osmocom/wireshark
14
0
Fork 1
Code Issues Pull requests Projects Releases Wiki Activity

Dissect the crypto attribute.

Browse source 
svn path=/trunk/; revision=40732
This commit is contained in:
Anders Broman 2012-01-26 17:52:13 +00:00
parent ab692eb7d4
commit 63e6945482
1 changed files with 462 additions and 305 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

767
epan/dissectors/packet-sdp.c
View file

@ -179,6 +179,14 @@ static int hf_key_mgmt_att_value = -1;
static int hf_key_mgmt_prtcl_id = -1;
static int hf_key_mgmt_data = -1;
static int hf_sdp_crypto_tag = -1;
static int hf_sdp_crypto_crypto_suite = -1;
static int hf_sdp_crypto_master_key = -1;
static int hf_sdp_crypto_master_salt = -1;
static int hf_sdp_crypto_lifetime = -1;
static int hf_sdp_crypto_mki = -1;
static int hf_sdp_crypto_mki_length = -1;
/* trees */
static int ett_sdp = -1;
static int ett_sdp_owner = -1;
@ -193,6 +201,7 @@ static int ett_sdp_media = -1;
static int ett_sdp_media_attribute = -1;
static int ett_sdp_fmtp = -1;
static int ett_sdp_key_mgmt = -1;
static int ett_sdp_crypto_key_parameters = -1;
#define SDP_MAX_RTP_CHANNELS 4
@ -985,69 +994,69 @@ static void dissect_key_mgmt(tvbuff_t *tvb, packet_info * pinfo, proto_item * ti
static void dissect_sdp_session_attribute(tvbuff_t *tvb, packet_info * pinfo, proto_item * ti){
proto_tree *sdp_session_attribute_tree;
gint offset, next_offset, tokenlen;
guint8 *field_name;
proto_tree *sdp_session_attribute_tree;
gint offset, next_offset, tokenlen;
guint8 *field_name;
offset = 0;
next_offset = 0;
tokenlen = 0;
offset = 0;
next_offset = 0;
tokenlen = 0;
sdp_session_attribute_tree = proto_item_add_subtree(ti,
ett_sdp_session_attribute);
sdp_session_attribute_tree = proto_item_add_subtree(ti,
ett_sdp_session_attribute);
next_offset = tvb_find_guint8(tvb,offset,-1,':');
next_offset = tvb_find_guint8(tvb,offset,-1,':');
if(next_offset == -1)
return;
tokenlen = next_offset - offset;
proto_tree_add_item(sdp_session_attribute_tree, hf_session_attribute_field,
tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
field_name = tvb_get_ephemeral_string(tvb, offset, tokenlen);
offset = next_offset + 1;
if (strcmp((char*)field_name, "ipbcp") == 0) {
offset = tvb_pbrk_guint8(tvb,offset,-1,(guint8 *)"0123456789", NULL);
if (offset == -1)
return;
next_offset = tvb_find_guint8(tvb,offset,-1,' ');
if (next_offset == -1)
return;
if(next_offset == -1)
return;
tokenlen = next_offset - offset;
proto_tree_add_item(sdp_session_attribute_tree,hf_ipbcp_version,tvb,offset,tokenlen,ENC_ASCII|ENC_NA);
proto_tree_add_item(sdp_session_attribute_tree, hf_session_attribute_field,
tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
offset = tvb_pbrk_guint8(tvb,offset,-1,(guint8 *)"ABCDEFGHIJKLMNOPQRSTUVWXYZ", NULL);
field_name = tvb_get_ephemeral_string(tvb, offset, tokenlen);
if (offset == -1)
return;
offset = next_offset + 1;
tokenlen = tvb_find_line_end(tvb,offset,-1, &next_offset, FALSE);
if (strcmp((char*)field_name, "ipbcp") == 0) {
offset = tvb_pbrk_guint8(tvb,offset,-1,(guint8 *)"0123456789", NULL);
if (tokenlen == -1)
return;
if (offset == -1)
return;
proto_tree_add_item(sdp_session_attribute_tree,hf_ipbcp_type,tvb,offset,tokenlen,ENC_ASCII|ENC_NA);
} else if (strcmp((char*)field_name, "key-mgmt") == 0) {
tvbuff_t *key_tvb;
proto_item *key_ti;
next_offset = tvb_find_guint8(tvb,offset,-1,' ');
key_tvb = tvb_new_subset_remaining(tvb, offset);
key_ti = proto_tree_add_item(sdp_session_attribute_tree, hf_key_mgmt_att_value, key_tvb, 0, -1, ENC_ASCII|ENC_NA);
if (next_offset == -1)
return;
dissect_key_mgmt(key_tvb, pinfo, key_ti);
} else {
proto_tree_add_item(sdp_session_attribute_tree, hf_session_attribute_value,
tvb, offset, -1, ENC_ASCII|ENC_NA);
}
tokenlen = next_offset - offset;
proto_tree_add_item(sdp_session_attribute_tree,hf_ipbcp_version,tvb,offset,tokenlen,ENC_ASCII|ENC_NA);
offset = tvb_pbrk_guint8(tvb,offset,-1,(guint8 *)"ABCDEFGHIJKLMNOPQRSTUVWXYZ", NULL);
if (offset == -1)
return;
tokenlen = tvb_find_line_end(tvb,offset,-1, &next_offset, FALSE);
if (tokenlen == -1)
return;
proto_tree_add_item(sdp_session_attribute_tree,hf_ipbcp_type,tvb,offset,tokenlen,ENC_ASCII|ENC_NA);
} else if (strcmp((char*)field_name, "key-mgmt") == 0) {
tvbuff_t *key_tvb;
proto_item *key_ti;
key_tvb = tvb_new_subset_remaining(tvb, offset);
key_ti = proto_tree_add_item(sdp_session_attribute_tree, hf_key_mgmt_att_value, key_tvb, 0, -1, ENC_ASCII|ENC_NA);
dissect_key_mgmt(key_tvb, pinfo, key_ti);
} else {
proto_tree_add_item(sdp_session_attribute_tree, hf_session_attribute_value,
tvb, offset, -1, ENC_ASCII|ENC_NA);
}
}
@ -1470,7 +1479,8 @@ typedef struct {
#define SDP_RTPMAP 1
#define SDP_FMTP 2
#define SDP_PATH 3
#define SDP_H248_ITEM 4
#define SDP_H248_ITEM 4
#define SDP_CRYPTO 5
static const sdp_names_t sdp_media_attribute_names[] = {
{ "Unknown-name"}, /* 0 Pad so that the real headers start at index 1 */
@ -1478,6 +1488,7 @@ static const sdp_names_t sdp_media_attribute_names[] = {
{ "fmtp"}, /* 2 */
{ "path"}, /* 3 */
{ "h248item"}, /* 4 */
{ "crypto"}, /* 5 */
};
static gint find_sdp_media_attribute_names(tvbuff_t *tvb, int offset, guint len)
@ -1494,281 +1505,398 @@ static gint find_sdp_media_attribute_names(tvbuff_t *tvb, int offset, guint len)
}
static void dissect_sdp_media_attribute(tvbuff_t *tvb, packet_info *pinfo, proto_item * ti, int length, transport_info_t *transport_info){
proto_tree *sdp_media_attribute_tree;
proto_item *fmtp_item, *media_format_item;
proto_tree *fmtp_tree;
gint offset, next_offset, tokenlen, n, colon_offset;
/*??guint8 *field_name;*/
guint8 *payload_type;
guint8 *attribute_value;
gint *key;
guint8 pt;
gint sdp_media_attrbute_code;
const char *msrp_res = "msrp://";
const char *h324ext_h223lcparm = "h324ext/h223lcparm";
gboolean has_more_pars = TRUE;
tvbuff_t *h245_tvb;
encoding_name_and_rate_t *encoding_name_and_rate;
proto_tree *sdp_media_attribute_tree, *parameter_item;
proto_item *fmtp_item, *media_format_item, *parameter_tree;
proto_tree *fmtp_tree;
gint offset, next_offset, tokenlen, n, colon_offset;
/*??guint8 *field_name;*/
guint8 *payload_type;
guint8 *attribute_value;
gint *key;
guint8 pt;
gint sdp_media_attrbute_code;
const char *msrp_res = "msrp://";
const char *h324ext_h223lcparm = "h324ext/h223lcparm";
gboolean has_more_pars = TRUE;
tvbuff_t *h245_tvb;
encoding_name_and_rate_t *encoding_name_and_rate;
guint8 master_key_length = 0, master_salt_length = 0;
offset = 0;
next_offset = 0;
tokenlen = 0;
offset = 0;
next_offset = 0;
tokenlen = 0;
/* Create attribute tree */
sdp_media_attribute_tree = proto_item_add_subtree(ti,
ett_sdp_media_attribute);
/* Find end of field */
colon_offset = tvb_find_guint8(tvb,offset,-1,':');
/* Create attribute tree */
sdp_media_attribute_tree = proto_item_add_subtree(ti,
ett_sdp_media_attribute);
/* Find end of field */
colon_offset = tvb_find_guint8(tvb,offset,-1,':');
if(colon_offset == -1)
return;
/* Attribute field name is token before ':' */
tokenlen = colon_offset - offset;
proto_tree_add_item(sdp_media_attribute_tree,
hf_media_attribute_field,
tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
/*??field_name = tvb_get_ephemeral_string(tvb, offset, tokenlen);*/
sdp_media_attrbute_code = find_sdp_media_attribute_names(tvb, offset, tokenlen);
/* Skip colon */
offset = colon_offset + 1;
/* skip leading wsp */
offset = tvb_skip_wsp(tvb,offset,tvb_length_remaining(tvb,offset));
/* Value is the remainder of the line */
attribute_value = tvb_get_ephemeral_string(tvb, offset, tvb_length_remaining(tvb, offset));
/*********************************************/
/* Special parsing for some field name types */
switch (sdp_media_attrbute_code){
case SDP_RTPMAP:
/* decode the rtpmap to see if it is DynamicPayload to dissect them automatic */
next_offset = tvb_find_guint8(tvb,offset,-1,' ');
if(next_offset == -1)
return;
tokenlen = next_offset - offset;
proto_tree_add_item(sdp_media_attribute_tree, hf_media_format, tvb,
offset, tokenlen, ENC_ASCII|ENC_NA);
payload_type = tvb_get_ephemeral_string(tvb, offset, tokenlen);
offset = next_offset + 1;
next_offset = tvb_find_guint8(tvb,offset,-1,'/');
if(next_offset == -1){
return;
}
tokenlen = next_offset - offset;
proto_tree_add_item(sdp_media_attribute_tree, hf_media_encoding_name, tvb,
offset, tokenlen, ENC_ASCII|ENC_NA);
key=g_malloc( sizeof(gint) );
*key=atol((char*)payload_type);
pt = atoi((char*)payload_type);
if (pt >= SDP_NO_OF_PT) {
return; /* Invalid */
}
transport_info->encoding_name[pt] = (char*)tvb_get_ephemeral_string(tvb, offset, tokenlen);
next_offset = next_offset + 1;
offset = next_offset;
while (length-1 >= next_offset){
if(!isdigit(tvb_get_guint8(tvb, next_offset)))
break;
next_offset++;
}
tokenlen = next_offset - offset;
proto_tree_add_item(sdp_media_attribute_tree, hf_media_sample_rate, tvb,
offset, tokenlen, ENC_ASCII|ENC_NA);
transport_info->sample_rate[pt] = atoi(tvb_get_ephemeral_string(tvb, offset, tokenlen));
/* As per RFC2327 it is possible to have multiple Media Descriptions ("m=").
For example:
a=rtpmap:101 G726-32/8000
m=audio 49170 RTP/AVP 0 97
a=rtpmap:97 telephone-event/8000
m=audio 49172 RTP/AVP 97 101
a=rtpmap:97 G726-24/8000
The Media attributes ("a="s) after the "m=" only apply for that "m=".
If there is an "a=" before the first "m=", that attribute applies for
all the session (all the "m="s).
*/
/* so, if this "a=" appear before any "m=", we add it to all the dynamic
* hash tables
*/
if (transport_info->media_count == 0) {
for (n=0; n < SDP_MAX_RTP_CHANNELS; n++) {
encoding_name_and_rate = g_malloc( sizeof(encoding_name_and_rate_t));
encoding_name_and_rate->encoding_name = g_strdup(transport_info->encoding_name[pt]);
encoding_name_and_rate->sample_rate = transport_info->sample_rate[pt];
if (n==0){
g_hash_table_insert(transport_info->media[n].rtp_dyn_payload,
key, encoding_name_and_rate);
}
else { /* we create a new key and encoding_name to assign to the other hash tables */
gint *key2;
key2=g_malloc( sizeof(gint) );
*key2=atol((char*)payload_type);
g_hash_table_insert(transport_info->media[n].rtp_dyn_payload,
key2, encoding_name_and_rate);
}
}
return;
/* if the "a=" is after an "m=", only apply to this "m=" */
}else
/* in case there is an overflow in SDP_MAX_RTP_CHANNELS, we keep always the last "m=" */
encoding_name_and_rate = g_malloc( sizeof(encoding_name_and_rate_t));
encoding_name_and_rate->encoding_name = g_strdup(transport_info->encoding_name[pt]);
encoding_name_and_rate->sample_rate = transport_info->sample_rate[pt];
if (transport_info->media_count == SDP_MAX_RTP_CHANNELS-1)
g_hash_table_insert(transport_info->media[ transport_info->media_count ].rtp_dyn_payload,
key, encoding_name_and_rate);
else
g_hash_table_insert(transport_info->media[ transport_info->media_count-1 ].rtp_dyn_payload,
key, encoding_name_and_rate);
break;
case SDP_FMTP:
if(sdp_media_attribute_tree){
guint8 media_format;
/* Reading the Format parameter(fmtp) */
/* Skip leading space, if any */
offset = tvb_skip_wsp(tvb,offset,tvb_length_remaining(tvb,offset));
/* Media format extends to the next space */
next_offset = tvb_find_guint8(tvb,offset,-1,' ');
if(next_offset == -1)
if(colon_offset == -1)
return;
tokenlen = next_offset - offset;
/* Attribute field name is token before ':' */
tokenlen = colon_offset - offset;
proto_tree_add_item(sdp_media_attribute_tree,
hf_media_attribute_field,
tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
/*??field_name = tvb_get_ephemeral_string(tvb, offset, tokenlen);*/
sdp_media_attrbute_code = find_sdp_media_attribute_names(tvb, offset, tokenlen);
/* Skip colon */
offset = colon_offset + 1;
/* skip leading wsp */
offset = tvb_skip_wsp(tvb,offset,tvb_length_remaining(tvb,offset));
/* Value is the remainder of the line */
attribute_value = tvb_get_ephemeral_string(tvb, offset, tvb_length_remaining(tvb, offset));
media_format_item = proto_tree_add_item(sdp_media_attribute_tree,
hf_media_format, tvb, offset,
tokenlen, ENC_ASCII|ENC_NA);
media_format = atoi((char*)tvb_get_ephemeral_string(tvb, offset, tokenlen));
if (media_format >= SDP_NO_OF_PT) {
return; /* Invalid */
}
/* Append encoding name to format if known */
proto_item_append_text(media_format_item, " [%s]",
transport_info->encoding_name[media_format]);
/*********************************************/
/* Special parsing for some field name types */
/*??payload_type = tvb_get_ephemeral_string(tvb, offset, tokenlen);*/
/* Move offset past the payload type */
offset = next_offset + 1;
switch (sdp_media_attrbute_code){
case SDP_RTPMAP:
/* decode the rtpmap to see if it is DynamicPayload to dissect them automatic */
next_offset = tvb_find_guint8(tvb,offset,-1,' ');
while(has_more_pars==TRUE){
next_offset = tvb_find_guint8(tvb,offset,-1,';');
offset = tvb_skip_wsp(tvb,offset,tvb_length_remaining(tvb,offset));
if(next_offset == -1)
return;
tokenlen = next_offset - offset;
proto_tree_add_item(sdp_media_attribute_tree, hf_media_format, tvb,
offset, tokenlen, ENC_ASCII|ENC_NA);
payload_type = tvb_get_ephemeral_string(tvb, offset, tokenlen);
offset = next_offset + 1;
next_offset = tvb_find_guint8(tvb,offset,-1,'/');
if(next_offset == -1){
has_more_pars = FALSE;
next_offset= tvb_length(tvb);
}else{
return;
}
/* There are at least 2 - add the first parameter */
tokenlen = next_offset - offset;
fmtp_item = proto_tree_add_item(sdp_media_attribute_tree,
hf_media_format_specific_parameter, tvb,
offset, tokenlen, ENC_ASCII|ENC_NA);
fmtp_tree = proto_item_add_subtree(fmtp_item, ett_sdp_fmtp);
proto_tree_add_item(sdp_media_attribute_tree, hf_media_encoding_name, tvb,
offset, tokenlen, ENC_ASCII|ENC_NA);
decode_sdp_fmtp(fmtp_tree, tvb, pinfo, offset, tokenlen,
transport_info->encoding_name[media_format]);
/* Move offset past "; " and onto firts char */
offset = next_offset + 1;
}
}
break;
case SDP_PATH:
/* msrp attributes that contain address needed for conversation */
/* RFC 4975
* path = path-label ":" path-list
* path-label = "path"
* path-list= MSRP-URI *(SP MSRP-URI)
* MSRP-URI = msrp-scheme "://" authority
* ["/" session-id] ";" transport *( ";" URI-parameter)
* ; authority as defined in RFC3986
*
* msrp-scheme = "msrp" / "msrps"
* RFC 3986
* The authority component is preceded by a double slash ("//") and is terminated by
* the next slash ("/"), question mark ("?"), or number sign ("#") character, or by
* the end of the URI.
*/
/* Check for "msrp://" */
if (strncmp((char*)attribute_value, msrp_res, strlen(msrp_res)) == 0){
int address_offset, port_offset, port_end_offset;
/* Address starts here */
address_offset = offset + (int)strlen(msrp_res);
/* Port is after next ':' */
port_offset = tvb_find_guint8(tvb, address_offset, -1, ':');
/* Check if port is present if not skipp */
if(port_offset!= -1){
/* Port ends with '/' */
port_end_offset = tvb_find_guint8(tvb, port_offset, -1, '/');
/* Attempt to convert address */
if (inet_pton(AF_INET, (char*)tvb_get_ephemeral_string(tvb, address_offset, port_offset-address_offset), &msrp_ipaddr) > 0) {
/* Get port number */
msrp_port_number = atoi((char*)tvb_get_ephemeral_string(tvb, port_offset+1, port_end_offset-port_offset-1));
/* Set flag so this info can be used */
msrp_transport_address_set = TRUE;
key=g_malloc( sizeof(gint) );
*key=atol((char*)payload_type);
pt = atoi((char*)payload_type);
if (pt >= SDP_NO_OF_PT) {
return; /* Invalid */
}
}
}
break;
case SDP_H248_ITEM:
/* Decode h248 item ITU-T Rec. H.248.12 (2001)/Amd.1 (11/2002)*/
if (strncmp((char*)attribute_value, h324ext_h223lcparm, strlen(msrp_res)) == 0){
/* A.5.1.3 H.223 Logical channel parameters
* This property indicates the H.245
* H223LogicalChannelsParameters structure encoded by applying the PER specified in
* ITU-T Rec. X.691. Value encoded as per A.5.1.2. For text encoding the mechanism defined
* in ITU-T Rec. H.248.15 is used.
*/
gint len;
asn1_ctx_t actx;
transport_info->encoding_name[pt] = (char*)tvb_get_ephemeral_string(tvb, offset, tokenlen);
len = (gint)strlen(attribute_value);
h245_tvb = ascii_bytes_to_tvb(tvb, pinfo, len, attribute_value);
/* arbitrary maximum length */
/* should go through a handle, however, the two h245 entry
points are different, one is over tpkt and the other is raw
*/
if (h245_tvb){
asn1_ctx_init(&actx, ASN1_ENC_PER, TRUE, pinfo);
dissect_h245_H223LogicalChannelParameters(h245_tvb, 0, &actx, sdp_media_attribute_tree, hf_SDPh223LogicalChannelParameters);
}
next_offset = next_offset + 1;
offset = next_offset;
while (length-1 >= next_offset){
if(!isdigit(tvb_get_guint8(tvb, next_offset)))
break;
next_offset++;
}
tokenlen = next_offset - offset;
proto_tree_add_item(sdp_media_attribute_tree, hf_media_sample_rate, tvb,
offset, tokenlen, ENC_ASCII|ENC_NA);
transport_info->sample_rate[pt] = atoi(tvb_get_ephemeral_string(tvb, offset, tokenlen));
/* As per RFC2327 it is possible to have multiple Media Descriptions ("m=").
For example:
a=rtpmap:101 G726-32/8000
m=audio 49170 RTP/AVP 0 97
a=rtpmap:97 telephone-event/8000
m=audio 49172 RTP/AVP 97 101
a=rtpmap:97 G726-24/8000
The Media attributes ("a="s) after the "m=" only apply for that "m=".
If there is an "a=" before the first "m=", that attribute applies for
all the session (all the "m="s).
*/
/* so, if this "a=" appear before any "m=", we add it to all the dynamic
* hash tables
*/
if (transport_info->media_count == 0) {
for (n=0; n < SDP_MAX_RTP_CHANNELS; n++) {
encoding_name_and_rate = g_malloc( sizeof(encoding_name_and_rate_t));
encoding_name_and_rate->encoding_name = g_strdup(transport_info->encoding_name[pt]);
encoding_name_and_rate->sample_rate = transport_info->sample_rate[pt];
if (n==0){
g_hash_table_insert(transport_info->media[n].rtp_dyn_payload,
key, encoding_name_and_rate);
}
else { /* we create a new key and encoding_name to assign to the other hash tables */
gint *key2;
key2=g_malloc( sizeof(gint) );
*key2=atol((char*)payload_type);
g_hash_table_insert(transport_info->media[n].rtp_dyn_payload,
key2, encoding_name_and_rate);
}
}
return;
/* if the "a=" is after an "m=", only apply to this "m=" */
}else
/* in case there is an overflow in SDP_MAX_RTP_CHANNELS, we keep always the last "m=" */
encoding_name_and_rate = g_malloc( sizeof(encoding_name_and_rate_t));
encoding_name_and_rate->encoding_name = g_strdup(transport_info->encoding_name[pt]);
encoding_name_and_rate->sample_rate = transport_info->sample_rate[pt];
if (transport_info->media_count == SDP_MAX_RTP_CHANNELS-1)
g_hash_table_insert(transport_info->media[ transport_info->media_count ].rtp_dyn_payload,
key, encoding_name_and_rate);
else
g_hash_table_insert(transport_info->media[ transport_info->media_count-1 ].rtp_dyn_payload,
key, encoding_name_and_rate);
break;
case SDP_FMTP:
if(sdp_media_attribute_tree){
guint8 media_format;
/* Reading the Format parameter(fmtp) */
/* Skip leading space, if any */
offset = tvb_skip_wsp(tvb,offset,tvb_length_remaining(tvb,offset));
/* Media format extends to the next space */
next_offset = tvb_find_guint8(tvb,offset,-1,' ');
if(next_offset == -1)
return;
tokenlen = next_offset - offset;
media_format_item = proto_tree_add_item(sdp_media_attribute_tree,
hf_media_format, tvb, offset,
tokenlen, ENC_ASCII|ENC_NA);
media_format = atoi((char*)tvb_get_ephemeral_string(tvb, offset, tokenlen));
if (media_format >= SDP_NO_OF_PT) {
return; /* Invalid */
}
/* Append encoding name to format if known */
proto_item_append_text(media_format_item, " [%s]",
transport_info->encoding_name[media_format]);
/*??payload_type = tvb_get_ephemeral_string(tvb, offset, tokenlen);*/
/* Move offset past the payload type */
offset = next_offset + 1;
while(has_more_pars==TRUE){
next_offset = tvb_find_guint8(tvb,offset,-1,';');
offset = tvb_skip_wsp(tvb,offset,tvb_length_remaining(tvb,offset));
if(next_offset == -1){
has_more_pars = FALSE;
next_offset= tvb_length(tvb);
}
/* There are at least 2 - add the first parameter */
tokenlen = next_offset - offset;
fmtp_item = proto_tree_add_item(sdp_media_attribute_tree,
hf_media_format_specific_parameter, tvb,
offset, tokenlen, ENC_ASCII|ENC_NA);
fmtp_tree = proto_item_add_subtree(fmtp_item, ett_sdp_fmtp);
decode_sdp_fmtp(fmtp_tree, tvb, pinfo, offset, tokenlen,
transport_info->encoding_name[media_format]);
/* Move offset past "; " and onto firts char */
offset = next_offset + 1;
}
}
break;
case SDP_PATH:
/* msrp attributes that contain address needed for conversation */
/* RFC 4975
* path = path-label ":" path-list
* path-label = "path"
* path-list= MSRP-URI *(SP MSRP-URI)
* MSRP-URI = msrp-scheme "://" authority
* ["/" session-id] ";" transport *( ";" URI-parameter)
* ; authority as defined in RFC3986
*
* msrp-scheme = "msrp" / "msrps"
* RFC 3986
* The authority component is preceded by a double slash ("//") and is terminated by
* the next slash ("/"), question mark ("?"), or number sign ("#") character, or by
* the end of the URI.
*/
/* Check for "msrp://" */
if (strncmp((char*)attribute_value, msrp_res, strlen(msrp_res)) == 0){
int address_offset, port_offset, port_end_offset;
/* Address starts here */
address_offset = offset + (int)strlen(msrp_res);
/* Port is after next ':' */
port_offset = tvb_find_guint8(tvb, address_offset, -1, ':');
/* Check if port is present if not skipp */
if(port_offset!= -1){
/* Port ends with '/' */
port_end_offset = tvb_find_guint8(tvb, port_offset, -1, '/');
/* Attempt to convert address */
if (inet_pton(AF_INET, (char*)tvb_get_ephemeral_string(tvb, address_offset, port_offset-address_offset), &msrp_ipaddr) > 0) {
/* Get port number */
msrp_port_number = atoi((char*)tvb_get_ephemeral_string(tvb, port_offset+1, port_end_offset-port_offset-1));
/* Set flag so this info can be used */
msrp_transport_address_set = TRUE;
}
}
}
break;
case SDP_H248_ITEM:
/* Decode h248 item ITU-T Rec. H.248.12 (2001)/Amd.1 (11/2002)*/
if (strncmp((char*)attribute_value, h324ext_h223lcparm, strlen(msrp_res)) == 0){
/* A.5.1.3 H.223 Logical channel parameters
* This property indicates the H.245
* H223LogicalChannelsParameters structure encoded by applying the PER specified in
* ITU-T Rec. X.691. Value encoded as per A.5.1.2. For text encoding the mechanism defined
* in ITU-T Rec. H.248.15 is used.
*/
gint len;
asn1_ctx_t actx;
len = (gint)strlen(attribute_value);
h245_tvb = ascii_bytes_to_tvb(tvb, pinfo, len, attribute_value);
/* arbitrary maximum length */
/* should go through a handle, however, the two h245 entry
points are different, one is over tpkt and the other is raw
*/
if (h245_tvb){
asn1_ctx_init(&actx, ASN1_ENC_PER, TRUE, pinfo);
dissect_h245_H223LogicalChannelParameters(h245_tvb, 0, &actx, sdp_media_attribute_tree, hf_SDPh223LogicalChannelParameters);
}
}
break;
case SDP_CRYPTO:
/* http://tools.ietf.org/html/rfc4568
* 9.1. Generic "Crypto" Attribute Grammar
*
* The ABNF grammar for the crypto attribute is defined below:
*
* "a=crypto:" tag 1*WSP crypto-suite 1*WSP key-params
* *(1*WSP session-param)
*
* tag = 1*9DIGIT
* crypto-suite = 1*(ALPHA / DIGIT / "_")
*
* key-params = key-param *(";" key-param)
* key-param = key-method ":" key-info
* key-method = "inline" / key-method-ext
* key-method-ext = 1*(ALPHA / DIGIT / "_")
* key-info = 1*(%x21-3A / %x3C-7E) ; visible (printing) chars
* ; except semi-colon
* session-param = 1*(VCHAR) ; visible (printing) characters
*
* where WSP, ALPHA, DIGIT, and VCHAR are defined in [RFC4234].
*
*/
/* We are at the first colon */
/* tag */
next_offset = tvb_find_guint8(tvb,offset,-1,' ');
tokenlen = next_offset - offset;
proto_tree_add_uint(sdp_media_attribute_tree, hf_sdp_crypto_tag, tvb, offset, tokenlen,
atoi((char*)tvb_get_ephemeral_string(tvb, offset, tokenlen)));
offset=next_offset+1;
/* crypto-suite */
next_offset = tvb_find_guint8(tvb,offset,-1,' ');
tokenlen = next_offset - offset;
proto_tree_add_item(sdp_media_attribute_tree, hf_sdp_crypto_crypto_suite, tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
if(tvb_strncaseeql(tvb, offset, "AES_CM_128_HMAC_SHA1_80",tokenlen) == 0){
master_key_length = 16; /* 128 bits = 16 octets */
master_salt_length = 14; /* 112 bits = 14 octets */
}else if(tvb_strncaseeql(tvb, offset, "AES_CM_128_HMAC_SHA1_32",tokenlen) == 0){
master_key_length = 16; /* 128 bits = 16 octets */
master_salt_length = 14; /* 112 bits = 14 octets */
}else if(tvb_strncaseeql(tvb, offset, "F8_128_HMAC_SHA1_80",tokenlen) == 0){
master_key_length = 16; /* 128 bits = 16 octets */
master_salt_length = 14; /* 112 bits = 14 octets */
}
offset=next_offset+1;
/* key-params */
while(has_more_pars==TRUE){
int param_end_offset;
tvbuff_t *key_salt_tvb;
gchar *data_p = NULL;
param_end_offset = tvb_find_guint8(tvb,offset,-1,';');
if(param_end_offset == -1){
has_more_pars = FALSE;
param_end_offset= tvb_length(tvb);
}
parameter_item = proto_tree_add_text(sdp_media_attribute_tree, tvb, offset, param_end_offset-offset, "Key parameters");
parameter_tree = proto_item_add_subtree(parameter_item, ett_sdp_crypto_key_parameters);
/* key-method or key-method-ext */
next_offset = tvb_find_guint8(tvb,offset,-1,':');
if(tvb_strncaseeql(tvb, offset, "inline", next_offset-offset) == 0){
/* XXX only for SRTP? */
/* srtp-key-info = key-salt ["|" lifetime] ["|" mki] */
offset = next_offset +1;
next_offset = tvb_find_guint8(tvb,offset,-1,'|');
if(next_offset == -1){
tokenlen = param_end_offset - offset;
}else{
tokenlen = next_offset - offset;
}
data_p = tvb_get_ephemeral_string(tvb, offset, tokenlen);
key_salt_tvb = base64_to_tvb(tvb, data_p);
add_new_data_source(pinfo, key_salt_tvb, "Key_Salt_tvb");
if(master_key_length !=0){
proto_tree_add_text(parameter_tree, tvb, offset, tokenlen, "Key and Salt");
proto_tree_add_item(parameter_tree, hf_sdp_crypto_master_key, key_salt_tvb, 0, master_key_length, ENC_ASCII|ENC_NA);
proto_tree_add_item(parameter_tree, hf_sdp_crypto_master_salt, key_salt_tvb, master_key_length, master_salt_length, ENC_ASCII|ENC_NA);
}else{
proto_tree_add_text(parameter_tree, key_salt_tvb, 0, -1, "Key and Salt");
}
/* ["|" lifetime] ["|" mki] are optional */
if(next_offset != -1){
offset = next_offset + 1;
next_offset = tvb_find_guint8(tvb,offset,-1,'|');
if(next_offset != -1){
/*lifetime = ["2^"] 1*(DIGIT) ; see section 6.1 for "2^" */
tokenlen = next_offset - offset;
proto_tree_add_item(parameter_tree, hf_sdp_crypto_lifetime, tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
offset = next_offset + 1;
}
/* mki = mki-value ":" mki-length
*
* mki-value = 1*DIGIT
*/
next_offset = tvb_find_guint8(tvb,offset,-1,':');
tokenlen = next_offset - offset;
proto_tree_add_item(parameter_tree, hf_sdp_crypto_mki, tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
offset = next_offset + 1;
/* mki-length = 1*3DIGIT ; range 1..128. */
next_offset = param_end_offset;
tokenlen = next_offset - offset;
proto_tree_add_item(parameter_tree, hf_sdp_crypto_mki_length, tvb, offset, tokenlen, ENC_ASCII|ENC_NA);
}
offset = param_end_offset;
}else{
tokenlen = param_end_offset - next_offset+1;
proto_tree_add_text(parameter_tree, tvb, next_offset+1, tokenlen, "%s",tvb_get_ephemeral_string(tvb, next_offset+1, tokenlen));
offset = param_end_offset;
}
}
break;
default:
/* No special treatment for values of this attribute type, just add as one item. */
proto_tree_add_item(sdp_media_attribute_tree, hf_media_attribute_value,
tvb, offset, -1, ENC_ASCII|ENC_NA);
break;
}
break;
default:
/* No special treatment for values of this attribute type, just add as one item. */
proto_tree_add_item(sdp_media_attribute_tree, hf_media_attribute_value,
tvb, offset, -1, ENC_ASCII|ENC_NA);
break;
}
}
void
@ -2027,6 +2155,34 @@ proto_register_sdp(void)
{ "Key Management Data",
"sdp.key_mgmt.data", FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_sdp_crypto_tag,
{ "tag",
"sdp.crypto.tag", FT_UINT32, BASE_DEC, NULL, 0x0,
NULL, HFILL }},
{ &hf_sdp_crypto_crypto_suite,
{ "Crypto suite",
"sdp.crypto.crypto_suite", FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_sdp_crypto_master_key,
{ "Master Key",
"sdp.crypto.master_key", FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_sdp_crypto_master_salt,
{ "Mater salt",
"sdp.crypto.master_salt", FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_sdp_crypto_lifetime,
{ "Lifetime",
"sdp.crypto.lifetime", FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_sdp_crypto_mki,
{ "mki-value",
"sdp.crypto.mki-valu", FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
{ &hf_sdp_crypto_mki_length,
{ "mki_length",
"sdp.crypto.mki_length", FT_STRING, BASE_NONE, NULL, 0x0,
NULL, HFILL }},
};
static gint *ett[] = {
&ett_sdp,
@ -2042,6 +2198,7 @@ proto_register_sdp(void)
&ett_sdp_media_attribute,
&ett_sdp_fmtp,
&ett_sdp_key_mgmt,
&ett_sdp_crypto_key_parameters,
};
module_t *sdp_module;