--- pgp/src/idea.c	2018/04/24 16:38:49	1.1.1.2
+++ pgp/src/idea.c	2018/04/24 16:39:32	1.1.1.3
@@ -7,7 +7,9 @@
  *	Zero-based indexing added, names changed from IPES to IDEA.
  *	CFB functions added.  Random number routines added.
  *
- *  Optimized for speed 21 Oct 92 by Colin Plumb <colin@nsq.gts.org>
+ *  Optimized for speed 21 Oct 92 by Colin Plumb.
+ *  Very minor speedup on 23 Feb 93 by Colin Plumb.
+ *  idearand() given a separate expanded key on 25 Feb 93, Colin Plumb.
  *
  *	There are two adjustments that can be made to this code to
  *	speed it up.  Defaults may be used for PCs.  Only the -DIDEA32
@@ -81,7 +83,7 @@ typedef word16 uint16;
 #define CONST
 #endif
 
-static void en_key_idea(word16 userkey[8], IDEAkey Z);
+static void en_key_idea(word16 *userkey, word16 *Z);
 static void de_key_idea(IDEAkey Z, IDEAkey DK);
 static void cipher_idea(word16 in[4], word16 out[4], CONST IDEAkey Z);
 
@@ -126,8 +128,8 @@ CONST static uint16 inv(uint16 x)
 
 	if (x <= 1)
 		return x;	/* 0 and 1 are self-inverse */
-	t1 = 0x10001 / x;	/* Since x >= 2, this fits into 16 bits */
-	y = 0x10001 % x;
+	t1 = 0x10001L / x;	/* Since x >= 2, this fits into 16 bits */
+	y = 0x10001L % x;
 	if (y == 1)
 		return low16(1-t1);
 	t0 = 1;
@@ -239,9 +241,11 @@ static void de_key_idea(IDEAkey Z, IDEAk
 /* Note that in and out can be the same buffer */ 
 static void cipher_idea(word16 in[4], word16 out[4], register CONST IDEAkey Z)
 {
-	register uint16 x1, x2, x3, x4, t1, t2;
+	register uint16 x1, x2, x3, x4, s2, s3;
+#ifndef SMALL_CACHE
 	register uint16 t16;
 	register word32 t32;
+#endif
 
 	int r = ROUNDS;
 
@@ -254,18 +258,20 @@ static void cipher_idea(word16 in[4], wo
 		x3 += *Z++;
 		MUL(x4, *Z++);
 
-		t2 = x1^x3;
-		MUL(t2, *Z++);
-		t1 = t2 + (x2^x4);
-		MUL(t1, *Z++);
-		t2 = t1+t2;
-
-		x1 ^= t1;
-		x4 ^= t2; 
-
-		t2 ^= x2;
-		x2 = x3^t1;
-		x3 = t2;
+		s3 = x3;
+		x3 ^= x1;
+		MUL(x3, *Z++);
+		s2 = x2;
+		x2 ^= x4;
+		x2 += x3;
+		MUL(x2, *Z++);
+		x3 += x2;
+
+		x1 ^= x2;
+		x4 ^= x3;
+
+		x2 ^= s3;
+		x3 ^= s2;
 	} while (--r);
 	MUL(x1, *Z++);
 	*out++ = x1;
@@ -423,13 +429,13 @@ static void cfbshift(register byteptr iv
 
 
 /* Key schedules for IDEA encryption and decryption */
-static IDEAkey Z, DK;
+static IDEAkey Z;
 static word16 *iv_idea;		/* pointer to IV for CFB or CBC */
 static boolean cfb_dc_idea; /* TRUE iff CFB decrypting */
 
 
 /* initkey_idea initializes IDEA for ECB mode operations */
-void initkey_idea(byte key[16], boolean decryp)
+static void initkey_idea(byte key[16], boolean decryp)
 {
 	word16 userkey[8];	/* IDEA key is 16 bytes long */
 	int i;
@@ -452,7 +458,7 @@ void initkey_idea(byte key[16], boolean
 /*	Run a 64-bit block thru IDEA in ECB (Electronic Code Book) mode,
 	using the currently selected key schedule.
 */
-void idea_ecb(word16 *inbuf, word16 *outbuf)
+static void idea_ecb(word16 *inbuf, word16 *outbuf)
 {
 	/* Assume each pair of bytes comprising a word is ordered MSB-first. */
 #ifndef HIGHFIRST	/* If this is a least-significant-byte-first CPU */
@@ -550,6 +556,7 @@ static word16 dtbuf_idea[4] = {0}; /* bu
 static word16 randseed_idea[4] = {0}; /* seed for IDEA random # generator */
 static word16 randbuf_idea[4] = {0}; /* buffer for IDEA random # generator */
 static byte randbuf_idea_counter = 0;	/* # of random bytes left in randbuf_idea */
+static IDEAkey randkey_idea;	/* Expanded key for IDEA random # generator */
 
 /*
  *	init_idearand - initialize idearand, IDEA random number generator.
@@ -562,7 +569,8 @@ static byte randbuf_idea_counter = 0;	/*
 void init_idearand(byte key[16], byte seed[8], word32 tstamp)
 {
 	int i;
-	initkey_idea(key, FALSE);	/* initialize IDEA */
+
+	en_key_idea((word16 *)key, randkey_idea);
 
 	for (i=0; i<4; i++)		/* capture timestamp material */
 	{	dtbuf_idea[i] = tstamp;	/* get bottom word */
@@ -570,7 +578,7 @@ void init_idearand(byte key[16], byte se
 		/* tstamp has only 4 bytes-- last 4 bytes will always be 0 */
 	}
 	/* Start with enciphered timestamp: */
-	idea_ecb(dtbuf_idea,dtbuf_idea);
+	cipher_idea(dtbuf_idea, dtbuf_idea, randkey_idea);
 
 	/* initialize seed material */
 	for (i=0; i<8; i++)
@@ -593,12 +601,12 @@ byte idearand(void)
 	{	/* Combine enciphered timestamp with seed material: */
 		for (i=0; i<4; i++)
 			randseed_idea[i] ^= dtbuf_idea[i];
-		idea_ecb(randseed_idea,randbuf_idea); /* fill new block */
+		cipher_idea(randseed_idea,randbuf_idea,randkey_idea); /* fill new block */
 
 		/* Compute new seed vector: */
 		for (i=0; i<4; i++)
 			randseed_idea[i] = randbuf_idea[i] ^ dtbuf_idea[i];
-		idea_ecb(randseed_idea,randseed_idea); /* fill new seed */
+		cipher_idea(randseed_idea,randseed_idea,randkey_idea); /* fill new seed */
 
 		randbuf_idea_counter = 8;	/* reset counter for full buffer */
 	}
@@ -615,7 +623,8 @@ void close_idearand(void)
 		randseed_idea[i] = 0;
 		dtbuf_idea[i] = 0;
 	}
-	close_idea();	/* erase current key schedule tables */
+	for (i = 0; i<KEYLEN; i++)
+		randkey_idea[i] = 0;
 }	/* close_idearand */
 
 /* end of idea.c */