diff --git a/library/pkparse.c b/library/pkparse.c
index c2e51e7..3440c2e 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -761,58 +761,62 @@
 
     p += len;
 
-    /*
-     * Is 'parameters' present?
-     */
-    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
-                    MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) ) == 0 )
+    pubkey_done = 0;
+    if( p != end )
     {
-        if( ( ret = pk_get_ecparams( &p, p + len, &params) ) != 0 ||
-            ( ret = pk_use_ecparams( &params, &eck->grp )  ) != 0 )
+        /*
+         * Is 'parameters' present?
+         */
+        if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
+                        MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) ) == 0 )
+        {
+            if( ( ret = pk_get_ecparams( &p, p + len, &params) ) != 0 ||
+                ( ret = pk_use_ecparams( &params, &eck->grp )  ) != 0 )
+            {
+                mbedtls_ecp_keypair_free( eck );
+                return( ret );
+            }
+        }
+        else if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
         {
             mbedtls_ecp_keypair_free( eck );
-            return( ret );
-        }
-    }
-    else if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
-    {
-        mbedtls_ecp_keypair_free( eck );
-        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
-    }
-
-    /*
-     * Is 'publickey' present? If not, or if we can't read it (eg because it
-     * is compressed), create it from the private key.
-     */
-    pubkey_done = 0;
-    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
-                    MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 1 ) ) == 0 )
-    {
-        end2 = p + len;
-
-        if( ( ret = mbedtls_asn1_get_bitstring_null( &p, end2, &len ) ) != 0 )
             return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
-
-        if( p + len != end2 )
-            return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
-                    MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
-
-        if( ( ret = pk_get_ecpubkey( &p, end2, eck ) ) == 0 )
-            pubkey_done = 1;
-        else
-        {
-            /*
-             * The only acceptable failure mode of pk_get_ecpubkey() above
-             * is if the point format is not recognized.
-             */
-            if( ret != MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE )
-                return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
         }
-    }
-    else if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
-    {
-        mbedtls_ecp_keypair_free( eck );
-        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+        /*
+         * Is 'publickey' present? If not, or if we can't read it (eg because it
+         * is compressed), create it from the private key.
+         */
+        pubkey_done = 0;
+        if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
+                        MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 1 ) ) == 0 )
+        {
+            end2 = p + len;
+
+            if( ( ret = mbedtls_asn1_get_bitstring_null( &p, end2, &len ) ) != 0 )
+                return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+            if( p + len != end2 )
+                return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
+                        MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
+
+            if( ( ret = pk_get_ecpubkey( &p, end2, eck ) ) == 0 )
+                pubkey_done = 1;
+            else
+            {
+                /*
+                 * The only acceptable failure mode of pk_get_ecpubkey() above
+                 * is if the point format is not recognized.
+                 */
+                if( ret != MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE )
+                    return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
+            }
+        }
+        else if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
+        {
+            mbedtls_ecp_keypair_free( eck );
+            return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+        }
     }
 
     if( ! pubkey_done &&