[openssl-users] CMS with Symmetric key

[Dr. Stephen Henson]

On Mon, Apr 04, 2016, Abe Racioppo wrote:

> Hey guys,
> 
> I'm trying to use the CMS operations in libcrypto but with a symmetric key
> encryption key instead of x509.
> 
> I'm thinking I want to use a combination of
> 
> CMS_RecipientInfo_set0_pkey,
> SMIME_write_CMS,
> and
> CMS_EncryptedData_encrypt.
> 
> Has anyone done this before and can give me some direction?  This is my
> first time working with openssl and am getting kinda lost.
> 

You have several options here.

You can just use the encrypted data type with a key directly.

You can use the enveloped data type with a symmetric wrapping key.

You can use the enveloped data type with a password based recipient info.

Which you use depends on the application you have in mind.

In the first case you just call CMS_EncryptData_encrypt() followed by
SMIME_write_CMS().

Steve.
--
Dr Stephen N. Henson. OpenSSL project core developer.
Commercial tech support now available see: http://www.openssl.org