diff --git a/src/_cffi_src/openssl/rsa.py b/src/_cffi_src/openssl/rsa.py
index 79c968b..45e5379 100644
--- a/src/_cffi_src/openssl/rsa.py
+++ b/src/_cffi_src/openssl/rsa.py
@@ -55,9 +55,11 @@
 int RSA_set0_key(RSA *, BIGNUM *, BIGNUM *, BIGNUM *);
 int RSA_set0_factors(RSA *, BIGNUM *, BIGNUM *);
 int RSA_set0_crt_params(RSA *, BIGNUM *, BIGNUM *, BIGNUM *);
-void RSA_get0_key(const RSA *, BIGNUM **, BIGNUM **, BIGNUM **);
-void RSA_get0_factors(const RSA *, BIGNUM **, BIGNUM **);
-void RSA_get0_crt_params(const RSA *, BIGNUM **, BIGNUM **, BIGNUM **);
+void RSA_get0_key(const RSA *, const BIGNUM **, const BIGNUM **,
+                  const BIGNUM **);
+void RSA_get0_factors(const RSA *, const BIGNUM **, const BIGNUM **);
+void RSA_get0_crt_params(const RSA *, const BIGNUM **, const BIGNUM **,
+                         const BIGNUM **);
 """
 
 MACROS = """
@@ -88,15 +90,12 @@
 #if OPENSSL_VERSION_NUMBER < 0x10100005 || defined(LIBRESSL_VERSION_NUMBER)
 int RSA_set0_key(RSA *r, BIGNUM *n, BIGNUM *e, BIGNUM *d)
 {
-    /* If the fields in r are NULL, the corresponding input
+    /* If the fields n and e in r are NULL, the corresponding input
      * parameters MUST be non-NULL for n and e.  d may be
      * left NULL (in case only the public key is used).
-     *
-     * It is an error to give the results from get0 on r
-     * as input parameters.
      */
-    if (n == r->n || e == r->e
-        || (r->d != NULL && d == r->d))
+    if ((r->n == NULL && n == NULL)
+        || (r->e == NULL && e == NULL))
         return 0;
 
     if (n != NULL) {
@@ -117,13 +116,11 @@
 
 int RSA_set0_factors(RSA *r, BIGNUM *p, BIGNUM *q)
 {
-    /* If the fields in r are NULL, the corresponding input
+    /* If the fields p and q in r are NULL, the corresponding input
      * parameters MUST be non-NULL.
-     *
-     * It is an error to give the results from get0 on r
-     * as input parameters.
      */
-    if (p == r->p || q == r->q)
+    if ((r->p == NULL && p == NULL)
+        || (r->q == NULL && q == NULL))
         return 0;
 
     if (p != NULL) {
@@ -140,13 +137,12 @@
 
 int RSA_set0_crt_params(RSA *r, BIGNUM *dmp1, BIGNUM *dmq1, BIGNUM *iqmp)
 {
-    /* If the fields in r are NULL, the corresponding input
+    /* If the fields dmp1, dmq1 and iqmp in r are NULL, the corresponding input
      * parameters MUST be non-NULL.
-     *
-     * It is an error to give the results from get0 on r
-     * as input parameters.
      */
-    if (dmp1 == r->dmp1 || dmq1 == r->dmq1 || iqmp == r->iqmp)
+    if ((r->dmp1 == NULL && dmp1 == NULL)
+        || (r->dmq1 == NULL && dmq1 == NULL)
+        || (r->iqmp == NULL && iqmp == NULL))
         return 0;
 
     if (dmp1 != NULL) {
@@ -165,7 +161,8 @@
     return 1;
 }
 
-void RSA_get0_key(const RSA *r, BIGNUM **n, BIGNUM **e, BIGNUM **d)
+void RSA_get0_key(const RSA *r,
+                  const BIGNUM **n, const BIGNUM **e, const BIGNUM **d)
 {
     if (n != NULL)
         *n = r->n;
@@ -175,7 +172,7 @@
         *d = r->d;
 }
 
-void RSA_get0_factors(const RSA *r, BIGNUM **p, BIGNUM **q)
+void RSA_get0_factors(const RSA *r, const BIGNUM **p, const BIGNUM **q)
 {
     if (p != NULL)
         *p = r->p;
@@ -184,7 +181,8 @@
 }
 
 void RSA_get0_crt_params(const RSA *r,
-                         BIGNUM **dmp1, BIGNUM **dmq1, BIGNUM **iqmp)
+                         const BIGNUM **dmp1, const BIGNUM **dmq1,
+                         const BIGNUM **iqmp)
 {
     if (dmp1 != NULL)
         *dmp1 = r->dmp1;