/xlv3/openssl/0.9.7e-sgipl1/work/0.9.7e-sgipl1/openssl-
0.9.7e/doc/crypto
Page 1 (printed 10/20/05)
PKCS7_encrypt(3) 9/Oct/2002 (0.9.7e) PKCS7_encrypt(3)
NAME
PKCS7_encrypt - create a PKCS#7 envelopedData structure
SYNOPSIS
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.
RETURN VALUES
PKCS7_encrypt() returns either a valid PKCS7 structure or
NULL if an error occurred. The error can be obtained from
ERR_get_error(3).
Page 1 (printed 10/20/05)
PKCS7_encrypt(3) 9/Oct/2002 (0.9.7e) PKCS7_encrypt(3)
BUGS
The lack of single pass processing and need to hold all data
in memory as mentioned in PKCS7_sign() also applies to
PKCS7_verify().
SEE ALSO
ERR_get_error(3), PKCS7_decrypt(3)
HISTORY
PKCS7_decrypt() was added to OpenSSL 0.9.5
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