Difference between revisions of "Talk:EVP Signing and Verifying"
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Jump to navigationJump to search (Created page with "== Clarification required == Why is if(1 != EVP_DigestSignFinal(mdctx, *sig, slen)) goto err; done two times?") |
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if(1 != EVP_DigestSignFinal(mdctx, *sig, slen)) goto err; | if(1 != EVP_DigestSignFinal(mdctx, *sig, slen)) goto err; | ||
done two times? | done two times? | ||
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| + | ---- | ||
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| + | Good question! I've added some extra code comments to explain it. Basically the first call has a NULL sig parameter to obtain the length of the signature. Memory is then allocated sufficient to hold the sig, and then the sig is obtained in the second call to EVP_DigestSignFinal. | ||
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| + | --[[User:Matt|Matt]] 21:16, 15 June 2013 (UTC) | ||
Revision as of 21:16, 15 June 2013
Clarification required
Why is
if(1 != EVP_DigestSignFinal(mdctx, *sig, slen)) goto err;
done two times?
Good question! I've added some extra code comments to explain it. Basically the first call has a NULL sig parameter to obtain the length of the signature. Memory is then allocated sufficient to hold the sig, and then the sig is obtained in the second call to EVP_DigestSignFinal.
--Matt 21:16, 15 June 2013 (UTC)
