/*
* Curl_ntlm_decode_type2_target()
*
* This is used to decode the "target info" in the ntlm type-2 message
* received.
*
* Parameters:
*
* data [in] - Pointer to the session handle
* buffer [in] - The decoded base64 ntlm header of Type 2
* size [in] - The input buffer size, atleast 32 bytes
* ntlm [in] - Pointer to ntlm data struct being used and modified.
*
* Returns CURLE_OK on success.
*/
CURLcode Curl_ntlm_decode_type2_target(struct SessionHandle *data,
unsigned char *buffer,
size_t size,
struct ntlmdata *ntlm)
{
unsigned int target_info_len = 0;
unsigned int target_info_offset = 0;
Curl_safefree(ntlm->target_info);
ntlm->target_info_len = 0;
if(size >= 48) {
target_info_len = readshort_le(&buffer[40]);
target_info_offset = readint_le(&buffer[44]);
if(target_info_len > 0) {
if(((target_info_offset + target_info_len) > size) ||
(target_info_offset < 48)) {
infof(data, "NTLM handshake failure (bad type-2 message). "
"Target Info Offset Len is set incorrect by the peer\n");
return CURLE_REMOTE_ACCESS_DENIED;
}
ntlm->target_info = malloc(target_info_len);
if(!ntlm->target_info)
return CURLE_OUT_OF_MEMORY;
memcpy(ntlm->target_info, &buffer[target_info_offset], target_info_len);
ntlm->target_info_len = target_info_len;
}
}
return CURLE_OK;
}
CURLntlm Curl_input_ntlm(struct connectdata *conn,
bool proxy, /* if proxy or not */
const char *header) /* rest of the www-authenticate:
header */
{
/* point to the correct struct with this */
struct ntlmdata *ntlm;
#ifndef USE_WINDOWS_SSPI
static const char type2_marker[] = { 0x02, 0x00, 0x00, 0x00 };
#endif
ntlm = proxy?&conn->proxyntlm:&conn->ntlm;
/* skip initial whitespaces */
while(*header && ISSPACE(*header))
header++;
if(checkprefix("NTLM", header)) {
header += strlen("NTLM");
while(*header && ISSPACE(*header))
header++;
if(*header) {
/* We got a type-2 message here:
Index Description Content
0 NTLMSSP Signature Null-terminated ASCII "NTLMSSP"
(0x4e544c4d53535000)
8 NTLM Message Type long (0x02000000)
12 Target Name security buffer(*)
20 Flags long
24 Challenge 8 bytes
(32) Context (optional) 8 bytes (two consecutive longs)
(40) Target Information (optional) security buffer(*)
32 (48) start of data block
*/
size_t size;
unsigned char *buffer;
size = Curl_base64_decode(header, &buffer);
if(!buffer)
return CURLNTLM_BAD;
ntlm->state = NTLMSTATE_TYPE2; /* we got a type-2 */
#ifdef USE_WINDOWS_SSPI
ntlm->type_2 = malloc(size+1);
if(ntlm->type_2 == NULL) {
free(buffer);
return CURLE_OUT_OF_MEMORY;
}
ntlm->n_type_2 = size;
memcpy(ntlm->type_2, buffer, size);
#else
ntlm->flags = 0;
if((size < 32) ||
(memcmp(buffer, NTLMSSP_SIGNATURE, 8) != 0) ||
(memcmp(buffer+8, type2_marker, sizeof(type2_marker)) != 0)) {
/* This was not a good enough type-2 message */
free(buffer);
return CURLNTLM_BAD;
}
ntlm->flags = readint_le(&buffer[20]);
memcpy(ntlm->nonce, &buffer[24], 8);
DEBUG_OUT({
fprintf(stderr, "**** TYPE2 header flags=0x%08.8lx ", ntlm->flags);
print_flags(stderr, ntlm->flags);
fprintf(stderr, "\n nonce=");
print_hex(stderr, (char *)ntlm->nonce, 8);
fprintf(stderr, "\n****\n");
fprintf(stderr, "**** Header %s\n ", header);
});
#endif
free(buffer);
}
/*
* Curl_ntlm_decode_type2_message()
*
* This is used to decode a ntlm type-2 message received from a: HTTP, SMTP
* or POP3 server. The message is first decoded from a base64 string into a
* raw ntlm message and checked for validity before the appropriate data for
* creating a type-3 message is written to the given ntlm data structure.
*
* Parameters:
*
* data [in] - Pointer to session handle.
* header [in] - Pointer to the input buffer.
* ntlm [in] - Pointer to ntlm data struct being used and modified.
*
* Returns CURLE_OK on success.
*/
CURLcode Curl_ntlm_decode_type2_message(struct SessionHandle *data,
const char* header,
struct ntlmdata* ntlm)
{
#ifndef USE_WINDOWS_SSPI
static const char type2_marker[] = { 0x02, 0x00, 0x00, 0x00 };
#endif
/* NTLM type-2 message structure:
Index Description Content
0 NTLMSSP Signature Null-terminated ASCII "NTLMSSP"
(0x4e544c4d53535000)
8 NTLM Message Type long (0x02000000)
12 Target Name security buffer
20 Flags long
24 Challenge 8 bytes
(32) Context 8 bytes (two consecutive longs) (*)
(40) Target Information security buffer (*)
(48) OS Version Structure 8 bytes (*)
32 (48) (56) Start of data block (*)
(*) -> Optional
*/
size_t size = 0;
unsigned char *buffer = NULL;
CURLcode error;
#if defined(CURL_DISABLE_VERBOSE_STRINGS) || defined(USE_WINDOWS_SSPI)
(void)data;
#endif
error = Curl_base64_decode(header, &buffer, &size);
if(error)
return error;
if(!buffer) {
infof(data, "NTLM handshake failure (unhandled condition)\n");
return CURLE_REMOTE_ACCESS_DENIED;
}
#ifdef USE_WINDOWS_SSPI
ntlm->type_2 = malloc(size + 1);
if(ntlm->type_2 == NULL) {
free(buffer);
return CURLE_OUT_OF_MEMORY;
}
ntlm->n_type_2 = (unsigned long)size;
memcpy(ntlm->type_2, buffer, size);
#else
ntlm->flags = 0;
if((size < 32) ||
(memcmp(buffer, NTLMSSP_SIGNATURE, 8) != 0) ||
(memcmp(buffer + 8, type2_marker, sizeof(type2_marker)) != 0)) {
/* This was not a good enough type-2 message */
free(buffer);
infof(data, "NTLM handshake failure (bad type-2 message)\n");
return CURLE_REMOTE_ACCESS_DENIED;
}
ntlm->flags = readint_le(&buffer[20]);
memcpy(ntlm->nonce, &buffer[24], 8);
DEBUG_OUT({
fprintf(stderr, "**** TYPE2 header flags=0x%08.8lx ", ntlm->flags);
ntlm_print_flags(stderr, ntlm->flags);
fprintf(stderr, "\n nonce=");
ntlm_print_hex(stderr, (char *)ntlm->nonce, 8);
fprintf(stderr, "\n****\n");
fprintf(stderr, "**** Header %s\n ", header);
});
