Sign, verify, encrypt, and decrypt RFC 5652 Cryptographic Message Syntax (CMS) messages. Compatible with (some invocations of) the openSSL cms tool.

ecms supports RSASSA-PSS, DSA, and EC signatures with SHA224, SHA256, SHA384, and SHA512 digests in sign and verify.

Legacy RSA signatures and SHA1 digests are supported for verify only.

RSAAES-OAEP KeyAgreeRecipientInfo and EC (dhSinglePass-stdDH-sha224-kdf-scheme, dhSinglePass-stdDH-sha256-kdf-scheme, dhSinglePass-stdDH-sha384-kdf-scheme, dhSinglePass-stdDH-sha512-kdf-scheme) KeyAgreeRecipientInfo

AuthEnvelopedData with AES GCM 128, 224, and 256

EnvelopedData with AES OFB/CFB/CBC 128, 224, and 256

KeyAgreeRecipientInfo with rsaEncryption is supported for decrypt only.