OpenPKG Specs: gcrypt/idea.c@4a34d7a82eab (annotated)

gcrypt/idea.c@4a34d7a82eab (annotated)

gcrypt/idea.c

Tue, 29 Mar 2011 20:04:34 +0200

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 29 Mar 2011 20:04:34 +0200
changeset 334: 4a34d7a82eab
permissions: -rw-r--r--

Rework package yet again, correcting and introducing new buildconf logic:
Conditionally disable bootstrap stage comparison correctly, correct
english grammar, better find system as(1) and ld(1), indotruce detailed
optimization option messages, more completely guess cpu types, allow
profiled bootstrapping without a preinstalled GCC because many other
compilers have long since implemented 64-bit arithmetic, instruct make
to build sequentially (not in sparallel) when building a profiled
bootstrap as GCC online documents recommend, and generally improve
comment blocks.

The single most important correction in this changeset relates to the
GCC changed optimization policy since at least GCC 4.5, in which -march
is always passed and not always correctly guessed. In the case of this
package, allowing GCC to guess the architecture leads to wild build
errors at various subcomponents (zlib, libgcc, libiberty...) and
bootstrap stages. It seems quite platform specific, and the safest
approach to correcting this seems to be explicitly always specifying the
-march argument when bootstrapping GCC. Because the best choice 'native'
is not available when bootstrapping using a foreign (non GCC) compiler,
a guess is made according to rpmmacros l_platform in that case.

It is questionable as to whether these recent optimization changes
on the part of GCC or this package are compatible with each other,
or if either are complete or correct at all. At least applying these
corrections allows this package to build again in most cases test.

 #include <config.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h> /* for memcmp() */
 #include <assert.h>
 #include "types.h"  /* for byte and u32 typedefs */
 #include "g10lib.h"
 #include "cipher.h"
 /* configuration stuff */
 #ifdef __alpha__
   #define SIZEOF_UNSIGNED_LONG 8
 #else
   #define SIZEOF_UNSIGNED_LONG 4
 #endif
 #if defined(__mc68000__) || defined (__sparc__) || defined (__PPC__) \
     || (defined(__mips__) && (defined(MIPSEB) || defined (__MIPSEB__)) ) \
     || defined(__powerpc__) \
     || defined(__hpux__) /* should be replaced by the Macro for the PA */
   #define BIG_ENDIAN_HOST 1
 #else
   #define LITTLE_ENDIAN_HOST 1
 #endif
 #ifndef DIM
   #define DIM(v) (sizeof(v)/sizeof((v)[0]))
   #define DIMof(type,member)   DIM(((type *)0)->member)
 #endif
 /* imports */
 void g10_log_fatal( const char *fmt, ... );
 /* local stuff */
 #define FNCCAST_SETKEY(f)  ((int(*)(void*, byte*, unsigned))(f))
 #define FNCCAST_CRYPT(f)   ((void(*)(void*, byte*, byte*))(f))
 #define IDEA_KEYSIZE 16
 #define IDEA_BLOCKSIZE 8
 #define IDEA_ROUNDS 8
 #define IDEA_KEYLEN (6*IDEA_ROUNDS+4)
 typedef struct {
     u16 ek[IDEA_KEYLEN];
     u16 dk[IDEA_KEYLEN];
     int have_dk;
 } IDEA_context;
 static u16
 mul_inv( u16 x )
 {
     u16 t0, t1;
     u16 q, y;
     if( x < 2 )
 	return x;
     t1 = 0x10001L / x;
     y =  0x10001L % x;
     if( y == 1 )
 	return (1-t1) & 0xffff;
     t0 = 1;
     do {
 	q = x / y;
 	x = x % y;
 	t0 += q * t1;
 	if( x == 1 )
 	    return t0;
 	q = y / x;
 	y = y % x;
 	t1 += q * t0;
     } while( y != 1 );
     return (1-t1) & 0xffff;
 }
 static void
 cipher( byte *outbuf, const byte *inbuf, u16 *key )
 {
     u16 x1, x2, x3,x4, s2, s3;
     u16 *in, *out;
     int r = IDEA_ROUNDS;
   #define MUL(x,y) \
 	do {u16 _t16; u32 _t32; 		    \
 	    if( (_t16 = (y)) ) {		    \
 		if( (x = (x)&0xffff) ) {	    \
 		    _t32 = (u32)x * _t16;	    \
 		    x = _t32 & 0xffff;		    \
 		    _t16 = _t32 >> 16;		    \
 		    x = ((x)-_t16) + (x<_t16?1:0);  \
 		}				    \
 		else {				    \
 		    x = 1 - _t16;		    \
 		}				    \
 	    }					    \
 	    else {				    \
 		x = 1 - x;			    \
 	    }					    \
 	} while(0)
     in = (u16*)inbuf;
     x1 = *in++;
     x2 = *in++;
     x3 = *in++;
     x4 = *in;
   #ifdef LITTLE_ENDIAN_HOST
     x1 = (x1>>8) | (x1<<8);
     x2 = (x2>>8) | (x2<<8);
     x3 = (x3>>8) | (x3<<8);
     x4 = (x4>>8) | (x4<<8);
   #endif
     do {
 	MUL(x1, *key++);
 	x2 += *key++;
 	x3 += *key++;
 	MUL(x4, *key++ );
 	s3 = x3;
 	x3 ^= x1;
 	MUL(x3, *key++);
 	s2 = x2;
 	x2 ^=x4;
 	x2 += x3;
 	MUL(x2, *key++);
 	x3 += x2;
 	x1 ^= x2;
 	x4 ^= x3;
 	x2 ^= s3;
 	x3 ^= s2;
     } while( --r );
     MUL(x1, *key++);
     x3 += *key++;
     x2 += *key++;
     MUL(x4, *key);
     out = (u16*)outbuf;
   #ifdef LITTLE_ENDIAN_HOST
     *out++ = (x1>>8) | (x1<<8);
     *out++ = (x3>>8) | (x3<<8);
     *out++ = (x2>>8) | (x2<<8);
     *out   = (x4>>8) | (x4<<8);
   #else
     *out++ = x1;
     *out++ = x3;
     *out++ = x2;
     *out   = x4;
   #endif
   #undef MUL
 }
 static void
 expand_key( const byte *userkey, u16 *ek )
 {
     int i,j;
     for(j=0; j < 8; j++ ) {
 	ek[j] = (*userkey << 8) + userkey[1];
 	userkey += 2;
     }
     for(i=0; j < IDEA_KEYLEN; j++ ) {
 	i++;
 	ek[i+7] = ek[i&7] << 9 | ek[(i+1)&7] >> 7;
 	ek += i & 8;
 	i &= 7;
     }
 }
 static void
 invert_key( u16 *ek, u16 dk[IDEA_KEYLEN] )
 {
     int i;
     u16 t1, t2, t3;
     u16 temp[IDEA_KEYLEN];
     u16 *p = temp + IDEA_KEYLEN;
     t1 = mul_inv( *ek++ );
     t2 = -*ek++;
     t3 = -*ek++;
     *--p = mul_inv( *ek++ );
     *--p = t3;
     *--p = t2;
     *--p = t1;
     for(i=0; i < IDEA_ROUNDS-1; i++ ) {
 	t1 = *ek++;
 	*--p = *ek++;
 	*--p = t1;
 	t1 = mul_inv( *ek++ );
 	t2 = -*ek++;
 	t3 = -*ek++;
 	*--p = mul_inv( *ek++ );
 	*--p = t2;
 	*--p = t3;
 	*--p = t1;
     }
     t1 = *ek++;
     *--p = *ek++;
     *--p = t1;
     t1 = mul_inv( *ek++ );
     t2 = -*ek++;
     t3 = -*ek++;
     *--p = mul_inv( *ek++ );
     *--p = t3;
     *--p = t2;
     *--p = t1;
     memcpy(dk, temp, sizeof(temp) );
     memset(temp, 0, sizeof(temp) );  /* burn temp */
 }
 static int
 do_idea_setkey( IDEA_context *c, const byte *key, unsigned int keylen )
 {
     assert(keylen == 16);
     c->have_dk = 0;
     expand_key( key, c->ek );
     invert_key( c->ek, c->dk );
     return 0;
 }
 static gcry_err_code_t
 idea_setkey (void *context, const byte *key, unsigned int keylen)
 {
   IDEA_context *ctx = context;
   int rc = do_idea_setkey (ctx, key, keylen);
   _gcry_burn_stack (23+6*sizeof(void*));
   return rc;
 }
 static void
 do_idea_encrypt( IDEA_context *c, byte *outbuf, const byte *inbuf )
 {
     cipher( outbuf, inbuf, c->ek );
 }
 static void
 idea_encrypt (void *context, byte *out, const byte *in)
 {
   IDEA_context *ctx = context;
   do_idea_encrypt (ctx, out, in);
   _gcry_burn_stack (24+3*sizeof (void*));
 }
 static void
 do_idea_decrypt( IDEA_context *c, byte *outbuf, const byte *inbuf )
 {
     if( !c->have_dk ) {
        c->have_dk = 1;
        invert_key( c->ek, c->dk );
     }
     cipher( outbuf, inbuf, c->dk );
 }
 static void
 idea_decrypt (void *context, byte *out, const byte *in)
 {
   IDEA_context *ctx = context;
   do_idea_decrypt (ctx, out, in);
   _gcry_burn_stack (24+3*sizeof (void*));
 }
 gcry_cipher_spec_t _gcry_cipher_spec_idea =
 {
     "IDEA", NULL, NULL, IDEA_BLOCKSIZE, 128, sizeof (IDEA_context),
     idea_setkey, idea_encrypt, idea_decrypt,
 };

OpenPKG Specs / annotate

gcrypt/idea.c@4a34d7a82eab (annotated)

gcrypt/idea.c