CMS_EnvelopedData_create(3) | OpenSSL | CMS_EnvelopedData_create(3)

# NAME

CMS_EnvelopedData_create_ex, CMS_EnvelopedData_create, CMS_AuthEnvelopedData_create, CMS_AuthEnvelopedData_create_ex - Create CMS envelope

# SYNOPSIS

     #include <openssl/cms.h>
     CMS_ContentInfo *
     CMS_EnvelopedData_create_ex(const EVP_CIPHER *cipher, OSSL_LIB_CTX *libctx,
                                 const char *propq);
     CMS_ContentInfo *CMS_EnvelopedData_create(const EVP_CIPHER *cipher);
     CMS_ContentInfo *
     CMS_AuthEnvelopedData_create_ex(const EVP_CIPHER *cipher, OSSL_LIB_CTX *libctx,
                                     const char *propq);
     CMS_ContentInfo *CMS_AuthEnvelopedData_create(const EVP_CIPHER *cipher);

# DESCRIPTION

CMS_EnvelopedData_create_ex() creates a CMS_ContentInfo structure with a type NID_pkcs7_enveloped. cipher is the symmetric cipher to use. The library context libctx and the property query propq are used when retrieving algorithms from providers.

CMS_AuthEnvelopedData_create_ex() creates a CMS_ContentInfo structure with a type NID_id_smime_ct_authEnvelopedData. cipher is the symmetric AEAD cipher to use. Currently only AES variants with GCM mode are supported. The library context libctx and the property query propq are used when retrieving algorithms from providers.

The algorithm passed in the cipher parameter must support ASN1 encoding of its parameters.

The recipients can be added later using CMS_add1_recipient_cert(3) or CMS_add0_recipient_key(3).

The CMS_ContentInfo structure needs to be finalized using CMS_final(3) and then freed using CMS_ContentInfo_free(3).

CMS_EnvelopedData_create() and CMS_AuthEnvelopedData_create() are similar to CMS_EnvelopedData_create_ex() and CMS_AuthEnvelopedData_create_ex() but use default values of NULL for the library context libctx and the property query propq.

# NOTES

Although CMS_EnvelopedData_create_ex(), and CMS_EnvelopedData_create(), CMS_AuthEnvelopedData_create_ex(), and CMS_AuthEnvelopedData_create() allocate a new CMS_ContentInfo structure, they are not usually used in applications. The wrappers CMS_encrypt(3) and CMS_decrypt(3) are often used instead.

# RETURN VALUES

If the allocation fails, CMS_EnvelopedData_create_ex(), CMS_EnvelopedData_create(), CMS_AuthEnvelopedData_create_ex(), CMS_AuthEnvelopedData_create(), CMS_AuthEnvelopedData_create(), and CMS_AuthEnvelopedData_create_ex() return NULL and set an error code that can be obtained by ERR_get_error(3). Otherwise, they return a pointer to the newly allocated structure.

# SEE ALSO

ERR_get_error(3), CMS_encrypt(3), CMS_decrypt(3), CMS_final(3), CMS_sign_ex(3), CMS_encrypt_ex(3)

# HISTORY

The CMS_EnvelopedData_create_ex() method was added in OpenSSL 3.0.

CMS_AuthEnvelopedData_create() and CMS_AuthEnvelopedData_create_ex() were added in OpenSSL 3.5.

# COPYRIGHT

Copyright 2020-2025 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

2026-06-09 | 3.5.7