/*
* sdp_debug_msg_filter
*
* DESCRIPTION
* Check the passed message buffer for sensitive data that should
* not be output (such as SRTP Master Key/Salt). Sensitive data
* will be replaced with the '*' character(s).
*
* PARAMETERS
* buffer: pointer to the message buffer to filter.
*
* length_bytes: size of message buffer in bytes.
*
* RETURN VALUE
* The buffer modified.
*/
char * sdp_debug_msg_filter (char *buffer, ulong length_bytes)
{
char *current;
char *last = buffer + length_bytes;
int result;
SDP_PRINT("\n%s:%d: Eliding sensitive data from debug output",
__FILE__, __LINE__);
/*
* For SRTP Master Key/Salt has the form:
* X-crypto:<crypto_suite_name> inline:<master_key_salt>||
* Where <master_key_salt> is the data to elide (filter).
*/
for (current=buffer;
current<=last-MIN_CRYPTO_STRING_SIZE_BYTES;
current++) {
if ((*current == 'x') || (*current == 'X')) {
result = cpr_strncasecmp(current, crypto_string, crypto_strlen);
if (!result) {
current += crypto_strlen;
if (current > last) break;
/* Skip over crypto suite name */
FIND_WHITESPACE(current, last);
/* Skip over whitespace */
SKIP_WHITESPACE(current, last);
/* identify inline keyword */
result = cpr_strncasecmp(current, inline_string, inline_strlen);
if (!result) {
current += inline_strlen;
if (current > last) break;
/* Hide sensitive key/salt data */
while (current<=last) {
if (*current == '|' || *current == '\n') {
/* Done */
break;
} else {
*current = '*';
current++;
}
}
}
}
}
}
return buffer;
}
/* Function: sdp_build
* Description: Build an SDP description in the specified buffer based
* on the information in the given SDP structure.
* Parameters: sdp_p The SDP handle returned by sdp_init_description
* fs A flex_string where the SDP description should be built.
* Returns: A result value indicating if the build was successful and
* if not, what type of error was encountered - e.g.,
* description was too long for the given buffer.
*/
sdp_result_e sdp_build (sdp_t *sdp_p, flex_string *fs)
{
int i, j;
sdp_result_e result = SDP_SUCCESS;
if (sdp_verify_sdp_ptr(sdp_p) == FALSE) {
return (SDP_INVALID_SDP_PTR);
}
if (!fs) {
return (SDP_NULL_BUF_PTR);
}
if (sdp_p->debug_flag[SDP_DEBUG_TRACE]) {
SDP_PRINT("%s Trace SDP Build:", sdp_p->debug_str);
}
sdp_p->conf_p->num_builds++;
for (i=0; ((i < SDP_TOKEN_M) &&
(result == SDP_SUCCESS)); i++) {
result = sdp_token[i].build_func(sdp_p, SDP_SESSION_LEVEL, fs);
/* ok not to check buffer space (yet) as the if() checks it */
}
/* If the session level was ok, build the media lines. */
if (result == SDP_SUCCESS) {
for (i=1; ((i <= sdp_p->mca_count) &&
(result == SDP_SUCCESS)); i++) {
result = sdp_token[SDP_TOKEN_M].build_func(sdp_p, (u16)i, fs);
/* ok not to check buffer space (yet) as the for() checks it */
for (j=SDP_TOKEN_I;
((j < SDP_TOKEN_M) && (result == SDP_SUCCESS));
j++) {
if ((j == SDP_TOKEN_U) || (j == SDP_TOKEN_E) ||
(j == SDP_TOKEN_P) || (j == SDP_TOKEN_T) ||
(j == SDP_TOKEN_R) || (j == SDP_TOKEN_Z)) {
/* These tokens not valid at media level. */
continue;
}
result = sdp_token[j].build_func(sdp_p, (u16)i, fs);
/* ok not to check buffer space (yet) as the for() checks it */
}
}
}
return (result);
}
/* Function: sdp_parse
* Description: Parse an SDP description in the specified buffer.
* Parameters: sdp_p The SDP handle returned by sdp_init_description
* bufp Pointer to the buffer containing the SDP
* description to parse.
* len The length of the buffer.
* Returns: A result value indicating if the parse was successful and
* if not, what type of error was encountered. The
* information from the parse is stored in the sdp_p structure.
*/
sdp_result_e sdp_parse (sdp_t *sdp_p, char **bufp, u16 len)
{
u8 i;
u16 cur_level = SDP_SESSION_LEVEL;
char *ptr;
char *next_ptr = NULL;
char *line_end;
sdp_token_e last_token = SDP_TOKEN_V;
sdp_result_e result=SDP_SUCCESS;
tinybool parse_done = FALSE;
tinybool end_found = FALSE;
tinybool first_line = TRUE;
tinybool unrec_token = FALSE;
if (sdp_verify_sdp_ptr(sdp_p) == FALSE) {
return (SDP_INVALID_SDP_PTR);
}
if ((bufp == NULL) || (*bufp == NULL)) {
return (SDP_NULL_BUF_PTR);
}
if (sdp_p->debug_flag[SDP_DEBUG_TRACE]) {
SDP_PRINT("%s Trace SDP Parse:", sdp_p->debug_str);
}
next_ptr = *bufp;
sdp_p->conf_p->num_parses++;
/* Initialize the last valid capability instance to zero. Used
* to help in parsing X-cpar attrs. */
sdp_p->cap_valid = FALSE;
sdp_p->last_cap_inst = 0;
/* We want to try to find the end of the SDP description, even if
* we find a parsing error.
*/
while (!end_found) {
/* If the last char of this line goes beyond the end of the buffer,
* we don't parse it.
*/
ptr = next_ptr;
line_end = sdp_findchar(ptr, "\n");
if (line_end >= (*bufp + len)) {
sdp_parse_error(sdp_p->peerconnection,
"%s End of line beyond end of buffer.",
sdp_p->debug_str);
end_found = TRUE;
break;
}
/* Print the line if we're tracing. */
if ((parse_done == FALSE) &&
(sdp_p->debug_flag[SDP_DEBUG_TRACE])) {
SDP_PRINT("%s ", sdp_p->debug_str);
SDP_PRINT("%*s", (int)(line_end - ptr), ptr);
}
/* Find out which token this line has, if any. */
for (i=0; i < SDP_MAX_TOKENS; i++) {
if (strncmp(ptr, sdp_token[i].name, SDP_TOKEN_LEN) == 0) {
break;
}
}
if (i == SDP_MAX_TOKENS) {
/* See if the second char on the next line is an '=' char.
* If so, we note this as an unrecognized token line. */
if (ptr[1] == '=') {
unrec_token = TRUE;
}
if (first_line == TRUE) {
sdp_parse_error(sdp_p->peerconnection,
"%s Attempt to parse text not recognized as "
"SDP text, parse fails.", sdp_p->debug_str);
/* If we haven't already printed out the line we
* were trying to parse, do it now.
*/
if (!sdp_p->debug_flag[SDP_DEBUG_TRACE]) {
SDP_PRINT("%s ", sdp_p->debug_str);
SDP_PRINT("%*s", (int)(line_end - ptr), ptr);
}
sdp_p->conf_p->num_not_sdp_desc++;
return (SDP_NOT_SDP_DESCRIPTION);
} else {
end_found = TRUE;
break;
}
}
/* This is the beginning of a new SDP description. */
if ((first_line != TRUE) && (i == SDP_TOKEN_V)) {
end_found = TRUE;
break;
}
/* Advance the next ptr to one char beyond the end of the line. */
next_ptr = line_end + 1;
if (next_ptr >= (*bufp + len)) {
end_found = TRUE;
}
/* If we've finished parsing and are just looking for the end of
* the SDP description, we don't need to do anything else here.
*/
if (parse_done == TRUE) {
continue;
}
/* Only certain tokens are valid at the media level. */
if (cur_level != SDP_SESSION_LEVEL) {
if ((i != SDP_TOKEN_I) && (i != SDP_TOKEN_C) &&
(i != SDP_TOKEN_B) && (i != SDP_TOKEN_K) &&
(i != SDP_TOKEN_A) && (i != SDP_TOKEN_M)) {
sdp_p->conf_p->num_invalid_token_order++;
sdp_parse_error(sdp_p->peerconnection,
"%s Warning: Invalid token %s found at media level",
sdp_p->debug_str, sdp_token[i].name);
continue;
}
}
/* Verify the token ordering. */
if (first_line == TRUE) {
if (i != SDP_TOKEN_V) {
if (sdp_p->conf_p->version_reqd == TRUE) {
sdp_parse_error(sdp_p->peerconnection,
"%s First line not v=, parse fails",
sdp_p->debug_str);
sdp_p->conf_p->num_invalid_token_order++;
result = SDP_INVALID_TOKEN_ORDERING;
parse_done = TRUE;
} else {
last_token = (sdp_token_e)i;
}
} else {
last_token = (sdp_token_e)i;
}
first_line = FALSE;
} else {
if (i < last_token) {
sdp_p->conf_p->num_invalid_token_order++;
sdp_parse_error(sdp_p->peerconnection,
"%s Warning: Invalid token ordering detected, "
"token %s found after token %s", sdp_p->debug_str,
sdp_token[i].name, sdp_token[last_token].name);
}
}
/* Finally parse the line. */
ptr += SDP_TOKEN_LEN;
result = sdp_token[i].parse_func(sdp_p, cur_level, (const char *)ptr);
last_token = (sdp_token_e)i;
if (last_token == SDP_TOKEN_M) {
if (cur_level == SDP_SESSION_LEVEL) {
cur_level = 1;
} else {
cur_level++;
}
/* The token ordering can start again at i= */
last_token = (sdp_token_e)(SDP_TOKEN_I - 1);
}
if (result != SDP_SUCCESS) {
parse_done = TRUE;
}
/* Skip the new line char at the end of this line and see if
* this is the end of the buffer.
*/
if ((line_end + 1) == (*bufp + len)) {
end_found = TRUE;
}
}
/* If we found no valid lines, return an error. */
if (first_line == TRUE) {
sdp_p->conf_p->num_not_sdp_desc++;
return (SDP_NOT_SDP_DESCRIPTION);
}
/* If no errors were found yet, validate the overall sdp. */
if (result == SDP_SUCCESS) {
result = sdp_validate_sdp(sdp_p);
}
/* Return the pointer where we left off. */
*bufp = next_ptr;
/* If the SDP is valid, but the next line following was an
* unrecognized <token>= line, indicate this on the return. */
if ((result == SDP_SUCCESS) && (unrec_token == TRUE)) {
return (SDP_UNRECOGNIZED_TOKEN);
} else {
return (result);
}
}
