From: M Hickford <mirth.hickford@gmail.com>
To: M Hickford via GitGitGadget <gitgitgadget@gmail.com>
Cc: git@vger.kernel.org, M Hickford <mirth.hickford@gmail.com>,
Matthew John Cheetham <mjcheetham@outlook.com>,
Taylor Blau <me@ttaylorr.com>, Jeff King <peff@peff.net>
Subject: Re: [PATCH] credential/wincred: store oauth_refresh_token
Date: Fri, 16 Jun 2023 23:30:03 +0100 [thread overview]
Message-ID: <CAGJzqs=K0_jYY-SOMjhLe_k3UzSgzEwy9mYVF=H=CA+ZUAv_uA@mail.gmail.com> (raw)
In-Reply-To: <pull.1534.git.1684567247339.gitgitgadget@gmail.com>
On Sat, 20 May 2023 at 08:20, M Hickford via GitGitGadget
<gitgitgadget@gmail.com> wrote:
>
> From: M Hickford <mirth.hickford@gmail.com>
>
> 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.
>
> Alternatives considered: store oauth_refresh_token in a wincred
> attribute. This would be insecure because wincred assumes attribute
> values to be non-confidential.
>
> Signed-off-by: M Hickford <mirth.hickford@gmail.com>
> ---
> credential/wincred: store oauth_refresh_token
>
> I'm not confident in C and found string manipulation difficult, so
> please review carefully.
>
> I tested on Linux, cross compiling with Zig make CC="zig cc -target
> x86_64-windows-gnu" and tested make GIT_TEST_CREDENTIAL_HELPER=wincred
> t0303-credential-external.sh (with a shell script git-credential-wincred
> that wraps wine64 git-credential-wincred.exe "$@")
>
> See also similar patch for credential-libsecret "[PATCH v4]
> credential/libsecret: store new attributes"
> https://lore.kernel.org/git/pull.1469.v4.git.git.1684306540947.gitgitgadget@gmail.com/T/#u
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1534%2Fhickford%2Fwincred-refresh-v1
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1534/hickford/wincred-refresh-v1
> Pull-Request: https://github.com/gitgitgadget/git/pull/1534
>
> .../wincred/git-credential-wincred.c | 40 ++++++++++++++++---
> t/t0303-credential-external.sh | 1 +
> 2 files changed, 35 insertions(+), 6 deletions(-)
>
> diff --git a/contrib/credential/wincred/git-credential-wincred.c b/contrib/credential/wincred/git-credential-wincred.c
> index 96f10613aee..dc34283b85e 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)
> {
> @@ -128,6 +128,11 @@ 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;
> @@ -137,9 +142,17 @@ static void get_credential(void)
> 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));
> + 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, wcslen(line));
> + while(line != NULL) {
> + part = wcstok_s(line, L"=", &remaining_parts);
> + if (!wcscmp(part, L"oauth_refresh_token")) {
> + write_item("oauth_refresh_token", remaining_parts, wcslen(remaining_parts));
> + }
> + line = wcstok_s(NULL, L"\r\n", &remaining_lines);
> + }
> for (int j = 0; j < creds[i]->AttributeCount; j++) {
> attr = creds[i]->Attributes + j;
> if (!wcscmp(attr->Keyword, L"git_password_expiry_utc")) {
> @@ -148,6 +161,7 @@ static void get_credential(void)
> break;
> }
> }
> + free(secret);
> break;
> }
>
> @@ -158,16 +172,26 @@ 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;
> @@ -182,6 +206,8 @@ static void store_credential(void)
> cred.TargetAlias = NULL;
> cred.UserName = wusername;
>
> + free(secret);
> +
> if (!CredWriteW(&cred, 0))
> die("CredWrite failed");
> }
> @@ -253,6 +279,8 @@ 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
> diff --git a/t/t0303-credential-external.sh b/t/t0303-credential-external.sh
> index f028fd14182..51886b8e259 100755
> --- a/t/t0303-credential-external.sh
> +++ b/t/t0303-credential-external.sh
> @@ -45,6 +45,7 @@ test -z "$GIT_TEST_CREDENTIAL_HELPER_SETUP" ||
> helper_test_clean "$GIT_TEST_CREDENTIAL_HELPER"
>
> helper_test "$GIT_TEST_CREDENTIAL_HELPER"
> +helper_test_oauth_refresh_token "$GIT_TEST_CREDENTIAL_HELPER"
>
> if test -z "$GIT_TEST_CREDENTIAL_HELPER_TIMEOUT"; then
> say "# skipping timeout tests (GIT_TEST_CREDENTIAL_HELPER_TIMEOUT not set)"
>
> base-commit: 9e49351c3060e1fa6e0d2de64505b7becf157f28
> --
> gitgitgadget
Hi. Is anyone familiar enough with Windows CRT to review this patch?
next prev parent reply other threads:[~2023-06-16 22:30 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-20 7:20 [PATCH] credential/wincred: store oauth_refresh_token M Hickford via GitGitGadget
2023-06-16 22:30 ` M Hickford [this message]
[not found] ` <CAGJzqskekExeug45Zh-uQ1dpHpKP8HS3obWQyz8B_DzSZiuAwA@mail.gmail.com>
2023-10-30 8:00 ` M Hickford
2023-11-06 6:16 ` [PATCH v2] " M Hickford via GitGitGadget
2023-11-14 7:40 ` Junio C Hamano
2023-11-24 8:00 ` M Hickford
2024-01-28 21:25 ` [PATCH v3] " M Hickford via GitGitGadget
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