Re: PKCS7_decrypt vs RSA OAEP padding

Jakob Bohm via openssl-users <openssl-users@xxxxxxxxxxx> · Thu, 15 Apr 2021 14:01:59 +0200



    On 2021-04-15 12:57, Michal Moravec wrote:

    
        Follow-up on my previous email:
        

        I modified my proof-of-problem program to load
          PKCS7 file into PKCS7 and convert it to CMS_ContentInfo using
          the BIO (See convert.c in the attachment). It is similar to
          this:
        

            handle_encrypted_content(SCEP *handle,
              SCEP_DATA *data, PKCS7 *p7env, X509 *dec_cert, EVP_PKEY
              *dec_key) {
            ...
            CMS_ContentInfo *cmsMessage = NULL;
            BIO *convert = NULL;
            conversion = BIO_new(BIO_s_mem());
            PEM_write_bio_PKCS7(conversion, p7env);
            cmsEnv = PEM_read_bio_CMS(conversion, NULL,
              NULL, NULL);
            CMS_decrypt(cmsEnv, dec_key, dec_cert, NULL,
              decData, 0);
          
        
        convert.c works well with my test data and
          CMS_decrypt successfully decrypts the CMS_ContentInfo.
        

        When I put this code into practice = using it in
          the actual library -> https://github.com/EtneteraLogicworks/libscep/commit/d94a24b28fcf3a1c1f0dc5e48e274627eed2b3f6
        Calling CMS_decrypt results in segfault inside
          libcrypto library:
        
        
            Apr 15 12:08:36 scepdev kernel: openxpkid
              (main[759]: segfault at ffffffffac6d8cd0 ip
              00007f6b4d3040a0 sp 00007ffde9477738 error 5 in
              libcrypto.so.1.1[7f6b4d29c000+19e000]
          
          
        I have no idea how to debug this :-( Way out of my
          league here.
        

    Try linking libcrypto.so.1.1 with debug symbols included (not 

      stripped).  This should make the error message point to the 

      function, maybe even show the call stack.

    
    Enjoy

Jakob
-- 
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