"M Hickford via GitGitGadget" <gitgitgadget@xxxxxxxxx> writes:
> From: M Hickford <mirth.hickford@xxxxxxxxx>
>
> a5c7656 (credential: new attribute oauth_refresh_token) introduced
> a new confidential credential attribute for helpers to store.
>
> We encode the new attribute in the CredentialBlob, separated by
> newline:
>
> hunter2
> oauth_refresh_token=xyzzy
>
> This is extensible and backwards compatible. The credential protocol
> already assumes that attribute values do not contain newlines.
>
> This fixes test "helper (wincred) gets oauth_refresh_token" when
> t0303-credential-external.sh is run with
> GIT_TEST_CREDENTIAL_HELPER=wincred. This test was added in a5c76569e7
> (credential: new attribute oauth_refresh_token, 2023-04-21).
>
> Alternatives considered: store oauth_refresh_token in a wincred
> attribute. This would be insecure because wincred assumes attribute
> values to be non-confidential.
Earlier, a5c76569 (credential: new attribute oauth_refresh_token,
2023-04-21) built the "git" side support for the token, and taught
credential-cache to store the necessary information. Then 0ce02e2f
(credential/libsecret: store new attributes, 2023-06-16) was written
for libsecret to support the same interface.
And this one adds corresponding support for wincred. Do I
understand what is going on around this patch correctly?
I do not do Windows, but some people on this list certainly do and
would be capable of giving the patch a necessary nudge ;-)
Thanks.
> .../wincred/git-credential-wincred.c | 46 ++++++++++++++++---
> 1 file changed, 40 insertions(+), 6 deletions(-)
>
> diff --git a/contrib/credential/wincred/git-credential-wincred.c b/contrib/credential/wincred/git-credential-wincred.c
> index 4cd56c42e24..5c6a7d65d4a 100644
> --- a/contrib/credential/wincred/git-credential-wincred.c
> +++ b/contrib/credential/wincred/git-credential-wincred.c
> @@ -35,7 +35,7 @@ static void *xmalloc(size_t size)
> }
>
> static WCHAR *wusername, *password, *protocol, *host, *path, target[1024],
> - *password_expiry_utc;
> + *password_expiry_utc, *oauth_refresh_token;
>
> static void write_item(const char *what, LPCWSTR wbuf, int wlen)
> {
> @@ -140,6 +140,11 @@ static void get_credential(void)
> DWORD num_creds;
> int i;
> CREDENTIAL_ATTRIBUTEW *attr;
> + WCHAR *secret;
> + WCHAR *line;
> + WCHAR *remaining_lines;
> + WCHAR *part;
> + WCHAR *remaining_parts;
>
> if (!CredEnumerateW(L"git:*", 0, &num_creds, &creds))
> return;
> @@ -149,9 +154,23 @@ static void get_credential(void)
> if (match_cred(creds[i], 0)) {
> 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));
> + if (creds[i]->CredentialBlobSize > 0) {
> + secret = xmalloc(creds[i]->CredentialBlobSize);
> + wcsncpy_s(secret, creds[i]->CredentialBlobSize, (LPCWSTR)creds[i]->CredentialBlob, creds[i]->CredentialBlobSize / sizeof(WCHAR));
> + line = wcstok_s(secret, L"\r\n", &remaining_lines);
> + write_item("password", line, line ? wcslen(line) : 0);
> + while(line != NULL) {
> + part = wcstok_s(line, L"=", &remaining_parts);
> + if (!wcscmp(part, L"oauth_refresh_token")) {
> + write_item("oauth_refresh_token", remaining_parts, remaining_parts ? wcslen(remaining_parts) : 0);
> + }
> + line = wcstok_s(NULL, L"\r\n", &remaining_lines);
> + }
> + } else {
> + write_item("password",
> + (LPCWSTR)creds[i]->CredentialBlob,
> + creds[i]->CredentialBlobSize / sizeof(WCHAR));
> + }
> for (int j = 0; j < creds[i]->AttributeCount; j++) {
> attr = creds[i]->Attributes + j;
> if (!wcscmp(attr->Keyword, L"git_password_expiry_utc")) {
> @@ -160,6 +179,7 @@ static void get_credential(void)
> break;
> }
> }
> + free(secret);
> break;
> }
>
> @@ -170,16 +190,26 @@ static void store_credential(void)
> {
> CREDENTIALW cred;
> CREDENTIAL_ATTRIBUTEW expiry_attr;
> + WCHAR *secret;
> + int wlen;
>
> if (!wusername || !password)
> return;
>
> + if (oauth_refresh_token) {
> + wlen = _scwprintf(L"%s\r\noauth_refresh_token=%s", password, oauth_refresh_token);
> + secret = xmalloc(sizeof(WCHAR) * wlen);
> + _snwprintf_s(secret, sizeof(WCHAR) * wlen, wlen, L"%s\r\noauth_refresh_token=%s", password, oauth_refresh_token);
> + } else {
> + secret = _wcsdup(password);
> + }
> +
> 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.CredentialBlobSize = wcslen(secret) * sizeof(WCHAR);
> + cred.CredentialBlob = (LPVOID)_wcsdup(secret);
> cred.Persist = CRED_PERSIST_LOCAL_MACHINE;
> cred.AttributeCount = 0;
> cred.Attributes = NULL;
> @@ -194,6 +224,8 @@ static void store_credential(void)
> cred.TargetAlias = NULL;
> cred.UserName = wusername;
>
> + free(secret);
> +
> if (!CredWriteW(&cred, 0))
> die("CredWrite failed");
> }
> @@ -265,6 +297,8 @@ static void read_credential(void)
> password = utf8_to_utf16_dup(v);
> else if (!strcmp(buf, "password_expiry_utc"))
> password_expiry_utc = utf8_to_utf16_dup(v);
> + else if (!strcmp(buf, "oauth_refresh_token"))
> + oauth_refresh_token = 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
>
> base-commit: bc5204569f7db44d22477485afd52ea410d83743
