.TH fmt_asn1derlength 3
.SH NAME
fmt_asn1derlength \- encode unsigned integer like ASN.1 DER length
.SH SYNTAX
.B #include <libowfat/fmt.h>

size_t \fBfmt_asn1derlength\fP(char *\fIdest\fR,unsigned long long \fIsource\fR);
.SH DESCRIPTION
fmt_asn1derlength encodes an unsigned integer using the ASN.1 DER
for encoding tag lengths.  This can take from 1 byte (0-0x7f) up to
sizeof(source)+1 bytes.

If \fIdest\fR equals FMT_LEN (i.e. is NULL), fmt_asn1derlength returns the
number of bytes it would have written.

For convenience, fmt.h defines the integer FMT_ASN1LENGTH to be big
enough to contain every possible fmt_asn1derlength output.
.SH "SEE ALSO"
scan_asn1derlength(3)