nsAuthSambaNTLM.cpp
/* vim:set ts=4 sw=4 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsAuth.h"
#include "nsAuthSambaNTLM.h"
#include "prenv.h"
#include "plbase64.h"
#include "prerror.h"
#include <stdlib.h>
nsAuthSambaNTLM::nsAuthSambaNTLM()
: mInitialMessage(nullptr), mChildPID(nullptr), mFromChildFD(nullptr),
mToChildFD(nullptr)
{
}
nsAuthSambaNTLM::~nsAuthSambaNTLM()
{
// ntlm_auth reads from stdin regularly so closing our file handles
// should cause it to exit.
Shutdown();
free(mInitialMessage);
}
void
nsAuthSambaNTLM::Shutdown()
{
if (mFromChildFD) {
PR_Close(mFromChildFD);
mFromChildFD = nullptr;
}
if (mToChildFD) {
PR_Close(mToChildFD);
mToChildFD = nullptr;
}
if (mChildPID) {
int32_t exitCode;
PR_WaitProcess(mChildPID, &exitCode);
mChildPID = nullptr;
}
}
NS_IMPL_ISUPPORTS1(nsAuthSambaNTLM, nsIAuthModule)
static bool
SpawnIOChild(char* const* aArgs, PRProcess** aPID,
PRFileDesc** aFromChildFD, PRFileDesc** aToChildFD)
{
PRFileDesc* toChildPipeRead;
PRFileDesc* toChildPipeWrite;
if (PR_CreatePipe(&toChildPipeRead, &toChildPipeWrite) != PR_SUCCESS)
return false;
PR_SetFDInheritable(toChildPipeRead, true);
PR_SetFDInheritable(toChildPipeWrite, false);
PRFileDesc* fromChildPipeRead;
PRFileDesc* fromChildPipeWrite;
if (PR_CreatePipe(&fromChildPipeRead, &fromChildPipeWrite) != PR_SUCCESS) {
PR_Close(toChildPipeRead);
PR_Close(toChildPipeWrite);
return false;
}
PR_SetFDInheritable(fromChildPipeRead, false);
PR_SetFDInheritable(fromChildPipeWrite, true);
PRProcessAttr* attr = PR_NewProcessAttr();
if (!attr) {
PR_Close(fromChildPipeRead);
PR_Close(fromChildPipeWrite);
PR_Close(toChildPipeRead);
PR_Close(toChildPipeWrite);
return false;
}
PR_ProcessAttrSetStdioRedirect(attr, PR_StandardInput, toChildPipeRead);
PR_ProcessAttrSetStdioRedirect(attr, PR_StandardOutput, fromChildPipeWrite);
PRProcess* process = PR_CreateProcess(aArgs[0], aArgs, nullptr, attr);
PR_DestroyProcessAttr(attr);
PR_Close(fromChildPipeWrite);
PR_Close(toChildPipeRead);
if (!process) {
LOG(("ntlm_auth exec failure [%d]", PR_GetError()));
PR_Close(fromChildPipeRead);
PR_Close(toChildPipeWrite);
return false;
}
*aPID = process;
*aFromChildFD = fromChildPipeRead;
*aToChildFD = toChildPipeWrite;
return true;
}
static bool WriteString(PRFileDesc* aFD, const nsACString& aString)
{
int32_t length = aString.Length();
const char* s = aString.BeginReading();
LOG(("Writing to ntlm_auth: %s", s));
while (length > 0) {
int result = PR_Write(aFD, s, length);
if (result <= 0)
return false;
s += result;
length -= result;
}
return true;
}
static bool ReadLine(PRFileDesc* aFD, nsACString& aString)
{
// ntlm_auth is defined to only send one line in response to each of our
// input lines. So this simple unbuffered strategy works as long as we
// read the response immediately after sending one request.
aString.Truncate();
for (;;) {
char buf[1024];
int result = PR_Read(aFD, buf, sizeof(buf));
if (result <= 0)
return false;
aString.Append(buf, result);
if (buf[result - 1] == '\n') {
LOG(("Read from ntlm_auth: %s", nsPromiseFlatCString(aString).get()));
return true;
}
}
}
/**
* Returns a heap-allocated array of PRUint8s, and stores the length in aLen.
* Returns nullptr if there's an error of any kind.
*/
static uint8_t* ExtractMessage(const nsACString& aLine, uint32_t* aLen)
{
// ntlm_auth sends blobs to us as base64-encoded strings after the "xx "
// preamble on the response line.
int32_t length = aLine.Length();
// The caller should verify there is a valid "xx " prefix and the line
// is terminated with a \n
NS_ASSERTION(length >= 4, "Line too short...");
const char* line = aLine.BeginReading();
const char* s = line + 3;
length -= 4; // lose first 3 chars plus trailing \n
NS_ASSERTION(s[length] == '\n', "aLine not newline-terminated");
if (length & 3) {
// The base64 encoded block must be multiple of 4. If not, something
// screwed up.
NS_WARNING("Base64 encoded block should be a multiple of 4 chars");
return nullptr;
}
// Calculate the exact length. I wonder why there isn't a function for this
// in plbase64.
int32_t numEquals;
for (numEquals = 0; numEquals < length; ++numEquals) {
if (s[length - 1 - numEquals] != '=')
break;
}
*aLen = (length/4)*3 - numEquals;
return reinterpret_cast<uint8_t*>(PL_Base64Decode(s, length, nullptr));
}
nsresult
nsAuthSambaNTLM::SpawnNTLMAuthHelper()
{
const char* username = PR_GetEnv("USER");
if (!username)
return NS_ERROR_FAILURE;
const char* const args[] = {
"ntlm_auth",
"--helper-protocol", "ntlmssp-client-1",
"--use-cached-creds",
"--username", username,
nullptr
};
bool isOK = SpawnIOChild(const_cast<char* const*>(args), &mChildPID, &mFromChildFD, &mToChildFD);
if (!isOK)
return NS_ERROR_FAILURE;
if (!WriteString(mToChildFD, NS_LITERAL_CSTRING("YR\n")))
return NS_ERROR_FAILURE;
nsCString line;
if (!ReadLine(mFromChildFD, line))
return NS_ERROR_FAILURE;
if (!StringBeginsWith(line, NS_LITERAL_CSTRING("YR "))) {
// Something went wrong. Perhaps no credentials are accessible.
return NS_ERROR_FAILURE;
}
// It gave us an initial client-to-server request packet. Save that
// because we'll need it later.
mInitialMessage = ExtractMessage(line, &mInitialMessageLen);
if (!mInitialMessage)
return NS_ERROR_FAILURE;
return NS_OK;
}
NS_IMETHODIMP
nsAuthSambaNTLM::Init(const char *serviceName,
uint32_t serviceFlags,
const PRUnichar *domain,
const PRUnichar *username,
const PRUnichar *password)
{
NS_ASSERTION(!username && !domain && !password, "unexpected credentials");
return NS_OK;
}
NS_IMETHODIMP
nsAuthSambaNTLM::GetNextToken(const void *inToken,
uint32_t inTokenLen,
void **outToken,
uint32_t *outTokenLen)
{
if (!inToken) {
/* someone wants our initial message */
*outToken = nsMemory::Clone(mInitialMessage, mInitialMessageLen);
if (!*outToken)
return NS_ERROR_OUT_OF_MEMORY;
*outTokenLen = mInitialMessageLen;
return NS_OK;
}
/* inToken must be a type 2 message. Get ntlm_auth to generate our response */
char* encoded = PL_Base64Encode(static_cast<const char*>(inToken), inTokenLen, nullptr);
if (!encoded)
return NS_ERROR_OUT_OF_MEMORY;
nsCString request;
request.AssignLiteral("TT ");
request.Append(encoded);
free(encoded);
request.Append('\n');
if (!WriteString(mToChildFD, request))
return NS_ERROR_FAILURE;
nsCString line;
if (!ReadLine(mFromChildFD, line))
return NS_ERROR_FAILURE;
if (!StringBeginsWith(line, NS_LITERAL_CSTRING("KK "))) {
// Something went wrong. Perhaps no credentials are accessible.
return NS_ERROR_FAILURE;
}
uint8_t* buf = ExtractMessage(line, outTokenLen);
if (!buf)
return NS_ERROR_FAILURE;
// *outToken has to be freed by nsMemory::Free, which may not be free()
*outToken = nsMemory::Clone(buf, *outTokenLen);
if (!*outToken) {
free(buf);
return NS_ERROR_OUT_OF_MEMORY;
}
// We're done. Close our file descriptors now and reap the helper
// process.
Shutdown();
return NS_SUCCESS_AUTH_FINISHED;
}
NS_IMETHODIMP
nsAuthSambaNTLM::Unwrap(const void *inToken,
uint32_t inTokenLen,
void **outToken,
uint32_t *outTokenLen)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsAuthSambaNTLM::Wrap(const void *inToken,
uint32_t inTokenLen,
bool confidential,
void **outToken,
uint32_t *outTokenLen)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
