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Diffstat (limited to 'doc/man3/OCSP_request_add1_nonce.pod')
| -rw-r--r-- | doc/man3/OCSP_request_add1_nonce.pod | 84 |
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diff --git a/doc/man3/OCSP_request_add1_nonce.pod b/doc/man3/OCSP_request_add1_nonce.pod new file mode 100644 index 000000000000..66e4c7b8fb78 --- /dev/null +++ b/doc/man3/OCSP_request_add1_nonce.pod @@ -0,0 +1,84 @@ +=pod + +=head1 NAME + +OCSP_request_add1_nonce, OCSP_basic_add1_nonce, OCSP_check_nonce, OCSP_copy_nonce - OCSP nonce functions + +=head1 SYNOPSIS + + #include <openssl/ocsp.h> + + int OCSP_request_add1_nonce(OCSP_REQUEST *req, unsigned char *val, int len); + int OCSP_basic_add1_nonce(OCSP_BASICRESP *resp, unsigned char *val, int len); + int OCSP_copy_nonce(OCSP_BASICRESP *resp, OCSP_REQUEST *req); + int OCSP_check_nonce(OCSP_REQUEST *req, OCSP_BASICRESP *resp); + +=head1 DESCRIPTION + +OCSP_request_add1_nonce() adds a nonce of value B<val> and length B<len> to +OCSP request B<req>. If B<val> is B<NULL> a random nonce is used. If B<len> +is zero or negative a default length will be used (currently 16 bytes). + +OCSP_basic_add1_nonce() is identical to OCSP_request_add1_nonce() except +it adds a nonce to OCSP basic response B<resp>. + +OCSP_check_nonce() compares the nonce value in B<req> and B<resp>. + +OCSP_copy_nonce() copys any nonce value present in B<req> to B<resp>. + +=head1 RETURN VALUES + +OCSP_request_add1_nonce() and OCSP_basic_add1_nonce() return 1 for success +and 0 for failure. + +OCSP_copy_nonce() returns 1 if a nonce was successfully copied, 2 if no nonce +was present in B<req> and 0 if an error occurred. + +OCSP_check_nonce() returns the result of the nonce comparison between B<req> +and B<resp>. The return value indicates the result of the comparison. If +nonces are present and equal 1 is returned. If the nonces are absent 2 is +returned. If a nonce is present in the response only 3 is returned. If nonces +are present and unequal 0 is returned. If the nonce is present in the request +only then -1 is returned. + +=head1 NOTES + +For most purposes the nonce value in a request is set to a random value so +the B<val> parameter in OCSP_request_add1_nonce() is usually NULL. + +An OCSP nonce is typically added to an OCSP request to thwart replay attacks +by checking the same nonce value appears in the response. + +Some responders may include a nonce in all responses even if one is not +supplied. + +Some responders cache OCSP responses and do not sign each response for +performance reasons. As a result they do not support nonces. + +The return values of OCSP_check_nonce() can be checked to cover each case. A +positive return value effectively indicates success: nonces are both present +and match, both absent or present in the response only. A non-zero return +additionally covers the case where the nonce is present in the request only: +this will happen if the responder doesn't support nonces. A zero return value +indicates present and mismatched nonces: this should be treated as an error +condition. + +=head1 SEE ALSO + +L<crypto(7)>, +L<OCSP_cert_to_id(3)>, +L<OCSP_REQUEST_new(3)>, +L<OCSP_resp_find_status(3)>, +L<OCSP_response_status(3)>, +L<OCSP_sendreq_new(3)> + +=head1 COPYRIGHT + +Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved. + +Licensed under the OpenSSL license (the "License"). You may not use +this file except in compliance with the License. You can obtain a copy +in the file LICENSE in the source distribution or at +L<https://www.openssl.org/source/license.html>. + +=cut |