diff --git a/testsuite/rsa2sexp-test.c b/testsuite/rsa2sexp-test.c
new file mode 100644
index 0000000000000000000000000000000000000000..7ff85dabe95d0b4836061daf3ae69e56747df172
--- /dev/null
+++ b/testsuite/rsa2sexp-test.c
@@ -0,0 +1,93 @@
+#include "testutils.h"
+
+#include "rsa.h"
+#include "buffer.h"
+
+int
+test_main(void)
+{
+#if HAVE_LIBGMP
+  struct rsa_public_key pub;
+  struct rsa_private_key priv;
+
+  struct nettle_buffer buffer;
+  
+  rsa_init_public_key(&pub);
+  rsa_init_private_key(&priv);
+
+  mpz_set_str(pub.n,
+	      "085c3408989acae4faec3cbbad91c90d34c1d259cd74121a"
+	      "36f38b0b51424a9b2be514a04377113a6cdafe79dd7d5f2e"
+	      "cc8b5e9661189b86a7b22239907c25", 16);
+  mpz_set_str(pub.e, "36ad4b1d", 16);
+
+  mpz_set_str(priv.d,
+	      "06ee6d4ff3c239e408150daf8117abfa36a40ad4455d9059"
+	      "a86d52f33a2de07418a0a699594588c64810248c9412d554"
+	      "f74af947c73c32007e87c92f0937ed", 16);
+
+  mpz_set_str(priv.p,
+	      "03259879b24315e9cf14254824c7935d807cdb6990f414a0"
+	      "f65e6065130a611f", 16);
+
+  mpz_set_str(priv.q,
+	      "02a81ba73bad45fc73b36deffce52d1b73e0747f4d8a8264"
+	      "8cecd310448ea63b", 16);
+
+  mpz_set_str(priv.a,
+	      "026cbdad5dd0046e093f060ecd5b4ac918e098b0278bb752"
+	      "b7cadd6a8944f0b9", 16);
+
+  mpz_set_str(priv.b,
+	      "0148751e622d6d58e3bb094afd6edacf7370351d068e2ce9"
+	      "f565c5528c4a7473", 16);
+
+  mpz_set_str(priv.c,
+	      "f8a458ea73a018dc6fa56863e3bc6de405f364f77dee6f09"
+	      "62679ea1a8282e", 16);
+
+  nettle_buffer_init(&buffer);
+  ASSERT(rsa_keypair_to_sexp(&buffer, &pub, &priv));
+  ASSERT(MEMEQH(buffer.size, buffer.contents,
+		"2831313a707269766174652d6b657928"
+		"333a72736128313a6e36333a085c3408"
+		"989acae4faec3cbbad91c90d34c1d259"
+		"cd74121a36f38b0b51424a9b2be514a0"
+		"4377113a6cdafe79dd7d5f2ecc8b5e96"
+		"61189b86a7b22239907c252928313a65"
+		"343a36ad4b1d2928313a6436333a06ee"
+		"6d4ff3c239e408150daf8117abfa36a4"
+		"0ad4455d9059a86d52f33a2de07418a0"
+		"a699594588c64810248c9412d554f74a"
+		"f947c73c32007e87c92f0937ed292831"
+		"3a7033323a03259879b24315e9cf1425"
+		"4824c7935d807cdb6990f414a0f65e60"
+		"65130a611f2928313a7133323a02a81b"
+		"a73bad45fc73b36deffce52d1b73e074"
+		"7f4d8a82648cecd310448ea63b292831"
+		"3a6133323a026cbdad5dd0046e093f06"
+		"0ecd5b4ac918e098b0278bb752b7cadd"
+		"6a8944f0b92928313a6233323a014875"
+		"1e622d6d58e3bb094afd6edacf737035"
+		"1d068e2ce9f565c5528c4a7473292831"
+		"3a6333313af8a458ea73a018dc6fa568"
+		"63e3bc6de405f364f77dee6f0962679e"
+		"a1a8282e292929"));
+
+  nettle_buffer_clear(&buffer);
+  ASSERT(rsa_keypair_to_sexp(&buffer, &pub, NULL));
+  ASSERT(MEMEQH(buffer.size, buffer.contents,
+		"2831303a7075626c69632d6b65792833"
+		"3a72736128313a6e36333a085c340898"
+		"9acae4faec3cbbad91c90d34c1d259cd"
+		"74121a36f38b0b51424a9b2be514a043"
+		"77113a6cdafe79dd7d5f2ecc8b5e9661"
+		"189b86a7b22239907c252928313a6534"
+		"3a36ad4b1d292929"));
+  
+  SUCCESS();
+  
+#else /* !HAVE_LIBGMP */
+  SKIP();
+#endif /* !HAVE_LIBGMP */
+}
diff --git a/testsuite/sexp-format-test.c b/testsuite/sexp-format-test.c
new file mode 100644
index 0000000000000000000000000000000000000000..0f0ffd2e9b1336dd2c66a043466c8d3515b35d25
--- /dev/null
+++ b/testsuite/sexp-format-test.c
@@ -0,0 +1,44 @@
+#include "testutils.h"
+#include "sexp.h"
+
+#include "buffer.h"
+#include "bignum.h"
+
+int
+test_main(void)
+{
+  struct nettle_buffer buffer;
+  const uint8_t e1[] = "(3:foo(3:bar17:xxxxxxxxxxxxxxxxx))";
+  
+  nettle_buffer_init(&buffer);
+  ASSERT(sexp_format(&buffer, "(%s(%s%s))",
+		     "foo", "bar", "xxxxxxxxxxxxxxxxx"));
+
+  ASSERT(buffer.size == strlen(e1));
+  ASSERT(MEMEQ(buffer.size, buffer.contents, e1));
+
+  nettle_buffer_clear(&buffer);
+  
+#if HAVE_LIBGMP
+  {
+    mpz_t x;
+    const uint8_t e2[] = "(3:foo(3:bar11:abcdefghijk))";
+    
+    nettle_mpz_init_set_str_256(x, 11, "abcdefghijk");
+    nettle_buffer_init(&buffer);
+
+    ASSERT(sexp_format(&buffer, "(%s(%s%b))",
+		     "foo", "bar", x));
+
+    ASSERT(buffer.size == strlen(e2));
+    ASSERT(MEMEQ(buffer.size, buffer.contents, e2));
+
+    nettle_buffer_clear(&buffer);
+    mpz_clear(x);
+  }
+#endif /* HAVE_LIBGMP */
+
+  SUCCESS();
+}
+
+  
diff --git a/testsuite/sexp2rsa-test.c b/testsuite/sexp2rsa-test.c
new file mode 100644
index 0000000000000000000000000000000000000000..3296644ed46e09e5cd4b0fd592aabbd6b0a23e7b
--- /dev/null
+++ b/testsuite/sexp2rsa-test.c
@@ -0,0 +1,50 @@
+#include "testutils.h"
+
+#include "rsa.h"
+
+int
+test_main(void)
+{
+#if HAVE_LIBGMP
+  struct rsa_public_key pub;
+  struct rsa_private_key priv;
+  
+  rsa_init_public_key(&pub);
+  rsa_init_private_key(&priv);
+
+  ASSERT(rsa_keypair_from_sexp
+	 (&pub, &priv,
+	  HL("2831313a707269766174652d6b657928"
+	     "333a72736128313a6e36333a085c3408"
+	     "989acae4faec3cbbad91c90d34c1d259"
+	     "cd74121a36f38b0b51424a9b2be514a0"
+	     "4377113a6cdafe79dd7d5f2ecc8b5e96"
+	     "61189b86a7b22239907c252928313a65"
+	     "343a36ad4b1d2928313a6436333a06ee"
+	     "6d4ff3c239e408150daf8117abfa36a4"
+	     "0ad4455d9059a86d52f33a2de07418a0"
+	     "a699594588c64810248c9412d554f74a"
+	     "f947c73c32007e87c92f0937ed292831"
+	     "3a7033323a03259879b24315e9cf1425"
+	     "4824c7935d807cdb6990f414a0f65e60"
+	     "65130a611f2928313a7133323a02a81b"
+	     "a73bad45fc73b36deffce52d1b73e074"
+	     "7f4d8a82648cecd310448ea63b292831"
+	     "3a6133323a026cbdad5dd0046e093f06"
+	     "0ecd5b4ac918e098b0278bb752b7cadd"
+	     "6a8944f0b92928313a6233323a014875"
+	     "1e622d6d58e3bb094afd6edacf737035"
+	     "1d068e2ce9f565c5528c4a7473292831"
+	     "3a6333313af8a458ea73a018dc6fa568"
+	     "63e3bc6de405f364f77dee6f0962679e"
+	     "a1a8282e292929")));
+
+  test_rsa_key(&pub, &priv);
+  
+  SUCCESS();
+  
+#else /* !HAVE_LIBGMP */
+  SKIP();
+#endif /* !HAVE_LIBGMP */
+}
+