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Merged
JacobBarthelmeh merged 1 commit into from
Aug 22, 2022
Merged

SFTP RealPath #440

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91 changes: 91 additions & 0 deletions src/ssh.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2194,6 +2194,97 @@ int wolfSSH_ChannelGetEof(WOLFSSH_CHANNEL* channel)
}


#if (defined(WOLFSSH_SFTP) || defined(WOLFSSH_SCP)) && \
!defined(NO_WOLFSSH_SERVER)
/*
* Paths starting with a slash are absolute, rooted at root. Any path that
* doesn't have a starting slash is assumed to be relative to the current
* path. If the path is empty, return the default path.
*
* The path "/." is stripped out. The path "/.." strips out the previous
* path value. The root path, "/", is always present.
*
* Example: "/home/fred/frob/frizz/../../../barney/bar/baz/./././../.."
* will return "/home/barney". "/../.." will return "/". "." will return
* currentPath.
*
* Note, this function does not care about OS and filesystem issues. The
* SFTP protocol describes how paths are handled in SFTP. Specialized
* behaviors are handled when actually calling the OS functions. Paths
* are further massaged there. For example, the C: drive is treated as
* the path "/C:", and is a directory like any other.
*
* @param currentPath RealPath of the current working directory
* @param defaultPath RealPath of the default directory, usually user's
* @param in requested new path
* @param out output of real path cleanup
* @param outSz size in bytes of buffer 'out'
* @return WS_SUCCESS, WS_BAD_ARGUMENT, or WS_INVALID_PATH_E
*/
int wolfSSH_RealPath(const char* currentPath, const char* defaultPath,
char* in, char* out, word32 outSz)
{
char* tail = NULL;
char* seg;
word32 inSz, segSz, curSz;

if (currentPath == NULL || defaultPath == NULL ||
in == NULL || out == NULL || outSz == 0)
return WS_BAD_ARGUMENT;

WMEMSET(out, 0, outSz);
inSz = (word32)WSTRLEN(in);
if (inSz == 0) {
WSTRNCPY(out, defaultPath, outSz);
}
else if (in[0] == '/') {
out[0] = '/';
}
else {
WSTRNCPY(out, currentPath, outSz);
}
out[outSz - 1] = 0;
curSz = (word32)WSTRLEN(out);

for (seg = WSTRTOK(in, "/", &tail); seg; seg = WSTRTOK(NULL, "/", &tail)) {
segSz = (word32)WSTRLEN(seg);

/* Try to match "." */
if (segSz == 1 && seg[0] == '.') {
/* Do nothing. Keep current directory. */
}
/* Try to match ".." */
else if (segSz == 2 && seg[0] == '.' && seg[1] == '.') {
char* prev = strrchr(out, '/');

if (prev != NULL) {
if (prev != out) {
prev[0] = 0;
curSz = (word32)WSTRLEN(out);
}
else {
/* preserve the root / */
prev[1] = 0;
curSz = 1;
}
}
}
/* Everything else is copied */
else {
if (curSz != 1) {
WSTRNCAT(out, "/", outSz - curSz);
curSz++;
}
WSTRNCAT(out, seg, outSz - curSz);
curSz += segSz;
}
}

return WS_SUCCESS;
}
#endif /* WOLFSSH_SFTP || WOLFSSH_SCP */


#ifdef WOLFSSH_SHOW_SIZES

void wolfSSH_ShowSizes(void)
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63 changes: 63 additions & 0 deletions tests/api.c
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Original file line number Diff line number Diff line change
Expand Up @@ -895,6 +895,68 @@ static void test_wstrcat(void)
}


#if (defined(WOLFSSH_SFTP) || defined(WOLFSSH_SCP)) && \
!defined(NO_WOLFSSH_SERVER)
struct RealPathTestCase {
const char* in;
const char* exp;
};

struct RealPathTestCase realPathTestCases[] = {
{ ".", "/C:/Users/fred" },
{ "", "/C:/Users/fred" },
{ "/C:/Users/fred/..", "/C:/Users" },
{ "..", "/C:/Users" },
{ "../..", "/C:" },
{ "../barney", "/C:/Users/barney" },
{ "/C:/Users/..", "/C:" },
{ "/C:/..", "/" },
{ "/C:/../../../../../../../..", "/" },
{ "/", "/" },
{ "/C:/Users/fred/../..", "/C:" },
{ "/C:/Users/fred/././././.", "/C:/Users/fred" },
{ "/C:/Users/fred/../././..", "/C:" },
{ "./.ssh", "/C:/Users/fred/.ssh" },
{ "./.ssh/../foo", "/C:/Users/fred/foo" },
{ "./.ssh/../foo", "/C:/Users/fred/foo" },
{ "///home//////////fred///", "/home/fred" },
{ "/home/C:/ok", "/home/C:/ok" },
{ "/home/fred/frob/frizz/../../../barney/bar/baz/./././../..",
"/home/barney" },
};
const char* defaultPath = "/C:/Users/fred";

static void test_wolfSSH_RealPath(void)
{
struct RealPathTestCase* tc;
char testPath[128];
char checkPath[128];
word32 testCount =
(sizeof realPathTestCases)/(sizeof(struct RealPathTestCase));
word32 i;
int err;

for (i = 0, tc = realPathTestCases; i < testCount; i++, tc++) {
WSTRNCPY(testPath, tc->in, sizeof(testPath) - 1);
testPath[sizeof(testPath) - 1] = 0;
WMEMSET(checkPath, 0, sizeof checkPath);
err = wolfSSH_RealPath(defaultPath, defaultPath, testPath,
checkPath, sizeof checkPath);
if (err || WSTRCMP(tc->exp, checkPath) != 0) {
printf("RealPath failure (case %u: %d)\n"
" defaultPath: %s\n"
" input: %s\n"
" expected: %s\n"
" output: %s\n", i, err,
defaultPath, tc->in, tc->exp, checkPath);
}
}
}
#else
static void test_wolfSSH_RealPath(void) { ; }
#endif


int main(void)
{
AssertIntEQ(wolfSSH_Init(), WS_SUCCESS);
Expand All @@ -907,6 +969,7 @@ int main(void)
test_wolfSSH_SetUsername();
test_wolfSSH_ConvertConsole();
test_wolfSSH_CTX_UsePrivateKey_buffer();
test_wolfSSH_RealPath();

/* SCP tests */
test_wolfSSH_SCP_CB();
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4 changes: 4 additions & 0 deletions wolfssh/ssh.h
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Original file line number Diff line number Diff line change
Expand Up @@ -321,6 +321,10 @@ enum WS_DisconnectReasonCodes {
};


WOLFSSH_API int wolfSSH_RealPath(const char* currentPath,
const char* defaultPath, char* in, char* out, word32 outSz);


WOLFSSH_API void wolfSSH_ShowSizes(void);


Expand Down