NetBSD/lib/libcrypto/man/SMIME_read_PKCS7.3

.\"	$NetBSD: SMIME_read_PKCS7.3,v 1.1 2003/07/24 14:16:43 itojun Exp $
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.\" ======================================================================
.\"
.IX Title "SMIME_read_PKCS7 3"
.TH SMIME_read_PKCS7 3 "0.9.7b" "2002-10-10" "OpenSSL"
.UC
.SH "NAME"
SMIME_read_PKCS7 \- parse S/MIME message.
.SH "LIBRARY"
libcrypto, -lcrypto
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
\&\s-1PKCS7\s0 *SMIME_read_PKCS7(\s-1BIO\s0 *in, \s-1BIO\s0 **bcont);
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
\&\fISMIME_read_PKCS7()\fR parses a message in S/MIME format.
.PP
\&\fBin\fR is a \s-1BIO\s0 to read the message from.
.PP
If cleartext signing is used then the content is saved in
a memory bio which is written to \fB*bcont\fR, otherwise
\&\fB*bcont\fR is set to \fB\s-1NULL\s0\fR.
.PP
The parsed PKCS#7 structure is returned or \fB\s-1NULL\s0\fR if an
error occurred.
.SH "NOTES"
.IX Header "NOTES"
If \fB*bcont\fR is not \fB\s-1NULL\s0\fR then the message is clear text
signed. \fB*bcont\fR can then be passed to \fIPKCS7_verify()\fR with
the \fB\s-1PKCS7_DETACHED\s0\fR flag set.
.PP
Otherwise the type of the returned structure can be determined
using \fIPKCS7_type()\fR.
.PP
To support future functionality if \fBbcont\fR is not \fB\s-1NULL\s0\fR
\&\fB*bcont\fR should be initialized to \fB\s-1NULL\s0\fR. For example:
.PP
.Vb 2
\& BIO *cont = NULL;
\& PKCS7 *p7;
.Ve
.Vb 1
\& p7 = SMIME_read_PKCS7(in, &cont);
.Ve
.SH "BUGS"
.IX Header "BUGS"
The \s-1MIME\s0 parser used by \fISMIME_read_PKCS7()\fR is somewhat primitive.
While it will handle most S/MIME messages more complex compound
formats may not work.
.PP
The parser assumes that the \s-1PKCS7\s0 structure is always base64
encoded and will not handle the case where it is in binary format
or uses quoted printable format.
.PP
The use of a memory \s-1BIO\s0 to hold the signed content limits the size
of message which can be processed due to memory restraints: a
streaming single pass option should be available.
.SH "RETURN VALUES"
.IX Header "RETURN VALUES"
\&\fISMIME_read_PKCS7()\fR returns a valid \fB\s-1PKCS7\s0\fR structure or \fB\s-1NULL\s0\fR
is an error occurred. The error can be obtained from \fIERR_get_error\fR\|(3).
.SH "SEE ALSO"
.IX Header "SEE ALSO"
ERR_get_error(3), PKCS7_type(3)
SMIME_read_PKCS7(3), PKCS7_sign(3),
PKCS7_verify(3), PKCS7_encrypt(3)
PKCS7_decrypt(3)
.SH "HISTORY"
.IX Header "HISTORY"
\&\fISMIME_read_PKCS7()\fR was added to OpenSSL 0.9.5