NAME

       scan_asn1derlength - decode an unsigned integer from ASN.1 DER length encoding

SYNTAX

       #include <scan.h>

       size_t scan_asn1derlength(const char *src,size_t len,unsigned long long *dest);

DESCRIPTION

       scan_asn1derlength  decodes an unsigned integer in ASN.1 DER length encoding from a memory
       area holding binary data.  It writes the decode value in dest and returns  the  number  of
       bytes it read from src.

       scan_asn1derlength  never  reads  more than len bytes from src.  If the sequence is longer
       than that, or the memory area contains an invalid sequence, scan_asn1derlength  returns  0
       and does not touch dest.

       The length of the longest ASN.1 DER length sequence is 128 bytes.  In practice the largest
       sequence is sizeof(*dest)+1.

SEE ALSO

       fmt_asn1derlength(3)

                                                                            scan_asn1derlength(3)