---
name: "CMS_EncryptedData_decrypt"
section: "3ssl"
platform: "linux"
package: "openssl"
version: "3.6.5-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/CMS_EncryptedData_decrypt"
---

# CMS\_EncryptedData\_decrypt(3ssl)

Decrypt CMS EncryptedData or EnvelopedData

## NAME

CMS\_EncryptedData\_decrypt, CMS\_EnvelopedData\_decrypt - Decrypt CMS EncryptedData or EnvelopedData

## SYNOPSIS

```
 #include <openssl/cms.h>
 int CMS_EncryptedData_decrypt(CMS_ContentInfo *cms,
                               const unsigned char *key, size_t keylen,
                               BIO *dcont, BIO *out, unsigned int flags);
 BIO *CMS_EnvelopedData_decrypt(CMS_EnvelopedData *env, BIO *detached_data,
                                EVP_PKEY *pkey, X509 *cert,
                                ASN1_OCTET_STRING *secret, unsigned int flags,
                                OSSL_LIB_CTX *libctx, const char *propq);
```

## DESCRIPTION

**CMS\_EncryptedData\_decrypt()** decrypts a *cms* EncryptedData object using the symmetric *key* of size *keylen* bytes. AEAD cipher algorithms are not supported. *out* is a BIO to write the content to and *flags* is an optional set of flags. *dcont* is used in the rare case where the encrypted content is detached. It will normally be set to NULL.

The following flags can be passed in the *flags* parameter.

If the **CMS\_TEXT** flag is set MIME headers for type `"text/plain"` are deleted from the content. If the content is not of type `"text/plain"` then an error is returned.

**CMS\_EnvelopedData\_decrypt()** decrypts, similarly to **CMS\_decrypt**(3), a CMS EnvelopedData object *env* using the symmetric key *secret* if it is not NULL, otherwise the private key of the recipient *pkey*. If *pkey* is given, it is recommended to provide also the associated certificate in *cert* - see **CMS\_decrypt**(3) and the NOTES on *cert* there. The optional parameters *flags* and *dcont* are used as described above. The optional parameters library context *libctx* and property query *propq* are used when retrieving algorithms from providers.

## RETURN VALUES

**CMS\_EncryptedData\_decrypt()** returns 0 if an error occurred otherwise returns 1.

**CMS\_EnvelopedData\_decrypt()** returns NULL if an error occurred, otherwise a BIO containing the decrypted content.

## SEE ALSO

**ERR\_get\_error**(3), **CMS\_EncryptedData\_encrypt**(3), **CMS\_decrypt**(3)

## HISTORY

**CMS\_EnvelopedData\_decrypt()** was added in OpenSSL 3.2.

## COPYRIGHT

Copyright 2020-2026 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\>.