-spec decrypt(Encrypted :: binary(),
              RecipientCert :: der_certificate(),
              RecipientKey :: der_private_key()) ->
                 {ok, Decrypted :: binary()} | {error, _}.

Decrypt CMS binary

-spec encrypt(Data :: binary(), Recipients :: [Certificate :: der_certificate(), ...]) ->
                 {ok, Encrypted :: binary()} | {error, _}.

Encrypt Data to Recipients

Equivalent to encrypt(Data, Recipients, #{ })

-spec encrypt(Data :: binary(),
              Recipients :: [der_certificate()],
              Opts ::
                  #{digest_type => digest_type(),
                    auth_attrs => [#{attrType := tuple(), attrValues := [binary()]}, ...],
                    cipher => cipher() | cipher_aead()}) ->
                 {ok, Encrypted :: binary()} | {error, _}.

Encrypt Data to Recipients

When not set in Opts: digest_type defaults to 'sha256' and cipher to 'aes_256_cbc'.

For cipher set to 'aes_128_gcm', 'aes_192_gcm', or 'aes_256_gcm' the encoded content is AuthEnvelopedData and AuthAttributes can be set as auth_attrs in Opts.

The encoded recipientInfos contain a KeyAgreeRecipientInfo for each Elliptic Curve certificate and a KeyTransRecipientInfo for each RSA certificate in Recipients.

RSA-OAEP is used in KeyTransRecipientInfos; the value of digest_type sets the Hash and MaskGen algorithms.

KeyAgreeRecipientInfo uses RFC3394 AES Key Wrap and dhSinglePass-stdDH Key Derivation, the value of digest_type sets Hash algorithm

-spec sign(Data :: binary(),
           Opts ::
               #{digest_type => digest_type(),
                 singning_time => calendar:datetime(),
                 resign => boolean(),
                 included_certs => [Certificate :: der_certificate()],
                 signers := [{SignCert :: der_certificate(), SignKey :: der_private_key()}, ...]}) ->
              {ok, Signed :: binary()} | {error, _}.

(re)sign Data

When not set in Opts: digest_type defaults to sha256, signing_time to the current time, resign to 'false' and included_certs to [].

digest_type controls DigestAlgorithm, DSA/EC SigatureAlgorithm and for RSA signatures also Hash and MaskGen algorithm in RSA-PSS parameters.

If resign is set to 'true', Data must contain SignedData. Additional signatures from keys in Signers, the certificates in Signers and any included_certs are added to the existing SignedData.

-spec sign(Data :: binary(), SignCert :: der_certificate(), SignKey :: der_private_key()) ->
              {ok, Signed :: binary()} | {error, _}.

Sign Data using SignCert and SignKey

Equivalent to sign(Data, #{ signers => [{SignCert, SignKey}])

-spec verify(InDER :: binary(), Trusted :: [der_certificate(), ...]) ->
                {ok, EContent :: binary()} | {error, _}.

Verify CMS DER binary InDER

returns {ok, EContent} if at least one signature is from a certificate in Trusted or from an included certificate that has been chain-validated against a certificate in Trusted.