5 PKCS7_encrypt - create a PKCS#7 envelopedData structure
9 #include <openssl/pkcs7.h>
11 PKCS7 *PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher, int flags);
15 PKCS7_encrypt() creates and returns a PKCS#7 envelopedData structure. B<certs>
16 is a list of recipient certificates. B<in> is the content to be encrypted.
17 B<cipher> is the symmetric cipher to use. B<flags> is an optional set of flags.
21 Only RSA keys are supported in PKCS#7 and envelopedData so the recipient certificates
22 supplied to this function must all contain RSA public keys, though they do not have to
23 be signed using the RSA algorithm.
25 EVP_des_ede3_cbc() (triple DES) is the algorithm of choice for S/MIME use because
26 most clients will support it.
28 Some old "export grade" clients may only support weak encryption using 40 or 64 bit
29 RC2. These can be used by passing EVP_rc2_40_cbc() and EVP_rc2_64_cbc() respectively.
31 The algorithm passed in the B<cipher> parameter must support ASN1 encoding of its
34 Many browsers implement a "sign and encrypt" option which is simply an S/MIME
35 envelopedData containing an S/MIME signed message. This can be readily produced
36 by storing the S/MIME signed message in a memory BIO and passing it to
39 The following flags can be passed in the B<flags> parameter.
41 If the B<PKCS7_TEXT> flag is set MIME headers for type B<text/plain> are prepended
44 Normally the supplied content is translated into MIME canonical format (as required
45 by the S/MIME specifications) if B<PKCS7_BINARY> is set no translation occurs. This
46 option should be used if the supplied data is in binary format otherwise the translation
47 will corrupt it. If B<PKCS7_BINARY> is set then B<PKCS7_TEXT> is ignored.
51 PKCS7_encrypt() returns either a valid PKCS7 structure or NULL if an error occurred.
52 The error can be obtained from ERR_get_error(3).
56 The lack of single pass processing and need to hold all data in memory as
57 mentioned in PKCS7_sign() also applies to PKCS7_verify().
61 L<ERR_get_error(3)|ERR_get_error(3)>, L<PKCS7_decrypt(3)|PKCS7_decrypt(3)>
65 PKCS7_decrypt() was added to OpenSSL 0.9.5