mercurial/bdiff.h

util: add utility method to check for bad ssh urls (SEC)

Our use of SSH has an exploit that will parse the first part of an url
blindly as a hostname. Prior to this set of security patches, a url
with '-oProxyCommand' could run arbitrary code on a user's machine. In
addition, at least on Windows, a pipe '|' can be abused to execute
arbitrary commands in a similar fashion.

We defend against this by checking ssh:// URLs and looking for a
hostname that starts with a - or contains a |.

When this happens, let's throw a big abort into the user's face so
that they can inspect what's going on.

#ifndef _HG_BDIFF_H_
#define _HG_BDIFF_H_

struct bdiff_line {
	int hash, n, e;
	ssize_t len;
	const char *l;
};

struct bdiff_hunk;
struct bdiff_hunk {
	int a1, a2, b1, b2;
	struct bdiff_hunk *next;
};

int bdiff_splitlines(const char *a, ssize_t len, struct bdiff_line **lr);
int bdiff_diff(struct bdiff_line *a, int an, struct bdiff_line *b, int bn,
	struct bdiff_hunk *base);
void bdiff_freehunks(struct bdiff_hunk *l);

#endif