Implement OpenSSH-compatible RSA key fingerprints and use them throughout

git-svn-id: svn://svn.tartarus.org/sgt/putty@637 cda61777-01e9-0310-a592-d414129be87e

diff --git a/pageant.c b/pageant.c
index 950889d..a9af585 100644 (file)
--- a/pageant.c
+++ b/pageant.c
@@ -143,8 +143,16 @@ void keylist_update(void) {
     if (keylist) {
         SendDlgItemMessage(keylist, 100, LB_RESETCONTENT, 0, 0);
         for (key = first234(rsakeys, &e); key; key = next234(&e)) {
+            char listentry[512], *p;
+            /*
+             * Replace two spaces in the fingerprint with tabs, for
+             * nice alignment in the box.
+             */
+            rsa_fingerprint(listentry, sizeof(listentry), key);
+            p = strchr(listentry, ' '); if (p) *p = '\t';
+            p = strchr(listentry, ' '); if (p) *p = '\t';
             SendDlgItemMessage (keylist, 100, LB_ADDSTRING,
-                                0, (LPARAM) key->comment);
+                                0, (LPARAM)listentry);
         }
         SendDlgItemMessage (keylist, 100, LB_SETCURSEL, (WPARAM) -1, 0);
     }
@@ -327,6 +335,7 @@ void answer_msg(void *msg) {
                 ret[4] = SSH_AGENT_SUCCESS;
             } else {
                 freersakey(key);
+                free(key);
             }
         }
         break;
@@ -413,10 +422,13 @@ static int CALLBACK KeyListProc(HWND hwnd, UINT msg,
 
     switch (msg) {
       case WM_INITDIALOG:
-        for (key = first234(rsakeys, &e); key; key = next234(&e)) {
-            SendDlgItemMessage (hwnd, 100, LB_ADDSTRING,
-                                0, (LPARAM) key->comment);
-        }
+        keylist = hwnd;
+       {
+           static int tabs[2] = {25, 175};
+           SendDlgItemMessage (hwnd, 100, LB_SETTABSTOPS, 2,
+                               (LPARAM) tabs);
+       }
+        keylist_update();
         return 0;
       case WM_COMMAND:
        switch (LOWORD(wParam)) {
@@ -463,12 +475,7 @@ static int CALLBACK KeyListProc(HWND hwnd, UINT msg,
                         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);
+                keylist_update();
             }
             return 0;
        }

diff --git a/pageant.rc b/pageant.rc
index d639098..e17cbcb 100644 (file)
--- a/pageant.rc
+++ b/pageant.rc
@@ -24,7 +24,7 @@ CAPTION "Pageant Key List"
 FONT 8, "MS Sans Serif"
 BEGIN
     LISTBOX 100, 10, 10, 280, 155,
-        LBS_HASSTRINGS | WS_VSCROLL | WS_TABSTOP
+        LBS_HASSTRINGS | LBS_USETABSTOPS | WS_VSCROLL | WS_TABSTOP
     PUSHBUTTON "&Add Key", 101, 60, 162, 60, 14
     PUSHBUTTON "&Remove Key", 102, 180, 162, 60, 14
     DEFPUSHBUTTON "&Close", IDOK, 240, 182, 50, 14

diff --git a/ssh.c b/ssh.c
index 3b4fcb2..0db92fc 100644 (file)
--- a/ssh.c
+++ b/ssh.c
@@ -1100,21 +1100,15 @@ static int do_ssh1_login(unsigned char *in, int inlen, int ispkt)
     j = makekey(pktin.body+8+i, &hostkey, &keystr2, 0);
 
     /*
-     * Hash the host key and print the hash in the log box. Just as
-     * a last resort in case the registry's host key checking is
-     * compromised, we'll allow the user some ability to verify
-     * host keys by eye.
+     * Log the host key fingerprint.
      */
-    MD5Init(&md5c);
-    MD5Update(&md5c, keystr2, hostkey.bytes);
-    MD5Final(session_id, &md5c);
     {
        char logmsg[80];
-       int i;
-       logevent("Host key MD5 is:");
+       logevent("Host key fingerprint is:");
        strcpy(logmsg, "      ");
-       for (i = 0; i < 16; i++)
-           sprintf(logmsg+strlen(logmsg), "%02x", session_id[i]);
+        hostkey.comment = NULL;
+        rsa_fingerprint(logmsg+strlen(logmsg), sizeof(logmsg)-strlen(logmsg),
+                        &hostkey);
        logevent(logmsg);
     }
 

diff --git a/ssh.h b/ssh.h
index 058c524..19a514c 100644 (file)
--- a/ssh.h
+++ b/ssh.h
@@ -48,6 +48,7 @@ void rsasign(unsigned char *data, int length, struct RSAKey *key);
 void rsasanitise(struct RSAKey *key);
 int rsastr_len(struct RSAKey *key);
 void rsastr_fmt(char *str, struct RSAKey *key);
+void rsa_fingerprint(char *str, int len, struct RSAKey *key);
 void freersakey(struct RSAKey *key);
 
 typedef unsigned int word32;

diff --git a/sshrsa.c b/sshrsa.c
index 324fbd1..5ea4cc7 100644 (file)
--- a/sshrsa.c
+++ b/sshrsa.c
@@ -9,35 +9,9 @@
 #include <stdlib.h>
 #include <string.h>
 
-#if defined TESTMODE || defined RSADEBUG
-#ifndef DLVL
-#define DLVL 10000
-#endif
-#define debug(x) bndebug(#x,x)
-static int level = 0;
-static void bndebug(char *name, Bignum b) {
-    int i;
-    int w = 50-level-strlen(name)-5*b[0];
-    if (level >= DLVL)
-       return;
-    if (w < 0) w = 0;
-    dprintf("%*s%s%*s", level, "", name, w, "");
-    for (i=b[0]; i>0; i--)
-       dprintf(" %04x", b[i]);
-    dprintf("\n");
-}
-#define dmsg(x) do {if(level<DLVL){dprintf("%*s",level,"");printf x;}} while(0)
-#define enter(x) do { dmsg(x); level += 4; } while(0)
-#define leave(x) do { level -= 4; dmsg(x); } while(0)
-#else
-#define debug(x)
-#define dmsg(x)
-#define enter(x)
-#define leave(x)
-#endif
-
 #include "ssh.h"
 
+
 int makekey(unsigned char *data, struct RSAKey *result,
            unsigned char **keystr, int order) {
     unsigned char *p = data;
@@ -77,8 +51,6 @@ void rsaencrypt(unsigned char *data, int length, struct RSAKey *key) {
     int w, i;
     unsigned char *p;
 
-    debug(key->exponent);
-
     memmove(data+key->bytes-length, data, length);
     data[0] = 0;
     data[1] = 2;
@@ -106,12 +78,8 @@ void rsaencrypt(unsigned char *data, int length, struct RSAKey *key) {
            b1[1+i/2] |= byte;
     }
 
-    debug(b1);
-
     modpow(b1, key->exponent, key->modulus, b2);
 
-    debug(b2);
-
     p = data;
     for (i=key->bytes; i-- ;) {
        unsigned char b;
@@ -160,49 +128,44 @@ void rsastr_fmt(char *str, struct RSAKey *key) {
     str[len] = '\0';
 }
 
+/*
+ * Generate a fingerprint string for the key. Compatible with the
+ * OpenSSH fingerprint code.
+ */
+void rsa_fingerprint(char *str, int len, struct RSAKey *key) {
+    struct MD5Context md5c;
+    unsigned char digest[16];
+    char buffer[16*3+40];
+    int numlen, slen, i;
+
+    MD5Init(&md5c);
+    numlen = ssh1_bignum_length(key->modulus) - 2;
+    for (i = numlen; i-- ;) {
+        unsigned char c = bignum_byte(key->modulus, i);
+        MD5Update(&md5c, &c, 1);
+    }
+    numlen = ssh1_bignum_length(key->exponent) - 2;
+    for (i = numlen; i-- ;) {
+        unsigned char c = bignum_byte(key->exponent, i);
+        MD5Update(&md5c, &c, 1);
+    }
+    MD5Final(digest, &md5c);
+
+    sprintf(buffer, "%d ", ssh1_bignum_bitcount(key->modulus));
+    for (i = 0; i < 16; i++)
+        sprintf(buffer+strlen(buffer), "%s%02x", i?":":"", digest[i]);
+    strncpy(str, buffer, len); str[len-1] = '\0';
+    slen = strlen(str);
+    if (key->comment && slen < len-1) {
+        str[slen] = ' ';
+        strncpy(str+slen+1, key->comment, len-slen-1);
+        str[len-1] = '\0';
+    }
+}
+
 void freersakey(struct RSAKey *key) {
     if (key->modulus) freebn(key->modulus);
     if (key->exponent) freebn(key->exponent);
     if (key->private_exponent) freebn(key->private_exponent);
     if (key->comment) free(key->comment);
 }
-
-#ifdef TESTMODE
-
-#ifndef NODDY
-#define p1 10007
-#define p2 10069
-#define p3 10177
-#else
-#define p1 3
-#define p2 7
-#define p3 13
-#endif
-
-unsigned short P1[2] = { 1, p1 };
-unsigned short P2[2] = { 1, p2 };
-unsigned short P3[2] = { 1, p3 };
-unsigned short bigmod[5] = { 4, 0, 0, 0, 32768U };
-unsigned short mod[5] = { 4, 0, 0, 0, 0 };
-unsigned short a[5] = { 4, 0, 0, 0, 0 };
-unsigned short b[5] = { 4, 0, 0, 0, 0 };
-unsigned short c[5] = { 4, 0, 0, 0, 0 };
-unsigned short One[2] = { 1, 1 };
-unsigned short Two[2] = { 1, 2 };
-
-int main(void) {
-    modmult(P1, P2, bigmod, a);   debug(a);
-    modmult(a, P3, bigmod, mod);  debug(mod);
-
-    sub(P1, One, a);              debug(a);
-    sub(P2, One, b);              debug(b);
-    modmult(a, b, bigmod, c);     debug(c);
-    sub(P3, One, a);              debug(a);
-    modmult(a, c, bigmod, b);     debug(b);
-
-    modpow(Two, b, mod, a);       debug(a);
-
-    return 0;
-}
-
-#endif

diff --git a/win_res.rc b/win_res.rc
index 1bf3bb7..eb89218 100644 (file)
--- a/win_res.rc
+++ b/win_res.rc
@@ -341,14 +341,14 @@ BEGIN
 END
 
 /* Accelerators used: co */
-IDD_LOGBOX DIALOG DISCARDABLE 100, 20, 160, 119
+IDD_LOGBOX DIALOG DISCARDABLE 100, 20, 260, 119
 STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
 CAPTION "PuTTY Event Log"
 FONT 8, "MS Sans Serif"
 BEGIN
-    DEFPUSHBUTTON "&Close", IDOK, 85, 102, 44, 14
-    PUSHBUTTON "C&opy", IDN_COPY, 31, 102, 44, 14
-    LISTBOX IDN_LIST, 3, 3, 154, 95, LBS_HASSTRINGS | LBS_USETABSTOPS | WS_VSCROLL | LBS_EXTENDEDSEL
+    DEFPUSHBUTTON "&Close", IDOK, 135, 102, 44, 14
+    PUSHBUTTON "C&opy", IDN_COPY, 81, 102, 44, 14
+    LISTBOX IDN_LIST, 3, 3, 254, 95, LBS_HASSTRINGS | LBS_USETABSTOPS | WS_VSCROLL | LBS_EXTENDEDSEL
 END
 
 /* No accelerators used */