diff --git a/crypto/asn1/tasn_dec.c b/crypto/asn1/tasn_dec.c
index 507a842..d852ad7 100644
--- a/crypto/asn1/tasn_dec.c
+++ b/crypto/asn1/tasn_dec.c
@@ -359,9 +359,9 @@
 			}
 
 		asn1_set_choice_selector(pval, i, it);
-		*in = p;
 		if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
 				goto auxerr;
+		*in = p;
 		return 1;
 
 		case ASN1_ITYPE_NDEF_SEQUENCE:
@@ -515,9 +515,9 @@
 		/* Save encoding */
 		if (!asn1_enc_save(pval, *in, p - *in, it))
 			goto auxerr;
-		*in = p;
 		if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
 				goto auxerr;
+		*in = p;
 		return 1;
 
 		default:
diff --git a/crypto/ec/ec_asn1.c b/crypto/ec/ec_asn1.c
index 31d8944..f540256 100644
--- a/crypto/ec/ec_asn1.c
+++ b/crypto/ec/ec_asn1.c
@@ -239,8 +239,9 @@
                                     long len) {
   EC_GROUP *group = NULL;
   ECPKPARAMETERS *params = NULL;
+  const uint8_t *in = *inp;
 
-  params = d2i_ECPKPARAMETERS(NULL, inp, len);
+  params = d2i_ECPKPARAMETERS(NULL, &in, len);
   if (params == NULL) {
     OPENSSL_PUT_ERROR(EC, EC_R_D2I_ECPKPARAMETERS_FAILURE);
     ECPKPARAMETERS_free(params);
@@ -260,6 +261,7 @@
   }
 
   ECPKPARAMETERS_free(params);
+  *inp = in;
   return group;
 }
 
@@ -280,12 +282,13 @@
   return ret;
 }
 
-EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const uint8_t **in, long len) {
+EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const uint8_t **inp, long len) {
   int ok = 0;
   EC_KEY *ret = NULL;
   EC_PRIVATEKEY *priv_key = NULL;
 
-  priv_key = d2i_EC_PRIVATEKEY(NULL, in, len);
+  const uint8_t *in = *inp;
+  priv_key = d2i_EC_PRIVATEKEY(NULL, &in, len);
   if (priv_key == NULL) {
     OPENSSL_PUT_ERROR(EC, ERR_R_EC_LIB);
     return NULL;
@@ -364,6 +367,7 @@
   if (a) {
     *a = ret;
   }
+  *inp = in;
   ok = 1;
 
 err:
diff --git a/crypto/evp/evp_asn1.c b/crypto/evp/evp_asn1.c
index 356c62b..08956e1 100644
--- a/crypto/evp/evp_asn1.c
+++ b/crypto/evp/evp_asn1.c
@@ -83,16 +83,20 @@
     goto err;
   }
 
+  const uint8_t *in = *inp;
   if (!ret->ameth->old_priv_decode ||
-      !ret->ameth->old_priv_decode(ret, inp, len)) {
+      !ret->ameth->old_priv_decode(ret, &in, len)) {
     if (ret->ameth->priv_decode) {
-      PKCS8_PRIV_KEY_INFO *p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, inp, len);
+      PKCS8_PRIV_KEY_INFO *p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, &in, len);
       if (!p8) {
         goto err;
       }
       EVP_PKEY_free(ret);
       ret = EVP_PKCS82PKEY(p8);
       PKCS8_PRIV_KEY_INFO_free(p8);
+      if (ret == NULL) {
+        goto err;
+      }
     } else {
       OPENSSL_PUT_ERROR(EVP, ERR_R_ASN1_LIB);
       goto err;
@@ -102,6 +106,7 @@
   if (out != NULL) {
     *out = ret;
   }
+  *inp = in;
   return ret;
 
 err:
@@ -129,7 +134,8 @@
     keytype = EVP_PKEY_EC;
   } else if (sk_ASN1_TYPE_num(inkey) == 3) {
     /* This seems to be PKCS8, not traditional format */
-    PKCS8_PRIV_KEY_INFO *p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, inp, len);
+    p = *inp;
+    PKCS8_PRIV_KEY_INFO *p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, &p, len);
     EVP_PKEY *ret;
 
     sk_ASN1_TYPE_pop_free(inkey, ASN1_TYPE_free);
@@ -139,6 +145,11 @@
     }
     ret = EVP_PKCS82PKEY(p8);
     PKCS8_PRIV_KEY_INFO_free(p8);
+    if (ret == NULL) {
+      return NULL;
+    }
+
+    *inp = p;
     if (out) {
       *out = ret;
     }
diff --git a/crypto/x509/x_x509.c b/crypto/x509/x_x509.c
index c975dd3..b8f318a 100644
--- a/crypto/x509/x_x509.c
+++ b/crypto/x509/x_x509.c
@@ -178,22 +178,21 @@
 
 X509 *d2i_X509_AUX(X509 **a, const unsigned char **pp, long length)
 {
-	const unsigned char *q;
+	const unsigned char *q = *pp;
 	X509 *ret;
 	int freeret = 0;
 
-	/* Save start position */
-	q = *pp;
-
 	if (!a || *a == NULL)
 		freeret = 1;
-	ret = d2i_X509(a, pp, length);
+	ret = d2i_X509(a, &q, length);
 	/* If certificate unreadable then forget it */
 	if(!ret) return NULL;
 	/* update length */
-	length -= *pp - q;
-	if(!length) return ret;
-	if(!d2i_X509_CERT_AUX(&ret->aux, pp, length)) goto err;
+	length -= q - *pp;
+	/* Parse auxiliary information if there is any. */
+	if (length > 0 && !d2i_X509_CERT_AUX(&ret->aux, &q, length))
+		goto err;
+	*pp = q;
 	return ret;
 	err:
 	if (freeret)