diff --git a/dsa.h b/dsa.h
index beb15ddab25e90a29d42200aa86ee926c4926755..5214c36a67e44b1ed61be55debaee2fee3a9ee6e 100644
--- a/dsa.h
+++ b/dsa.h
@@ -153,6 +153,10 @@ dsa_generate_keypair(struct dsa_public_key *pub,
 
 struct sexp_iterator;
 
+int
+dsa_signature_from_sexp(struct dsa_signature *rs,
+			struct sexp_iterator *i);
+
 int
 dsa_keypair_from_sexp_alist(struct dsa_public_key *pub,
 			    struct dsa_private_key *priv,
diff --git a/sexp2dsa.c b/sexp2dsa.c
index 357b3cf85401d05560c7ba0dceb1c3013f559df6..4d99cf4a7d0cf9cbef434399ab293732570ab4ea 100644
--- a/sexp2dsa.c
+++ b/sexp2dsa.c
@@ -87,4 +87,20 @@ dsa_keypair_from_sexp(struct dsa_public_key *pub,
     && dsa_keypair_from_sexp_alist(pub, priv, limit, &i);
 }
 
+int
+dsa_signature_from_sexp(struct dsa_signature *rs,
+			struct sexp_iterator *i)
+{
+  static const uint8_t *names[2] = { "r", "s" };
+  struct sexp_iterator values[2];
+
+  if (!sexp_iterator_assoc(i, 2, names, values))
+    return 0;
+
+  GET(rs->r, 160, &values[0]);
+  GET(rs->s, 160, &values[1]);
+
+  return 1;
+}
+
 #endif /* WITH_PUBLIC_KEY */