PKCS7_DECRYPT(3) | Library Functions Manual | PKCS7_DECRYPT(3)

# NAME

`PKCS7_decrypt` — decrypt content from a PKCS#7 envelopedData structure

# SYNOPSIS

library “libcrypto”
`#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. pkey is the private key of the recipient, cert is the recipient's certificate, data is a BIO to write the content to and flags is an optional set of flags.

Although the recipient's certificate is not needed to decrypt the data, it is needed to locate the appropriate recipients in the PKCS#7 structure.

If the `PKCS7_TEXT` flag is set, MIME headers for type text/plain are deleted from the content. If the content is not of type text/plain, an error is returned.

# RETURN VALUES

`PKCS7_decrypt`() returns 1 for success or 0 for failure.

The error can be obtained from ERR_get_error(3).

# SEE ALSO

PKCS7_encrypt(3), PKCS7_new(3), PKCS7_verify(3)

# HISTORY

`PKCS7_decrypt`() first appeared in OpenSSL 0.9.5 and has been available since OpenBSD 2.7.

# 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.

The lack of single pass processing and need to hold all data in memory as mentioned in PKCS7_sign(3) also applies to `PKCS7_decrypt`().

June 8, 2025 | Debian