diff options
Diffstat (limited to 'contrib/credential/wincred/git-credential-wincred.c')
| -rw-r--r-- | contrib/credential/wincred/git-credential-wincred.c | 357 |
1 files changed, 357 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..cbaec5f --- /dev/null +++ b/contrib/credential/wincred/git-credential-wincred.c @@ -0,0 +1,357 @@ +/* + * A git credential helper that interface with Windows' Credential Manager + * + */ +#include <windows.h> +#include <stdio.h> +#include <io.h> +#include <fcntl.h> + +/* common helpers */ + +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; +} + +static char *xstrdup(const char *str) +{ + char *ret = strdup(str); + 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 *CredUnPackAuthenticationBufferWT)(DWORD, PVOID, DWORD, + LPWSTR, DWORD *, LPWSTR, DWORD *, LPWSTR, DWORD *); +typedef BOOL (WINAPI *CredEnumerateWT)(LPCWSTR, DWORD, DWORD *, + PCREDENTIALW **); +typedef BOOL (WINAPI *CredPackAuthenticationBufferWT)(DWORD, LPWSTR, LPWSTR, + PBYTE, DWORD *); +typedef VOID (WINAPI *CredFreeT)(PVOID); +typedef BOOL (WINAPI *CredDeleteWT)(LPCWSTR, DWORD, DWORD); + +static HMODULE advapi, credui; +static CredWriteWT CredWriteW; +static CredUnPackAuthenticationBufferWT CredUnPackAuthenticationBufferW; +static CredEnumerateWT CredEnumerateW; +static CredPackAuthenticationBufferWT CredPackAuthenticationBufferW; +static CredFreeT CredFree; +static CredDeleteWT CredDeleteW; + +static void load_cred_funcs(void) +{ + /* load DLLs */ + advapi = LoadLibrary("advapi32.dll"); + credui = LoadLibrary("credui.dll"); + if (!advapi || !credui) + die("failed to load DLLs"); + + /* get function pointers */ + CredWriteW = (CredWriteWT)GetProcAddress(advapi, "CredWriteW"); + CredUnPackAuthenticationBufferW = (CredUnPackAuthenticationBufferWT) + GetProcAddress(credui, "CredUnPackAuthenticationBufferW"); + CredEnumerateW = (CredEnumerateWT)GetProcAddress(advapi, + "CredEnumerateW"); + CredPackAuthenticationBufferW = (CredPackAuthenticationBufferWT) + GetProcAddress(credui, "CredPackAuthenticationBufferW"); + CredFree = (CredFreeT)GetProcAddress(advapi, "CredFree"); + CredDeleteW = (CredDeleteWT)GetProcAddress(advapi, "CredDeleteW"); + if (!CredWriteW || !CredUnPackAuthenticationBufferW || + !CredEnumerateW || !CredPackAuthenticationBufferW || !CredFree || + !CredDeleteW) + die("failed to load functions"); +} + +static char target_buf[1024]; +static char *protocol, *host, *path, *username; +static WCHAR *wusername, *password, *target; + +static void write_item(const char *what, WCHAR *wbuf) +{ + char *buf; + int len = WideCharToMultiByte(CP_UTF8, 0, wbuf, -1, NULL, 0, NULL, + FALSE); + buf = xmalloc(len); + + if (!WideCharToMultiByte(CP_UTF8, 0, wbuf, -1, buf, len, NULL, FALSE)) + die("WideCharToMultiByte failed!"); + + printf("%s=", what); + fwrite(buf, 1, len - 1, stdout); + putchar('\n'); + free(buf); +} + +static int match_attr(const CREDENTIALW *cred, const WCHAR *keyword, + const char *want) +{ + int i; + if (!want) + return 1; + + for (i = 0; i < cred->AttributeCount; ++i) + if (!wcscmp(cred->Attributes[i].Keyword, keyword)) + return !strcmp((const char *)cred->Attributes[i].Value, + want); + + return 0; /* not found */ +} + +static int match_cred(const CREDENTIALW *cred) +{ + return (!wusername || !wcscmp(wusername, cred->UserName)) && + match_attr(cred, L"git_protocol", protocol) && + match_attr(cred, L"git_host", host) && + match_attr(cred, L"git_path", path); +} + +static void get_credential(void) +{ + WCHAR *user_buf, *pass_buf; + DWORD user_buf_size = 0, pass_buf_size = 0; + CREDENTIALW **creds, *cred = NULL; + 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])) { + cred = creds[i]; + break; + } + if (!cred) + return; + + CredUnPackAuthenticationBufferW(0, cred->CredentialBlob, + cred->CredentialBlobSize, NULL, &user_buf_size, NULL, NULL, + NULL, &pass_buf_size); + + user_buf = xmalloc(user_buf_size * sizeof(WCHAR)); + pass_buf = xmalloc(pass_buf_size * sizeof(WCHAR)); + + if (!CredUnPackAuthenticationBufferW(0, cred->CredentialBlob, + cred->CredentialBlobSize, user_buf, &user_buf_size, NULL, NULL, + pass_buf, &pass_buf_size)) + die("CredUnPackAuthenticationBuffer failed"); + + CredFree(creds); + + /* zero-terminate (sizes include zero-termination) */ + user_buf[user_buf_size - 1] = L'\0'; + pass_buf[pass_buf_size - 1] = L'\0'; + + write_item("username", user_buf); + write_item("password", pass_buf); + + free(user_buf); + free(pass_buf); +} + +static void write_attr(CREDENTIAL_ATTRIBUTEW *attr, const WCHAR *keyword, + const char *value) +{ + attr->Keyword = (LPWSTR)keyword; + attr->Flags = 0; + attr->ValueSize = strlen(value) + 1; /* store zero-termination */ + attr->Value = (LPBYTE)value; +} + +static void store_credential(void) +{ + CREDENTIALW cred; + BYTE *auth_buf; + DWORD auth_buf_size = 0; + CREDENTIAL_ATTRIBUTEW attrs[CRED_MAX_ATTRIBUTES]; + + if (!wusername || !password) + return; + + /* query buffer size */ + CredPackAuthenticationBufferW(0, wusername, password, + NULL, &auth_buf_size); + + auth_buf = xmalloc(auth_buf_size); + + if (!CredPackAuthenticationBufferW(0, wusername, password, + auth_buf, &auth_buf_size)) + die("CredPackAuthenticationBuffer failed"); + + cred.Flags = 0; + cred.Type = CRED_TYPE_GENERIC; + cred.TargetName = target; + cred.Comment = L"saved by git-credential-wincred"; + cred.CredentialBlobSize = auth_buf_size; + cred.CredentialBlob = auth_buf; + cred.Persist = CRED_PERSIST_LOCAL_MACHINE; + cred.AttributeCount = 1; + cred.Attributes = attrs; + cred.TargetAlias = NULL; + cred.UserName = wusername; + + write_attr(attrs, L"git_protocol", protocol); + + if (host) { + write_attr(attrs + cred.AttributeCount, L"git_host", host); + cred.AttributeCount++; + } + + if (path) { + write_attr(attrs + cred.AttributeCount, L"git_path", path); + cred.AttributeCount++; + } + + 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; + + if (!strcmp(buf, "\n")) + break; + buf[strlen(buf)-1] = '\0'; + + v = strchr(buf, '='); + if (!v) + die("bad input: %s", buf); + *v++ = '\0'; + + if (!strcmp(buf, "protocol")) + protocol = xstrdup(v); + else if (!strcmp(buf, "host")) + host = xstrdup(v); + else if (!strcmp(buf, "path")) + path = xstrdup(v); + else if (!strcmp(buf, "username")) { + username = xstrdup(v); + wusername = utf8_to_utf16_dup(v); + } else if (!strcmp(buf, "password")) + password = utf8_to_utf16_dup(v); + else + die("unrecognized input"); + } +} + +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 */ + strncat(target_buf, "git:", sizeof(target_buf)); + strncat(target_buf, protocol, sizeof(target_buf)); + strncat(target_buf, "://", sizeof(target_buf)); + if (username) { + strncat(target_buf, username, sizeof(target_buf)); + strncat(target_buf, "@", sizeof(target_buf)); + } + if (host) + strncat(target_buf, host, sizeof(target_buf)); + if (path) { + strncat(target_buf, "/", sizeof(target_buf)); + strncat(target_buf, path, sizeof(target_buf)); + } + + target = utf8_to_utf16_dup(target_buf); + + 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; +} |