diff --git a/doc/api_ref/ffi.rst b/doc/api_ref/ffi.rst
index f797b0d6e15..30ee56fc970 100644
--- a/doc/api_ref/ffi.rst
+++ b/doc/api_ref/ffi.rst
@@ -1737,13 +1737,27 @@ X.509 Certificates
                                             const char* key, size_t index, \
                                             uint8_t out[], size_t* out_len)
 
-   Get a value from the issuer DN field.
+   Get a value from the issuer DN field. If the index is out of range,
+   :cpp:enumerator:`BOTAN_FFI_ERROR_BAD_PARAMETER` is returned for historical
+   reasons.
+
+.. cpp:function:: int botan_x509_cert_get_issuer_dn_count(botan_x509_cert_t cert, \
+                                                          const char* key, size_t* count)
+
+   Get the number of values for a given key in the issuer DN field.
 
 .. cpp:function:: int botan_x509_cert_get_subject_dn(botan_x509_cert_t cert, \
                                              const char* key, size_t index, \
                                              uint8_t out[], size_t* out_len)
 
-   Get a value from the subject DN field.
+   Get a value from the subject DN field. If the index is out of range,
+   :cpp:enumerator:`BOTAN_FFI_ERROR_BAD_PARAMETER` is returned for historical
+   reasons.
+
+.. cpp:function:: int botan_x509_cert_get_subject_dn_count(botan_x509_cert_t cert, \
+                                                           const char* key, size_t* count)
+
+   Get the number of values for a given key in the subject DN field.
 
 .. cpp:function:: int botan_x509_cert_to_string(botan_x509_cert_t cert, char out[], size_t* out_len)
 
diff --git a/src/lib/ffi/ffi.h b/src/lib/ffi/ffi.h
index 0fa22566799..e70b2208a16 100644
--- a/src/lib/ffi/ffi.h
+++ b/src/lib/ffi/ffi.h
@@ -2182,15 +2182,30 @@ BOTAN_FFI_EXPORT(3, 11) int botan_x509_cert_is_ca(botan_x509_cert_t cert);
  */
 BOTAN_FFI_EXPORT(3, 11) int botan_x509_cert_get_path_length_constraint(botan_x509_cert_t cert, size_t* path_limit);
 
-/* TODO(Botan4) this should use char for the out param */
+/**
+ * Enumerates the names of the given @p key in the issuer DN. If @p index is
+ * out of bounds, BOTAN_FFI_ERROR_BAD_PARAMETER is returned.
+ *
+ * TODO(Botan4) use BOTAN_FFI_ERROR_OUT_OF_RANGE instead of BAD_PARAMETER
+ * TODO(Botan4) this should use char for the out param
+ */
 BOTAN_FFI_EXPORT(2, 0)
 int botan_x509_cert_get_issuer_dn(
    botan_x509_cert_t cert, const char* key, size_t index, uint8_t out[], size_t* out_len);
+BOTAN_FFI_EXPORT(3, 11) int botan_x509_cert_get_issuer_dn_count(botan_x509_cert_t cert, const char* key, size_t* count);
 
-/* TODO(Botan4) this should use char for the out param */
+/**
+ * Enumerates the names of the given @p key in the subject DN. If @p index is
+ * out of bounds, BOTAN_FFI_ERROR_BAD_PARAMETER is returned.
+ *
+ * TODO(Botan4) use BOTAN_FFI_ERROR_OUT_OF_RANGE instead of BAD_PARAMETER
+ * TODO(Botan4) this should use char for the out param
+ */
 BOTAN_FFI_EXPORT(2, 0)
 int botan_x509_cert_get_subject_dn(
    botan_x509_cert_t cert, const char* key, size_t index, uint8_t out[], size_t* out_len);
+BOTAN_FFI_EXPORT(3, 11)
+int botan_x509_cert_get_subject_dn_count(botan_x509_cert_t cert, const char* key, size_t* count);
 
 BOTAN_FFI_EXPORT(2, 0) int botan_x509_cert_to_string(botan_x509_cert_t cert, char out[], size_t* out_len);
 
diff --git a/src/lib/ffi/ffi_cert.cpp b/src/lib/ffi/ffi_cert.cpp
index 7709ab04334..763f868a827 100644
--- a/src/lib/ffi/ffi_cert.cpp
+++ b/src/lib/ffi/ffi_cert.cpp
@@ -137,7 +137,7 @@ int botan_x509_cert_get_issuer_dn(
          // TODO(Botan4) change the type of out and remove this cast
          return write_str_output(reinterpret_cast<char*>(out), out_len, c.issuer_info(key).at(index));
       } else {
-         return BOTAN_FFI_ERROR_BAD_PARAMETER;
+         return BOTAN_FFI_ERROR_BAD_PARAMETER;  // TODO(Botan4): use BOTAN_FFI_ERROR_OUT_OF_RANGE
       }
    });
 #else
@@ -146,6 +146,22 @@ int botan_x509_cert_get_issuer_dn(
 #endif
 }
 
+int botan_x509_cert_get_issuer_dn_count(botan_x509_cert_t cert, const char* key, size_t* count) {
+#if defined(BOTAN_HAS_X509_CERTIFICATES)
+   return BOTAN_FFI_VISIT(cert, [=](const auto& c) -> int {
+      if(Botan::any_null_pointers(count)) {
+         return BOTAN_FFI_ERROR_NULL_POINTER;
+      }
+
+      *count = c.issuer_info(key).size();
+      return BOTAN_FFI_SUCCESS;
+   });
+#else
+   BOTAN_UNUSED(cert, key, count);
+   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
+#endif
+}
+
 int botan_x509_cert_get_subject_dn(
    botan_x509_cert_t cert, const char* key, size_t index, uint8_t out[], size_t* out_len) {
 #if defined(BOTAN_HAS_X509_CERTIFICATES)
@@ -155,7 +171,7 @@ int botan_x509_cert_get_subject_dn(
          // TODO(Botan4) change the type of out and remove this cast
          return write_str_output(reinterpret_cast<char*>(out), out_len, c.subject_info(key).at(index));
       } else {
-         return BOTAN_FFI_ERROR_BAD_PARAMETER;
+         return BOTAN_FFI_ERROR_BAD_PARAMETER;  // TODO(Botan4): use BOTAN_FFI_ERROR_OUT_OF_RANGE
       }
    });
 #else
@@ -164,6 +180,22 @@ int botan_x509_cert_get_subject_dn(
 #endif
 }
 
+int botan_x509_cert_get_subject_dn_count(botan_x509_cert_t cert, const char* key, size_t* count) {
+#if defined(BOTAN_HAS_X509_CERTIFICATES)
+   return BOTAN_FFI_VISIT(cert, [=](const auto& c) -> int {
+      if(Botan::any_null_pointers(count)) {
+         return BOTAN_FFI_ERROR_NULL_POINTER;
+      }
+
+      *count = c.subject_info(key).size();
+      return BOTAN_FFI_SUCCESS;
+   });
+#else
+   BOTAN_UNUSED(cert, key, count);
+   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
+#endif
+}
+
 int botan_x509_cert_to_string(botan_x509_cert_t cert, char out[], size_t* out_len) {
    return copy_view_str(reinterpret_cast<uint8_t*>(out), out_len, botan_x509_cert_view_as_string, cert);
 }
diff --git a/src/tests/test_ffi.cpp b/src/tests/test_ffi.cpp
index 0ad8bf206eb..9dfd50b1d24 100644
--- a/src/tests/test_ffi.cpp
+++ b/src/tests/test_ffi.cpp
@@ -968,6 +968,12 @@ class FFI_ECDSA_Certificate_Test final : public FFI_Test {
             }
    #endif
 
+            size_t rdn_count;
+            TEST_FFI_OK(botan_x509_cert_get_issuer_dn_count, (cert, "Name", &rdn_count));
+            result.test_eq("issuer DN 'name' count", rdn_count, 1);
+            TEST_FFI_OK(botan_x509_cert_get_issuer_dn_count, (cert, "Organizational Unit", &rdn_count));
+            result.test_eq("issuer DN 'organizational unit' count", rdn_count, 0);
+
             size_t dn_len = 0;
             TEST_FFI_RC(BOTAN_FFI_ERROR_INSUFFICIENT_BUFFER_SPACE,
                         botan_x509_cert_get_issuer_dn,
@@ -977,6 +983,11 @@ class FFI_ECDSA_Certificate_Test final : public FFI_Test {
             TEST_FFI_OK(botan_x509_cert_get_issuer_dn, (cert, "Name", 0, dn.data(), &dn_len));
             result.test_eq("issuer dn", reinterpret_cast<const char*>(dn.data()), "ISRG Root X2");
 
+            TEST_FFI_OK(botan_x509_cert_get_subject_dn_count, (cert, "Name", &rdn_count));
+            result.test_eq("subject DN 'name' count", rdn_count, 1);
+            TEST_FFI_OK(botan_x509_cert_get_subject_dn_count, (cert, "Organizational Unit", &rdn_count));
+            result.test_eq("subject DN 'organizational unit' count", rdn_count, 0);
+
             dn_len = 0;
             TEST_FFI_RC(BOTAN_FFI_ERROR_INSUFFICIENT_BUFFER_SPACE,
                         botan_x509_cert_get_subject_dn,