diff options
Diffstat (limited to 'contrib/credential/wincred')
| -rw-r--r-- | contrib/credential/wincred/Makefile | 22 | ||||
| -rw-r--r-- | contrib/credential/wincred/git-credential-wincred.c | 331 |
2 files changed, 353 insertions, 0 deletions
diff --git a/contrib/credential/wincred/Makefile b/contrib/credential/wincred/Makefile new file mode 100644 index 0000000..6e992c0 --- /dev/null +++ b/contrib/credential/wincred/Makefile @@ -0,0 +1,22 @@ +all: git-credential-wincred.exe + +-include ../../../config.mak.autogen +-include ../../../config.mak + +CC ?= gcc +RM ?= rm -f +CFLAGS ?= -O2 -Wall + +prefix ?= /usr/local +libexecdir ?= $(prefix)/libexec/git-core + +INSTALL ?= install + +git-credential-wincred.exe : git-credential-wincred.c + $(LINK.c) $^ $(LOADLIBES) $(LDLIBS) -o $@ + +install: git-credential-wincred.exe + $(INSTALL) -m 755 $^ $(libexecdir) + +clean: + $(RM) git-credential-wincred.exe 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; +} |