NAME

       scan_asn1dertag - decode an unsigned integer from ASN.1 DER length encoding

SYNTAX

       #include <scan.h>

       size_t scan_asn1dertag(const char *src,size_t len,unsigned long long *dest);

DESCRIPTION

       scan_asn1dertag  decodes  an unsigned integer in ASN.1 DER tag 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_asn1dertag  never reads more than len bytes from src.  If the sequence is longer than
       that, or the memory area contains an invalid sequence, scan_asn1dertag 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_asn1dertag(3)

                                                                               scan_asn1dertag(3)