PKCS7_encrypt(3)

PKCS7_encrypt(3)             OpenSSL             PKCS7_encrypt(3)

NAME

     PKCS7_encrypt - create a PKCS#7 envelopedData structure

SYNOPSIS

      #include <openssl/pkcs7.h>

      PKCS7 *PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher, int flags);

DESCRIPTION

     PKCS7_encrypt() creates and returns a PKCS#7 envelopedData
     structure. certs is a list of recipient certificates. in is
     the content to be encrypted.  cipher is the symmetric cipher
     to use. flags is an optional set of flags.

NOTES

     Only RSA keys are supported in PKCS#7 and envelopedData so
     the recipient certificates supplied to this function must
     all contain RSA public keys, though they do not have to be
     signed using the RSA algorithm.

     EVP_des_ede3_cbc() (triple DES) is the algorithm of choice
     for S/MIME use because most clients will support it.

     Some old "export grade" clients may only support weak
     encryption using 40 or 64 bit RC2. These can be used by
     passing EVP_rc2_40_cbc() and EVP_rc2_64_cbc() respectively.

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

     Many browsers implement a "sign and encrypt" option which is
     simply an S/MIME envelopedData containing an S/MIME signed
     message. This can be readily produced by storing the S/MIME
     signed message in a memory BIO and passing it to
     PKCS7_encrypt().

     The following flags can be passed in the flags parameter.

     If the PKCS7_TEXT flag is set MIME headers for type
     text/plain are prepended to the data.

     Normally the supplied content is translated into MIME
     canonical format (as required by the S/MIME specifications)
     if PKCS7_BINARY is set no translation occurs. This option
     should be used if the supplied data is in binary format
     otherwise the translation will corrupt it. If PKCS7_BINARY
     is set then PKCS7_TEXT is ignored.

     If the PKCS7_STREAM flag is set a partial PKCS7 structure is
     output suitable for streaming I/O: no data is read from the
     BIO in.

1.0.2t               Last change: 2019-09-10                    1

PKCS7_encrypt(3)             OpenSSL             PKCS7_encrypt(3)

NOTES

     If the flag PKCS7_STREAM is set the returned PKCS7 structure
     is not complete and outputting its contents via a function
     that does not properly finalize the PKCS7 structure will
     give unpredictable results.

     Several functions including SMIME_write_PKCS7(),
     i2d_PKCS7_bio_stream(), PEM_write_bio_PKCS7_stream()
     finalize the structure. Alternatively finalization can be
     performed by obtaining the streaming ASN1 BIO directly using
     BIO_new_PKCS7().

RETURN VALUES

     PKCS7_encrypt() returns either a PKCS7 structure or NULL if
     an error occurred.  The error can be obtained from
     ERR_get_error(3).

SEE ALSO

     ERR_get_error(3), PKCS7_decrypt(3)

HISTORY

     PKCS7_decrypt() was added to OpenSSL 0.9.5 The PKCS7_STREAM
     flag was first supported in OpenSSL 1.0.0.

1.0.2t               Last change: 2019-09-10                    2