contrib/credential/wincred/git-credential-wincred.c - jrn/git - Git at Google

 /*
  * A git credential helper that interface with Windows' Credential Manager
  *
  */
 #include <windows.h>
 #include <stdio.h>
 #include <io.h>
 #include <fcntl.h>

 /* common helpers */

 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))

 static void die(const char *err, ...)
 {
 	char msg[4096];
 	va_list params;
 	va_start(params, err);
 	vsnprintf(msg, sizeof(msg), err, params);
 	fprintf(stderr, "%s\n", msg);
 	va_end(params);
 	exit(1);
 }

 static void *xmalloc(size_t size)
 {
 	void *ret = malloc(size);
 	if (!ret && !size)
 		ret = malloc(1);
 	if (!ret)
 		 die("Out of memory");
 	return ret;
 }

 /* MinGW doesn't have wincred.h, so we need to define stuff */

 typedef struct _CREDENTIAL_ATTRIBUTEW {
 	LPWSTR Keyword;
 	DWORD  Flags;
 	DWORD  ValueSize;
 	LPBYTE Value;
 } CREDENTIAL_ATTRIBUTEW, *PCREDENTIAL_ATTRIBUTEW;

 typedef struct _CREDENTIALW {
 	DWORD                  Flags;
 	DWORD                  Type;
 	LPWSTR                 TargetName;
 	LPWSTR                 Comment;
 	FILETIME               LastWritten;
 	DWORD                  CredentialBlobSize;
 	LPBYTE                 CredentialBlob;
 	DWORD                  Persist;
 	DWORD                  AttributeCount;
 	PCREDENTIAL_ATTRIBUTEW Attributes;
 	LPWSTR                 TargetAlias;
 	LPWSTR                 UserName;
 } CREDENTIALW, *PCREDENTIALW;

 #define CRED_TYPE_GENERIC 1
 #define CRED_PERSIST_LOCAL_MACHINE 2
 #define CRED_MAX_ATTRIBUTES 64

 typedef BOOL (WINAPI *CredWriteWT)(PCREDENTIALW, DWORD);
 typedef BOOL (WINAPI *CredEnumerateWT)(LPCWSTR, DWORD, DWORD *,
     PCREDENTIALW **);
 typedef VOID (WINAPI *CredFreeT)(PVOID);
 typedef BOOL (WINAPI *CredDeleteWT)(LPCWSTR, DWORD, DWORD);

 static HMODULE advapi;
 static CredWriteWT CredWriteW;
 static CredEnumerateWT CredEnumerateW;
 static CredFreeT CredFree;
 static CredDeleteWT CredDeleteW;

 static void load_cred_funcs(void)
 {
 	/* load DLLs */
 	advapi = LoadLibraryExA("advapi32.dll", NULL,
 				LOAD_LIBRARY_SEARCH_SYSTEM32);
 	if (!advapi)
 		die("failed to load advapi32.dll");

 	/* get function pointers */
 	CredWriteW = (CredWriteWT)GetProcAddress(advapi, "CredWriteW");
 	CredEnumerateW = (CredEnumerateWT)GetProcAddress(advapi,
 	    "CredEnumerateW");
 	CredFree = (CredFreeT)GetProcAddress(advapi, "CredFree");
 	CredDeleteW = (CredDeleteWT)GetProcAddress(advapi, "CredDeleteW");
 	if (!CredWriteW || !CredEnumerateW || !CredFree || !CredDeleteW)
 		die("failed to load functions");
 }

 static WCHAR *wusername, *password, *protocol, *host, *path, target[1024];

 static void write_item(const char *what, LPCWSTR wbuf, int wlen)
 {
 	char *buf;

 	if (!wbuf || !wlen) {
 		printf("%s=\n", what);
 		return;
 	}

 	int len = WideCharToMultiByte(CP_UTF8, 0, wbuf, wlen, NULL, 0, NULL,
 	    FALSE);
 	buf = xmalloc(len);

 	if (!WideCharToMultiByte(CP_UTF8, 0, wbuf, wlen, buf, len, NULL, FALSE))
 		die("WideCharToMultiByte failed!");

 	printf("%s=", what);
 	fwrite(buf, 1, len, stdout);
 	putchar('\n');
 	free(buf);
 }

 /*
  * Match an (optional) expected string and a delimiter in the target string,
  * consuming the matched text by updating the target pointer.
  */

 static LPCWSTR wcsstr_last(LPCWSTR str, LPCWSTR find)
 {
 	LPCWSTR res = NULL, pos;
 	for (pos = wcsstr(str, find); pos; pos = wcsstr(pos + 1, find))
 		res = pos;
 	return res;
 }

 static int match_part_with_last(LPCWSTR *ptarget, LPCWSTR want, LPCWSTR delim, int last)
 {
 	LPCWSTR delim_pos, start = *ptarget;
 	int len;

 	/* find start of delimiter (or end-of-string if delim is empty) */
 	if (*delim)
 		delim_pos = last ? wcsstr_last(start, delim) : wcsstr(start, delim);
 	else
 		delim_pos = start + wcslen(start);

 	/*
 	 * match text up to delimiter, or end of string (e.g. the '/' after
 	 * host is optional if not followed by a path)
 	 */
 	if (delim_pos)
 		len = delim_pos - start;
 	else
 		len = wcslen(start);

 	/* update ptarget if we either found a delimiter or need a match */
 	if (delim_pos || want)
 		*ptarget = delim_pos ? delim_pos + wcslen(delim) : start + len;

 	return !want || (!wcsncmp(want, start, len) && !want[len]);
 }

 static int match_part(LPCWSTR *ptarget, LPCWSTR want, LPCWSTR delim)
 {
 	return match_part_with_last(ptarget, want, delim, 0);
 }

 static int match_part_last(LPCWSTR *ptarget, LPCWSTR want, LPCWSTR delim)
 {
 	return match_part_with_last(ptarget, want, delim, 1);
 }

 static int match_cred(const CREDENTIALW *cred)
 {
 	LPCWSTR target = cred->TargetName;
 	if (wusername && wcscmp(wusername, cred->UserName ? cred->UserName : L""))
 		return 0;

 	return match_part(&target, L"git", L":") &&
 		match_part(&target, protocol, L"://") &&
 		match_part_last(&target, wusername, L"@") &&
 		match_part(&target, host, L"/") &&
 		match_part(&target, path, L"");
 }

 static void get_credential(void)
 {
 	CREDENTIALW **creds;
 	DWORD num_creds;
 	int i;

 	if (!CredEnumerateW(L"git:*", 0, &num_creds, &creds))
 		return;

 	/* search for the first credential that matches username */
 	for (i = 0; i < num_creds; ++i)
 		if (match_cred(creds[i])) {
 			write_item("username", creds[i]->UserName,
 				creds[i]->UserName ? wcslen(creds[i]->UserName) : 0);
 			write_item("password",
 				(LPCWSTR)creds[i]->CredentialBlob,
 				creds[i]->CredentialBlobSize / sizeof(WCHAR));
 			break;
 		}

 	CredFree(creds);
 }

 static void store_credential(void)
 {
 	CREDENTIALW cred;

 	if (!wusername || !password)
 		return;

 	cred.Flags = 0;
 	cred.Type = CRED_TYPE_GENERIC;
 	cred.TargetName = target;
 	cred.Comment = L"saved by git-credential-wincred";
 	cred.CredentialBlobSize = (wcslen(password)) * sizeof(WCHAR);
 	cred.CredentialBlob = (LPVOID)password;
 	cred.Persist = CRED_PERSIST_LOCAL_MACHINE;
 	cred.AttributeCount = 0;
 	cred.Attributes = NULL;
 	cred.TargetAlias = NULL;
 	cred.UserName = wusername;

 	if (!CredWriteW(&cred, 0))
 		die("CredWrite failed");
 }

 static void erase_credential(void)
 {
 	CREDENTIALW **creds;
 	DWORD num_creds;
 	int i;

 	if (!CredEnumerateW(L"git:*", 0, &num_creds, &creds))
 		return;

 	for (i = 0; i < num_creds; ++i) {
 		if (match_cred(creds[i]))
 			CredDeleteW(creds[i]->TargetName, creds[i]->Type, 0);
 	}

 	CredFree(creds);
 }

 static WCHAR *utf8_to_utf16_dup(const char *str)
 {
 	int wlen = MultiByteToWideChar(CP_UTF8, 0, str, -1, NULL, 0);
 	WCHAR *wstr = xmalloc(sizeof(WCHAR) * wlen);
 	MultiByteToWideChar(CP_UTF8, 0, str, -1, wstr, wlen);
 	return wstr;
 }

 static void read_credential(void)
 {
 	char buf[1024];

 	while (fgets(buf, sizeof(buf), stdin)) {
 		char *v;
 		int len = strlen(buf);
 		/* strip trailing CR / LF */
 		while (len && strchr("\r\n", buf[len - 1]))
 			buf[--len] = 0;

 		if (!*buf)
 			break;

 		v = strchr(buf, '=');
 		if (!v)
 			die("bad input: %s", buf);
 		*v++ = '\0';

 		if (!strcmp(buf, "protocol"))
 			protocol = utf8_to_utf16_dup(v);
 		else if (!strcmp(buf, "host"))
 			host = utf8_to_utf16_dup(v);
 		else if (!strcmp(buf, "path"))
 			path = utf8_to_utf16_dup(v);
 		else if (!strcmp(buf, "username")) {
 			wusername = utf8_to_utf16_dup(v);
 		} else if (!strcmp(buf, "password"))
 			password = utf8_to_utf16_dup(v);
 		else
 			die("unrecognized input");
 	}
 }

 int main(int argc, char *argv[])
 {
 	const char *usage =
 	    "usage: git credential-wincred <get|store|erase>\n";

 	if (!argv[1])
 		die(usage);

 	/* git use binary pipes to avoid CRLF-issues */
 	_setmode(_fileno(stdin), _O_BINARY);
 	_setmode(_fileno(stdout), _O_BINARY);

 	read_credential();

 	load_cred_funcs();

 	if (!protocol || !(host || path))
 		return 0;

 	/* prepare 'target', the unique key for the credential */
 	wcscpy(target, L"git:");
 	wcsncat(target, protocol, ARRAY_SIZE(target));
 	wcsncat(target, L"://", ARRAY_SIZE(target));
 	if (wusername) {
 		wcsncat(target, wusername, ARRAY_SIZE(target));
 		wcsncat(target, L"@", ARRAY_SIZE(target));
 	}
 	if (host)
 		wcsncat(target, host, ARRAY_SIZE(target));
 	if (path) {
 		wcsncat(target, L"/", ARRAY_SIZE(target));
 		wcsncat(target, path, ARRAY_SIZE(target));
 	}

 	if (!strcmp(argv[1], "get"))
 		get_credential();
 	else if (!strcmp(argv[1], "store"))
 		store_credential();
 	else if (!strcmp(argv[1], "erase"))
 		erase_credential();
 	/* otherwise, ignore unknown action */
 	return 0;
 }
	/*
	* A git credential helper that interface with Windows' Credential Manager
	*
	*/
	#include <windows.h>
	#include <stdio.h>
	#include <io.h>
	#include <fcntl.h>

	/* common helpers */

	#define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))

	static void die(const char *err, ...)
	{
	char msg[4096];
	va_list params;
	va_start(params, err);
	vsnprintf(msg, sizeof(msg), err, params);
	fprintf(stderr, "%s\n", msg);
	va_end(params);
	exit(1);
	}

	static void *xmalloc(size_t size)
	{
	void *ret = malloc(size);
	if (!ret && !size)
	ret = malloc(1);
	if (!ret)
	die("Out of memory");
	return ret;
	}

	/* MinGW doesn't have wincred.h, so we need to define stuff */

	typedef struct _CREDENTIAL_ATTRIBUTEW {
	LPWSTR Keyword;
	DWORD Flags;
	DWORD ValueSize;
	LPBYTE Value;
	} CREDENTIAL_ATTRIBUTEW, *PCREDENTIAL_ATTRIBUTEW;

	typedef struct _CREDENTIALW {
	DWORD Flags;
	DWORD Type;
	LPWSTR TargetName;
	LPWSTR Comment;
	FILETIME LastWritten;
	DWORD CredentialBlobSize;
	LPBYTE CredentialBlob;
	DWORD Persist;
	DWORD AttributeCount;
	PCREDENTIAL_ATTRIBUTEW Attributes;
	LPWSTR TargetAlias;
	LPWSTR UserName;
	} CREDENTIALW, *PCREDENTIALW;

	#define CRED_TYPE_GENERIC 1
	#define CRED_PERSIST_LOCAL_MACHINE 2
	#define CRED_MAX_ATTRIBUTES 64

	typedef BOOL (WINAPI *CredWriteWT)(PCREDENTIALW, DWORD);
	typedef BOOL (WINAPI CredEnumerateWT)(LPCWSTR, DWORD, DWORD ,
	PCREDENTIALW **);
	typedef VOID (WINAPI *CredFreeT)(PVOID);
	typedef BOOL (WINAPI *CredDeleteWT)(LPCWSTR, DWORD, DWORD);

	static HMODULE advapi;
	static CredWriteWT CredWriteW;
	static CredEnumerateWT CredEnumerateW;
	static CredFreeT CredFree;
	static CredDeleteWT CredDeleteW;

	static void load_cred_funcs(void)
	{
	/* load DLLs */
	advapi = LoadLibraryExA("advapi32.dll", NULL,
	LOAD_LIBRARY_SEARCH_SYSTEM32);
	if (!advapi)
	die("failed to load advapi32.dll");

	/* get function pointers */
	CredWriteW = (CredWriteWT)GetProcAddress(advapi, "CredWriteW");
	CredEnumerateW = (CredEnumerateWT)GetProcAddress(advapi,
	"CredEnumerateW");
	CredFree = (CredFreeT)GetProcAddress(advapi, "CredFree");
	CredDeleteW = (CredDeleteWT)GetProcAddress(advapi, "CredDeleteW");
	if (!CredWriteW \|\| !CredEnumerateW \|\| !CredFree \|\| !CredDeleteW)
	die("failed to load functions");
	}

	static WCHAR wusername, password, protocol, host, *path, target[1024];

	static void write_item(const char *what, LPCWSTR wbuf, int wlen)
	{
	char *buf;

	if (!wbuf \|\| !wlen) {
	printf("%s=\n", what);
	return;
	}

	int len = WideCharToMultiByte(CP_UTF8, 0, wbuf, wlen, NULL, 0, NULL,
	FALSE);
	buf = xmalloc(len);

	if (!WideCharToMultiByte(CP_UTF8, 0, wbuf, wlen, buf, len, NULL, FALSE))
	die("WideCharToMultiByte failed!");

	printf("%s=", what);
	fwrite(buf, 1, len, stdout);
	putchar('\n');
	free(buf);
	}

	/*
	* Match an (optional) expected string and a delimiter in the target string,
	* consuming the matched text by updating the target pointer.
	*/

	static LPCWSTR wcsstr_last(LPCWSTR str, LPCWSTR find)
	{
	LPCWSTR res = NULL, pos;
	for (pos = wcsstr(str, find); pos; pos = wcsstr(pos + 1, find))
	res = pos;
	return res;
	}

	static int match_part_with_last(LPCWSTR *ptarget, LPCWSTR want, LPCWSTR delim, int last)
	{
	LPCWSTR delim_pos, start = *ptarget;
	int len;

	/* find start of delimiter (or end-of-string if delim is empty) */
	if (*delim)
	delim_pos = last ? wcsstr_last(start, delim) : wcsstr(start, delim);
	else
	delim_pos = start + wcslen(start);

	/*
	* match text up to delimiter, or end of string (e.g. the '/' after
	* host is optional if not followed by a path)
	*/
	if (delim_pos)
	len = delim_pos - start;
	else
	len = wcslen(start);

	/* update ptarget if we either found a delimiter or need a match */
	if (delim_pos \|\| want)
	*ptarget = delim_pos ? delim_pos + wcslen(delim) : start + len;

	return !want \|\| (!wcsncmp(want, start, len) && !want[len]);
	}

	static int match_part(LPCWSTR *ptarget, LPCWSTR want, LPCWSTR delim)
	{
	return match_part_with_last(ptarget, want, delim, 0);
	}

	static int match_part_last(LPCWSTR *ptarget, LPCWSTR want, LPCWSTR delim)
	{
	return match_part_with_last(ptarget, want, delim, 1);
	}

	static int match_cred(const CREDENTIALW *cred)
	{
	LPCWSTR target = cred->TargetName;
	if (wusername && wcscmp(wusername, cred->UserName ? cred->UserName : L""))
	return 0;

	return match_part(&target, L"git", L":") &&
	match_part(&target, protocol, L"://") &&
	match_part_last(&target, wusername, L"@") &&
	match_part(&target, host, L"/") &&
	match_part(&target, path, L"");
	}

	static void get_credential(void)
	{
	CREDENTIALW **creds;
	DWORD num_creds;
	int i;

	if (!CredEnumerateW(L"git:*", 0, &num_creds, &creds))
	return;

	/* search for the first credential that matches username */
	for (i = 0; i < num_creds; ++i)
	if (match_cred(creds[i])) {
	write_item("username", creds[i]->UserName,
	creds[i]->UserName ? wcslen(creds[i]->UserName) : 0);
	write_item("password",
	(LPCWSTR)creds[i]->CredentialBlob,
	creds[i]->CredentialBlobSize / sizeof(WCHAR));
	break;
	}

	CredFree(creds);
	}

	static void store_credential(void)
	{
	CREDENTIALW cred;

	if (!wusername \|\| !password)
	return;

	cred.Flags = 0;
	cred.Type = CRED_TYPE_GENERIC;
	cred.TargetName = target;
	cred.Comment = L"saved by git-credential-wincred";
	cred.CredentialBlobSize = (wcslen(password)) * sizeof(WCHAR);
	cred.CredentialBlob = (LPVOID)password;
	cred.Persist = CRED_PERSIST_LOCAL_MACHINE;
	cred.AttributeCount = 0;
	cred.Attributes = NULL;
	cred.TargetAlias = NULL;
	cred.UserName = wusername;

	if (!CredWriteW(&cred, 0))
	die("CredWrite failed");
	}

	static void erase_credential(void)
	{
	CREDENTIALW **creds;
	DWORD num_creds;
	int i;

	if (!CredEnumerateW(L"git:*", 0, &num_creds, &creds))
	return;

	for (i = 0; i < num_creds; ++i) {
	if (match_cred(creds[i]))
	CredDeleteW(creds[i]->TargetName, creds[i]->Type, 0);
	}

	CredFree(creds);
	}

	static WCHAR utf8_to_utf16_dup(const char str)
	{
	int wlen = MultiByteToWideChar(CP_UTF8, 0, str, -1, NULL, 0);
	WCHAR wstr = xmalloc(sizeof(WCHAR) wlen);
	MultiByteToWideChar(CP_UTF8, 0, str, -1, wstr, wlen);
	return wstr;
	}

	static void read_credential(void)
	{
	char buf[1024];

	while (fgets(buf, sizeof(buf), stdin)) {
	char *v;
	int len = strlen(buf);
	/* strip trailing CR / LF */
	while (len && strchr("\r\n", buf[len - 1]))
	buf[--len] = 0;

	if (!*buf)
	break;

	v = strchr(buf, '=');
	if (!v)
	die("bad input: %s", buf);
	*v++ = '\0';

	if (!strcmp(buf, "protocol"))
	protocol = utf8_to_utf16_dup(v);
	else if (!strcmp(buf, "host"))
	host = utf8_to_utf16_dup(v);
	else if (!strcmp(buf, "path"))
	path = utf8_to_utf16_dup(v);
	else if (!strcmp(buf, "username")) {
	wusername = utf8_to_utf16_dup(v);
	} else if (!strcmp(buf, "password"))
	password = utf8_to_utf16_dup(v);
	else
	die("unrecognized input");
	}
	}

	int main(int argc, char *argv[])
	{
	const char *usage =
	"usage: git credential-wincred <get\|store\|erase>\n";

	if (!argv[1])
	die(usage);

	/* git use binary pipes to avoid CRLF-issues */
	_setmode(_fileno(stdin), _O_BINARY);
	_setmode(_fileno(stdout), _O_BINARY);

	read_credential();

	load_cred_funcs();

	if (!protocol \|\| !(host \|\| path))
	return 0;

	/* prepare 'target', the unique key for the credential */
	wcscpy(target, L"git:");
	wcsncat(target, protocol, ARRAY_SIZE(target));
	wcsncat(target, L"://", ARRAY_SIZE(target));
	if (wusername) {
	wcsncat(target, wusername, ARRAY_SIZE(target));
	wcsncat(target, L"@", ARRAY_SIZE(target));
	}
	if (host)
	wcsncat(target, host, ARRAY_SIZE(target));
	if (path) {
	wcsncat(target, L"/", ARRAY_SIZE(target));
	wcsncat(target, path, ARRAY_SIZE(target));
	}

	if (!strcmp(argv[1], "get"))
	get_credential();
	else if (!strcmp(argv[1], "store"))
	store_credential();
	else if (!strcmp(argv[1], "erase"))
	erase_credential();
	/* otherwise, ignore unknown action */
	return 0;
	}