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)