicyQualifierInfo OPTIONAL }
//
// CertPolicyId ::= OBJECT IDENTIFIER
//
// PolicyQualifierInfo ::= SEQUENCE {
// policyQualifierId PolicyQualifierId,
// qualifier ANY DEFINED BY policyQualifierId }
//
// PolicyQualifierId ::= OBJECT IDENTIFIER ( id-qt-cps | id-qt-unotice )
//
// Qualifier ::= CHOICE {
// cPSuri CPSuri,
// userNotice UserNotice }
//
// CPSuri ::= IA5String
//
// UserNotice ::= SEQUENCE {
// noticeRef NoticeReference OPTIONAL,
// explicitText DisplayText OPTIONAL }
//
// NoticeReference ::= SEQUENCE {
// organization DisplayText,
// noticeNumbers SEQUENCE OF INTEGER }
//
// DisplayText ::= CHOICE {
// ia5String IA5String (SIZE (1..200)),
// visibleString VisibleString (SIZE (1..200)),
// bmpString BMPString (SIZE (1..200)),
// utf8String UTF8String (SIZE (1..200)) }
bool ParseCertificatePoliciesExtension(const der::Input& extension_value,
bool fail_parsing_unknown_qualifier_oids,
std::vector<der::Input>* policies,
CertErrors* errors) {
DCHECK(errors);
// certificatePolicies ::= SEQUENCE SIZE (1..MAX) OF PolicyInformation
der::Parser extension_parser(extension_value);
der::Parser policies_sequence_parser;
if (!extension_parser.ReadSequence(&policies_sequence_parser))
return false;
// Should not have trailing data after certificatePolicies sequence.
if (extension_parser.HasMore())
return false;
// The certificatePolicies sequence should have at least 1 element.
if (!policies_sequence_parser.HasMore()) {
errors->AddError(kPoliciesEmptySequence);
return false;
}
policies->clear();
while (policies_sequence_parser.HasMore()) {
// PolicyInformation ::= SEQUENCE {
der::Parser policy_information_parser;
if (!policies_sequence_parser.ReadSequence(&policy_information_parser))
return false;
// policyIdentifier CertPolicyId,
der::Input policy_oid;
if (!policy_information_parser.ReadTag(der::kOid, &policy_oid))
return false;
// Build the |policies| vector in sorted order (sorted on DER encoded policy
// OID). Use a binary search to check whether a duplicate policy is present,
// and if not, where to insert the policy to maintain the sorted order.
std::vector<der::Input>::iterator i =
std::lower_bound(policies->begin(), policies->end(), policy_oid);
// RFC 5280 section 4.2.1.4: A certificate policy OID MUST NOT appear more
// than once in a certificate policies extension.
if (i != policies->end() && *i == policy_oid) {
errors->AddError(kPoliciesDuplicateOid,
CreateCertErrorParams1Der("oid", policy_oid));
return false;
}
policies->insert(i, policy_oid);
if (!policy_information_parser.HasMore())
continue;
// policyQualifiers SEQUENCE SIZE (1..MAX) OF
// PolicyQualifierInfo OPTIONAL }
der::Parser policy_qualifiers_sequence_parser;
if (!policy_information_parser.ReadSequence(
&policy_qualifiers_sequence_parser)) {
return false;
}
// Should not have trailing data after policyQualifiers sequence.
if (policy_information_parser.HasMore()) {
errors->AddError(kPolicyInformationTrailingData);
return false;
}
// RFC 5280 section 4.2.1.4: When qualifiers are used with the special
// policy anyPolicy, they MUST be limited to the qualifiers identified in
// this section.
if (!ParsePolicyQualifiers(
fail_parsing_unknown_qualifier_oids || policy_oid == AnyPolicy(),
&policy_qualifiers_sequence_parser, errors)) {
errors->AddError(kFailedParsingPolicyQualifiers);
return false;
}
}
return true;
}
// From RFC 5280:
//
// PolicyConstraints ::= SEQUENCE {
// requireExplicitPolicy [0] SkipCerts OPTIONAL,
// inhibitPolicyMapping [1] SkipCerts OPTIONAL }
//
// SkipCerts ::= INTEGER (0..MAX)
bool ParsePolicyConstraints(const der::Input& policy_constraints_tlv,
ParsedPolicyConstraints* out) {
der::Parser parser(policy_constraints_tlv);
// PolicyConstraints ::= SEQUENCE {
der::Parser sequence_parser;
if (!parser.ReadSequence(&sequence_parser))
return false;
// RFC 5280 prohibits CAs from issuing PolicyConstraints as an empty sequence:
//
// Conforming CAs MUST NOT issue certificates where policy constraints
// is an empty sequence. That is, either the inhibitPolicyMapping field
// or the requireExplicitPolicy field MUST be present. The behavior of
// clients that encounter an empty policy constraints field is not
// addressed in this profile.
if (!sequence_parser.HasMore())
return false;
der::Input value;
if (!sequence_parser.ReadOptionalTag(der::ContextSpecificPrimitive(0), &value,
&out->has_require_explicit_policy)) {
return false;
}
if (out->has_require_explicit_policy) {
if (!ParseUint8(value, &out->require_explicit_policy)) {
// TODO(eroman): Surface reason for failure if length was longer than
// uint8.
return false;
}
} else {
out->require_explicit_policy = 0;
}
if (!sequence_parser.ReadOptionalTag(der::ContextSpecificPrimitive(1), &value,
&out->has_inhibit_policy_mapping)) {
return false;
}
if (out->has_inhibit_policy_mapping) {
if (!ParseUint8(value, &out->inhibit_policy_mapping)) {
// TODO(eroman): Surface reason for failure if length was longer than
// uint8.
return false;
}
} else {
out->inhibit_policy_mapping = 0;
}
// There should be no remaining data.
if (sequence_parser.HasMore() || parser.HasMore())
return false;
return true;
}
// From RFC 5280:
//
// InhibitAnyPolicy ::= SkipCerts
//
// SkipCerts ::= INTEGER (0..MAX)
bool ParseInhibitAnyPolicy(const der::Input& inhibit_any_policy_tlv,
uint8_t* num_certs) {
der::Parser parser(inhibit_any_policy_tlv);
// TODO(eroman): Surface reason for failure if length was longer than uint8.
if (!parser.ReadUint8(num_certs))
return false;
// There should be no remaining data.
if (parser.HasMore())
return false;
return true;
}
// From RFC 5280:
//
// PolicyMappings ::= SEQUENCE SIZE (1..MAX) OF SEQUENCE {
// issuerDomainPolicy CertPolicyId,
// subjectDomainPolicy CertPolicyId }
bool ParsePolicyMappings(const der::Input& policy_mappings_tlv,
std::vector<ParsedPolicyMapping>* mappings) {
mappings->clear();
der::Parser parser(policy_mappings_tlv);
// PolicyMappings ::= SEQUENCE SIZE (1..MAX) OF SEQUENCE {
der::Parser sequence_parser;
if (!parser.ReadSequence(&sequence_parser))
return false;
// Must be at least 1 mapping.
if (!sequence_parser.HasMore())
return false;
while (sequence_parser.HasMore()) {
der::Parser mapping_parser;
if (!sequence_parser.ReadSequence(&mapping_parser))
return false;
ParsedPolicyMapping mapping;
if (!mapping_parser.ReadTag(der::kOid, &mapping.issuer_domain_policy))
return false;
if (!mapping_parser.ReadTag(der::kOid, &mapping.subject_domain_policy))
return false;
// There shouldn't be extra unconsumed data.
if (mapping_parser.HasMore())
return false;
mappings->push_back(mapping);
}
// There shouldn't be extra unconsumed data.
if (parser.HasMore())
return false;
return true;
}
} // namespace net