<div dir="ltr"><font face="monospace">I am not sure why the code you have shared is trying to decrypt the signature. </font><div><font face="monospace">If it is done as part of signature verification, don't do this. Use the actual EVP_PKEY_verify API with corresponding public key.</font><div><font face="monospace"><br></font></div><div><font face="monospace">If you certainly need the decrypted signature, you should do public encryption with NONE padding.<br></font><div><font face="monospace">A Private key is not necessary.</font></div><div><font face="monospace"><br></font></div><div><font face="monospace">Thanks,</font></div><div><font face="monospace">Thulasi</font></div></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, 29 Jan 2021 at 17:47, Narayana, Sunil Kumar <<a href="mailto:sanarayana@rbbn.com">sanarayana@rbbn.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex">
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<p class="MsoNormal"><span>Yeah, it sounds correct. But since it’s an old application code & we are not sure why was it done so, we are little worried to change.<u></u><u></u></span></p>
<p class="MsoNormal"><span>Can you please take a look the attachment which has the complete flow, and provide your views which helps us to change it to </span><span style="font-family:"Courier New"">PEM_read_PrivateKey()
or variants as you suggested</span><span> <u></u>
<u></u></span></p>
<p class="MsoNormal"><span><u></u> <u></u></span></p>
<p class="MsoNormal"><span>Regards,<u></u><u></u></span></p>
<p class="MsoNormal"><span>Sunil <u></u><u></u></span></p>
<p class="MsoNormal"><span><u></u> <u></u></span></p>
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<p class="MsoNormal"><b><span lang="EN-US">From:</span></b><span lang="EN-US"> Thulasi Goriparthi <<a href="mailto:thulasi.goriparthi@gmail.com" target="_blank">thulasi.goriparthi@gmail.com</a>>
<br>
<b>Sent:</b> 29 January 2021 17:24<br>
<b>To:</b> Narayana, Sunil Kumar <<a href="mailto:sanarayana@rbbn.com" target="_blank">sanarayana@rbbn.com</a>><br>
<b>Cc:</b> <a href="mailto:openssl-users@openssl.org" target="_blank">openssl-users@openssl.org</a><br>
<b>Subject:</b> Re: <Replacement for RSA_public_decrypt><u></u><u></u></span></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">NOTICE: This email was received from an EXTERNAL sender<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">Isn't it obvious to use PEM_read_PrivateKey() or variants to load the private key as EVP_PKEY </span><u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">and use EVP_PKEY_decrypt* as specified in
<a href="https://protect-us.mimecast.com/s/pIHaCqx23xSzZMNwiZOok8?domain=openssl.org" target="_blank">
https://www.openssl.org/docs/man1.0.2/man3/EVP_PKEY_decrypt.html</a> ?</span><u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">Thanks,</span><u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">Thulasi.</span><u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">On Fri, 29 Jan 2021 at 16:59, Narayana, Sunil Kumar <<a href="mailto:sanarayana@rbbn.com" target="_blank">sanarayana@rbbn.com</a>> wrote:<u></u><u></u></p>
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<p class="MsoNormal">Hi Thulasi,<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Currently in (1.0.1) we are following the following sequence, which now need to replace with EVP.<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"><u>Current sequence</u><u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">//to create RSA pubkey<u></u><u></u></p>
<p class="MsoNormal">rsa = PEM_read_bio_RSA_PUBKEY(keybio, NULL, NULL, NULL); // !!!
<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">//to decrypt using RSA utility<u></u><u></u></p>
<p class="MsoNormal">RSA_public_decrypt(len, (unsigned char*)buffer,decrypted,rsa, RSA_PKCS1_PADDING) ;<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">As you mentioned , if we use
<span style="font-family:"Courier New";color:black;background-color:rgb(248,248,248);background-position:initial initial;background-repeat:initial initial">PEM_read_bio_PUBKEY to get EVP_PKEY, it will be a pubkey right ? but in order to decrypt as per the example in
<a href="https://protect-us.mimecast.com/s/iJORCrkY3ki1EBZJTzdO87?domain=openssl.org" target="_blank">
https://www.openssl.org/docs/manmaster/man3/EVP_PKEY_decrypt_init.html</a></span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-family:"Courier New";color:black;background-color:rgb(248,248,248);background-position:initial initial;background-repeat:initial initial">We need to use an RSA private key</span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-family:"Courier New";color:black;background-color:rgb(248,248,248);background-position:initial initial;background-repeat:initial initial"> </span><u></u><u></u></p>
<p class="MsoNormal"><span style="font-family:"Courier New";color:black;background-color:rgb(248,248,248);background-position:initial initial;background-repeat:initial initial">Please suggest.</span><u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Regards,<u></u><u></u></p>
<p class="MsoNormal">Sunil<u></u><u></u></p>
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<div style="border-style:solid none none;border-top-width:1pt;border-top-color:rgb(225,225,225);padding:3pt 0cm 0cm">
<p class="MsoNormal"><b><span lang="EN-US">From:</span></b><span lang="EN-US"> Thulasi Goriparthi <<a href="mailto:thulasi.goriparthi@gmail.com" target="_blank">thulasi.goriparthi@gmail.com</a>>
<br>
<b>Sent:</b> 29 January 2021 13:07<br>
<b>To:</b> Narayana, Sunil Kumar <<a href="mailto:sanarayana@rbbn.com" target="_blank">sanarayana@rbbn.com</a>><br>
<b>Cc:</b> <a href="mailto:openssl-users@openssl.org" target="_blank">openssl-users@openssl.org</a><br>
<b>Subject:</b> Re: <Replacement for RSA_public_decrypt></span><u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
<div class="MsoNormal" align="center" style="text-align:center">
<hr size="2" width="100%" align="center">
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<p class="MsoNormal">NOTICE: This email was received from an EXTERNAL sender<u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:"Courier New";color:black;background-color:rgb(248,248,248);background-position:initial initial;background-repeat:initial initial">Hope, you are referring to </span><span style="font-family:"Courier New";color:black"><a href="https://protect-us.mimecast.com/s/v2osCv2j32i2xk8Vtz2d4K?domain=openssl.org" target="_blank">https://www.openssl.org/docs/man1.0.2/man3/EVP_PKEY_encrypt.html</a></span><u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">Use <span style="color:black;background-color:rgb(248,248,248);background-position:initial initial;background-repeat:initial initial">PEM_read_bio_PUBKEY to get EVP_PKEY.</span></span><u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:"Courier New";color:black;background-color:rgb(248,248,248);background-position:initial initial;background-repeat:initial initial">eng is for engine reference. If you have no engine, it can be NULL.</span><u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">Thanks,</span><u></u><u></u></p>
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<p class="MsoNormal"><span style="font-family:"Courier New"">Thulasi.</span><u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal">On Fri, 29 Jan 2021 at 10:13, Narayana, Sunil Kumar <<a href="mailto:sanarayana@rbbn.com" target="_blank">sanarayana@rbbn.com</a>> wrote:<u></u><u></u></p>
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<p class="MsoNormal" style="background-color:white;background-position:initial initial;background-repeat:initial initial">
<span style="color:rgb(33,33,33)">Dear Openssl team,</span><u></u><u></u></p>
<p class="MsoNormal" style="background-color:white;background-position:initial initial;background-repeat:initial initial">
<span style="color:rgb(33,33,33)"> </span><u></u><u></u></p>
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<p class="MsoNormal"> While migrating from 1.0.2 to 3.0 we observe that RSA_public_decrypt() API been deprecated in 3.0.<u></u><u></u></p>
<p class="MsoNormal">We referred the example provided in man page but we are not clear in generating the initial ‘key’ required to create CTX.
<u></u><u></u></p>
<p class="MsoNormal">Please suggest on (key , eng) params to proceed
<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Also currently we are using PEM_read_bio_RSA_PUBKEY() to generate RSA, I think this might not require in case of EVP, please suggest.<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">/*<u></u><u></u></p>
<p class="MsoNormal"> * NB: assumes key, eng, in, inlen are already set up<u></u><u></u></p>
<p class="MsoNormal"> * and that key is an RSA private key<u></u><u></u></p>
<p class="MsoNormal"> */<u></u><u></u></p>
<p class="MsoNormal">ctx = EVP_PKEY_CTX_new(key, eng);<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Regards,<u></u><u></u></p>
<p class="MsoNormal">Sunil<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
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<p class="MsoNormal"> <u></u><u></u></p>
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