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Is there a way to read the CMS enveloped data structure from a Base64 encoded signed enveloped message?
What I am particularly interested is to read is which kind of algorithm is used for ephemeral key encryption. I have received this message from another party and am supposed to extract the data, but when I read the key encryption algorithm, using BouncyCastle implementation, I get a different value from what is expected (and claimed to be).
It would be of great help if I could use a third party tool to verify that the key encryption is not as what is supposed to be (or to prove myself wrong).
I tried using the openssl, with command such as openssl cms -cmsout -print -in ~/Downloads/encryptedSignedData.txt, but it reports an error, no matter which -inform argument I use.
Any hint is highly appreciated!
Stanislav
Posted 2017-02-01T18:53:37.260
Reputation: 31
Commandline
openssl cmssupports only SMIME (which is base64 with linebreaks plus S/MIME headers) PEM (which is base64 with linebreaks plus----BEGIN/END whatever-----lines) or DER (binary). If your data is base64 with linebreaks but NO header/trailer (not SMIME or PEM) try converting it to binary:openssl base64 -d <infile | openssl cms -cmsout -print. Otherwise show (in your Q) exactly whatever headers/trailers you do have. – dave_thompson_085 – 2017-02-02T10:17:19.317