diff options
| -rw-r--r-- | asn1/pres/pres.cnf | 2 | ||||
| -rw-r--r-- | epan/dissectors/packet-ber.c | 88 | ||||
| -rw-r--r-- | epan/dissectors/packet-pres.c | 2 |
3 files changed, 78 insertions, 14 deletions
diff --git a/asn1/pres/pres.cnf b/asn1/pres/pres.cnf index bfefbfd120..4e573ef2fd 100644 --- a/asn1/pres/pres.cnf +++ b/asn1/pres/pres.cnf @@ -56,7 +56,7 @@ CPR-PPDU/normal-mode-parameters/provider-reason cPR_PPDU__provider-reason oid=find_oid_by_pres_ctx_id(actx->pinfo, presentation_context_identifier); if(oid){ - next_tvb = tvb_new_subset_remaining(tvb, offset); + dissect_ber_octet_string(implicit_tag, actx, tree, tvb, offset, hf_index, &next_tvb); call_ber_oid_callback(oid, next_tvb, offset, actx->pinfo, global_tree); } else { if (!pres_try_users_table(presentation_context_identifier, tvb, offset, actx->pinfo)) { diff --git a/epan/dissectors/packet-ber.c b/epan/dissectors/packet-ber.c index 89297b0930..b13341b10d 100644 --- a/epan/dissectors/packet-ber.c +++ b/epan/dissectors/packet-ber.c @@ -138,6 +138,12 @@ static dissector_table_t ber_oid_dissector_table=NULL; static dissector_table_t ber_syntax_dissector_table=NULL; static GHashTable *syntax_table=NULL; +static gint8 last_class; +static gboolean last_pc; +static gint32 last_tag; +static guint32 last_length; +static gboolean last_ind; + static const value_string ber_class_codes[] = { { BER_CLASS_UNI, "UNIVERSAL" }, { BER_CLASS_APP, "APPLICATION" }, @@ -780,9 +786,24 @@ printf ("\n"); if (tag) *tag = tmp_tag; + last_class = tmp_class; + last_pc = tmp_pc; + last_tag = tmp_tag; + return offset; } +static void get_last_ber_identifier(gint8 *class, gboolean *pc, gint32 *tag) +{ + if (class) + *class = last_class; + if (pc) + *pc = last_pc; + if (tag) + *tag = last_tag; + +} + int dissect_ber_identifier(packet_info *pinfo _U_, proto_tree *tree, tvbuff_t *tvb, int offset, gint8 *class, gboolean *pc, gint32 *tag) { int old_offset = offset; @@ -831,13 +852,12 @@ static gboolean try_get_ber_length(tvbuff_t *tvb, int *bl_offset, guint32 *length, gboolean *ind) { int offset = *bl_offset; guint8 oct, len; - guint32 tmp_len; + guint32 tmp_len; + gint8 tclass; + gint32 ttag; guint32 tmp_length; gboolean tmp_ind; int tmp_offset; - gint8 tclass; - gint32 ttag; - tmp_length = 0; tmp_ind = FALSE; @@ -858,8 +878,8 @@ try_get_ber_length(tvbuff_t *tvb, int *bl_offset, guint32 *length, gboolean *ind } } else { /* 8.1.3.6 */ + /* indefinite length encoded - must be constructed */ - /* indefinite length encoded - must be constructed */ tmp_offset = offset; do { @@ -873,7 +893,6 @@ try_get_ber_length(tvbuff_t *tvb, int *bl_offset, guint32 *length, gboolean *ind tmp_length = tmp_offset - offset; tmp_ind = TRUE; - } } @@ -889,21 +908,44 @@ printf("get BER length %d, offset %d (remaining %d)\n", tmp_length, offset, tvb_ *bl_offset = offset; return TRUE; } - + int get_ber_length(tvbuff_t *tvb, int offset, guint32 *length, gboolean *ind) { int bl_offset = offset; guint32 bl_length; + + gint8 save_class; + gboolean save_pc; + gint32 save_tag; + + /* save last tag */ + save_class = last_class; + save_pc = last_pc; + save_tag = last_tag; + try_get_ber_length(tvb, &bl_offset, &bl_length, ind); + /* restore last tag */ + last_class = save_class; + last_pc = save_pc; + last_tag = save_tag; + if (length) *length = bl_length; return bl_offset; } +static void get_last_ber_length(guint32 *length, gboolean *ind) +{ + if (length) + *length = last_length; + if (ind) + *ind = last_ind; +} + /* this function dissects the length octets of the BER TLV. * We only handle (TAGs and) LENGTHs that fit inside 32 bit integers. */ @@ -932,6 +974,9 @@ dissect_ber_length(packet_info *pinfo _U_, proto_tree *tree, tvbuff_t *tvb, int printf("dissect BER length %d, offset %d (remaining %d)\n", tmp_length, offset, tvb_length_remaining(tvb, offset)); #endif + last_length = tmp_length; + last_ind = tmp_ind; + return offset; } @@ -943,7 +988,7 @@ static void ber_defragment_init(void) { reassembled_table_init(&octet_reassembled_table); } -static int +int reassemble_octet_string(asn1_ctx_t *actx, proto_tree *tree, tvbuff_t *tvb, int offset, guint32 con_len, gboolean ind, tvbuff_t **out_tvb) { fragment_data *fd_head = NULL; @@ -1036,6 +1081,7 @@ dissect_ber_constrained_octet_string(gboolean implicit_tag, asn1_ctx_t *actx, pr int end_offset; proto_item *it, *cause; guint32 i; + guint32 len_remain; #ifdef DEBUG_BER { @@ -1080,10 +1126,28 @@ printf("OCTET STRING dissect_ber_octet_string(%s) entered\n",name); return end_offset; } } else { - /* implicit tag so just trust the length of the tvb */ - pc=FALSE; - len=tvb_length_remaining(tvb,offset); - end_offset=offset+len; + /* implicit tag so get from last tag/length */ + + get_last_ber_identifier(&class, &pc, &tag); + get_last_ber_length(&len, &ind); + + end_offset=offset+len; + + /* caller may have created new buffer for indefinite length data Verify via length */ + len_remain = (guint32)tvb_length_remaining(tvb, offset); + if((ind) && (len_remain == len - 2)) { + /* new buffer received so adjust length and indefinite flag */ + len -=2; + end_offset -= 2; + ind = FALSE; + } else if (len_remain < len) { + /* error - short frame */ + cause = proto_tree_add_text(tree, tvb, offset, len, "BER Error: length:%u longer than tvb_length_remaining:%d", len, len_remain); + proto_item_set_expert_flags(cause, PI_MALFORMED, PI_WARN); + expert_add_info_format(actx->pinfo, cause, PI_MALFORMED, PI_WARN, "BER Error length"); + return end_offset; + } + } actx->created_item = NULL; diff --git a/epan/dissectors/packet-pres.c b/epan/dissectors/packet-pres.c index 3d883215e9..3f4310933c 100644 --- a/epan/dissectors/packet-pres.c +++ b/epan/dissectors/packet-pres.c @@ -671,7 +671,7 @@ dissect_pres_T_octet_aligned(gboolean implicit_tag _U_, tvbuff_t *tvb _U_, int o oid=find_oid_by_pres_ctx_id(actx->pinfo, presentation_context_identifier); if(oid){ - next_tvb = tvb_new_subset_remaining(tvb, offset); + dissect_ber_octet_string(implicit_tag, actx, tree, tvb, offset, hf_index, &next_tvb); call_ber_oid_callback(oid, next_tvb, offset, actx->pinfo, global_tree); } else { if (!pres_try_users_table(presentation_context_identifier, tvb, offset, actx->pinfo)) { |