=pod

=head1 NAME

PKCS7_decrypt - decrypt content from a PKCS#7 envelopedData structure

=head1 SYNOPSIS

 #include <openssl/pkcs7.h>

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

=head1 DESCRIPTION

PKCS7_decrypt() extracts and decrypts the content from a PKCS#7 envelopedData
structure. B<pkey> is the private key of the recipient, B<cert> is the
recipients certificate, B<data> is a BIO to write the content to and
B<flags> is an optional set of flags.

=head1 NOTES

Although the recipients certificate is not needed to decrypt the data it is needed
to locate the appropriate (of possible several) recipients in the PKCS#7 structure.

The following flags can be passed in the B<flags> parameter.

If the B<PKCS7_TEXT> flag is set MIME headers for type B<text/plain> are deleted
from the content. If the content is not of type B<text/plain> then an error is
returned.

=head1 RETURN VALUES

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

=head1 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() also applies to PKCS7_verify().

=head1 SEE ALSO

L<ERR_get_error(3)>, L<PKCS7_encrypt(3)>

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