Version: openssl 1.0.1u OS: RHEL 6.5 Arch: x86_64 GNU/Linux I'm getting a critical error when openssl try to sign the basic response. The overall basic response itself seems fine since openssl can still decode the response if i use -no_signature_verify... Without it, i get: Response Verify Failure 140479349708456:error:04091077:rsa routines:INT_RSA_VERIFY:wrong signature length:rsa_sign.c:186: 140479349708456:error:0D0C5006:asn1 encoding routines:ASN1_item_verify:EVP lib:a_verify.c:218: 140479349708456:error:27069075:OCSP routines:OCSP_basic_verify:signature failure:ocsp_vfy.c:105: Any hint on troubleshooting this would be great. Here is how I call the OCSP_basic_sign: OCSP_BASICRESP *bresp; X509 *signer; EVP_PKEY *key; ... OCSP_basic_sign(bresp, signer, key, EVP_sha1(), NULL, 0); But getting the following error internally from OCSP_basic_sign: OPENSSL ERROR: error:0306E06C:bignum routines:BN_mod_inverse:no inverse OPENSSL ERROR: error:0D0DC006:asn1 encoding routines:ASN1_item_sign_ctx:EVP lib Running it through dbg, it failed at ASN1_item_sign_ctx In crypto/asn1/a_sign.c 303 if (!EVP_DigestSignUpdate(ctx, buf_in, inl) 304 || !EVP_DigestSignFinal(ctx, buf_out, &outl)) { 305 outl = 0; 306 ASN1err(ASN1_F_ASN1_ITEM_SIGN_CTX, ERR_R_EVP_LIB); 307 goto err; 308 } (gdb) print inl $1 = 284 (gdb) print outl $2 = 256 (gdb) print *ctx $4 = {digest = 0x7fb2ecf12b80, engine = 0x0, flags = 0, md_data = 0x7fb2ef1629d0, pctx = 0x7fb2ef162970, update = 0x7fb2ecc2515a <update>} (gdb) print *ctx->digest $5 = {type = 64, pkey_type = 65, md_size = 20, flags = 12, init = 0x7fb2ecc2513c <init>, update = 0x7fb2ecc2515a <update>, final = 0x7fb2ecc2518b <final>, copy = 0, cleanup = 0, sign = 0x7fb2ecbf0c70 <RSA_sign>, verify = 0x7fb2ecbf1568 <RSA_verify>, required_pkey_type = {6, 19, 0, 0, 0}, block_size = 64, ctx_size = 104, md_ctrl = 0} -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mta.openssl.org/pipermail/openssl-users/attachments/20161005/b953b69d/attachment.html>