der_decode_subject_public_key_info: fix compile error

also make it possible to define min/max RSA key sizes externally

This closes #59

src/headers/tomcrypt_custom.h

@@ -367,6 +367,30 @@
 
 #endif /* LTC_NO_PK */
 
+/* define these PK sizes out of LTC_NO_PK
+ * to have them always defined
+ */
+#if defined(LTC_MRSA)
+/* Min and Max RSA key sizes (in bits) */
+#ifndef MIN_RSA_SIZE
+#define MIN_RSA_SIZE 1024
+#endif
+#ifndef MAX_RSA_SIZE
+#define MAX_RSA_SIZE 4096
+#endif
+#endif
+
+/* in cases where you want ASN.1/DER functionality, but no
+ * RSA, you can define this externally if 1024 is not enough
+ */
+#if defined(LTC_MRSA)
+#define LTC_DER_MAX_PUBKEY_SIZE MAX_RSA_SIZE
+#elif !defined(LTC_DER_MAX_PUBKEY_SIZE)
+/* this includes DSA */
+#define LTC_DER_MAX_PUBKEY_SIZE 1024
+#endif
+
+
 /* PKCS #1 (RSA) and #5 (Password Handling) stuff */
 #ifndef LTC_NO_PKCS
 

src/headers/tomcrypt_pk.h

@@ -28,10 +28,6 @@ int pk_get_oid(int pk, oid_st *st);
 /* ---- RSA ---- */
 #ifdef LTC_MRSA
 
-/* Min and Max RSA key sizes (in bits) */
-#define MIN_RSA_SIZE 1024
-#define MAX_RSA_SIZE 4096
-
 /** RSA PKCS style key */
 typedef struct Rsa_key {
     /** Type of key, PK_PRIVATE or PK_PUBLIC */