Index: src/crypto/x509.c
===================================================================
--- src/crypto/x509.c	(revision 58)
+++ src/crypto/x509.c	(working copy)
@@ -688,6 +688,48 @@
     return Py_None;
 }
 
+static char crypto_X509_modulus_doc[] = "\n\
+Print the RSA / DSA key modulus.\n\
+\n\
+@return: modulus\n\
+";
+
+static PyObject *
+crypto_X509_modulus(crypto_X509Obj *self, PyObject *args)
+{
+    EVP_PKEY *pkey;
+    PyObject *str;
+    char *tmp_str;
+    int str_len;
+    BIO *bio = BIO_new(BIO_s_mem());
+
+    if (!PyArg_ParseTuple(args, ":modulus"))
+    {
+        BIO_free(bio);
+        return NULL;
+    }
+
+    if ((pkey = X509_get_pubkey(self->x509)) == NULL)
+    {
+        BIO_free(bio);
+        exception_from_error_queue(crypto_Error);
+        return NULL;
+    }
+
+    if (pkey->type == EVP_PKEY_RSA)
+        BN_print(bio, pkey->pkey.rsa->n);
+    else
+    if (pkey->type == EVP_PKEY_DSA)
+        BN_print(bio, pkey->pkey.dsa->pub_key);
+
+    EVP_PKEY_free(pkey);
+    str_len = BIO_get_mem_data(bio, &tmp_str);
+    str = PyString_FromStringAndSize(tmp_str, str_len);
+    BIO_free(bio);
+
+    return str;
+}
+
 /*
  * ADD_METHOD(name) expands to a correct PyMethodDef declaration
  *   {  'name', (PyCFunction)crypto_X509_name, METH_VARARGS }
@@ -718,6 +760,7 @@
     ADD_METHOD(subject_name_hash),
     ADD_METHOD(digest),
     ADD_METHOD(add_extensions),
+    ADD_METHOD(modulus),
     { NULL, NULL }
 };
 #undef ADD_METHOD
Index: src/crypto/pkey.c
===================================================================
--- src/crypto/pkey.c	(revision 58)
+++ src/crypto/pkey.c	(working copy)
@@ -106,7 +106,50 @@
     return PyInt_FromLong(self->pkey->type);
 }
 
+static char crypto_PKey_modulus_doc[] = "\n\
+Print the RSA / DSA key modulus.\n\
+\n\
+@return: modulus\n\
+";
 
+static PyObject *
+crypto_PKey_modulus(crypto_PKeyObj *self, PyObject *args)
+{
+    EVP_PKEY *pkey;
+    PyObject *str;
+    char *tmp_str;
+    int str_len;
+    BIO *bio = BIO_new(BIO_s_mem());
+    RSA *rsa=NULL;
+    DSA *dsa=NULL;
+
+    if (!PyArg_ParseTuple(args, ":modulus"))
+    {
+        BIO_free(bio);
+        return NULL;
+    }
+
+    if (self->pkey->type == EVP_PKEY_RSA)
+    {
+        rsa = EVP_PKEY_get1_RSA(self->pkey);
+        BN_print(bio, rsa->n);
+    }
+    else
+    if (self->pkey->type == EVP_PKEY_DSA)
+    {
+        dsa = EVP_PKEY_get1_DSA(pkey);
+        BN_print(bio, dsa->pub_key);
+    }
+
+    str_len = BIO_get_mem_data(bio, &tmp_str);
+    str = PyString_FromStringAndSize(tmp_str, str_len);
+    BIO_free(bio);
+
+    return str;
+}
+
+
+
 /*
  * ADD_METHOD(name) expands to a correct PyMethodDef declaration
  *   {  'name', (PyCFunction)crypto_PKey_name, METH_VARARGS }
@@ -119,6 +162,7 @@
     ADD_METHOD(generate_key),
     ADD_METHOD(bits),
     ADD_METHOD(type),
+    ADD_METHOD(modulus),
     { NULL, NULL }
 };
 #undef ADD_METHOD