Add CertificateParametersBuilder as a replacement for X509_Cert_Options

src/cli/perf_x509.cpp

@@ -15,12 +15,14 @@
    #include <botan/ber_dec.h>
    #include <botan/bigint.h>
    #include <botan/der_enc.h>
+   #include <botan/dns_name.h>
+   #include <botan/email.h>
    #include <botan/pk_algs.h>
    #include <botan/pk_keys.h>
    #include <botan/rng.h>
+   #include <botan/x509_builder.h>
    #include <botan/x509_ca.h>
    #include <botan/x509_ext.h>
-   #include <botan/x509self.h>
 #endif
 
 namespace Botan_CLI {
@@ -44,14 +46,23 @@ class PerfTest_ASN1_Parsing final : public PerfTest {
       }
 
       static CA create_ca(Botan::RandomNumberGenerator& rng) {
-         auto root_cert_options = Botan::X509_Cert_Options("Benchmark Root/DE/RS/CS");
-         root_cert_options.dns = "unobtainium.example.com";
-         root_cert_options.email = "idont@exist.com";
-         root_cert_options.is_CA = true;
-
          auto root_key = create_private_key(rng);
          BOTAN_ASSERT_NONNULL(root_key);
-         auto root_cert = Botan::X509::create_self_signed_cert(root_cert_options, *root_key, get_hash_function(), rng);
+
+         Botan::CertificateParametersBuilder root_cert_params;
+         root_cert_params.add_common_name("Benchmark Root")
+            .add_country("DE")
+            .add_organization("RS")
+            .add_organizational_unit("CS")
+            .add_dns(Botan::DNSName::from_string("unobtainium.example.com").value())
+            .add_email(Botan::EmailAddress::from_string("idont@exist.com").value())
+            .set_as_ca_certificate();
+
+         const auto not_before = std::chrono::system_clock::now();
+         const auto not_after = not_before + std::chrono::seconds(86400);
+
+         auto root_cert =
+            root_cert_params.into_self_signed_cert(not_before, not_after, *root_key, rng, get_hash_function());
          auto ca = Botan::X509_CA(root_cert, *root_key, get_hash_function(), rng);
 
          return CA{

src/lib/utils/types.h

@@ -86,7 +86,7 @@ namespace Botan {
 *        TLS::Client, TLS::Server, TLS::Policy, TLS::Protocol_Version, TLS::Callbacks, TLS::Ciphersuite,
 *        TLS::Session, TLS::Session_Summary, TLS::Session_Manager, Credentials_Manager
 * <dt>X.509<dd>
-*        X509_Certificate, X509_CRL, X509_CA, Certificate_Extension, PKCS10_Request, X509_Cert_Options,
+*        X509_Certificate, X509_CRL, X509_CA, Certificate_Extension, PKCS10_Request, CertificateParametersBuilder,
 *        Certificate_Store, Certificate_Store_In_SQL, Certificate_Store_In_SQLite
 * <dt>eXtendable Output Functions<dd>
 *        @ref Ascon_XOF128 "Ascon-XOF128", @ref SHAKE_XOF "SHAKE"

src/lib/x509/info.txt

@@ -26,6 +26,7 @@ ocsp.h
 pkcs10.h
 pkix_enums.h
 pkix_types.h
+x509_builder.h
 x509_ca.h
 x509_crl.h
 x509_ext.h

src/lib/x509/pkix_enums.h

@@ -180,6 +180,8 @@ class BOTAN_PUBLIC_API(3, 0) Key_Constraints final {
 
       void operator|=(Key_Constraints::Bits other) { m_value |= other; }
 
+      void operator|=(Key_Constraints other) { m_value |= other.m_value; }
+
       // Return true if all bits in mask are set
       bool includes(Key_Constraints::Bits other) const { return (m_value & other) == other; }
 

src/lib/x509/x509_builder.cpp

@@ -0,0 +1,304 @@
+/*
+* (C) 2025 Jack Lloyd
+*
+* Botan is released under the Simplified BSD License (see license.txt)
+*/
+
+#include <botan/x509_builder.h>
+
+#include <botan/assert.h>
+#include <botan/dns_name.h>
+#include <botan/email.h>
+#include <botan/ipv4_address.h>
+#include <botan/ipv6_address.h>
+#include <botan/pubkey.h>
+#include <botan/uri.h>
+#include <botan/x509_ca.h>
+#include <botan/x509_ext.h>
+#include <botan/internal/fmt.h>
+
+namespace Botan {
+
+class CertificateParametersBuilder::State final {
+   public:
+      const X509_DN& subject_dn() const { return m_subject_dn; }
+
+      Extensions finalize_extensions(const Public_Key& key) const {
+         auto extensions = m_extensions;
+
+         extensions.replace(setup_alt_name(extensions));
+
+         extensions.add_new(
+            std::make_unique<Cert_Extension::Basic_Constraints>(m_is_ca_request, m_path_limit.value_or(0)), true);
+
+         const Key_Constraints usage = this->usage();
+
+         if(!usage.empty()) {
+            if(!usage.compatible_with(key)) {
+               throw Invalid_Argument("The requested key usage is incompatible with the algorithm");
+            }
+
+            extensions.add_new(std::make_unique<Cert_Extension::Key_Usage>(usage), true);
+         }
+
+         if(!m_ext_usage.empty()) {
+            extensions.add_new(std::make_unique<Cert_Extension::Extended_Key_Usage>(m_ext_usage));
+         }
+
+         return extensions;
+      }
+
+      Key_Constraints usage() const {
+         if(m_is_ca_request) {
+            return Key_Constraints::ca_constraints();
+         } else {
+            return m_usage;
+         }
+      }
+
+      void add_common_name(std::string_view cn) { add_subject_dn("common_name", "X520.CommonName", cn); }
+
+      void add_country(std::string_view country) { add_subject_dn("country", "X520.Country", country); }
+
+      void add_state(std::string_view state) { add_subject_dn("state", "X520.State", state); }
+
+      void add_locality(std::string_view locality) { add_subject_dn("locality", "X520.Locality", locality); }
+
+      void add_serial_number(std::string_view sn) { add_subject_dn("serial_number", "X520.SerialNumber", sn); }
+
+      void add_organization(std::string_view org) { add_subject_dn("organization", "X520.Organization", org); }
+
+      void add_organizational_unit(std::string_view org_unit) {
+         add_subject_dn("organizational_unit", "X520.OrganizationalUnit", org_unit);
+      }
+
+      void add_extension(std::unique_ptr<Certificate_Extension> extn, bool is_critical) {
+         if(!m_extensions.add_new(std::move(extn), is_critical)) {
+            throw Invalid_Argument("CertificateParametersBuilder::add_extension: cannot add same extension twice");
+         }
+      }
+
+      void add_email(const EmailAddress& email) { m_email.push_back(email); }
+
+      void add_dns(const DNSName& dns) { m_dns.push_back(dns); }
+
+      void add_uri(const URI& uri) { m_uri.push_back(uri); }
+
+      void add_xmpp(std::string_view xmpp) { m_xmpp.emplace_back(xmpp); }
+
+      void add_ipv4(const IPv4Address& ipv4) { m_ipv4.push_back(ipv4); }
+
+      void add_ipv6(const IPv6Address& ipv6) { m_ipv6.push_back(ipv6); }
+
+      void add_allowed_usage(Key_Constraints usage) { m_usage |= usage; }
+
+      void add_allowed_extended_usage(const OID& usage) { m_ext_usage.push_back(usage); }
+
+      void set_as_ca_certificate(std::optional<size_t> path_limit) {
+         if(m_is_ca_request) {
+            throw Invalid_State("CertificateParametersBuilder::set_as_ca_certificate cannot be called twice");
+         } else {
+            m_is_ca_request = true;
+            m_path_limit = path_limit;
+         }
+      }
+
+   private:
+      void add_subject_dn(std::string_view fn_suffix, std::string_view attr, std::string_view value) {
+         const auto oid = OID::from_string(attr);
+         const size_t ub = X509_DN::lookup_ub(oid);
+
+         if(value.empty()) {
+            throw Invalid_Argument(fmt("CertificateParametersBuilder::add_{}: empty name is prohibited", fn_suffix));
+         }
+
+         if(value.size() > ub) {
+            throw Invalid_Argument(
+               fmt("CertificateParametersBuilder::add_{}: name exceeds maximum allowed length ({}) for this type",
+                   fn_suffix,
+                   ub));
+         }
+         m_subject_dn.add_attribute(oid, value);
+      }
+
+      std::unique_ptr<Certificate_Extension> setup_alt_name(const Extensions& extensions) const {
+         AlternativeName subject_alt;
+
+         /*
+         If the extension was already created in extensions we need to merge the
+         values provided with the extension value
+         */
+         if(const auto* ext = extensions.get_extension_object_as<Cert_Extension::Subject_Alternative_Name>()) {
+            subject_alt = ext->get_alt_name();
+         }
+
+         for(const auto& dns : m_dns) {
+            subject_alt.add_dns(dns.name());
+         }
+         for(const auto& uri : m_uri) {
+            subject_alt.add_uri(uri.original_input());
+         }
+         for(const auto& email : m_email) {
+            subject_alt.add_email(email.to_string());
+         }
+         for(const auto& xmpp : m_xmpp) {
+            subject_alt.add_other_name(OID::from_string("PKIX.XMPPAddr"), ASN1_String(xmpp, ASN1_Type::Utf8String));
+         }
+         for(const auto& ipv4 : m_ipv4) {
+            subject_alt.add_ipv4_address(ipv4);
+         }
+         for(const auto& ipv6 : m_ipv6) {
+            subject_alt.add_ipv6_address(ipv6);
+         }
+
+         return std::make_unique<Cert_Extension::Subject_Alternative_Name>(subject_alt);
+      }
+
+      X509_DN m_subject_dn;
+      Extensions m_extensions;
+      Key_Constraints m_usage;
+      std::vector<EmailAddress> m_email;
+      std::vector<DNSName> m_dns;
+      std::vector<URI> m_uri;
+      std::vector<std::string> m_xmpp;
+      std::vector<IPv4Address> m_ipv4;
+      std::vector<IPv6Address> m_ipv6;
+      std::vector<OID> m_ext_usage;
+      bool m_is_ca_request = false;
+      std::optional<size_t> m_path_limit;
+};
+
+CertificateParametersBuilder::CertificateParametersBuilder() :
+      m_state(std::make_unique<CertificateParametersBuilder::State>()) {}
+
+CertificateParametersBuilder::CertificateParametersBuilder(CertificateParametersBuilder&& other) noexcept = default;
+
+CertificateParametersBuilder::~CertificateParametersBuilder() = default;
+
+X509_Certificate CertificateParametersBuilder::into_self_signed_cert(std::chrono::system_clock::time_point not_before,
+                                                                     std::chrono::system_clock::time_point not_after,
+                                                                     const Private_Key& key,
+                                                                     RandomNumberGenerator& rng,
+                                                                     std::optional<std::string_view> hash_fn,
+                                                                     std::optional<std::string_view> padding) const {
+   auto signer_p = X509_Object::choose_sig_format(key, rng, hash_fn.value_or(""), padding.value_or(""));
+   auto& signer = *signer_p;
+
+   const AlgorithmIdentifier sig_algo = signer.algorithm_identifier();
+   BOTAN_ASSERT_NOMSG(sig_algo.oid().has_value());
+
+   Extensions extensions = m_state->finalize_extensions(key);
+
+   const std::vector<uint8_t> pub_key = key.subject_public_key();
+   auto skid = std::make_unique<Cert_Extension::Subject_Key_ID>(pub_key, signer.hash_function());
+
+   extensions.add_new(std::make_unique<Cert_Extension::Authority_Key_ID>(skid->get_key_id()));
+   extensions.add_new(std::move(skid));
+
+   const auto& subject_dn = m_state->subject_dn();
+
+   return X509_CA::make_cert(
+      signer, rng, sig_algo, pub_key, X509_Time(not_before), X509_Time(not_after), subject_dn, subject_dn, extensions);
+}
+
+PKCS10_Request CertificateParametersBuilder::into_pkcs10_request(
+   const Private_Key& key,
+   RandomNumberGenerator& rng,
+   std::optional<std::string_view> hash_fn,
+   std::optional<std::string_view> padding,
+   std::optional<std::string_view> challenge_password) const {
+   const auto& subject_dn = m_state->subject_dn();
+
+   const auto extensions = m_state->finalize_extensions(key);
+
+   return PKCS10_Request::create(
+      key, subject_dn, extensions, hash_fn.value_or(""), rng, padding.value_or(""), challenge_password.value_or(""));
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_common_name(std::string_view cn) {
+   m_state->add_common_name(cn);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_country(std::string_view country) {
+   m_state->add_country(country);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_organization(std::string_view org) {
+   m_state->add_organization(org);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_organizational_unit(std::string_view org_unit) {
+   m_state->add_organizational_unit(org_unit);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_locality(std::string_view locality) {
+   m_state->add_locality(locality);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_state(std::string_view state) {
+   m_state->add_state(state);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_serial_number(std::string_view serial) {
+   m_state->add_serial_number(serial);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_email(const EmailAddress& email) {
+   m_state->add_email(email);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_uri(const URI& uri) {
+   m_state->add_uri(uri);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_dns(const DNSName& dns) {
+   m_state->add_dns(dns);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_ipv4(const IPv4Address& ipv4) {
+   m_state->add_ipv4(ipv4);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_ipv6(const IPv6Address& ipv6) {
+   m_state->add_ipv6(ipv6);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_xmpp(std::string_view xmpp) {
+   m_state->add_xmpp(xmpp);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_allowed_usage(Key_Constraints kc) {
+   m_state->add_allowed_usage(kc);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_allowed_extended_usage(const OID& usage) {
+   m_state->add_allowed_extended_usage(usage);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::add_extension(std::unique_ptr<Certificate_Extension> extn,
+                                                                          bool is_critical) {
+   m_state->add_extension(std::move(extn), is_critical);
+   return (*this);
+}
+
+CertificateParametersBuilder& CertificateParametersBuilder::set_as_ca_certificate(std::optional<size_t> path_limit) {
+   m_state->set_as_ca_certificate(path_limit);
+   return (*this);
+}
+
+}  // namespace Botan