d2i: don't update input pointer on failure

Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
MR #1005
(cherry picked from commit a46c9789ce)

crypto/asn1/d2i_pr.c

@@ -72,6 +72,7 @@ EVP_PKEY *d2i_PrivateKey(int type, EVP_PKEY **a, const unsigned char **pp,
                          long length)
 {
     EVP_PKEY *ret;
+    const unsigned char *p = *pp;
 
     if ((a == NULL) || (*a == NULL)) {
         if ((ret = EVP_PKEY_new()) == NULL) {
@@ -94,10 +95,10 @@ EVP_PKEY *d2i_PrivateKey(int type, EVP_PKEY **a, const unsigned char **pp,
     }
 
     if (!ret->ameth->old_priv_decode ||
-        !ret->ameth->old_priv_decode(ret, pp, length)) {
+        !ret->ameth->old_priv_decode(ret, &p, length)) {
         if (ret->ameth->priv_decode) {
             PKCS8_PRIV_KEY_INFO *p8 = NULL;
-            p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, pp, length);
+            p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, &p, length);
             if (!p8)
                 goto err;
             EVP_PKEY_free(ret);
@@ -109,6 +110,7 @@ EVP_PKEY *d2i_PrivateKey(int type, EVP_PKEY **a, const unsigned char **pp,
             goto err;
         }
     }
+    *pp = p;
     if (a != NULL)
         (*a) = ret;
     return (ret);
@@ -136,6 +138,7 @@ EVP_PKEY *d2i_AutoPrivateKey(EVP_PKEY **a, const unsigned char **pp,
      * input is surrounded by an ASN1 SEQUENCE.
      */
     inkey = d2i_ASN1_SEQUENCE_ANY(NULL, &p, length);
+    p = *pp;
     /*
      * Since we only need to discern "traditional format" RSA and DSA keys we
      * can just count the elements.
@@ -146,7 +149,7 @@ EVP_PKEY *d2i_AutoPrivateKey(EVP_PKEY **a, const unsigned char **pp,
         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, pp, length);
+        PKCS8_PRIV_KEY_INFO *p8 = d2i_PKCS8_PRIV_KEY_INFO(NULL, &p, length);
         EVP_PKEY *ret;
 
         sk_ASN1_TYPE_pop_free(inkey, ASN1_TYPE_free);
@@ -157,6 +160,8 @@ EVP_PKEY *d2i_AutoPrivateKey(EVP_PKEY **a, const unsigned char **pp,
         }
         ret = EVP_PKCS82PKEY(p8);
         PKCS8_PRIV_KEY_INFO_free(p8);
+        if (ret != NULL)
+            *pp = p;
         if (a) {
             *a = ret;
         }

crypto/asn1/tasn_dec.c

@@ -350,9 +350,9 @@ int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
         }
 
         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:
@@ -489,9 +489,9 @@ int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
         /* 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:

crypto/asn1/x_pubkey.c

@@ -188,13 +188,16 @@ EVP_PKEY *d2i_PUBKEY(EVP_PKEY **a, const unsigned char **pp, long length)
 {
     X509_PUBKEY *xpk;
     EVP_PKEY *pktmp;
-    xpk = d2i_X509_PUBKEY(NULL, pp, length);
+    const unsigned char *q;
+    q = *pp;
+    xpk = d2i_X509_PUBKEY(NULL, &q, length);
     if (!xpk)
         return NULL;
     pktmp = X509_PUBKEY_get(xpk);
     X509_PUBKEY_free(xpk);
     if (!pktmp)
         return NULL;
+    *pp = q;
     if (a) {
         EVP_PKEY_free(*a);
         *a = pktmp;

crypto/asn1/x_x509.c

@@ -180,16 +180,17 @@ X509 *d2i_X509_AUX(X509 **a, const unsigned char **pp, long length)
     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;
+    length -= q - *pp;
     if (!length)
         return ret;
-    if (!d2i_X509_CERT_AUX(&ret->aux, pp, length))
+    if (!d2i_X509_CERT_AUX(&ret->aux, &q, length))
         goto err;
+    *pp = q;
     return ret;
  err:
     if (freeret) {

crypto/ec/ec_asn1.c

@@ -970,8 +970,9 @@ EC_GROUP *d2i_ECPKParameters(EC_GROUP **a, const unsigned char **in, long len)
 {
     EC_GROUP *group = NULL;
     ECPKPARAMETERS *params = NULL;
+    const unsigned char *p = *in;
 
-    if ((params = d2i_ECPKPARAMETERS(NULL, in, len)) == NULL) {
+    if ((params = d2i_ECPKPARAMETERS(NULL, &p, len)) == NULL) {
         ECerr(EC_F_D2I_ECPKPARAMETERS, EC_R_D2I_ECPKPARAMETERS_FAILURE);
         ECPKPARAMETERS_free(params);
         return NULL;
@@ -989,6 +990,7 @@ EC_GROUP *d2i_ECPKParameters(EC_GROUP **a, const unsigned char **in, long len)
         *a = group;
 
     ECPKPARAMETERS_free(params);
+    *in = p;
     return (group);
 }
 
@@ -1016,8 +1018,9 @@ EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const unsigned char **in, long len)
     int ok = 0;
     EC_KEY *ret = NULL;
     EC_PRIVATEKEY *priv_key = NULL;
+    const unsigned char *p = *in;
 
-    if ((priv_key = d2i_EC_PRIVATEKEY(NULL, in, len)) == NULL) {
+    if ((priv_key = d2i_EC_PRIVATEKEY(NULL, &p, len)) == NULL) {
         ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_EC_LIB);
         return NULL;
     }
@@ -1096,6 +1099,7 @@ EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const unsigned char **in, long len)
 
     if (a)
         *a = ret;
+    *in = p;
     ok = 1;
  err:
     if (!ok) {