* common/compliance.c (gnupg_cipher_is_allowed): Allow GCM for gpgsm
in decrypt mode.
* tests/cms/samplemsgs/pwri-sample.gcm.p7m: Remove duplicated authtag
--
We allow GCM in de-vs mode for decryption although this has not been
evaluation. It is decryption and thus no serious harm may happen.
* tests/cms/samplemsgs/: Add sample messages.
* sm/gpgsm.c (main): Use gpgrt_fcancel on decryption error.
* sm/decrypt.c (decrypt_gcm_filter): New.
(gpgsm_decrypt): Use this filter if requested. Check authtag.
--
Note that the sample message pwri-sample.gcm.p7m is broken: The
authtag is duplicated to the authEncryptedContentInfo. I used a
temporary code during testing hack to that test message out.
