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-rw-r--r--contrib/credential/wincred/git-credential-wincred.c331
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;
+}