I think you are right about some kind of munging of the .c source via some header file. I just don't know exactly how to track that down. Here are the files that reference _Stoul in libcrypto.a: ec_pmeth.c rsa_pmeth.c dsa_pmeth.c dh_pmeth.c b_sock.c asn1_gen.c a_strnid.c ocsp_ht.c ts_conf.c <table class="TM_EMAIL_NOTICE"><tr><td><pre> TREND MICRO EMAIL NOTICE The information contained in this email and any attachments is confidential and may be subject to copyright or other intellectual property protection. If you are not the intended recipient, you are not authorized to use or disclose this information, and we request that you notify us by reply mail or telephone and delete the original message from your mail system. </pre></td></tr></table>