Kerberos: fix decryption of DCERPC with Kerberos encryption

Bug: 10538
Change-Id: I4e6feaf218da7f977f6c63d8bc204635f387672c
Reviewed-on: https://code.wireshark.org/review/4566
Reviewed-by: Pascal Quantin <pascal.quantin@gmail.com>

2 files changed, 17 insertions, 15 deletions

diff --git a/asn1/kerberos/kerberos.cnf b/asn1/kerberos/kerberos.cnf
index 4059cb9b89..edafd6032b 100644
--- a/asn1/kerberos/kerberos.cnf
+++ b/asn1/kerberos/kerberos.cnf
@@ -305,14 +305,15 @@ guint32 msgtype;
 									&gbl_keytype);
 	private_data->key.keytype = gbl_keytype;
 
-#.FN_BODY EncryptionKey/keyvalue
+#.FN_BODY EncryptionKey/keyvalue VAL_PTR=&out_tvb
+	tvbuff_t *out_tvb;
 	kerberos_private_data_t *private_data = kerberos_get_private_data(actx);
 
-	private_data->key.keylength = tvb_length_remaining(tvb, offset);
-	private_data->key.keyvalue = tvb_get_ptr(tvb, offset, private_data->key.keylength);
-
 %(DEFAULT_BODY)s
 
+	private_data->key.keylength = tvb_reported_length(out_tvb);
+	private_data->key.keyvalue = tvb_get_ptr(out_tvb, 0, private_data->key.keylength);
+
 #.FN_BODY EncryptionKey
 	kerberos_private_data_t *private_data = kerberos_get_private_data(actx);
 
diff --git a/epan/dissectors/packet-kerberos.c b/epan/dissectors/packet-kerberos.c
index 6912d0d59e..36f9337aff 100644
--- a/epan/dissectors/packet-kerberos.c
+++ b/epan/dissectors/packet-kerberos.c
@@ -2229,14 +2229,15 @@ dissect_kerberos_T_keytype(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int off
 static int
 dissect_kerberos_T_keyvalue(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
 #line 309 "../../asn1/kerberos/kerberos.cnf"
+	tvbuff_t *out_tvb;
 	kerberos_private_data_t *private_data = kerberos_get_private_data(actx);
 
-	private_data->key.keylength = tvb_length_remaining(tvb, offset);
-	private_data->key.keyvalue = tvb_get_ptr(tvb, offset, private_data->key.keylength);
-
   offset = dissect_ber_octet_string(implicit_tag, actx, tree, tvb, offset, hf_index,
-                                       NULL);
+                                       &out_tvb);
+
 
+	private_data->key.keylength = tvb_reported_length(out_tvb);
+	private_data->key.keyvalue = tvb_get_ptr(out_tvb, 0, private_data->key.keylength);
 
 
 
@@ -2252,7 +2253,7 @@ static const ber_sequence_t EncryptionKey_sequence[] = {
 
 static int
 dissect_kerberos_EncryptionKey(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
-#line 317 "../../asn1/kerberos/kerberos.cnf"
+#line 318 "../../asn1/kerberos/kerberos.cnf"
 	kerberos_private_data_t *private_data = kerberos_get_private_data(actx);
 
 	  offset = dissect_ber_sequence(implicit_tag, actx, tree, tvb, offset,
@@ -2274,7 +2275,7 @@ dissect_kerberos_EncryptionKey(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int
 
 static int
 dissect_kerberos_T_ad_type(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
-#line 328 "../../asn1/kerberos/kerberos.cnf"
+#line 329 "../../asn1/kerberos/kerberos.cnf"
 	kerberos_private_data_t *private_data = kerberos_get_private_data(actx);
 	offset = dissect_ber_integer(implicit_tag, actx, tree, tvb, offset, hf_index,
 									&(private_data->ad_type));
@@ -2288,7 +2289,7 @@ dissect_kerberos_T_ad_type(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int off
 
 static int
 dissect_kerberos_T_ad_data(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
-#line 333 "../../asn1/kerberos/kerberos.cnf"
+#line 334 "../../asn1/kerberos/kerberos.cnf"
 	kerberos_private_data_t *private_data = kerberos_get_private_data(actx);
 
 	switch(private_data->ad_type){
@@ -2434,7 +2435,7 @@ static const value_string kerberos_ADDR_TYPE_vals[] = {
 
 static int
 dissect_kerberos_ADDR_TYPE(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
-#line 344 "../../asn1/kerberos/kerberos.cnf"
+#line 345 "../../asn1/kerberos/kerberos.cnf"
 	kerberos_private_data_t *private_data = kerberos_get_private_data(actx);
   offset = dissect_ber_integer(implicit_tag, actx, tree, tvb, offset, hf_index,
                                                 &(private_data->addr_type));
@@ -2865,7 +2866,7 @@ static const ber_sequence_t KDC_REQ_BODY_sequence[] = {
 
 static int
 dissect_kerberos_KDC_REQ_BODY(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
-#line 348 "../../asn1/kerberos/kerberos.cnf"
+#line 349 "../../asn1/kerberos/kerberos.cnf"
 	conversation_t *conversation;
 
 	/*
@@ -3117,7 +3118,7 @@ dissect_kerberos_AP_REP(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset
 
 static int
 dissect_kerberos_T_kRB_SAFE_BODY_user_data(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
-#line 371 "../../asn1/kerberos/kerberos.cnf"
+#line 372 "../../asn1/kerberos/kerberos.cnf"
 	tvbuff_t *new_tvb;
 	offset=dissect_ber_octet_string(FALSE, actx, tree, tvb, offset, hf_index, &new_tvb);
 	if (new_tvb) {
@@ -3439,7 +3440,7 @@ dissect_kerberos_EncAPRepPart(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int
 
 static int
 dissect_kerberos_T_encKrbPrivPart_user_data(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int offset _U_, asn1_ctx_t *actx _U_, proto_tree *tree _U_, int hf_index _U_) {
-#line 378 "../../asn1/kerberos/kerberos.cnf"
+#line 379 "../../asn1/kerberos/kerberos.cnf"
 	tvbuff_t *new_tvb;
 	offset=dissect_ber_octet_string(FALSE, actx, tree, tvb, offset, hf_index, &new_tvb);
 	if (new_tvb) {