+/*
+ * Pageant: the PuTTY Authentication Agent.
+ */
+
+#include <windows.h>
+#include <stdio.h> /* FIXME */
+#include "putty.h" /* FIXME */
+#include "ssh.h"
+#include "tree234.h"
+
+#define IDI_MAINICON 200
+#define IDI_TRAYICON 201
+
+#define WM_XUSER (WM_USER + 0x2000)
+#define WM_SYSTRAY (WM_XUSER + 6)
+#define WM_SYSTRAY2 (WM_XUSER + 7)
+#define WM_CLOSEMEM (WM_XUSER + 10)
+
+#define IDM_CLOSE 0x0010
+#define IDM_VIEWKEYS 0x0020
+
+#define APPNAME "Pageant"
+
+#define MAILSLOTNAME "\\\\.\\mailslot\\pageant_listener"
+
+#define SSH_AGENTC_REQUEST_RSA_IDENTITIES 1
+#define SSH_AGENT_RSA_IDENTITIES_ANSWER 2
+#define SSH_AGENTC_RSA_CHALLENGE 3
+#define SSH_AGENT_RSA_RESPONSE 4
+#define SSH_AGENT_FAILURE 5
+#define SSH_AGENT_SUCCESS 6
+#define SSH_AGENTC_ADD_RSA_IDENTITY 7
+#define SSH_AGENTC_REMOVE_RSA_IDENTITY 8
+
+HINSTANCE instance;
+HWND hwnd;
+HWND keylist;
+HMENU systray_menu;
+
+tree234 *rsakeys;
+
+/*
+ * We need this to link with the RSA code, because rsaencrypt()
+ * pads its data with random bytes. Since we only use rsadecrypt(),
+ * which is deterministic, this should never be called.
+ *
+ * If it _is_ called, there is a _serious_ problem, because it
+ * won't generate true random numbers. So we must scream, panic,
+ * and exit immediately if that should happen.
+ */
+int random_byte(void) {
+ MessageBox(hwnd, "Internal Error", APPNAME, MB_OK | MB_ICONERROR);
+ exit(0);
+}
+
+/*
+ * This function is needed to link with the DES code. We need not
+ * have it do anything at all.
+ */
+void logevent(char *msg) {
+}
+
+#define GET_32BIT(cp) \
+ (((unsigned long)(unsigned char)(cp)[0] << 24) | \
+ ((unsigned long)(unsigned char)(cp)[1] << 16) | \
+ ((unsigned long)(unsigned char)(cp)[2] << 8) | \
+ ((unsigned long)(unsigned char)(cp)[3]))
+
+#define PUT_32BIT(cp, value) { \
+ (cp)[0] = (unsigned char)((value) >> 24); \
+ (cp)[1] = (unsigned char)((value) >> 16); \
+ (cp)[2] = (unsigned char)((value) >> 8); \
+ (cp)[3] = (unsigned char)(value); }
+
+#define PASSPHRASE_MAXLEN 512
+
+/*
+ * Dialog-box function for the passphrase box.
+ */
+static int CALLBACK PassphraseProc(HWND hwnd, UINT msg,
+ WPARAM wParam, LPARAM lParam) {
+ static char *passphrase;
+
+ switch (msg) {
+ case WM_INITDIALOG:
+ passphrase = (char *)lParam;
+ *passphrase = 0;
+ return 0;
+ case WM_COMMAND:
+ switch (LOWORD(wParam)) {
+ case IDOK:
+ if (*passphrase)
+ EndDialog (hwnd, 1);
+ else
+ MessageBeep (0);
+ return 0;
+ case IDCANCEL:
+ EndDialog (hwnd, 0);
+ return 0;
+ case 102: /* edit box */
+ if (HIWORD(wParam) == EN_CHANGE) {
+ GetDlgItemText (hwnd, 102, passphrase, PASSPHRASE_MAXLEN-1);
+ passphrase[PASSPHRASE_MAXLEN-1] = '\0';
+ }
+ return 0;
+ }
+ return 0;
+ case WM_CLOSE:
+ EndDialog (hwnd, 0);
+ return 0;
+ }
+ return 0;
+}
+
+/*
+ * This function loads a key from a file and adds it.
+ */
+void add_keyfile(char *filename) {
+ char passphrase[PASSPHRASE_MAXLEN];
+ struct RSAKey *key;
+ int needs_pass;
+ int ret;
+ int attempts;
+
+ needs_pass = rsakey_encrypted(filename);
+ attempts = 0;
+ key = malloc(sizeof(*key));
+ do {
+ if (needs_pass) {
+ int dlgret;
+ dlgret = DialogBoxParam(instance, MAKEINTRESOURCE(210),
+ NULL, PassphraseProc,
+ (LPARAM)passphrase);
+ if (!dlgret) {
+ free(key);
+ return; /* operation cancelled */
+ }
+ } else
+ *passphrase = '\0';
+ ret = loadrsakey(filename, key, passphrase);
+ attempts++;
+ } while (ret == -1);
+ if (ret == 0) {
+ MessageBox(NULL, "Couldn't load public key.", APPNAME,
+ MB_OK | MB_ICONERROR);
+ free(key);
+ return;
+ }
+ if (add234(rsakeys, key) != key)
+ free(key); /* already present, don't waste RAM */
+}
+
+/*
+ * This is the main agent function that answers messages.
+ */
+void answer_msg(void *in, int inlen, void **out, int *outlen) {
+ unsigned char *ret;
+ unsigned char *p = in;
+ int type;
+
+ *out = NULL; /* default `no go' response */
+
+ /*
+ * Basic sanity checks. len >= 5, and len[0:4] holds len-4.
+ */
+ if (inlen < 5 || GET_32BIT(p) != (unsigned long)(inlen-4))
+ return;
+
+ /*
+ * Get the message type.
+ */
+ type = p[4];
+
+ p += 5;
+
+ switch (type) {
+ case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
+ /*
+ * Reply with SSH_AGENT_RSA_IDENTITIES_ANSWER.
+ */
+ {
+ enum234 e;
+ struct RSAKey *key;
+ int len, nkeys;
+
+ /*
+ * Count up the number and length of keys we hold.
+ */
+ len = nkeys = 0;
+ for (key = first234(rsakeys, &e); key; key = next234(&e)) {
+ nkeys++;
+ len += 4; /* length field */
+ len += ssh1_bignum_length(key->exponent);
+ len += ssh1_bignum_length(key->modulus);
+ len += 4 + strlen(key->comment);
+ }
+
+ /*
+ * Packet header is the obvious five bytes, plus four
+ * bytes for the key count.
+ */
+ len += 5 + 4;
+ if ((ret = malloc(len)) != NULL) {
+ PUT_32BIT(ret, len-4);
+ ret[4] = SSH_AGENT_RSA_IDENTITIES_ANSWER;
+ PUT_32BIT(ret+5, nkeys);
+ p = ret + 5 + 4;
+ for (key = first234(rsakeys, &e); key; key = next234(&e)) {
+ PUT_32BIT(p, ssh1_bignum_bitcount(key->modulus));
+ p += 4;
+ p += ssh1_write_bignum(p, key->exponent);
+ p += ssh1_write_bignum(p, key->modulus);
+ PUT_32BIT(p, strlen(key->comment));
+ memcpy(p+4, key->comment, strlen(key->comment));
+ p += 4 + strlen(key->comment);
+ }
+ }
+ }
+ break;
+ case SSH_AGENTC_RSA_CHALLENGE:
+ /*
+ * Reply with either SSH_AGENT_RSA_RESPONSE or
+ * SSH_AGENT_FAILURE, depending on whether we have that key
+ * or not.
+ */
+ {
+ struct RSAKey reqkey, *key;
+ Bignum challenge, response;
+ unsigned char response_source[48], response_md5[16];
+ struct MD5Context md5c;
+ int i, len;
+
+ p += 4;
+ p += ssh1_read_bignum(p, &reqkey.exponent);
+ p += ssh1_read_bignum(p, &reqkey.modulus);
+ p += ssh1_read_bignum(p, &challenge);
+ memcpy(response_source+32, p, 16); p += 16;
+ if (GET_32BIT(p) != 1 ||
+ (key = find234(rsakeys, &reqkey, NULL)) == NULL) {
+ freebn(reqkey.exponent);
+ freebn(reqkey.modulus);
+ freebn(challenge);
+ goto failure;
+ }
+ response = rsadecrypt(challenge, key);
+ for (i = 0; i < 32; i++)
+ response_source[i] = bignum_byte(response, 31-i);
+
+ MD5Init(&md5c);
+ MD5Update(&md5c, response_source, 48);
+ MD5Final(response_md5, &md5c);
+ memset(response_source, 0, 48); /* burn the evidence */
+ freebn(response); /* and that evidence */
+ freebn(challenge); /* yes, and that evidence */
+ freebn(reqkey.exponent); /* and free some memory ... */
+ freebn(reqkey.modulus); /* ... while we're at it. */
+
+ /*
+ * Packet is the obvious five byte header, plus sixteen
+ * bytes of MD5.
+ */
+ len = 5 + 16;
+ if ((ret = malloc(len)) != NULL) {
+ PUT_32BIT(ret, len-4);
+ ret[4] = SSH_AGENT_RSA_RESPONSE;
+ memcpy(ret+5, response_md5, 16);
+ }
+ }
+ break;
+#if 0 /* FIXME: implement these */
+ case SSH_AGENTC_ADD_RSA_IDENTITY:
+ /*
+ * Add to the list and return SSH_AGENT_SUCCESS, or
+ * SSH_AGENT_FAILURE if the key was malformed.
+ */
+ break;
+ case SSH_AGENTC_REMOVE_RSA_IDENTITY:
+ /*
+ * Remove from the list and return SSH_AGENT_SUCCESS, or
+ * perhaps SSH_AGENT_FAILURE if it wasn't in the list to
+ * start with.
+ */
+ break;
+#endif
+ default:
+ failure:
+ /*
+ * Unrecognised message. Return SSH_AGENT_FAILURE.
+ */
+ if ((ret = malloc(5)) != NULL) {
+ PUT_32BIT(ret, 1);
+ ret[4] = SSH_AGENT_FAILURE;
+ }
+ break;
+ }
+
+ if (ret) {
+ *out = ret;
+ *outlen = 4 + GET_32BIT(ret);
+ }
+}
+
+/*
+ * Key comparison function for the 2-3-4 tree of RSA keys.
+ */
+int cmpkeys(void *av, void *bv) {
+ struct RSAKey *a = (struct RSAKey *)av;
+ struct RSAKey *b = (struct RSAKey *)bv;
+ Bignum am, bm;
+ int alen, blen;
+
+ am = a->modulus;
+ bm = b->modulus;
+ /*
+ * Compare by length of moduli.
+ */
+ alen = ssh1_bignum_bitcount(am);
+ blen = ssh1_bignum_bitcount(bm);
+ if (alen > blen) return +1; else if (alen < blen) return -1;
+ /*
+ * Now compare by moduli themselves.
+ */
+ alen = (alen + 7) / 8; /* byte count */
+ while (alen-- > 0) {
+ int abyte, bbyte;
+ abyte = bignum_byte(am, alen);
+ bbyte = bignum_byte(bm, alen);
+ if (abyte > bbyte) return +1; else if (abyte < bbyte) return -1;
+ }
+ /*
+ * Give up.
+ */
+ return 0;
+}
+
+static void error(char *s) {
+ MessageBox(hwnd, s, APPNAME, MB_OK | MB_ICONERROR);
+}
+
+/*
+ * Dialog-box function for the key list box.
+ */
+static int CALLBACK KeyListProc(HWND hwnd, UINT msg,
+ WPARAM wParam, LPARAM lParam) {
+ enum234 e;
+ struct RSAKey *key;
+ OPENFILENAME of;
+ char filename[FILENAME_MAX];
+
+ switch (msg) {
+ case WM_INITDIALOG:
+ for (key = first234(rsakeys, &e); key; key = next234(&e)) {
+ SendDlgItemMessage (hwnd, 100, LB_ADDSTRING,
+ 0, (LPARAM) key->comment);
+ }
+ return 0;
+ case WM_COMMAND:
+ switch (LOWORD(wParam)) {
+ case IDOK:
+ case IDCANCEL:
+ keylist = NULL;
+ DestroyWindow(hwnd);
+ return 0;
+ case 101: /* add key */
+ if (HIWORD(wParam) == BN_CLICKED ||
+ HIWORD(wParam) == BN_DOUBLECLICKED) {
+ memset(&of, 0, sizeof(of));
+#ifdef OPENFILENAME_SIZE_VERSION_400
+ of.lStructSize = OPENFILENAME_SIZE_VERSION_400;
+#else
+ of.lStructSize = sizeof(of);
+#endif
+ of.hwndOwner = hwnd;
+ of.lpstrFilter = "All Files\0*\0\0\0";
+ of.lpstrCustomFilter = NULL;
+ of.nFilterIndex = 1;
+ of.lpstrFile = filename; *filename = '\0';
+ of.nMaxFile = sizeof(filename);
+ of.lpstrFileTitle = NULL;
+ of.lpstrInitialDir = NULL;
+ of.lpstrTitle = "Select Public Key File";
+ of.Flags = 0;
+ if (GetOpenFileName(&of)) {
+ add_keyfile(filename);
+ }
+ SendDlgItemMessage(hwnd, 100, LB_RESETCONTENT, 0, 0);
+ for (key = first234(rsakeys, &e); key; key = next234(&e)) {
+ SendDlgItemMessage (hwnd, 100, LB_ADDSTRING,
+ 0, (LPARAM) key->comment);
+ }
+ SendDlgItemMessage (hwnd, 100, LB_SETCURSEL, (WPARAM) -1, 0);
+ }
+ return 0;
+ case 102: /* remove key */
+ if (HIWORD(wParam) == BN_CLICKED ||
+ HIWORD(wParam) == BN_DOUBLECLICKED) {
+ int n = SendDlgItemMessage (hwnd, 100, LB_GETCURSEL, 0, 0);
+ if (n == LB_ERR || n == 0) {
+ MessageBeep(0);
+ break;
+ }
+ for (key = first234(rsakeys, &e); key; key = next234(&e))
+ if (n-- == 0)
+ break;
+ del234(rsakeys, key);
+ freersakey(key); free(key);
+ SendDlgItemMessage(hwnd, 100, LB_RESETCONTENT, 0, 0);
+ for (key = first234(rsakeys, &e); key; key = next234(&e)) {
+ SendDlgItemMessage (hwnd, 100, LB_ADDSTRING,
+ 0, (LPARAM) key->comment);
+ }
+ SendDlgItemMessage (hwnd, 100, LB_SETCURSEL, (WPARAM) -1, 0);
+ }
+ return 0;
+ }
+ return 0;
+ case WM_CLOSE:
+ keylist = NULL;
+ DestroyWindow(hwnd);
+ return 0;
+ }
+ return 0;
+}
+
+static LRESULT CALLBACK WndProc (HWND hwnd, UINT message,
+ WPARAM wParam, LPARAM lParam) {
+ int ret;
+ static int menuinprogress;
+
+ switch (message) {
+ case WM_SYSTRAY:
+ if (lParam == WM_RBUTTONUP) {
+ POINT cursorpos;
+ GetCursorPos(&cursorpos);
+ PostMessage(hwnd, WM_SYSTRAY2, cursorpos.x, cursorpos.y);
+ }
+ break;
+ case WM_SYSTRAY2:
+ if (!menuinprogress) {
+ menuinprogress = 1;
+ SetForegroundWindow(hwnd);
+ ret = TrackPopupMenu(systray_menu,
+ TPM_RIGHTALIGN | TPM_BOTTOMALIGN |
+ TPM_RIGHTBUTTON,
+ wParam, lParam, 0, hwnd, NULL);
+ menuinprogress = 0;
+ }
+ break;
+ case WM_COMMAND:
+ case WM_SYSCOMMAND:
+ switch (wParam & ~0xF) { /* low 4 bits reserved to Windows */
+ case IDM_CLOSE:
+ SendMessage(hwnd, WM_CLOSE, 0, 0);
+ break;
+ case IDM_VIEWKEYS:
+ if (!keylist) {
+ keylist = CreateDialog (instance, MAKEINTRESOURCE(211),
+ NULL, KeyListProc);
+ ShowWindow (keylist, SW_SHOWNORMAL);
+ }
+ break;
+ }
+ break;
+ case WM_DESTROY:
+ PostQuitMessage (0);
+ return 0;
+ case WM_COPYDATA:
+ {
+ COPYDATASTRUCT *cds;
+ void *in, *out, *ret;
+ int inlen, outlen;
+ HANDLE filemap;
+ char mapname[64];
+ int id;
+
+ cds = (COPYDATASTRUCT *)lParam;
+ /*
+ * FIXME: use dwData somehow.
+ */
+ in = cds->lpData;
+ inlen = cds->cbData;
+ answer_msg(in, inlen, &out, &outlen);
+ if (out) {
+ id = 0;
+ do {
+ sprintf(mapname, "PageantReply%08x", ++id);
+ filemap = CreateFileMapping(INVALID_HANDLE_VALUE,
+ NULL, PAGE_READWRITE,
+ 0, outlen+sizeof(int),
+ mapname);
+ } while (filemap == INVALID_HANDLE_VALUE);
+ ret = MapViewOfFile(filemap, FILE_MAP_WRITE, 0, 0,
+ outlen+sizeof(int));
+ if (ret) {
+ *((int *)ret) = outlen;
+ memcpy(((int *)ret)+1, out, outlen);
+ UnmapViewOfFile(ret);
+ return id;
+ }
+ } else
+ return 0; /* invalid request */
+ }
+ break;
+ case WM_CLOSEMEM:
+ /*
+ * FIXME!
+ */
+ break;
+ }
+
+ return DefWindowProc (hwnd, message, wParam, lParam);
+}
+
+int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show) {
+ WNDCLASS wndclass;
+ HANDLE mailslot;
+ MSG msg;
+
+ instance = inst;
+
+ if (!prev) {
+ wndclass.style = 0;
+ wndclass.lpfnWndProc = WndProc;
+ wndclass.cbClsExtra = 0;
+ wndclass.cbWndExtra = 0;
+ wndclass.hInstance = inst;
+ wndclass.hIcon = LoadIcon (inst,
+ MAKEINTRESOURCE(IDI_MAINICON));
+ wndclass.hCursor = LoadCursor (NULL, IDC_IBEAM);
+ wndclass.hbrBackground = GetStockObject (BLACK_BRUSH);
+ wndclass.lpszMenuName = NULL;
+ wndclass.lpszClassName = APPNAME;
+
+ RegisterClass (&wndclass);
+ }
+
+ hwnd = keylist = NULL;
+
+ hwnd = CreateWindow (APPNAME, APPNAME,
+ WS_OVERLAPPEDWINDOW | WS_VSCROLL,
+ CW_USEDEFAULT, CW_USEDEFAULT,
+ 100, 100, NULL, NULL, inst, NULL);
+
+ /* Set up a system tray icon */
+ {
+ BOOL res;
+ NOTIFYICONDATA tnid;
+ HICON hicon;
+
+#ifdef NIM_SETVERSION
+ tnid.uVersion = 0;
+ res = Shell_NotifyIcon(NIM_SETVERSION, &tnid);
+#endif
+
+ tnid.cbSize = sizeof(NOTIFYICONDATA);
+ tnid.hWnd = hwnd;
+ tnid.uID = 1; /* unique within this systray use */
+ tnid.uFlags = NIF_MESSAGE | NIF_ICON | NIF_TIP;
+ tnid.uCallbackMessage = WM_SYSTRAY;
+ tnid.hIcon = hicon = LoadIcon (instance, MAKEINTRESOURCE(201));
+ strcpy(tnid.szTip, "Pageant (PuTTY authentication agent)");
+
+ res = Shell_NotifyIcon(NIM_ADD, &tnid);
+
+ if (hicon)
+ DestroyIcon(hicon);
+
+ systray_menu = CreatePopupMenu();
+ AppendMenu (systray_menu, MF_ENABLED, IDM_VIEWKEYS, "View Keys");
+ AppendMenu (systray_menu, MF_ENABLED, IDM_CLOSE, "Terminate");
+ }
+
+ ShowWindow (hwnd, SW_HIDE);
+
+ /*
+ * Create the mailslot.
+ */
+ {
+ SECURITY_ATTRIBUTES sa;
+ sa.nLength = sizeof(sa);
+ sa.lpSecurityDescriptor = NULL;
+ sa.bInheritHandle = TRUE;
+ mailslot = CreateMailslot(MAILSLOTNAME, 0, 0, &sa);
+ }
+
+ /*
+ * Initialise storage for RSA keys.
+ */
+ rsakeys = newtree234(cmpkeys);
+
+ while (GetMessage(&msg, NULL, 0, 0) == 1) {
+ TranslateMessage(&msg);
+ DispatchMessage(&msg);
+ }
+
+ /* Clean up the system tray icon */
+ {
+ NOTIFYICONDATA tnid;
+
+ tnid.cbSize = sizeof(NOTIFYICONDATA);
+ tnid.hWnd = hwnd;
+ tnid.uID = 1;
+
+ Shell_NotifyIcon(NIM_DELETE, &tnid);
+
+ DestroyMenu(systray_menu);
+ }
+
+ exit(msg.wParam);
+}