Const correctness
diff --git a/include/polarssl/x509_csr.h b/include/polarssl/x509_csr.h
index 30ef7c5..7e38300 100644
--- a/include/polarssl/x509_csr.h
+++ b/include/polarssl/x509_csr.h
@@ -155,7 +155,8 @@
* \return 0 if subject name was parsed successfully, or
* a specific error code
*/
-int x509write_csr_set_subject_name( x509write_csr *ctx, char *subject_name );
+int x509write_csr_set_subject_name( x509write_csr *ctx,
+ const char *subject_name );
/**
* \brief Set the key for a CSR (public key will be included,