PKCS7_DECRYPT(3ossl)

📦
version 15.1 · 3 versions
, in freebsd 15.1

💅 NAME — PKCS7_DECRYPT(3ossl)

okay so this is OpenSSL’s PKCS7_DECRYPT(3ossl) page, and it’s all about PKCS7_decrypt — the function that decrypts content from a PKCS#7 envelopedData structure. Very “open the envelope, bestie” energy. 💌

✨ SYNOPSIS ✨

#include <openssl/pkcs7.h>

int PKCS7_decrypt(PKCS7 *p7, EVP_PKEY *pkey, X509 *cert, BIO *data, int flags);

🫶 DESCRIPTION 🫶

PKCS7_decrypt() extracts and decrypts the content from a PKCS#7 envelopedData structure. Slay.

Here’s the cast, no cap:

  • pkey is the private key of the recipient.
  • cert is the recipient’s certificate.
  • data is a BIO to write the content to.
  • flags is an optional set of flags.

🧠 NOTES 🧠

Even though the recipient certificate is not needed to decrypt the data, it is needed to locate the appropriate recipient in the PKCS#7 structure — and yes, there can be several. So it’s giving “find the right person in the group chat” energy. 🫶

The following flags can be passed in the flags parameter.

  • PKCS7_TEXT — if this 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. Not flexible, but iconic. 💅

🎀 RETURN VALUES 🎀

PKCS7_decrypt() returns either 1 for success or 0 for failure. The error can be obtained from ERR_get_error(3).

So: 1 = slay, 0 = check the error, bestie. 😭

💀 BUGS 💀

PKCS7_decrypt() must be passed the correct recipient key and certificate. It would be better if it could look up the correct key and certificate from a database.

Also, this is exactly what the page says, so don’t come for me: the lack of single pass processing and need to hold all data in memory as mentioned in PKCS7_sign() also applies to PKCS7_verify(). That’s the BUGS section being its whole dramatic self. 💀

🔎 SEE ALSO 🔎

Copyright 2002-2016 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>.

XOXO, bestie 💖 — this OpenSSL 3.5.6 page is dated 2026-04-07 and signs off as PKCS7_DECRYPT(3ossl).

📦 where this page comes from