1 files changed, 331 insertions, 0 deletions
diff --git a/contrib/credential/wincred/git-credential-wincred.c b/contrib/credential/wincred/git-credential-wincred.c
new file mode 100644
index 0000000..ead6e26
--- /dev/null
+++ b/contrib/credential/wincred/git-credential-wincred.c
@@ -0,0 +1,331 @@
+/*
+ * 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]))
+
+__attribute__((format (printf, 1, 2)))
+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);
+		/*
+		 * Ignore other lines; we don't know what they mean, but
+		 * this future-proofs us when later versions of git do
+		 * learn new lines, and the helpers are updated to match.
+		 */
+	}
+}
+
+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;
+}