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tpws: unify http and tls position finders

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bol-van
2024-06-18 17:38:13 +03:00
parent fd4dc89360
commit d43d88b9d0
5 changed files with 98 additions and 74 deletions
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83
tpws/tamper.c
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@@ -8,48 +8,13 @@
#include <string.h>
#include <stdio.h>
// pHost points to "Host: ..."
static bool find_host(uint8_t **pHost,uint8_t *buf,size_t bs)
{
if (!*pHost)
{
*pHost = memmem(buf, bs, "\nHost:", 6);
if (*pHost)
{
(*pHost)++;
VPRINT("Found Host: at pos %td",*pHost - buf)
}
}
return !!*pHost;
}
static size_t tls_pos(enum tlspos tpos_type, size_t tpos_pos, const uint8_t *tls, size_t sz, uint8_t type)
{
size_t elen;
const uint8_t *ext;
switch(tpos_type)
{
case tlspos_sni:
case tlspos_sniext:
if (TLSFindExt(tls,sz,0,&ext,&elen,false))
return (tpos_type==tlspos_sni) ? ext-tls+6 : ext-tls+1;
// fall through
case tlspos_pos:
return tpos_pos;
default:
return 0;
}
}
static const char *http_methods[] = { "GET /","POST /","HEAD /","OPTIONS /","PUT /","DELETE /","CONNECT /","TRACE /",NULL };
// segment buffer has at least 5 extra bytes to extend data block
void tamper_out(t_ctrack *ctrack, uint8_t *segment,size_t segment_buffer_size,size_t *size, size_t *split_pos, uint8_t *split_flags)
{
uint8_t *p, *pp, *pHost = NULL;
size_t method_len = 0, pos;
const char **method;
bool bIsHttp = false, bBypass = false, bHaveHost = false, bHostExcluded = false;
const char *method;
bool bBypass = false, bHaveHost = false, bHostExcluded = false;
char bRemovedHostSpace = 0;
char *pc, Host[256];
@@ -58,22 +23,13 @@ void tamper_out(t_ctrack *ctrack, uint8_t *segment,size_t segment_buffer_size,si
*split_pos=0;
*split_flags=0;
for (method = http_methods; *method; method++)
if ((method = HttpMethod(segment,*size)))
{
method_len = strlen(*method);
if (method_len <= *size && !memcmp(segment, *method, method_len))
{
bIsHttp = true;
method_len -= 2; // "GET /" => "GET"
break;
}
}
if (bIsHttp)
{
VPRINT("Data block looks like http request start : %s", *method)
method_len = strlen(method)-2;
VPRINT("Data block looks like http request start : %s", method)
if (!ctrack->l7proto) ctrack->l7proto=HTTP;
// cpu saving : we search host only if and when required. we do not research host every time we need its position
if ((params.hostlist || params.hostlist_exclude) && find_host(&pHost,segment,*size))
if ((params.hostlist || params.hostlist_exclude) && HttpFindHost(&pHost,segment,*size))
{
p = pHost + 5;
while (p < (segment + *size) && (*p == ' ' || *p == '\t')) p++;
@@ -135,7 +91,7 @@ void tamper_out(t_ctrack *ctrack, uint8_t *segment,size_t segment_buffer_size,si
(*size)++; // block will grow by 1 byte
if (pHost) pHost++; // Host: position will move by 1 byte
}
if ((params.hostdot || params.hosttab) && *size<segment_buffer_size && find_host(&pHost,segment,*size))
if ((params.hostdot || params.hosttab) && *size<segment_buffer_size && HttpFindHost(&pHost,segment,*size))
{
p = pHost + 5;
while (p < (segment + *size) && *p != '\r' && *p != '\n') p++;
@@ -148,7 +104,7 @@ void tamper_out(t_ctrack *ctrack, uint8_t *segment,size_t segment_buffer_size,si
(*size)++; // block will grow by 1 byte
}
}
if (params.domcase && find_host(&pHost,segment,*size))
if (params.domcase && HttpFindHost(&pHost,segment,*size))
{
p = pHost + 5;
pos = p - segment;
@@ -156,7 +112,7 @@ void tamper_out(t_ctrack *ctrack, uint8_t *segment,size_t segment_buffer_size,si
for (; p < (segment + *size) && *p != '\r' && *p != '\n'; p++)
*p = (((size_t)p) & 1) ? tolower(*p) : toupper(*p);
}
if (params.hostnospace && find_host(&pHost,segment,*size) && (pHost+5)<(segment+*size) && pHost[5] == ' ')
if (params.hostnospace && HttpFindHost(&pHost,segment,*size) && (pHost+5)<(segment+*size) && pHost[5] == ' ')
{
p = pHost + 6;
pos = p - segment;
@@ -165,12 +121,12 @@ void tamper_out(t_ctrack *ctrack, uint8_t *segment,size_t segment_buffer_size,si
(*size)--; // block will shrink by 1 byte
bRemovedHostSpace = 1;
}
if (params.hostcase && find_host(&pHost,segment,*size))
if (params.hostcase && HttpFindHost(&pHost,segment,*size))
{
VPRINT("Changing 'Host:' => '%c%c%c%c:' at pos %td", params.hostspell[0], params.hostspell[1], params.hostspell[2], params.hostspell[3], pHost - segment)
memcpy(pHost, params.hostspell, 4);
}
if (params.hostpad && find_host(&pHost,segment,*size))
if (params.hostpad && HttpFindHost(&pHost,segment,*size))
{
// add : XXXXX: <padding?[\r\n|\n]
char s[8];
@@ -217,18 +173,7 @@ void tamper_out(t_ctrack *ctrack, uint8_t *segment,size_t segment_buffer_size,si
pHost = NULL; // invalidate
}
}
switch (params.split_http_req)
{
case httpreqpos_method:
*split_pos = method_len - 1 + params.methodeol + (params.methodeol && !params.unixeol);
break;
case httpreqpos_host:
if (find_host(&pHost,segment,*size))
*split_pos = pHost + 6 - bRemovedHostSpace - segment;
break;
default:
if (params.split_pos < *size) *split_pos = params.split_pos;
}
*split_pos = HttpPos(params.split_http_req, params.split_pos, segment, *size);
if (params.disorder_http) *split_flags |= SPLIT_FLAG_DISORDER;
if (params.oob_http) *split_flags |= SPLIT_FLAG_OOB;
}
@@ -258,11 +203,11 @@ void tamper_out(t_ctrack *ctrack, uint8_t *segment,size_t segment_buffer_size,si
}
else
{
spos = tls_pos(params.split_tls, params.split_pos, segment, *size, 0);
spos = TLSPos(params.split_tls, params.split_pos, segment, *size, 0);
if ((5+*size)<=segment_buffer_size)
{
tpos = tls_pos(params.tlsrec, params.tlsrec_pos+5, segment, *size, 0);
tpos = TLSPos(params.tlsrec, params.tlsrec_pos+5, segment, *size, 0);
if (tpos>5)
{
// construct 2 TLS records from one