diff --git a/bignum.c b/bignum.c
index 97e90a7..c2b39b1 100644
--- a/bignum.c
+++ b/bignum.c
@@ -93,7 +93,7 @@ void bytes_to_mp(mp_int *mp, const unsigned char* bytes, unsigned int len) {
 
 /* hash the ssh representation of the mp_int mp */
 void hash_process_mp(const struct ltc_hash_descriptor *hash_desc, 
-				hash_state *hs, mp_int *mp) {
+				hash_state *hs, const mp_int *mp) {
 	buffer * buf;
 
 	buf = buf_new(512 + 20); /* max buffer is a 4096 bit key, 
diff --git a/bignum.h b/bignum.h
index bab65ef..861acb0 100644
--- a/bignum.h
+++ b/bignum.h
@@ -33,6 +33,6 @@ void m_mp_alloc_init_multi(mp_int **mp, ...) ATTRIB_SENTINEL;
 void m_mp_free_multi(mp_int **mp, ...)  ATTRIB_SENTINEL;
 void bytes_to_mp(mp_int *mp, const unsigned char* bytes, unsigned int len);
 void hash_process_mp(const struct ltc_hash_descriptor *hash_desc, 
-				hash_state *hs, mp_int *mp);
+				hash_state *hs, const mp_int *mp);
 
 #endif /* DROPBEAR_BIGNUM_H_ */
diff --git a/buffer.c b/buffer.c
index a3ed426..1377b77 100644
--- a/buffer.c
+++ b/buffer.c
@@ -299,7 +299,7 @@ void buf_putbytes(buffer *buf, const unsigned char *bytes, unsigned int len) {
 
 /* for our purposes we only need positive (or 0) numbers, so will
  * fail if we get negative numbers */
-void buf_putmpint(buffer* buf, mp_int * mp) {
+void buf_putmpint(buffer* buf, const mp_int * mp) {
 	size_t written;
 	unsigned int len, pad = 0;
 	TRACE2(("enter buf_putmpint"))
diff --git a/buffer.h b/buffer.h
index 279e9c4..0ba6683 100644
--- a/buffer.h
+++ b/buffer.h
@@ -65,7 +65,7 @@ void buf_putint(buffer* buf, unsigned int val);
 void buf_putstring(buffer* buf, const char* str, unsigned int len);
 void buf_putbufstring(buffer *buf, const buffer* buf_str);
 void buf_putbytes(buffer *buf, const unsigned char *bytes, unsigned int len);
-void buf_putmpint(buffer* buf, mp_int * mp);
+void buf_putmpint(buffer* buf, const mp_int * mp);
 int buf_getmpint(buffer* buf, mp_int* mp);
 unsigned int buf_getint(buffer* buf);
 
diff --git a/dbrandom.c b/dbrandom.c
index 755645c..41aaa48 100644
--- a/dbrandom.c
+++ b/dbrandom.c
@@ -347,7 +347,7 @@ void genrandom(unsigned char* buf, unsigned int len) {
  * rand must be an initialised *mp_int for the result.
  * the result rand satisfies:  0 < rand < max 
  * */
-void gen_random_mpint(mp_int *max, mp_int *rand) {
+void gen_random_mpint(const mp_int *max, mp_int *rand) {
 
 	unsigned char *randbuf = NULL;
 	unsigned int len = 0;
diff --git a/dbrandom.h b/dbrandom.h
index 7f49b6a..1db2c2f 100644
--- a/dbrandom.h
+++ b/dbrandom.h
@@ -30,6 +30,6 @@
 void seedrandom(void);
 void genrandom(unsigned char* buf, unsigned int len);
 void addrandom(const unsigned char * buf, unsigned int len);
-void gen_random_mpint(mp_int *max, mp_int *rand);
+void gen_random_mpint(const mp_int *max, mp_int *rand);
 
 #endif /* DROPBEAR_RANDOM_H_ */
diff --git a/dbutil.c b/dbutil.c
index 08206f9..e8831c5 100644
--- a/dbutil.c
+++ b/dbutil.c
@@ -442,7 +442,7 @@ void printhex(const char * label, const unsigned char * buf, int len) {
 	}
 }
 
-void printmpint(const char *label, mp_int *mp) {
+void printmpint(const char *label, const mp_int *mp) {
 	buffer *buf = buf_new(1000);
 	buf_putmpint(buf, mp);
 	fprintf(stderr, "%d bits ", mp_count_bits(mp));
diff --git a/dbutil.h b/dbutil.h
index 64af170..df2f89b 100644
--- a/dbutil.h
+++ b/dbutil.h
@@ -53,7 +53,7 @@ void dropbear_trace3(const char* format, ...) ATTRIB_PRINTF(1,2);
 void dropbear_trace4(const char* format, ...) ATTRIB_PRINTF(1,2);
 void dropbear_trace5(const char* format, ...) ATTRIB_PRINTF(1,2);
 void printhex(const char * label, const unsigned char * buf, int len);
-void printmpint(const char *label, mp_int *mp);
+void printmpint(const char *label, const mp_int *mp);
 void debug_start_net(void);
 extern int debug_trace;
 #endif
diff --git a/genrsa.c b/genrsa.c
index 71a46a6..e249d6e 100644
--- a/genrsa.c
+++ b/genrsa.c
@@ -34,7 +34,7 @@
 #if DROPBEAR_RSA
 
 static void getrsaprime(mp_int* prime, mp_int *primeminus, 
-		mp_int* rsa_e, unsigned int size_bytes);
+		const mp_int* rsa_e, unsigned int size_bytes);
 
 /* mostly taken from libtomcrypt's rsa key generation routine */
 dropbear_rsa_key * gen_rsa_priv_key(unsigned int size) {
@@ -89,7 +89,7 @@ dropbear_rsa_key * gen_rsa_priv_key(unsigned int size) {
 
 /* return a prime suitable for p or q */
 static void getrsaprime(mp_int* prime, mp_int *primeminus, 
-		mp_int* rsa_e, unsigned int size_bytes) {
+		const mp_int* rsa_e, unsigned int size_bytes) {
 
 	unsigned char *buf;
 	int trials;