Changeset 876:d89fb130c10d

Timestamp:

08/17/08 01:23:07 (3 months ago)

Author:

Phil <phil@secdev.org>

Message:

Fixed SNMPv1 traps (D. Loss, ticket #99)

Files:

• scapy/asn1/asn1.py (modified) (2 diffs)
• scapy/asn1/ber.py (modified) (3 diffs)
• scapy/asn1fields.py (modified) (1 diff)
• scapy/layers/snmp.py (modified) (2 diffs)

scapy/asn1/asn1.py

@@ -160 +160 @@
-    CHAR_STRING = 29
-    BMP_STRING = 30
+    IPADDRESS = 0x40
-    COUNTER32 = 0x41
-    TIME_TICKS = 0x43
@@ -240 +241 @@
-    tag = ASN1_Class_UNIVERSAL.VIDEOTEX_STRING
-
+class ASN1_IPADDRESS(ASN1_STRING):
+    tag = ASN1_Class_UNIVERSAL.IPADDRESS
+
-class ASN1_UTC_TIME(ASN1_STRING):
-    tag = ASN1_Class_UNIVERSAL.UTC_TIME

scapy/asn1/ber.py

@@ -5 +5 @@
-
-from scapy.error import warning
-
+Encoding_Error,ASN1_
-
-##################
@@ -18 +18 @@
-class BER_Exception(Exception):
-    pass
+
+class BER_Encoding_Error(ASN1_Encoding_Error):
+    def __init__(self, msg, encoded=None, remaining=None):
+        Exception.__init__(self, msg)
+        self.remaining = remaining
+        self.encoded = encoded
+    def __str__(self):
+        s = Exception.__str__(self)
+        if isinstance(self.encoded, BERcodec_Object):
+            s+="\n### Already encoded ###\n%s" % self.encoded.strshow()
+        else:
+            s+="\n### Already encoded ###\n%r" % self.encoded
+        s+="\n### Remaining ###\n%r" % self.remaining
+        return s
-
-class BER_Decoding_Error(ASN1_Decoding_Error):
@@ -240 +254 @@
-    tag = ASN1_Class_UNIVERSAL.IA5_STRING
-
+class BERcodec_IPADDRESS(BERcodec_STRING):
+    tag = ASN1_Class_UNIVERSAL.IPADDRESS
+    
+    @classmethod
+    def enc(cls, ipaddr_ascii):
+        try:
+            s = inet_aton(ipaddr_ascii)
+        except Exception:
+            raise BER_Encoding_Error("IPv4 address could not be encoded") 
+        return chr(cls.tag)+BER_len_enc(len(s))+s
+    
+    @classmethod
+    def do_dec(cls, s, context=None, safe=False):
+        l,s,t = cls.check_type_check_len(s)
+        try:
+            ipaddr_ascii = inet_ntoa(s)
+        except Exception:
+            raise BER_Decoding_Error("IP address could not be decoded", decoded=obj)
+        return cls.asn1_object(ipaddr_ascii), t
+
-class BERcodec_UTC_TIME(BERcodec_STRING):
-    tag = ASN1_Class_UNIVERSAL.UTC_TIME

scapy/asn1fields.py

@@ -161 +161 @@
-class ASN1F_BIT_STRING(ASN1F_STRING):
-    ASN1_tag = ASN1_Class_UNIVERSAL.BIT_STRING
+    
+class ASN1F_IPADDRESS(ASN1F_STRING):
+    ASN1_tag = ASN1_Class_UNIVERSAL.IPADDRESS    
+
+class ASN1F_TIME_TICKS(ASN1F_INTEGER):
+    ASN1_tag = ASN1_Class_UNIVERSAL.TIME_TICKS
-
-class ASN1F_UTC_TIME(ASN1F_STRING):

scapy/layers/snmp.py

@@ -180 +180 @@
-class SNMPtrapv1(ASN1_Packet):
-    ASN1_codec = ASN1_Codecs.BER
-
-
-
+
+
-                                       ASN1F_enum_INTEGER("generic_trap", 0, SNMP_trap_types),
-                                       ASN1F_INTEGER("specific_trap", 0),
-INTEGER
+TIME_TICKS
-                                       ASN1F_SEQUENCE_OF("varbindlist", [], SNMPvarbind)
-                                       )
@@ -232 +231 @@
-bind_layers( UDP,           SNMP,          sport=161)
-bind_layers( UDP,           SNMP,          dport=161)
+bind_layers( UDP,           SNMP,          sport=162) 
+bind_layers( UDP,           SNMP,          dport=162) 
+
-def snmpwalk(dst, oid="1", community="public"):
-    try: