Patch to x3270 to make it ignore protected fields, and allow them to be modified. This provided some significant pwnage on an assessment where the mainframe (IMS) application appeared to pass the username from one field to another. I'm still researching this, and it could turn out to be very specific to the set of apps I'm testing (maybe CICS ap…

x3270-hack.patch

diff -u x3270-3.3/ctlr.c x3270-3.3-hacked/ctlr.c
--- x3270-3.3/ctlr.c	2013-07-11 17:03:24.000000000 -0500
+++ x3270-3.3-hacked/ctlr.c	2013-11-22 15:30:50.000000000 -0600
@@ -334,8 +334,10 @@
 		ea_buf[-1].fa = FA_PRINTABLE | FA_MODIFY;
 		aea_buf[-1].fa = FA_PRINTABLE | FA_MODIFY;
 	} else {
-		ea_buf[-1].fa = FA_PRINTABLE | FA_PROTECT;
-		aea_buf[-1].fa = FA_PRINTABLE | FA_PROTECT;
+		//ea_buf[-1].fa = FA_PRINTABLE | FA_PROTECT;
+		ea_buf[-1].fa = FA_PRINTABLE;
+		//aea_buf[-1].fa = FA_PRINTABLE | FA_PROTECT;
+		aea_buf[-1].fa = FA_PRINTABLE;
 	}
 	if (!IN_3270 || (IN_SSCP && (kybdlock & KL_OIA_TWAIT))) {
 		kybdlock_clr(KL_OIA_TWAIT, "ctlr_connect");
@@ -454,7 +456,7 @@
 		baddr = nbaddr;
 		INC_BA(nbaddr);
 		if (ea_buf[baddr].fa &&
-		    !FA_IS_PROTECTED(ea_buf[baddr].fa) &&
+		    //!FA_IS_PROTECTED(ea_buf[baddr].fa) &&
 		    !ea_buf[nbaddr].fa)
 			return nbaddr;
 	} while (nbaddr != baddr0);
@@ -1159,7 +1161,7 @@
 		f = False;
 		do {
 			fa = ea_buf[baddr].fa;
-			if (!FA_IS_PROTECTED(fa)) {
+			//if (!FA_IS_PROTECTED(fa)) {
 				mdt_clear(baddr);
 				do {
 					INC_BA(baddr);
@@ -1171,12 +1173,12 @@
 						ctlr_add(baddr, EBC_null, 0);
 					}
 				} while (!ea_buf[baddr].fa);
-			}
-			else {
-				do {
-					INC_BA(baddr);
-				} while (!ea_buf[baddr].fa);
-			}
+			//}
+			//else {
+				//do {
+					//INC_BA(baddr);
+				//} while (!ea_buf[baddr].fa);
+			//}
 		} while (baddr != sbaddr);
 		if (!f)
 			cursor_move(0);
@@ -1346,8 +1348,9 @@
 			 * of an unprotected field, simply advance one
 			 * position.
 			 */
-			if (ea_buf[buffer_addr].fa &&
-			    !FA_IS_PROTECTED(ea_buf[buffer_addr].fa)) {
+			if (ea_buf[buffer_addr].fa) {
+			//if (ea_buf[buffer_addr].fa &&
+			 //   !FA_IS_PROTECTED(ea_buf[buffer_addr].fa)) {
 				INC_BA(buffer_addr);
 				last_zpt = False;
 				last_cmd = True;
@@ -1512,7 +1515,8 @@
 			do {
 				if (ea_buf[buffer_addr].fa)
 					current_fa = ea_buf[buffer_addr].fa;
-				else if (!FA_IS_PROTECTED(current_fa)) {
+				//else if (!FA_IS_PROTECTED(current_fa)) {
+				else {
 					ctlr_add(buffer_addr, EBC_null,
 					    CS_BASE);
 				}
diff -u x3270-3.3/fprint_screen.c x3270-3.3-hacked/fprint_screen.c
--- x3270-3.3/fprint_screen.c	2013-07-11 17:03:24.000000000 -0500
+++ x3270-3.3-hacked/fprint_screen.c	2013-11-22 15:42:53.000000000 -0600
@@ -80,7 +80,8 @@
 		HOST_COLOR_BLUE,         /* protected */
 		HOST_COLOR_WHITE         /* protected, intensified */
 #       define DEFCOLOR_MAP(f) \
-		((((f) & FA_PROTECT) >> 4) | (((f) & FA_INT_HIGH_SEL) >> 3))
+		(((f) & FA_INT_HIGH_SEL) >> 3)
+		//((((f) & FA_PROTECT) >> 4) | (((f) & FA_INT_HIGH_SEL) >> 3))
 	};
 
 	if (appres.m3279)
diff -u x3270-3.3/kybd.c x3270-3.3-hacked/kybd.c
--- x3270-3.3/kybd.c	2013-07-11 17:03:24.000000000 -0500
+++ x3270-3.3-hacked/kybd.c	2013-11-22 15:39:37.000000000 -0600
@@ -830,10 +830,10 @@
 	baddr = cursor_addr;
 	faddr = find_field_attribute(baddr);
 	fa = get_field_attribute(baddr);
-	if (ea_buf[baddr].fa || FA_IS_PROTECTED(fa)) {
-		operator_error(KL_OERR_PROTECTED);
-		return False;
-	}
+	//if (ea_buf[baddr].fa || FA_IS_PROTECTED(fa)) {
+		//operator_error(KL_OERR_PROTECTED);
+		//return False;
+	//}
 	if (appres.numeric_lock && FA_IS_NUMERIC(fa) &&
 	    !((code >= EBC_0 && code <= EBC_9) ||
 	      code == EBC_minus || code == EBC_period)) {
@@ -1121,10 +1121,10 @@
 	faddr = find_field_attribute(baddr);
 
 	/* Protected? */
-	if (ea_buf[baddr].fa || FA_IS_PROTECTED(fa)) {
-		operator_error(KL_OERR_PROTECTED);
-		return False;
-	}
+	//if (ea_buf[baddr].fa || FA_IS_PROTECTED(fa)) {
+		//operator_error(KL_OERR_PROTECTED);
+		//return False;
+	//}
 
 	/* Numeric? */
 	if (appres.numeric_lock && FA_IS_NUMERIC(fa)) {
@@ -1598,7 +1598,7 @@
 		nbaddr = baddr;
 		INC_BA(nbaddr);
 		if (ea_buf[baddr].fa &&
-		    !FA_IS_PROTECTED(ea_buf[baddr].fa) &&
+		    //!FA_IS_PROTECTED(ea_buf[baddr].fa) &&
 		    !ea_buf[nbaddr].fa)
 			break;
 		DEC_BA(baddr);
@@ -1813,10 +1813,10 @@
 
 	/* Can't delete a field attribute. */
 	fa = get_field_attribute(baddr);
-	if (FA_IS_PROTECTED(fa) || ea_buf[baddr].fa) {
-		operator_error(KL_OERR_PROTECTED);
-		return False;
-	}
+	//if (FA_IS_PROTECTED(fa) || ea_buf[baddr].fa) {
+		//operator_error(KL_OERR_PROTECTED);
+		//return False;
+	//}
 	if (ea_buf[baddr].cc == EBC_so || ea_buf[baddr].cc == EBC_si) {
 		/*
 		 * Can't delete SO or SI, unless it's adjacent to its
@@ -1948,10 +1948,10 @@
 
 	baddr = cursor_addr;
 	faddr = find_field_attribute(baddr);
-	if (faddr == baddr || FA_IS_PROTECTED(ea_buf[baddr].fa)) {
-		operator_error(KL_OERR_PROTECTED);
-		return;
-	}
+	//if (faddr == baddr || FA_IS_PROTECTED(ea_buf[baddr].fa)) {
+		//operator_error(KL_OERR_PROTECTED);
+		//return;
+	//}
 	if (baddr && faddr == baddr - 1)
 		return;
 	do_left();
@@ -2125,7 +2125,7 @@
 	prot = FA_IS_PROTECTED(get_field_attribute(baddr));
 
 	/* Skip to before this word, if in one now. */
-	if (!prot) {
+	//if (!prot) {
 		c = ea_buf[baddr].cc;
 		while (!ea_buf[baddr].fa && c != EBC_space && c != EBC_null) {
 			DEC_BA(baddr);
@@ -2133,7 +2133,7 @@
 				return;
 			c = ea_buf[baddr].cc;
 		}
-	}
+	//}
 	baddr0 = baddr;
 
 	/* Find the end of the preceding word. */
@@ -2144,7 +2144,8 @@
 			prot = FA_IS_PROTECTED(get_field_attribute(baddr));
 			continue;
 		}
-		if (!prot && c != EBC_space && c != EBC_null)
+		//if (!prot && c != EBC_space && c != EBC_null)
+		if (c != EBC_space && c != EBC_null)
 			break;
 		DEC_BA(baddr);
 	} while (baddr != baddr0);
@@ -2217,7 +2218,8 @@
 		c = ea_buf[baddr].cc;
 		if (ea_buf[baddr].fa)
 			prot = FA_IS_PROTECTED(ea_buf[baddr].fa);
-		else if (!prot && c != EBC_space && c != EBC_null)
+		//else if (!prot && c != EBC_space && c != EBC_null)
+		else if (c != EBC_space && c != EBC_null)
 			return baddr;
 		INC_BA(baddr);
 	} while (baddr != baddr0);
@@ -2274,13 +2276,13 @@
 		return;
 
 	/* If not in an unprotected field, go to the next unprotected word. */
-	if (ea_buf[cursor_addr].fa ||
-	    FA_IS_PROTECTED(get_field_attribute(cursor_addr))) {
-		baddr = nu_word(cursor_addr);
-		if (baddr != -1)
-			cursor_move(baddr);
-		return;
-	}
+	//if (ea_buf[cursor_addr].fa ||
+	    //FA_IS_PROTECTED(get_field_attribute(cursor_addr))) {
+		//baddr = nu_word(cursor_addr);
+		//if (baddr != -1)
+			//cursor_move(baddr);
+		//return;
+	//}
 
 	/* If there's another word in this field, go to it. */
 	baddr = nt_word(cursor_addr);
@@ -2405,7 +2407,8 @@
 	baddr = (baddr / COLS) * COLS;			/* 1st col */
 	faddr = find_field_attribute(baddr);
 	fa = ea_buf[faddr].fa;
-	if (faddr != baddr && !FA_IS_PROTECTED(fa))
+	//if (faddr != baddr && !FA_IS_PROTECTED(fa))
+	if (faddr != baddr)
 		cursor_move(baddr);
 	else
 		cursor_move(next_unprotected(baddr));
@@ -2689,10 +2692,10 @@
 #endif /*]*/
 	baddr = cursor_addr;
 	fa = get_field_attribute(baddr);
-	if (FA_IS_PROTECTED(fa) || ea_buf[baddr].fa) {
-		operator_error(KL_OERR_PROTECTED);
-		return;
-	}
+	//if (FA_IS_PROTECTED(fa) || ea_buf[baddr].fa) {
+		//operator_error(KL_OERR_PROTECTED);
+		//return;
+	//}
 	if (formatted) {	/* erase to next field attribute */
 		do {
 			ctlr_add(baddr, EBC_null, 0);
@@ -2754,7 +2757,7 @@
 		f = False;
 		do {
 			fa = ea_buf[baddr].fa;
-			if (!FA_IS_PROTECTED(fa)) {
+			//if (!FA_IS_PROTECTED(fa)) {
 				mdt_clear(baddr);
 				do {
 					INC_BA(baddr);
@@ -2766,11 +2769,11 @@
 						ctlr_add(baddr, EBC_null, 0);
 					}
 				} while (!ea_buf[baddr].fa);
-			} else {	/* skip protected */
-				do {
-					INC_BA(baddr);
-				} while (!ea_buf[baddr].fa);
-			}
+			//} else {	/* skip protected */
+				//do {
+					//INC_BA(baddr);
+				//} while (!ea_buf[baddr].fa);
+			//}
 		} while (baddr != sbaddr);
 		if (!f)
 			cursor_move(0);
@@ -2816,10 +2819,10 @@
 	fa = get_field_attribute(baddr);
 
 	/* Make sure we're on a modifiable field. */
-	if (FA_IS_PROTECTED(fa) || ea_buf[baddr].fa) {
-		operator_error(KL_OERR_PROTECTED);
-		return;
-	}
+	//if (FA_IS_PROTECTED(fa) || ea_buf[baddr].fa) {
+		//operator_error(KL_OERR_PROTECTED);
+		//return;
+	//}
 
 	/* Backspace over any spaces to the left of the cursor. */
 	for (;;) {
@@ -2882,10 +2885,10 @@
 
 	baddr = cursor_addr;
 	fa = get_field_attribute(baddr);
-	if (FA_IS_PROTECTED(fa) || ea_buf[baddr].fa) {
-		operator_error(KL_OERR_PROTECTED);
-		return;
-	}
+	//if (FA_IS_PROTECTED(fa) || ea_buf[baddr].fa) {
+		//operator_error(KL_OERR_PROTECTED);
+		//return;
+	//}
 	while (!ea_buf[baddr].fa)
 		DEC_BA(baddr);
 	INC_BA(baddr);
@@ -2996,8 +2999,8 @@
 	baddr = cursor_addr;
 	faddr = find_field_attribute(baddr);
 	fa = ea_buf[faddr].fa;
-	if (faddr == baddr || FA_IS_PROTECTED(fa))
-		return;
+	//if (faddr == baddr || FA_IS_PROTECTED(fa))
+		//return;
 
 	baddr = faddr;
 	while (True) {
@@ -3336,11 +3339,11 @@
 		}
 		faddr = find_field_attribute(baddr);
 		fa = ea_buf[faddr].fa;
-		if (faddr == baddr || FA_IS_PROTECTED(fa)) {
-			baddr = next_unprotected(baddr);
-			if (baddr <= b0)
-				return False;
-		}
+		//if (faddr == baddr || FA_IS_PROTECTED(fa)) {
+			//baddr = next_unprotected(baddr);
+			//if (baddr <= b0)
+				//return False;
+		//}
 	}
 
 	cursor_move(baddr);
@@ -3947,26 +3950,26 @@
 		return 0;
 
 	fa = get_field_attribute(cursor_addr);
-	if (ea_buf[cursor_addr].fa || FA_IS_PROTECTED(fa)) {
-		/*
-		 * The cursor is not in an unprotected field.  Find the
-		 * next one.
-		 */
-		baddr = next_unprotected(cursor_addr);
-
-		/* If there isn't any, give up. */
-		if (!baddr)
-			return 0;
+	//if (ea_buf[cursor_addr].fa || FA_IS_PROTECTED(fa)) {
+		///*
+		 //* The cursor is not in an unprotected field.  Find the
+		 //* next one.
+		 //*/
+		//baddr = next_unprotected(cursor_addr);
+
+		///* If there isn't any, give up. */
+		//if (!baddr)
+			//return 0;
 
 		/* Move the cursor there. */
-	} else {
+	//} else {
 		/* Already in an unprotected field.  Find its start. */
 		baddr = cursor_addr;
 		while (!ea_buf[baddr].fa) {
 			DEC_BA(baddr);
 		}
 		INC_BA(baddr);
-	}
+	//}
 
 	/* Move the cursor to the beginning of the field. */
 	cursor_move(baddr);
diff -u x3270-3.3/macros.c x3270-3.3-hacked/macros.c
--- x3270-3.3/macros.c	2013-07-24 17:02:10.000000000 -0500
+++ x3270-3.3-hacked/macros.c	2013-11-22 15:39:57.000000000 -0600
@@ -2498,9 +2498,9 @@
 		unsigned char fa;
 
 		fa = get_field_attribute(cursor_addr);
-		if (FA_IS_PROTECTED(fa))
-			prot_stat = 'P';
-		else
+		//if (FA_IS_PROTECTED(fa))
+			//prot_stat = 'P';
+		//else
 			prot_stat = 'U';
 	}
 
diff -u x3270-3.3/screen.c x3270-3.3-hacked/screen.c
--- x3270-3.3/screen.c	2013-09-06 09:59:02.000000000 -0500
+++ x3270-3.3-hacked/screen.c	2013-11-22 15:31:41.000000000 -0600
@@ -2403,9 +2403,10 @@
 			else
 				field_color = fa_color(fa);
 			if (visible_control) {
-				if (FA_IS_PROTECTED(fa))
-					b.bits.cc = EBC_P;
-				else if (FA_IS_MODIFIED(fa))
+				//if (FA_IS_PROTECTED(fa))
+					//b.bits.cc = EBC_P;
+				//else if (FA_IS_MODIFIED(fa))
+				if (FA_IS_MODIFIED(fa))
 					b.bits.cc = EBC_M;
 				else
 					b.bits.cc = EBC_U;
diff -u x3270-3.3/select.c x3270-3.3-hacked/select.c
--- x3270-3.3/select.c	2013-07-11 17:03:27.000000000 -0500
+++ x3270-3.3-hacked/select.c	2013-11-22 15:32:15.000000000 -0600
@@ -820,7 +820,8 @@
 	for (baddr = 0; baddr < ROWS*COLS; baddr++) {
 		if (ea_buf[baddr].fa)
 			fa = ea_buf[baddr].fa;
-		else if ((IN_ANSI || !FA_IS_PROTECTED(fa)) && SELECTED(baddr))
+		//else if ((IN_ANSI || !FA_IS_PROTECTED(fa)) && SELECTED(baddr))
+		else if (IN_ANSI && SELECTED(baddr))
 			target[baddr/ULBS] |= 1 << (baddr%ULBS);
 	}