diff options
Diffstat (limited to 'doc/man/man3/lber-encode.3')
| -rw-r--r-- | doc/man/man3/lber-encode.3 | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/doc/man/man3/lber-encode.3 b/doc/man/man3/lber-encode.3 new file mode 100644 index 0000000..2bce2ce --- /dev/null +++ b/doc/man/man3/lber-encode.3 @@ -0,0 +1,288 @@ +.TH LBER_ENCODE 3 "RELEASEDATE" "OpenLDAP LDVERSION" +.\" $OpenLDAP$ +.\" Copyright 1998-2021 The OpenLDAP Foundation All Rights Reserved. +.\" Copying restrictions apply. See COPYRIGHT/LICENSE. +.SH NAME +ber_alloc_t, ber_flush, ber_flush2, ber_printf, ber_put_int, ber_put_enum, ber_put_ostring, ber_put_string, ber_put_null, ber_put_boolean, ber_put_bitstring, ber_start_seq, ber_start_set, ber_put_seq, ber_put_set \- OpenLDAP LBER simplified Basic Encoding Rules library routines for encoding +.SH LIBRARY +OpenLDAP LBER (liblber, \-llber) +.SH SYNOPSIS +.B #include <lber.h> +.LP +.BI "BerElement *ber_alloc_t(int " options ");" +.LP +.BI "int ber_flush(Sockbuf *" sb ", BerElement *" ber ", int " freeit ");" +.LP +.BI "int ber_flush2(Sockbuf *" sb ", BerElement *" ber ", int " freeit ");" +.LP +.BI "int ber_printf(BerElement *" ber ", const char *" fmt ", ...);" +.LP +.BI "int ber_put_int(BerElement *" ber ", ber_int_t " num ", ber_tag_t " tag ");" +.LP +.BI "int ber_put_enum(BerElement *" ber ", ber_int_t " num ", ber_tag_t " tag ");" +.LP +.BI "int ber_put_ostring(BerElement *" ber ", const char *" str ", ber_len_t " len ", ber_tag_t " tag ");" +.LP +.BI "int ber_put_string(BerElement *" ber ", const char *" str ", ber_tag_t " tag ");" +.LP +.BI "int ber_put_null(BerElement *" ber ", ber_tag_t " tag ");" +.LP +.BI "int ber_put_boolean(BerElement *" ber ", ber_int_t " bool ", ber_tag_t " tag ");" +.LP +.BI "int ber_put_bitstring(BerElement *" ber ", const char *" str ", ber_len_t " blen ", ber_tag_t " tag ");" +.LP +.BI "int ber_start_seq(BerElement *" ber ", ber_tag_t " tag ");" +.LP +.BI "int ber_start_set(BerElement *" ber ", ber_tag_t " tag ");" +.LP +.BI "int ber_put_seq(BerElement *" ber ");" +.LP +.BI "int ber_put_set(BerElement *" ber ");" +.SH DESCRIPTION +.LP +These routines provide a subroutine interface to a simplified +implementation of the Basic Encoding Rules of ASN.1. The version +of BER these routines support is the one defined for the LDAP +protocol. The encoding rules are the same as BER, except that +only definite form lengths are used, and bitstrings and octet strings +are always encoded in primitive form. This +man page describes the encoding routines in the lber library. See +.BR lber-decode (3) +for details on the corresponding decoding routines. Consult +.BR lber-types (3) +for information about types, allocators, and deallocators. +.LP +Normally, the only routines that need to be called by an application +are +.BR ber_alloc_t () +to allocate a BER element for encoding, +.BR ber_printf () +to do the actual encoding, and +.BR ber_flush2 () +to actually write the element. The other routines are provided for those +applications that need more control than +.BR ber_printf () +provides. In +general, these routines return the length of the element encoded, or +\-1 if an error occurred. +.LP +The +.BR ber_alloc_t () +routine is used to allocate a new BER element. It +should be called with an argument of LBER_USE_DER. +.LP +The +.BR ber_flush2 () +routine is used to actually write the element to a socket +(or file) descriptor, once it has been fully encoded (using +.BR ber_printf () +and friends). See +.BR lber-sockbuf (3) +for more details on the Sockbuf implementation of the \fIsb\fP parameter. +If the \fIfreeit\fP parameter is non-zero, the supplied \fIber\fP will +be freed. +If \fILBER_FLUSH_FREE_ON_SUCCESS\fP is used, the \fIber\fP is only freed +when successfully flushed, otherwise it is left intact; +if \fILBER_FLUSH_FREE_ON_ERROR\fP is used, the \fIber\fP is only freed +when an error occurs, otherwise it is left intact; +if \fILBER_FLUSH_FREE_ALWAYS\fP is used, the \fIber\fP is freed anyway. +This function differs from the original +.BR ber_flush (3) +function, whose behavior corresponds to that indicated +for \fILBER_FLUSH_FREE_ON_SUCCESS\fP. +Note that in the future, the behavior of +.BR ber_flush (3) +with \fIfreeit\fP non-zero might change into that of +.BR ber_flush2 (3) +with \fIfreeit\fP set to \fILBER_FLUSH_FREE_ALWAYS\fP. +.LP +The +.BR ber_printf () +routine is used to encode a BER element in much the same way that +.BR sprintf (3) +works. One important difference, though, is +that some state information is kept with the \fIber\fP parameter so +that multiple calls can be made to +.BR ber_printf () +to append things to the end of the BER element. +.BR Ber_printf () +writes to \fIber\fP, a pointer to a BerElement such as returned by +.BR ber_alloc_t (). +It interprets and +formats its arguments according to the format string \fIfmt\fP. +The format string can contain the following characters: +.RS +.LP +.TP 3 +.B b +Boolean. An ber_int_t parameter should be supplied. A boolean element +is output. +.TP +.B e +Enumeration. An ber_int_t parameter should be supplied. An +enumeration element is output. +.TP +.B i +Integer. An ber_int_t parameter should be supplied. An integer element +is output. +.TP +.B B +Bitstring. A char * pointer to the start of the bitstring is supplied, +followed by the number of bits in the bitstring. A bitstring element +is output. +.TP +.B n +Null. No parameter is required. A null element is output. +.TP +.B o +Octet string. A char * is supplied, followed by the length of the +string pointed to. An octet string element is output. +.TP +.B O +Octet string. A struct berval * is supplied. +An octet string element is output. +.TP +.B s +Octet string. A null-terminated string is supplied. An octet string +element is output, not including the trailing NULL octet. +.TP +.B t +Tag. A ber_tag_t specifying the tag to give the next element +is provided. This works across calls. +.TP +.B v +Several octet strings. A null-terminated array of char *'s is +supplied. Note that a construct like '{v}' is required to get +an actual SEQUENCE OF octet strings. +.TP +.B V +Several octet strings. A null-terminated array of struct berval *'s +is supplied. Note that a construct like '{V}' is required to get +an actual SEQUENCE OF octet strings. +.TP +.B W +Several octet strings. An array of struct berval's is supplied. The +array is terminated by a struct berval with a NULL bv_val. +Note that a construct like '{W}' is required to get +an actual SEQUENCE OF octet strings. +.TP +.B { +Begin sequence. No parameter is required. +.TP +.B } +End sequence. No parameter is required. +.TP +.B [ +Begin set. No parameter is required. +.TP +.B ] +End set. No parameter is required. +.RE +.LP +The +.BR ber_put_int () +routine writes the integer element \fInum\fP to the BER element \fIber\fP. +.LP +The +.BR ber_put_enum () +routine writes the enumeration element \fInum\fP to the BER element \fIber\fP. +.LP +The +.BR ber_put_boolean () +routine writes the boolean value given by \fIbool\fP to the BER element. +.LP +The +.BR ber_put_bitstring () +routine writes \fIblen\fP bits starting +at \fIstr\fP as a bitstring value to the given BER element. Note +that \fIblen\fP is the length \fIin bits\fP of the bitstring. +.LP +The +.BR ber_put_ostring () +routine writes \fIlen\fP bytes starting at +\fIstr\fP to the BER element as an octet string. +.LP +The +.BR ber_put_string () +routine writes the null-terminated string (minus +the terminating '\0') to the BER element as an octet string. +.LP +The +.BR ber_put_null () +routine writes a NULL element to the BER element. +.LP +The +.BR ber_start_seq () +routine is used to start a sequence in the BER element. The +.BR ber_start_set () +routine works similarly. +The end of the sequence or set is marked by the nearest matching call to +.BR ber_put_seq () +or +.BR ber_put_set (), +respectively. +.SH EXAMPLES +Assuming the following variable declarations, and that the variables +have been assigned appropriately, an lber encoding of +the following ASN.1 object: +.LP +.nf + AlmostASearchRequest := SEQUENCE { + baseObject DistinguishedName, + scope ENUMERATED { + baseObject (0), + singleLevel (1), + wholeSubtree (2) + }, + derefAliases ENUMERATED { + neverDerefaliases (0), + derefInSearching (1), + derefFindingBaseObj (2), + alwaysDerefAliases (3) + }, + sizelimit INTEGER (0 .. 65535), + timelimit INTEGER (0 .. 65535), + attrsOnly BOOLEAN, + attributes SEQUENCE OF AttributeType + } +.fi +.LP +can be achieved like so: +.LP +.nf + int rc; + ber_int_t scope, ali, size, time, attrsonly; + char *dn, **attrs; + BerElement *ber; + + /* ... fill in values ... */ + + ber = ber_alloc_t( LBER_USE_DER ); + + if ( ber == NULL ) { + /* error */ + } + + rc = ber_printf( ber, "{siiiib{v}}", dn, scope, ali, + size, time, attrsonly, attrs ); + + if( rc == \-1 ) { + /* error */ + } else { + /* success */ + } +.fi +.SH ERRORS +If an error occurs during encoding, generally these routines return \-1. +.LP +.SH NOTES +.LP +The return values for all of these functions are declared in the +<lber.h> header file. +.SH SEE ALSO +.BR lber-decode (3), +.BR lber-memory (3), +.BR lber-sockbuf (3), +.BR lber-types (3) +.SH ACKNOWLEDGEMENTS +.so ../Project |