FFI: Return serial numbers as botan_mp_t for X.509 certificates and CRL entries

doc/api_ref/ffi.rst

@@ -1701,7 +1701,11 @@ X.509 Certificates
 
 .. cpp:function:: int botan_x509_cert_get_serial_number(botan_x509_cert_t cert, uint8_t out[], size_t* out_len)
 
-   Return the serial number of the certificate.
+   Return the serial number of the certificate as big-endian encoded bytes.
+
+.. cpp:function:: int botan_x509_cert_serial_number(botan_x509_cert_t cert, botan_mp_t* serial_number)
+
+   Return the serial number of the certificate as a multi-precision integer.
 
 .. cpp:function:: int botan_x509_cert_is_ca(botan_x509_cert_t cert)
 
@@ -1985,9 +1989,13 @@ X.509 Certificate Revocation Lists
 
    Get the revocation date for the given CRL entry, as seconds since epoch.
 
+.. cpp:function:: int botan_x509_crl_entry_serial_number(botan_x509_crl_entry_t entry, botan_mp_t* serial_number)
+
+   Get the serial number for the given CRL entry as a multi-precision integer.
+
 .. cpp:function:: int botan_x509_crl_entry_view_serial_number(botan_x509_crl_entry_t entry, botan_view_ctx ctx, botan_view_bin_fn view)
 
-   View the serial number for the given CRL entry.
+   View the serial number for the given CRL entry, as big-endian encoded bytes.
 
 .. cpp:function:: int botan_x509_crl_entry_destroy(botan_x509_crl_entry_t entry)
 

src/lib/ffi/ffi.h

@@ -2161,6 +2161,7 @@ BOTAN_FFI_EXPORT(2, 0)
 int botan_x509_cert_get_fingerprint(botan_x509_cert_t cert, const char* hash, uint8_t out[], size_t* out_len);
 
 BOTAN_FFI_EXPORT(2, 0) int botan_x509_cert_get_serial_number(botan_x509_cert_t cert, uint8_t out[], size_t* out_len);
+BOTAN_FFI_EXPORT(3, 11) int botan_x509_cert_serial_number(botan_x509_cert_t cert, botan_mp_t* serial_number);
 BOTAN_FFI_EXPORT(2, 0) int botan_x509_cert_get_authority_key_id(botan_x509_cert_t cert, uint8_t out[], size_t* out_len);
 BOTAN_FFI_EXPORT(2, 0) int botan_x509_cert_get_subject_key_id(botan_x509_cert_t cert, uint8_t out[], size_t* out_len);
 
@@ -2415,6 +2416,12 @@ BOTAN_FFI_EXPORT(3, 11) int botan_x509_crl_entry_reason(botan_x509_crl_entry_t e
 BOTAN_FFI_EXPORT(3, 11)
 int botan_x509_crl_entry_revocation_date(botan_x509_crl_entry_t entry, uint64_t* time_since_epoch);
 
+/**
+* Return the serial number associated with the given CRL @p entry.
+*/
+BOTAN_FFI_EXPORT(3, 11)
+int botan_x509_crl_entry_serial_number(botan_x509_crl_entry_t entry, botan_mp_t* serial_number);
+
 /**
 * View the serial number associated with the given CRL @p entry.
 */

src/lib/ffi/ffi_cert.cpp

@@ -15,6 +15,7 @@
    #include <botan/x509_crl.h>
    #include <botan/x509cert.h>
    #include <botan/x509path.h>
+   #include <botan/internal/ffi_mp.h>
    #include <botan/internal/ffi_oid.h>
 #endif
 
@@ -273,6 +274,22 @@ int botan_x509_cert_get_serial_number(botan_x509_cert_t cert, uint8_t out[], siz
 #endif
 }
 
+int botan_x509_cert_serial_number(botan_x509_cert_t cert, botan_mp_t* serial_number) {
+#if defined(BOTAN_HAS_X509_CERTIFICATES)
+   return BOTAN_FFI_VISIT(cert, [=](const Botan::X509_Certificate& c) {
+      if(Botan::any_null_pointers(serial_number)) {
+         return BOTAN_FFI_ERROR_NULL_POINTER;
+      }
+
+      auto serial_bn = Botan::BigInt::from_bytes(c.serial_number());
+      return ffi_new_object(serial_number, std::make_unique<Botan::BigInt>(std::move(serial_bn)));
+   });
+#else
+   BOTAN_UNUSED(cert, serial_number);
+   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
+#endif
+}
+
 int botan_x509_cert_get_fingerprint(botan_x509_cert_t cert, const char* hash, uint8_t out[], size_t* out_len) {
 #if defined(BOTAN_HAS_X509_CERTIFICATES)
    // TODO(Botan4) change the type of out and remove this cast
@@ -887,6 +904,22 @@ int botan_x509_crl_entry_reason(botan_x509_crl_entry_t entry, int* reason_code)
 #endif
 }
 
+int botan_x509_crl_entry_serial_number(botan_x509_crl_entry_t entry, botan_mp_t* serial_number) {
+#if defined(BOTAN_HAS_X509_CERTIFICATES)
+   return BOTAN_FFI_VISIT(entry, [=](const Botan::CRL_Entry& e) {
+      if(Botan::any_null_pointers(serial_number)) {
+         return BOTAN_FFI_ERROR_NULL_POINTER;
+      }
+
+      auto serial_bn = Botan::BigInt::from_bytes(e.serial_number());
+      return ffi_new_object(serial_number, std::make_unique<Botan::BigInt>(std::move(serial_bn)));
+   });
+#else
+   BOTAN_UNUSED(entry, serial_number);
+   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
+#endif
+}
+
 int botan_x509_crl_entry_view_serial_number(botan_x509_crl_entry_t entry, botan_view_ctx ctx, botan_view_bin_fn view) {
 #if defined(BOTAN_HAS_X509_CERTIFICATES)
    return BOTAN_FFI_VISIT(

src/tests/test_ffi.cpp

@@ -732,6 +732,7 @@ class FFI_CRL_Test final : public FFI_Test {
 
          botan_x509_cert_t cert2;
          std::vector<uint8_t> cert2_serial;
+         botan_mp_t cert2_serial_bn;
          size_t cert2_serial_len = 0;
          REQUIRE_FFI_OK(botan_x509_cert_load_file, (&cert2, Test::data_file("x509/nist/test20/int.crt").c_str()));
          TEST_FFI_RC(0, botan_x509_is_revoked, (crl, cert2));
@@ -741,6 +742,7 @@ class FFI_CRL_Test final : public FFI_Test {
                      (cert2, nullptr, &cert2_serial_len));
          cert2_serial.resize(cert2_serial_len);
          TEST_FFI_OK(botan_x509_cert_get_serial_number, (cert2, cert2_serial.data(), &cert2_serial_len));
+         TEST_FFI_OK(botan_x509_cert_serial_number, (cert2, &cert2_serial_bn));
          TEST_FFI_OK(botan_x509_cert_destroy, (cert2));
 
          size_t entries;
@@ -749,14 +751,20 @@ class FFI_CRL_Test final : public FFI_Test {
          TEST_FFI_OK(botan_x509_crl_entries_count, (bytecrl, &entries));
          result.test_eq("no revoked cert", entries, 0);
 
+         ViewBytesSink serial;
+         TEST_FFI_OK(botan_mp_view_bin, (cert2_serial_bn, serial.delegate(), serial.callback()));
+         result.test_eq("serial == serial_bn", serial.get(), cert2_serial);
+         TEST_FFI_OK(botan_mp_destroy, (cert2_serial_bn));
+
          botan_x509_crl_entry_t entry;
          TEST_FFI_OK(botan_x509_crl_entries, (crl, 0, &entry));
 
-         ViewBytesSink serial;
          uint64_t ts;
          int reason;
+         botan_mp_t entry_serial_bn;
 
          TEST_FFI_OK(botan_x509_crl_entry_view_serial_number, (entry, serial.delegate(), serial.callback()));
+         TEST_FFI_OK(botan_x509_crl_entry_serial_number, (entry, &entry_serial_bn));
          TEST_FFI_OK(botan_x509_crl_entry_revocation_date, (entry, &ts));
          TEST_FFI_OK(botan_x509_crl_entry_reason, (entry, &reason));
          TEST_FFI_OK(botan_x509_crl_entry_destroy, (entry));
@@ -766,6 +774,10 @@ class FFI_CRL_Test final : public FFI_Test {
          result.test_is_eq("Revocation time", ts, Botan::calendar_point(1999, 1, 1, 12, 0, 0).seconds_since_epoch());
          result.test_eq("Revoked cert serial", serial.get(), cert2_serial);
 
+         TEST_FFI_OK(botan_mp_view_bin, (entry_serial_bn, serial.delegate(), serial.callback()));
+         result.test_eq("Revoked cert serial_bn", serial.get(), cert2_serial);
+         TEST_FFI_OK(botan_mp_destroy, (entry_serial_bn));
+
          TEST_FFI_RC(BOTAN_FFI_ERROR_OUT_OF_RANGE, botan_x509_crl_entries, (crl, 1, &entry));
          TEST_FFI_RC(BOTAN_FFI_ERROR_OUT_OF_RANGE, botan_x509_crl_entries, (bytecrl, 0, &entry));