credential/wincred: store oauth_refresh_token

From: M Hickford <[email protected]>

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 <[email protected]>

---
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/[email protected]/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(-)

contrib/credential/wincred/git-credential-wincred.c +34 -6

index 96f10613aee..dc34283b85e 100644
@@ -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

t/t0303-credential-external.sh +1 -0

index f028fd14182..51886b8e259 100755
@@ -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. A small patch to git-credential-wincred needs review on the Git
mailing list https://lore.kernel.org/git/[email protected]/
. Does anyone here have the expertise to review?

Quoted 160 lines · M Hickford via GitGitGadget

From: M Hickford <[email protected]>

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 <[email protected]>

---
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/[email protected]/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(-)

contrib/credential/wincred/git-credential-wincred.c +34 -6

index 96f10613aee..dc34283b85e 100644
@@ -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

t/t0303-credential-external.sh +1 -0

index f028fd14182..51886b8e259 100755
@@ -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

From: M Hickford <[email protected]>

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.

 .../wincred/git-credential-wincred.c          | 46 ++++++++++++++++---
 1 file changed, 40 insertions(+), 6 deletions(-)

contrib/credential/wincred/git-credential-wincred.c +40 -6

index 4cd56c42e24..5c6a7d65d4a 100644
@@ -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

Quoted 14 lines · M Hickford via GitGitGadget

From: M Hickford <[email protected]>

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.

Quoted 8 lines

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.

Quoted 112 lines

 .../wincred/git-credential-wincred.c          | 46 ++++++++++++++++---
 1 file changed, 40 insertions(+), 6 deletions(-)

contrib/credential/wincred/git-credential-wincred.c +40 -6

index 4cd56c42e24..5c6a7d65d4a 100644
@@ -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