From Martin Peylo (bug 2507):

The attached patch enables asn2wrs.py and packet-ber.c to decode UTCTime
according to the definitions in X.680.

svn path=/trunk/; revision=25897

3 files changed, 144 insertions, 0 deletions

diff --git a/epan/dissectors/packet-ber.c b/epan/dissectors/packet-ber.c
index d4c47cec6d..2167155b00 100644
--- a/epan/dissectors/packet-ber.c
+++ b/epan/dissectors/packet-ber.c
@@ -3717,6 +3717,140 @@ dissect_ber_GeneralizedTime(gboolean implicit_tag, asn1_ctx_t *actx, proto_tree
 	return offset;
 }
 
+
+int
+dissect_ber_UTCTime(gboolean implicit_tag, asn1_ctx_t *actx, proto_tree *tree, tvbuff_t *tvb, int offset, gint hf_id)
+{
+	char outstr[33];
+	char *outstrptr = outstr;
+	const guint8 *instr;
+	gint8 class;
+	gboolean pc;
+	gint32 tag;
+	guint32 len, i, n;
+	int hoffset;
+	proto_item *cause;
+
+	if(!implicit_tag){
+		hoffset = offset;
+		offset = dissect_ber_identifier(actx->pinfo, tree, tvb, offset, &class, &pc, &tag);
+		offset = dissect_ber_length(actx->pinfo, tree, tvb, offset, &len, NULL);
+
+		/* sanity check: we only handle UTCTime */
+		if( (class!=BER_CLASS_UNI) || (tag!=BER_UNI_TAG_UTCTime) ) {
+			tvb_ensure_bytes_exist(tvb, hoffset, 2);
+			cause = proto_tree_add_text(tree, tvb, offset, len,
+					"BER Error: UTCTime expected but class:%s(%d) %s tag:%d was unexpected",
+					val_to_str(class,ber_class_codes,"Unknown"), class,
+					pc ? ber_pc_codes_short.true_string : ber_pc_codes_short.false_string, tag);
+			proto_item_set_expert_flags(cause, PI_MALFORMED, PI_WARN);
+			expert_add_info_format(actx->pinfo, cause, PI_MALFORMED, PI_WARN, "BER Error: UTCTime expected");
+			if (decode_unexpected) {
+				proto_tree *unknown_tree = proto_item_add_subtree(cause, ett_ber_unknown);
+				dissect_unknown_ber(actx->pinfo, tvb, hoffset, unknown_tree);
+			}
+			return offset+len;
+		}
+	} else {
+		len = tvb_length_remaining(tvb,offset);
+	}
+
+	instr = tvb_get_ptr(tvb, offset, len);
+
+	/* YYMMDDhhmm */
+	for(i=0;i<10;i++) {
+		if(instr[i] < '0' || instr[i] > '9') {
+			cause = proto_tree_add_text(tree, tvb, offset, len,
+					"BER Error: malformed UTCTime encoding, "
+					"first 10 octets have to contain YYMMDDhhmm in digits");
+			goto malformed;
+		}
+	}
+	g_snprintf(outstrptr, 15, "%.2s-%.2s-%.2s %.2s:%.2s", instr, instr+2, instr+4, instr+6, instr+8);
+	outstrptr+= 14;
+
+	/* (ss)? */
+	if(len >= 12) {
+		if(instr[i] >= '0' && instr[i] <= '9') {
+			i++;
+			if(instr[i] >= '0' && instr[i] <= '9') {
+				i++;
+				g_snprintf(outstrptr, 4, ":%.2s", instr+10);
+				outstrptr+=3;
+			} else {
+				cause = proto_tree_add_text(tree, tvb, offset, len,
+						"BER Error: malformed UTCTime encoding, "
+						"if 11th octet is a digit for seconds, "
+						"the 12th octet has to be a digit, too");
+				goto malformed;
+			}
+		}
+	}
+
+	/* Z|([+-]hhmm) */
+	switch (instr[i]) {
+		case 'Z':
+			if(len!=i+1) {
+				cause = proto_tree_add_text(tree, tvb, offset, len,
+						"BER Error: malformed UTCTime encoding, "
+						"there must be no further octets after \'Z\'");
+				goto malformed;
+			}
+			g_snprintf(outstrptr, 7, " (UTC)");
+			i++;
+			break;
+		case '-':
+		case '+':
+			if(len!=i+5) {
+				cause = proto_tree_add_text(tree, tvb, offset, len,
+						"BER Error: malformed UTCTime encoding, "
+						"4 digits must follow on \'+\' resp. \'-\'");
+				goto malformed;
+			}
+			for(n=i+1;n<i+5;n++) {
+				if(instr[n] < '0' || instr[n] > '9') {
+					cause = proto_tree_add_text(tree, tvb, offset, len,
+							"BER Error: malformed UTCTime encoding, "
+							"4 digits must follow on \'+\' resp. \'-\'");
+					goto malformed;
+				}
+			}
+			g_snprintf(outstrptr, 12, " (UTC%c%.4s)", instr[i], instr+i+1);
+			i+=5;
+			break;
+		default:
+			cause = proto_tree_add_text(tree, tvb, offset, len,
+					"BER Error: malformed UTCTime encoding, "
+					"unexpected character in %dth octet, "
+					"must be \'Z\', \'+\' or \'-\'", i+1);
+			goto malformed;
+			break;
+	}
+
+	if(len!=i) {
+		cause = proto_tree_add_text(tree, tvb, offset, len,
+				"BER Error: malformed UTCTime encoding, "
+				"%d unexpected character%s after %dth octet",
+				len-i, (len==i-1?"s":""), i);
+		goto malformed;
+	}
+
+	if(hf_id >= 0){
+		proto_tree_add_string(tree, hf_id, tvb, offset, len, outstr);
+	}
+
+	return offset+len;
+malformed:
+	proto_item_set_expert_flags(cause, PI_MALFORMED, PI_WARN);
+	expert_add_info_format(actx->pinfo, cause, PI_MALFORMED, PI_WARN, "BER Error: malformed UTCTime encoding");
+	g_snprintf(outstr, (len>29)?31:len+1, "%s", instr);
+	if(hf_id >= 0){
+		proto_tree_add_string(tree, hf_id, tvb, offset, len, outstr);
+	}
+	return offset+len;
+}
+
+
 /* 8.6 Encoding of a bitstring value */
 int dissect_ber_bitstring(gboolean implicit_tag, asn1_ctx_t *actx, proto_tree *parent_tree, tvbuff_t *tvb, int offset, const asn_namedbit *named_bits, gint hf_id, gint ett_id, tvbuff_t **out_tvb)
 {
diff --git a/epan/dissectors/packet-ber.h b/epan/dissectors/packet-ber.h
index 6145e763ac..fde968e073 100644
--- a/epan/dissectors/packet-ber.h
+++ b/epan/dissectors/packet-ber.h
@@ -200,6 +200,8 @@ extern int dissect_ber_old_set_of(gboolean implicit_tag, asn1_ctx_t *actx, proto
 
 extern int dissect_ber_GeneralizedTime(gboolean implicit_tag, asn1_ctx_t *actx, proto_tree *tree, tvbuff_t *tvb, int offset, gint hf_id);
 
+extern int dissect_ber_UTCTime(gboolean implicit_tag, asn1_ctx_t *actx, proto_tree *tree, tvbuff_t *tvb, int offset, gint hf_id);
+ 
 typedef struct _asn_namedbit {
 	guint32 bit;
 	int *p_id;
diff --git a/tools/asn2wrs.py b/tools/asn2wrs.py
index cf2020aba5..ddcbbfa116 100755
--- a/tools/asn2wrs.py
+++ b/tools/asn2wrs.py
@@ -4846,6 +4846,14 @@ class UTCTime (RestrictedCharacterStringType):
   def eth_tsname(self):
     return 'UTCTime'
 
+  def eth_type_default_body(self, ectx, tname):
+    if (ectx.Ber()):
+      body = ectx.eth_fn_call('dissect_%(ER)s_%(STRING_TYPE)s', ret='offset',
+                              par=(('%(IMPLICIT_TAG)s', '%(ACTX)s', '%(TREE)s', '%(TVB)s', '%(OFFSET)s', '%(HF_INDEX)s'),))
+      return body
+    else:
+      return RestrictedCharacterStringType.eth_type_default_body(self, ectx, tname)
+
 class ObjectDescriptor (RestrictedCharacterStringType):
   def eth_tsname(self):
     return 'ObjectDescriptor'