+/* This works like d2i_PrivateKey() except it automatically works out the type */
+
+EVP_PKEY *d2i_AutoPrivateKey(EVP_PKEY **a, const unsigned char **pp,
+ long length)
+{
+ STACK_OF(ASN1_TYPE) *inkey;
+ const unsigned char *p;
+ int keytype;
+ p = *pp;
+ /* Dirty trick: read in the ASN1 data into a STACK_OF(ASN1_TYPE):
+ * by analyzing it we can determine the passed structure: this
+ * assumes the input is surrounded by an ASN1 SEQUENCE.
+ */
+ inkey = d2i_ASN1_SEQUENCE_ANY(NULL, &p, length);
+ /* Since we only need to discern "traditional format" RSA and DSA
+ * keys we can just count the elements.
+ */
+ if(sk_ASN1_TYPE_num(inkey) == 6)
+ keytype = EVP_PKEY_DSA;
+ else if (sk_ASN1_TYPE_num(inkey) == 4)
+ 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);
+ EVP_PKEY *ret;
+
+ sk_ASN1_TYPE_pop_free(inkey, ASN1_TYPE_free);
+ if (!p8)
+ {
+ ASN1err(ASN1_F_D2I_AUTOPRIVATEKEY,ASN1_R_UNSUPPORTED_PUBLIC_KEY_TYPE);
+ return NULL;
+ }
+ ret = EVP_PKCS82PKEY(p8);
+ PKCS8_PRIV_KEY_INFO_free(p8);
+ if (a) {
+ *a = ret;
+ }
+ return ret;
+ }
+ else keytype = EVP_PKEY_RSA;
+ sk_ASN1_TYPE_pop_free(inkey, ASN1_TYPE_free);
+ return d2i_PrivateKey(keytype, a, pp, length);
+}