diff options
Diffstat (limited to 'src/lib/x509/ocsp.cpp')
| -rw-r--r-- | src/lib/x509/ocsp.cpp | 208 |
1 files changed, 122 insertions, 86 deletions
diff --git a/src/lib/x509/ocsp.cpp b/src/lib/x509/ocsp.cpp index 761c5b436..af7126580 100644 --- a/src/lib/x509/ocsp.cpp +++ b/src/lib/x509/ocsp.cpp @@ -14,7 +14,10 @@ #include <botan/base64.h> #include <botan/pubkey.h> #include <botan/x509path.h> -#include <botan/http_util.h> + +#if defined(BOTAN_HAS_HTTP_UTIL) + #include <botan/http_util.h> +#endif namespace Botan { @@ -22,6 +25,7 @@ namespace OCSP { namespace { +// TODO: should this be in a header somewhere? void decode_optional_list(BER_Decoder& ber, ASN1_Tag tag, std::vector<X509_Certificate>& output) @@ -44,65 +48,18 @@ void decode_optional_list(BER_Decoder& ber, } } -void check_signature(const std::vector<byte>& tbs_response, - const AlgorithmIdentifier& sig_algo, - const std::vector<byte>& signature, - const X509_Certificate& cert) - { - std::unique_ptr<Public_Key> pub_key(cert.subject_public_key()); - - const std::vector<std::string> sig_info = - split_on(OIDS::lookup(sig_algo.oid), '/'); - - if(sig_info.size() != 2 || sig_info[0] != pub_key->algo_name()) - throw Exception("Information in OCSP response does not match cert"); - - std::string padding = sig_info[1]; - Signature_Format format = - (pub_key->message_parts() >= 2) ? DER_SEQUENCE : IEEE_1363; - - PK_Verifier verifier(*pub_key, padding, format); - - if(!verifier.verify_message(ASN1::put_in_sequence(tbs_response), signature)) - throw Exception("Signature on OCSP response does not verify"); - } +} -void check_signature(const std::vector<byte>& tbs_response, - const AlgorithmIdentifier& sig_algo, - const std::vector<byte>& signature, - const Certificate_Store& trusted_roots, - const std::vector<X509_Certificate>& certs) +Request::Request(const X509_Certificate& issuer_cert, + const X509_Certificate& subject_cert) : + m_issuer(issuer_cert), + m_subject(subject_cert), + m_certid(m_issuer, m_subject) { - if(certs.size() < 1) - throw Invalid_Argument("Short cert chain for check_signature"); - - if(trusted_roots.certificate_known(certs[0])) - return check_signature(tbs_response, sig_algo, signature, certs[0]); - - // Otherwise attempt to chain the signing cert to a trust root - - if(!certs[0].allowed_extended_usage("PKIX.OCSPSigning")) - throw Exception("OCSP response cert does not allow OCSP signing"); - - auto result = x509_path_validate(certs, Path_Validation_Restrictions(), trusted_roots); - - if(!result.successful_validation()) - throw Exception("Certificate validation failure: " + result.result_string()); - - if(!trusted_roots.certificate_known(result.trust_root())) // not needed anymore? - throw Exception("Certificate chain roots in unknown/untrusted CA"); - - const std::vector<std::shared_ptr<const X509_Certificate>>& cert_path = result.cert_path(); - - check_signature(tbs_response, sig_algo, signature, *cert_path[0]); } -} - std::vector<byte> Request::BER_encode() const { - CertID certid(m_issuer, m_subject); - return DER_Encoder().start_cons(SEQUENCE) .start_cons(SEQUENCE) .start_explicit(0) @@ -110,7 +67,7 @@ std::vector<byte> Request::BER_encode() const .end_explicit() .start_cons(SEQUENCE) .start_cons(SEQUENCE) - .encode(certid) + .encode(m_certid) .end_cons() .end_cons() .end_cons() @@ -122,8 +79,7 @@ std::string Request::base64_encode() const return Botan::base64_encode(BER_encode()); } -Response::Response(const Certificate_Store& trusted_roots, - const std::vector<byte>& response_bits) +Response::Response(const std::vector<byte>& response_bits) { BER_Decoder response_outer = BER_Decoder(response_bits).start_cons(SEQUENCE); @@ -145,71 +101,141 @@ Response::Response(const Certificate_Store& trusted_roots, BER_Decoder basicresponse = BER_Decoder(response_bytes.get_next_octet_string()).start_cons(SEQUENCE); - std::vector<byte> tbs_bits; - AlgorithmIdentifier sig_algo; - std::vector<byte> signature; - std::vector<X509_Certificate> certs; - basicresponse.start_cons(SEQUENCE) - .raw_bytes(tbs_bits) + .raw_bytes(m_tbs_bits) .end_cons() - .decode(sig_algo) - .decode(signature, BIT_STRING); - decode_optional_list(basicresponse, ASN1_Tag(0), certs); + .decode(m_sig_algo) + .decode(m_signature, BIT_STRING); + decode_optional_list(basicresponse, ASN1_Tag(0), m_certs); size_t responsedata_version = 0; - X509_DN name; - std::vector<byte> key_hash; - X509_Time produced_at; Extensions extensions; - BER_Decoder(tbs_bits) + BER_Decoder(m_tbs_bits) .decode_optional(responsedata_version, ASN1_Tag(0), ASN1_Tag(CONSTRUCTED | CONTEXT_SPECIFIC)) - .decode_optional(name, ASN1_Tag(1), + .decode_optional(m_signer_name, ASN1_Tag(1), ASN1_Tag(CONSTRUCTED | CONTEXT_SPECIFIC)) - .decode_optional_string(key_hash, OCTET_STRING, 2, + .decode_optional_string(m_key_hash, OCTET_STRING, 2, ASN1_Tag(CONSTRUCTED | CONTEXT_SPECIFIC)) - .decode(produced_at) + .decode(m_produced_at) .decode_list(m_responses) .decode_optional(extensions, ASN1_Tag(1), ASN1_Tag(CONSTRUCTED | CONTEXT_SPECIFIC)); + } + + response_outer.end_cons(); + } + +Certificate_Status_Code Response::verify_signature(const X509_Certificate& issuer) const + { + try + { + std::unique_ptr<Public_Key> pub_key(issuer.subject_public_key()); + + const std::vector<std::string> sig_info = + split_on(OIDS::lookup(m_sig_algo.oid), '/'); - if(certs.empty()) + if(sig_info.size() != 2 || sig_info[0] != pub_key->algo_name()) + return Certificate_Status_Code::OCSP_RESPONSE_INVALID; + + std::string padding = sig_info[1]; + Signature_Format format = (pub_key->message_parts() >= 2) ? DER_SEQUENCE : IEEE_1363; + + PK_Verifier verifier(*pub_key, padding, format); + + if(verifier.verify_message(ASN1::put_in_sequence(m_tbs_bits), m_signature)) + return Certificate_Status_Code::OCSP_SIGNATURE_OK; + else + return Certificate_Status_Code::OCSP_SIGNATURE_ERROR; + } + catch(Exception&) + { + return Certificate_Status_Code::OCSP_SIGNATURE_ERROR; + } + } + +Certificate_Status_Code Response::check_signature(const std::vector<Certificate_Store*>& trusted_roots, + const std::vector<std::shared_ptr<const X509_Certificate>>& ee_cert_path) const + { + std::shared_ptr<const X509_Certificate> signing_cert; + + for(size_t i = 0; i != trusted_roots.size(); ++i) + { + if(m_signer_name.empty() && m_key_hash.empty()) + return Certificate_Status_Code::OCSP_RESPONSE_INVALID; + + if(!m_signer_name.empty()) { - if(auto cert = trusted_roots.find_cert(name, std::vector<byte>())) - certs.push_back(*cert); - else - throw Exception("Could not find certificate that signed OCSP response"); + signing_cert = trusted_roots[i]->find_cert(m_signer_name, std::vector<byte>()); + if(signing_cert) + { + break; + } + } + + if(m_key_hash.size() > 0) + { + signing_cert = trusted_roots[i]->find_cert_by_pubkey_sha1(m_key_hash); + if(signing_cert) + { + break; + } } + } - check_signature(tbs_bits, sig_algo, signature, trusted_roots, certs); + if(!signing_cert) + { + for(size_t i = 1; i < ee_cert_path.size(); ++i) + { + // Check all CA certificates in the (assumed validated) EE cert path + if(!m_signer_name.empty() && ee_cert_path[i]->subject_dn() == m_signer_name) + { + signing_cert = ee_cert_path[i]; + break; + } + + if(m_key_hash.size() > 0 && ee_cert_path[i]->subject_public_key_bitstring_sha1() == m_key_hash) + { + signing_cert = ee_cert_path[i]; + break; + } + } } - response_outer.end_cons(); + // TODO: this ignores m_certs + + if(!signing_cert) + return Certificate_Status_Code::OCSP_ISSUER_NOT_FOUND; + + if(!signing_cert->allowed_extended_usage("PKIX.OCSPSigning")) + return Certificate_Status_Code::OCSP_RESPONSE_MISSING_KEYUSAGE; + + return this->verify_signature(*signing_cert); } Certificate_Status_Code Response::status_for(const X509_Certificate& issuer, - const X509_Certificate& subject) const + const X509_Certificate& subject, + std::chrono::system_clock::time_point ref_time) const { for(const auto& response : m_responses) { if(response.certid().is_id_for(issuer, subject)) { - X509_Time current_time(std::chrono::system_clock::now()); + X509_Time x509_ref_time(ref_time); if(response.cert_status() == 1) return Certificate_Status_Code::CERT_IS_REVOKED; - if(response.this_update() > current_time) + if(response.this_update() > x509_ref_time) return Certificate_Status_Code::OCSP_NOT_YET_VALID; - if(response.next_update().time_is_set() && current_time > response.next_update()) + if(response.next_update().time_is_set() && x509_ref_time > response.next_update()) return Certificate_Status_Code::OCSP_HAS_EXPIRED; if(response.cert_status() == 0) @@ -222,9 +248,11 @@ Certificate_Status_Code Response::status_for(const X509_Certificate& issuer, return Certificate_Status_Code::OCSP_CERT_NOT_LISTED; } +#if defined(BOTAN_HAS_HTTP_UTIL) + Response online_check(const X509_Certificate& issuer, const X509_Certificate& subject, - const Certificate_Store* trusted_roots) + Certificate_Store* trusted_roots) { const std::string responder_url = subject.ocsp_responder(); @@ -241,11 +269,19 @@ Response online_check(const X509_Certificate& issuer, // Check the MIME type? - OCSP::Response response(*trusted_roots, http.body()); + OCSP::Response response(http.body()); + + std::vector<Certificate_Store*> trusted_roots_vec; + trusted_roots_vec.push_back(trusted_roots); + + if(trusted_roots) + response.check_signature(trusted_roots_vec); return response; } +#endif + } } |