Handling of counter 64 values fail with large numbers

[madari]

Hi,

I'm running into a problem where gosnmp (and WapSNMP if that matters) fails to decode large counter 64 values.

Here's an example with logging enabled. I added a log line to parseInt64 to dump the input bytes:

Packet sanity verified, we got all the bytes ([62])
parseInt64: 01
Parsed version [1]
Parsed community [redacted]
getResponseLength: [43]
parseInt64: d4 6a 68 fa
requestID: [3563743482]
parseInt64: 00
errorStatus: [0]
parseInt64: 00
error-index: [0]
vblLength: [29]
OID: [.1.3.6.1.2.1.31.1.1.1.11.502]
[decodeValue: type is Counter64]
parseInt64: 00 ff ff ff ff ff 1e e5 3a
decodeValue: err is [integer too large]

9 bytes are passed into parseInt64: 00 ff ff ff ff ff 1e e5 3a, which causes it to immediately fail. snmp4j (and net-snmp) both successfully parse this value simply dropping the leading 0-octet.

Please see http://grepcode.com/file/repo1.maven.org/maven2/org.snmp4j/snmp4j/1.8.1/org/snmp4j/asn1/BER.java#BER.decodeUnsignedInt64%28org.snmp4j.asn1.BERInputStream%2Corg.snmp4j.asn1.BER.MutableByte%29 for how this is handled in snmp4j.