Problem in snmpset for octet string.

[Ananth S. <ana...@wi...>]

Hi,

I have a MIB variable that is of type OCTET-STRING and represents the
Hash value of a configuration file; it is used to authenticate the file
received. 

pktcMtaDevProvConfigHash  OBJECT-TYPE 
    SYNTAX      OCTET STRING (SIZE(16|20)) 
    MAX-ACCESS  read-write 
    STATUS      current 
    DESCRIPTION 
            "Hash of the contents of the config file, calculated and
sent to 
            the MTA prior to sending the config file.  If the
authenthenication
            algorithm is MD5, the length is 128 bits,  If the
authentication 
            algorithm is SHA-1, the length is 160 bits." 
    ::= { pktcMtaDevServer 7 } 

The hash of this value seems to be containing nulls because the actual
length of the SHA1 hash is 20 whereas a strlen operation on it returns
17.

In snmp_add_var function, we process octet strings under case 's','x'
or'd'.
snmp_hex_to_binary and snmp_decimal_to_binary check for hex or deximal
digits whereas strlen(value) is assigned to value_len is performed if it
is of type 's'.
This strlen seem to be returning 17 whereas the hash string is actually
20 bytes in length.
Due to this, the other end(agent) gets a 17-byte value which is wrong.

Can we modify snmp_add_var to take in the value_len also so that such
cases are taken care of?

Thanks,
Ananth.