Constify the parameter getters for RSA, DSA and DH

Including documentation changes

Reviewed-by: Stephen Henson <steve@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>
diff --git a/doc/crypto/RSA_get0_key.pod b/doc/crypto/RSA_get0_key.pod
index 19c7f3d..77e0d3b 100644
--- a/doc/crypto/RSA_get0_key.pod
+++ b/doc/crypto/RSA_get0_key.pod
@@ -14,10 +14,12 @@
  int RSA_set0_key(RSA *r, BIGNUM *n, BIGNUM *e, BIGNUM *d);
  int RSA_set0_factors(RSA *r, BIGNUM *p, BIGNUM *q);
  int RSA_set0_crt_params(RSA *r,BIGNUM *dmp1, BIGNUM *dmq1, BIGNUM *iqmp);
- void RSA_get0_key(const RSA *r, BIGNUM **n, BIGNUM **e, BIGNUM **d);
- void RSA_get0_factors(const RSA *r, BIGNUM **p, BIGNUM **q);
+ void RSA_get0_key(const RSA *r,
+                   const BIGNUM **n, const BIGNUM **e, const BIGNUM **d);
+ void RSA_get0_factors(const RSA *r, const BIGNUM **p, const BIGNUM **q);
  void RSA_get0_crt_params(const RSA *r,
-                          BIGNUM **dmp1, BIGNUM **dmq1, BIGNUM **iqmp);
+                          const BIGNUM **dmp1, const BIGNUM **dmq1,
+                          const BIGNUM **iqmp);
  void RSA_clear_flags(RSA *r, int flags);
  int RSA_test_flags(const RSA *r, int flags);
  void RSA_set_flags(RSA *r, int flags);