diff --git a/Makefile.in b/Makefile.in

index 3b0e1cb..ebef2c4 100644

--- a/Makefile.in

+++ b/Makefile.in

@@ -176,7 +176,7 @@ DISTFILES = $(SOURCES) $(HEADERS) getopt.h .bootstrap run-tests \

 	cast128_sboxes.h desinfo.h desCode.h \

 	nettle-internal.h nettle-write.h prime-list.h \

 	gmp-glue.h ecc-internal.h \

-	mini-gmp.h mini-gmp.c asm.m4 \

+	mini-gmp.h mini-gmp.c asm.m4 bignum-internal.h \

 	nettle.texinfo nettle.info nettle.html nettle.pdf sha-example.c

 # Rules building static libraries

diff --git a/bignum-internal.h b/bignum-internal.h

new file mode 100644

index 0000000..26a7cdb

--- /dev/null

+++ b/bignum-internal.h

@@ -0,0 +1,36 @@

+/* bignum-internal.h

+ *

+ */

+

+/* nettle, low-level cryptographics library

+ *

+ * Copyright (C) 2013 Red Hat

+ *  

+ * 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., 51 Franklin Street, Fifth Floor, Boston,

+ * MA 02111-1301, USA.

+ */

+

+#ifndef BIGNUM_INTERNAL_H

+# define BIGNUM_INTERNAL_H

+

+#include <gmp-glue.h>

+

+#define TMP_GMP_DECL(name, type) type *name; \

+	unsigned tmp_##name##_size

+#define TMP_GMP_ALLOC(name, size) \

+	(name = gmp_alloc(&tmp_##name##_size, sizeof (*name) * (size)))

+#define TMP_GMP_FREE(name) (gmp_free(name, tmp_##name##_size))

+

+#endif

diff --git a/bignum-next-prime.c b/bignum-next-prime.c

index 58a4df8..bc89399 100644

--- a/bignum-next-prime.c

+++ b/bignum-next-prime.c

@@ -31,6 +31,7 @@

 #include <stdlib.h>

 #include "bignum.h"

+#include "bignum-internal.h"

 #include "nettle-internal.h"

@@ -77,9 +78,8 @@ nettle_next_prime(mpz_t p, mpz_t n, unsigned count, unsigned prime_limit,

 		  void *progress_ctx, nettle_progress_func *progress)

 {

   mpz_t tmp;

-  TMP_DECL(moduli, unsigned, NUMBER_OF_PRIMES);

-  

   unsigned difference;

+  TMP_GMP_DECL(moduli, unsigned);

   if (prime_limit > NUMBER_OF_PRIMES)

     prime_limit = NUMBER_OF_PRIMES;

@@ -112,7 +112,8 @@ nettle_next_prime(mpz_t p, mpz_t n, unsigned count, unsigned prime_limit,

      between the 5760 odd numbers in this interval that have no factor

      in common with 15015.

    */

-  TMP_ALLOC(moduli, prime_limit);

+  TMP_GMP_ALLOC(moduli, prime_limit);

+

   {

     unsigned i;

     for (i = 0; i < prime_limit; i++)

@@ -159,4 +160,5 @@ nettle_next_prime(mpz_t p, mpz_t n, unsigned count, unsigned prime_limit,

 #endif

     }

   mpz_clear(tmp);

+  TMP_GMP_FREE(moduli);

 }

diff --git a/bignum-random.c b/bignum-random.c

index f305f04..07ae1ba 100644

--- a/bignum-random.c

+++ b/bignum-random.c

@@ -30,6 +30,7 @@

 #include <stdlib.h>

 #include "bignum.h"

+#include "bignum-internal.h"

 #include "nettle-internal.h"

 void

@@ -38,15 +39,17 @@ nettle_mpz_random_size(mpz_t x,

 		       unsigned bits)

 {

   unsigned length = (bits + 7) / 8;

-  TMP_DECL(data, uint8_t, NETTLE_MAX_BIGNUM_SIZE);

-  TMP_ALLOC(data, length);

+  TMP_GMP_DECL(data, uint8_t);

-  random(ctx, length, data);

+  TMP_GMP_ALLOC(data, length);

+  random(ctx, length, data);

   nettle_mpz_set_str_256_u(x, length, data);

   if (bits % 8)

     mpz_fdiv_r_2exp(x, x, bits);

+  

+  TMP_GMP_FREE(data);

 }

 /* Returns a random number x, 0 <= x < n */

diff --git a/gmp-glue.c b/gmp-glue.c

index a2633a5..991e793 100644

--- a/gmp-glue.c

+++ b/gmp-glue.c

@@ -239,3 +239,24 @@ gmp_free_limbs (mp_limb_t *p, mp_size_t n)

   free_func (p, (size_t) n * sizeof(mp_limb_t));

 }

+

+void* gmp_alloc(unsigned* out_n, size_t n)

+{

+	void *(*alloc_func)(size_t);

+	assert (n > 0);

+

+	mp_get_memory_functions(&alloc_func, NULL, NULL);

+	

+	*out_n = n;

+	return alloc_func (n);

+}

+

+void gmp_free(void* p, size_t n)

+{

+  void (*free_func)(void *, size_t);

+  assert (n > 0);

+  assert (p != 0);

+  mp_get_memory_functions (NULL, NULL, &free_func);

+

+  free_func (p, (size_t) n);

+}

diff --git a/gmp-glue.h b/gmp-glue.h

index 269667f..ff936a1 100644

--- a/gmp-glue.h

+++ b/gmp-glue.h

@@ -65,6 +65,8 @@

 #define mpn_set_base256 _nettle_mpn_set_base256

 #define gmp_alloc_limbs _nettle_gmp_alloc_limbs

 #define gmp_free_limbs _nettle_gmp_free_limbs

+#define gmp_free _nettle_gmp_free

+#define gmp_alloc _nettle_gmp_alloc

 /* Use only in-place operations, so we can fall back to addmul_1/submul_1 */

 #ifdef mpn_cnd_add_n

@@ -155,5 +157,7 @@ gmp_alloc_limbs (mp_size_t n);

 void

 gmp_free_limbs (mp_limb_t *p, mp_size_t n);

+void* gmp_alloc(unsigned* out_n, size_t n);

+void gmp_free(void* p, size_t n);

 #endif /* NETTLE_GMP_GLUE_H_INCLUDED */

diff --git a/pkcs1-decrypt.c b/pkcs1-decrypt.c

index 754fd51..89b4dcf 100644

--- a/pkcs1-decrypt.c

+++ b/pkcs1-decrypt.c

@@ -31,6 +31,7 @@

 #include "pkcs1.h"

 #include "bignum.h"

+#include "bignum-internal.h"

 #include "nettle-internal.h"

 int

@@ -38,35 +39,50 @@ pkcs1_decrypt (unsigned key_size,

 	       const mpz_t m,

 	       unsigned *length, uint8_t *message)

 {

-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);

+  TMP_GMP_DECL(em, uint8_t);

   uint8_t *terminator;

-  unsigned padding;

-  unsigned message_length;

-

-  TMP_ALLOC(em, key_size);

+  size_t padding;

+  size_t message_length;

+  int ret;

+ 

+  TMP_GMP_ALLOC(em, key_size);

   nettle_mpz_get_str_256(key_size, em, m);

-

+ 

   /* Check format */

   if (em[0] || em[1] != 2)

-    return 0;

-

+    {

+     ret = 0;

+     goto cleanup;

+    }

+ 

   terminator = memchr(em + 2, 0, key_size - 2);

-

+ 

   if (!terminator)

-    return 0;

+    {

+     ret = 0;

+     goto cleanup;

+    }

   padding = terminator - (em + 2);

   if (padding < 8)

-    return 0;

-

+    {

+     ret = 0;

+     goto cleanup;

+    }

+ 

   message_length = key_size - 3 - padding;

-

+ 

   if (*length < message_length)

-    return 0;

+    {

+     ret = 0;

+     goto cleanup;

+    }

   memcpy(message, terminator + 1, message_length);

   *length = message_length;

-

-  return 1;

+ 

+  ret = 1;

+cleanup:

+  TMP_GMP_FREE(em);

+  return ret;

 }

-	       

diff --git a/pkcs1-encrypt.c b/pkcs1-encrypt.c

index cde19bc..5246455 100644

--- a/pkcs1-encrypt.c

+++ b/pkcs1-encrypt.c

@@ -34,6 +34,7 @@

 #include "pkcs1.h"

 #include "bignum.h"

+#include "bignum-internal.h"

 #include "nettle-internal.h"

 int

@@ -43,7 +44,7 @@ pkcs1_encrypt (unsigned key_size,

 	       unsigned length, const uint8_t *message,

 	       mpz_t m)

 {

-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);

+  TMP_GMP_DECL(em, uint8_t);

   unsigned padding;

   unsigned i;

@@ -63,7 +64,7 @@ pkcs1_encrypt (unsigned key_size,

   padding = key_size - length - 3;

   assert(padding >= 8);

-  TMP_ALLOC(em, key_size - 1);

+  TMP_GMP_ALLOC(em, key_size - 1);

   em[0] = 2;

   random(random_ctx, padding, em + 1);

@@ -77,5 +78,7 @@ pkcs1_encrypt (unsigned key_size,

   memcpy(em + padding + 2, message, length);

   nettle_mpz_set_str_256_u(m, key_size - 1, em);

+  

+  TMP_GMP_FREE(em);

   return 1;

 }

diff --git a/pkcs1-rsa-digest.c b/pkcs1-rsa-digest.c

index e4a6c52..3379b8f 100644

--- a/pkcs1-rsa-digest.c

+++ b/pkcs1-rsa-digest.c

@@ -29,21 +29,27 @@

 #include "pkcs1.h"

 #include "bignum.h"

+#include "bignum-internal.h"

 #include "nettle-internal.h"

 int

 pkcs1_rsa_digest_encode(mpz_t m, unsigned key_size,

 			unsigned di_length, const uint8_t *digest_info)

 {

-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);

-  TMP_ALLOC(em, key_size);

+  TMP_GMP_DECL(em, uint8_t);

+

+  TMP_GMP_ALLOC(em, key_size);

   if (_pkcs1_signature_prefix(key_size, em,

 			      di_length, digest_info, 0))

     {

       nettle_mpz_set_str_256_u(m, key_size, em);

+      TMP_GMP_FREE(em);

       return 1;

     }

   else

-    return 0;

+    {

+      TMP_GMP_FREE(em);

+      return 0;

+    }

 }

diff --git a/pkcs1-rsa-md5.c b/pkcs1-rsa-md5.c

index 00514fc..e5edaf3 100644

--- a/pkcs1-rsa-md5.c

+++ b/pkcs1-rsa-md5.c

@@ -34,6 +34,7 @@

 #include "rsa.h"

 #include "bignum.h"

+#include "bignum-internal.h"

 #include "pkcs1.h"

 #include "nettle-internal.h"

@@ -65,8 +66,9 @@ int

 pkcs1_rsa_md5_encode(mpz_t m, unsigned key_size, struct md5_ctx *hash)

 {

   uint8_t *p;

-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);

-  TMP_ALLOC(em, key_size);

+  TMP_GMP_DECL(em, uint8_t);

+

+  TMP_GMP_ALLOC(em, key_size);

   p = _pkcs1_signature_prefix(key_size, em,

 			      sizeof(md5_prefix),

@@ -76,18 +78,23 @@ pkcs1_rsa_md5_encode(mpz_t m, unsigned key_size, struct md5_ctx *hash)

     {

       md5_digest(hash, MD5_DIGEST_SIZE, p);

       nettle_mpz_set_str_256_u(m, key_size, em);

+      TMP_GMP_FREE(em);

       return 1;

     }

   else

-    return 0;

+    {

+      TMP_GMP_FREE(em);

+      return 0;

+    }

 }

 int

 pkcs1_rsa_md5_encode_digest(mpz_t m, unsigned key_size, const uint8_t *digest)

 {

   uint8_t *p;

-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);

-  TMP_ALLOC(em, key_size);

+  TMP_GMP_DECL(em, uint8_t);

+

+  TMP_GMP_ALLOC(em, key_size);

   p = _pkcs1_signature_prefix(key_size, em,

 			      sizeof(md5_prefix),

@@ -97,8 +104,12 @@ pkcs1_rsa_md5_encode_digest(mpz_t m, unsigned key_size, const uint8_t *digest)

     {

       memcpy(p, digest, MD5_DIGEST_SIZE);

       nettle_mpz_set_str_256_u(m, key_size, em);

+      TMP_GMP_FREE(em);

       return 1;

     }

   else

-    return 0;

+    {

+      TMP_GMP_FREE(em);

+      return 0;

+    }

 }

diff --git a/pkcs1-rsa-sha1.c b/pkcs1-rsa-sha1.c

index 2951618..2a68121 100644

--- a/pkcs1-rsa-sha1.c

+++ b/pkcs1-rsa-sha1.c

@@ -34,6 +34,7 @@

 #include "rsa.h"

 #include "bignum.h"

+#include "bignum-internal.h"

 #include "pkcs1.h"

 #include "nettle-internal.h"

@@ -65,8 +66,9 @@ int

 pkcs1_rsa_sha1_encode(mpz_t m, unsigned key_size, struct sha1_ctx *hash)

 {

   uint8_t *p;

-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);

-  TMP_ALLOC(em, key_size);

+  TMP_GMP_DECL(em, uint8_t);

+

+  TMP_GMP_ALLOC(em, key_size);

   p = _pkcs1_signature_prefix(key_size, em,

 			      sizeof(sha1_prefix),

@@ -76,18 +78,23 @@ pkcs1_rsa_sha1_encode(mpz_t m, unsigned key_size, struct sha1_ctx *hash)

     {

       sha1_digest(hash, SHA1_DIGEST_SIZE, p);

       nettle_mpz_set_str_256_u(m, key_size, em);

+      TMP_GMP_FREE(em);

       return 1;

     }

   else

-    return 0;

+    {

+      TMP_GMP_FREE(em);

+      return 0;

+    }

 }

 int

 pkcs1_rsa_sha1_encode_digest(mpz_t m, unsigned key_size, const uint8_t *digest)

 {

   uint8_t *p;

-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);

-  TMP_ALLOC(em, key_size);

+  TMP_GMP_DECL(em, uint8_t);

+

+  TMP_GMP_ALLOC(em, key_size);

   p = _pkcs1_signature_prefix(key_size, em,

 			      sizeof(sha1_prefix),

@@ -97,8 +104,12 @@ pkcs1_rsa_sha1_encode_digest(mpz_t m, unsigned key_size, const uint8_t *digest)

     {

       memcpy(p, digest, SHA1_DIGEST_SIZE);

       nettle_mpz_set_str_256_u(m, key_size, em);

+      TMP_GMP_FREE(em);

       return 1;

     }

   else

-    return 0;

+    {

+      TMP_GMP_FREE(em);

+      return 0;

+    }

 }

diff --git a/pkcs1-rsa-sha256.c b/pkcs1-rsa-sha256.c

index cb07375..3aaabe1 100644

--- a/pkcs1-rsa-sha256.c

+++ b/pkcs1-rsa-sha256.c

@@ -34,6 +34,7 @@

 #include "rsa.h"

 #include "bignum.h"

+#include "bignum-internal.h"

 #include "pkcs1.h"

 #include "nettle-internal.h"

@@ -63,8 +64,9 @@ int

 pkcs1_rsa_sha256_encode(mpz_t m, unsigned key_size, struct sha256_ctx *hash)

 {

   uint8_t *p;

-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);

-  TMP_ALLOC(em, key_size);

+  TMP_GMP_DECL(em, uint8_t);

+

+  TMP_GMP_ALLOC(em, key_size);

   p = _pkcs1_signature_prefix(key_size, em,

 			      sizeof(sha256_prefix),

@@ -74,18 +76,23 @@ pkcs1_rsa_sha256_encode(mpz_t m, unsigned key_size, struct sha256_ctx *hash)

     {

       sha256_digest(hash, SHA256_DIGEST_SIZE, p);

       nettle_mpz_set_str_256_u(m, key_size, em);

+      TMP_GMP_FREE(em);

       return 1;

     }

   else

-    return 0;	

+    {

+      TMP_GMP_FREE(em);

+      return 0;

+    }

 }

 int

 pkcs1_rsa_sha256_encode_digest(mpz_t m, unsigned key_size, const uint8_t *digest)

 {

   uint8_t *p;

-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);

-  TMP_ALLOC(em, key_size);

+  TMP_GMP_DECL(em, uint8_t);

+

+  TMP_GMP_ALLOC(em, key_size);

   p = _pkcs1_signature_prefix(key_size, em,

 			      sizeof(sha256_prefix),

@@ -95,8 +102,12 @@ pkcs1_rsa_sha256_encode_digest(mpz_t m, unsigned key_size, const uint8_t *digest

     {

       memcpy(p, digest, SHA256_DIGEST_SIZE);

       nettle_mpz_set_str_256_u(m, key_size, em);

+      TMP_GMP_FREE(em);

       return 1;

     }

   else

-    return 0;

+    {

+      TMP_GMP_FREE(em);

+      return 0;

+    }

 }

diff --git a/pkcs1-rsa-sha512.c b/pkcs1-rsa-sha512.c

index 3afd790..bd3d277 100644

--- a/pkcs1-rsa-sha512.c

+++ b/pkcs1-rsa-sha512.c

@@ -34,6 +34,7 @@

 #include "rsa.h"

 #include "bignum.h"

+#include "bignum-internal.h"

 #include "pkcs1.h"

 #include "nettle-internal.h"

@@ -63,8 +64,9 @@ int

 pkcs1_rsa_sha512_encode(mpz_t m, unsigned key_size, struct sha512_ctx *hash)

 {

   uint8_t *p;

-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);

-  TMP_ALLOC(em, key_size);

+  TMP_GMP_DECL(em, uint8_t);

+

+  TMP_GMP_ALLOC(em, key_size);

   p = _pkcs1_signature_prefix(key_size, em,

 			      sizeof(sha512_prefix),

@@ -74,18 +76,23 @@ pkcs1_rsa_sha512_encode(mpz_t m, unsigned key_size, struct sha512_ctx *hash)

     {

       sha512_digest(hash, SHA512_DIGEST_SIZE, p);

       nettle_mpz_set_str_256_u(m, key_size, em);

+      TMP_GMP_FREE(em);

       return 1;

     }

   else

-    return 0;

+    {

+      TMP_GMP_FREE(em);

+      return 0;

+    }

 }

 int

 pkcs1_rsa_sha512_encode_digest(mpz_t m, unsigned key_size, const uint8_t *digest)

 {

   uint8_t *p;

-  TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);

-  TMP_ALLOC(em, key_size);

+  TMP_GMP_DECL(em, uint8_t);

+

+  TMP_GMP_ALLOC(em, key_size);

   p = _pkcs1_signature_prefix(key_size, em,

 			      sizeof(sha512_prefix),

@@ -95,8 +102,12 @@ pkcs1_rsa_sha512_encode_digest(mpz_t m, unsigned key_size, const uint8_t *digest

     {

       memcpy(p, digest, SHA512_DIGEST_SIZE);

       nettle_mpz_set_str_256_u(m, key_size, em);

+      TMP_GMP_FREE(em);

       return 1;

     }

   else

-    return 0;

+    {

+      TMP_GMP_FREE(em);

+      return 0;

+    }

 }