diff --git a/der2dsa.c b/der2dsa.c
new file mode 100644
index 0000000000000000000000000000000000000000..61529b48a8df743dd9e2c86c34a634ae4485e3df
--- /dev/null
+++ b/der2dsa.c
@@ -0,0 +1,117 @@
+/* der2dsa.c
+ *
+ * Decoding of DSA keys in OpenSSL and X509.1 format.
+ */
+
+/* nettle, low-level cryptographics library
+ *
+ * Copyright (C) 2005, 2009 Niels M�ller, Magnus Holmgren
+ *  
+ * The nettle library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at your
+ * option) any later version.
+ * 
+ * The nettle library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the nettle library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#if HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "dsa.h"
+
+#include "bignum.h"
+#include "asn1.h"
+
+#define GET(i, x, l)					\
+(asn1_der_iterator_next((i)) == ASN1_ITERATOR_PRIMITIVE	\
+ && (i)->type == ASN1_INTEGER				\
+ && asn1_der_get_bignum((i), (x), (l))			\
+ && mpz_sgn((x)) > 0)
+
+int
+dsa_public_key_from_der_iterators(struct dsa_public_key *pub,
+				 unsigned limit,
+				 struct asn1_der_iterator *i,
+				 struct asn1_der_iterator *j)
+{
+  /* DSAPublicKey ::= INTEGER
+     Dss-Parms ::= SEQUENCE {
+	 p  INTEGER,
+	 q  INTEGER,
+	 g  INTEGER
+     }
+  */
+
+  return (i->type == ASN1_INTEGER
+	  && asn1_der_get_bignum(i, pub->y, limit)
+	  && mpz_sgn(pub->y) > 0
+	  && j->type == ASN1_INTEGER
+	  && asn1_der_get_bignum(j, pub->p, limit)
+	  && mpz_sgn(pub->p) > 0
+	  && GET(j, pub->q, limit)
+	  && GET(j, pub->g, limit)
+	  && asn1_der_iterator_next(i) == ASN1_ITERATOR_END);
+}
+
+/* FIXME: Rename this and the next function to something
+   openssl-specific? */
+int
+dsa_private_key_from_der_iterator(struct dsa_public_key *pub,
+				  struct dsa_private_key *priv,
+				  unsigned limit,
+				  struct asn1_der_iterator *i)
+{
+  /* DSAPrivateKey ::= SEQUENCE {
+         version           Version,
+	 p                 INTEGER,
+	 q                 INTEGER,
+	 g                 INTEGER,
+	 pub_key           INTEGER,  -- y
+	 priv_key          INTEGER,  -- x
+    }
+  */
+
+  uint32_t version;
+  
+  return (i->type == ASN1_SEQUENCE
+	  asn1_der_decode_constructed_last(i) == ASN1_ITERATOR_PRIMITIVE
+	  && i->type == ASN1_INTEGER
+	  && asn1_der_get_uint32(i, &version)
+	  && version == 0
+	  && GET(i, pub->p, limit)
+	  && GET(i, pub->q, limit)
+	  && GET(i, pub->g, limit)
+	  && GET(i, pub->y, limit)
+	  && GET(i, priv->x, limit)
+	  && asn1_der_iterator_next(i) == ASN1_ITERATOR_END);
+}
+
+int
+dsa_keypair_from_der(struct dsa_public_key *pub,
+		     struct dsa_private_key *priv,
+		     unsigned limit,
+		     unsigned length, const uint8_t *data)
+{
+  struct asn1_der_iterator i;
+  enum asn1_iterator_result res;
+
+  res = asn1_der_iterator_first(&i, length, data);
+
+  if (res != ASN1_ITERATOR_CONSTRUCTED)
+    return 0;
+
+  if (priv)
+    return dsa_private_key_from_der_iterator(pub, priv, limit, &i);
+  else
+    return 0;
+}
diff --git a/dsa2sexp.c b/dsa2sexp.c
new file mode 100644
index 0000000000000000000000000000000000000000..7cc05499948417244f017bf917537b166ec5ac85
--- /dev/null
+++ b/dsa2sexp.c
@@ -0,0 +1,54 @@
+/* dsa2sexp.c
+ *
+ */
+
+/* nettle, low-level cryptographics library
+ *
+ * Copyright (C) 2002-2009 Niels M�ller
+ *  
+ * The nettle library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at your
+ * option) any later version.
+ * 
+ * The nettle library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the nettle library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#if HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "dsa.h"
+
+#include "sexp.h"
+
+int
+dsa_keypair_to_sexp(struct nettle_buffer *buffer,
+		    const char *algorithm_name,
+		    const struct dsa_public_key *pub,
+		    const struct dsa_private_key *priv)
+{
+  if (!algorithm_name)
+    algorithm_name = "dsa";
+  
+  if (priv)
+    return sexp_format(buffer,
+		       "(private-key(%0s(p%b)(q%b)"
+		       "(g%b)(y%b)(x%b)))",
+		       algorithm_name, pub->p, pub->q,
+		       pub->g, pub->y, priv->x);
+  else
+    return sexp_format(buffer,
+		       "(public-key(%0s(p%b)(q%b)"
+		       "(g%b)(y%b)))",
+		       algorithm_name, pub->p, pub->q,
+		       pub->g, pub->y);
+}