Update head to match stable 1.0

1 files changed, 446 insertions, 0 deletions

diff --git a/mpi/mpicoder.c b/mpi/mpicoder.c
new file mode 100644
index 000000000..f6d266fe7
--- /dev/null
+++ b/mpi/mpicoder.c
@@ -0,0 +1,446 @@
+/* mpicoder.c  -  Coder for the external representation of MPIs
+ * Copyright (C) 1998, 1999 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <assert.h>
+
+#include "mpi.h"
+#include "mpi-internal.h"
+#include "iobuf.h"
+#include "memory.h"
+#include "util.h"
+
+#ifdef M_DEBUG
+  #undef mpi_read
+#endif
+
+#define MAX_EXTERN_MPI_BITS 16384
+
+/****************
+ * write an mpi to out.
+ */
+int
+mpi_write( IOBUF out, MPI a )
+{
+    int rc;
+    unsigned nbits = mpi_get_nbits(a);
+    byte *p, *buf;
+    unsigned n;
+
+    if( nbits > MAX_EXTERN_MPI_BITS )
+	log_bug("mpi_encode: mpi too large (%u bits)\n", nbits);
+
+    iobuf_put(out, (nbits >>8) );
+    iobuf_put(out, (nbits) );
+
+    p = buf = mpi_get_buffer( a, &n, NULL );
+    rc = iobuf_write( out, p, n );
+    m_free(buf);
+    return rc;
+}
+
+
+/****************
+ * Read an external representation of an mpi and return the MPI
+ * The external format is a 16 bit unsigned value stored in network byte order,
+ * giving the number of bits for the following integer. The integer is stored
+ * with MSB first (left padded with zeroes to align on a byte boundary).
+ */
+MPI
+#ifdef M_DEBUG
+mpi_debug_read(IOBUF inp, unsigned *ret_nread, int secure, const char *info)
+#else
+mpi_read(IOBUF inp, unsigned *ret_nread, int secure)
+#endif
+{
+    int c, i, j;
+    unsigned nbits, nbytes, nlimbs, nread=0;
+    mpi_limb_t a;
+    MPI val = MPI_NULL;
+
+    if( (c = iobuf_get(inp)) == -1 )
+	goto leave;
+    nbits = c << 8;
+    if( (c = iobuf_get(inp)) == -1 )
+	goto leave;
+    nbits |= c;
+    if( nbits > MAX_EXTERN_MPI_BITS ) {
+	log_error("mpi too large (%u bits)\n", nbits);
+	goto leave;
+    }
+    nread = 2;
+
+    nbytes = (nbits+7) / 8;
+    nlimbs = (nbytes+BYTES_PER_MPI_LIMB-1) / BYTES_PER_MPI_LIMB;
+  #ifdef M_DEBUG
+    val = secure? mpi_debug_alloc_secure( nlimbs, info )
+		: mpi_debug_alloc( nlimbs, info );
+  #else
+    val = secure? mpi_alloc_secure( nlimbs )
+		: mpi_alloc( nlimbs );
+  #endif
+    i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;
+    i %= BYTES_PER_MPI_LIMB;
+    val->nbits = nbits;
+    j= val->nlimbs = nlimbs;
+    val->sign = 0;
+    for( ; j > 0; j-- ) {
+	a = 0;
+	for(; i < BYTES_PER_MPI_LIMB; i++ ) {
+	    a <<= 8;
+	    a |= iobuf_get(inp) & 0xff; nread++;
+	}
+	i = 0;
+	val->d[j-1] = a;
+    }
+
+  leave:
+    if( nread > *ret_nread )
+	log_bug("mpi crosses packet border");
+    else
+	*ret_nread = nread;
+    return val;
+}
+
+
+MPI
+mpi_read_from_buffer(byte *buffer, unsigned *ret_nread, int secure)
+{
+    int i, j;
+    unsigned nbits, nbytes, nlimbs, nread=0;
+    mpi_limb_t a;
+    MPI val = MPI_NULL;
+
+    if( *ret_nread < 2 )
+	goto leave;
+    nbits = buffer[0] << 8 | buffer[1];
+    if( nbits > MAX_EXTERN_MPI_BITS ) {
+	log_error("mpi too large (%u bits)\n", nbits);
+	goto leave;
+    }
+    buffer += 2;
+    nread = 2;
+
+    nbytes = (nbits+7) / 8;
+    nlimbs = (nbytes+BYTES_PER_MPI_LIMB-1) / BYTES_PER_MPI_LIMB;
+    val = secure? mpi_alloc_secure( nlimbs )
+		: mpi_alloc( nlimbs );
+    i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;
+    i %= BYTES_PER_MPI_LIMB;
+    val->nbits = nbits;
+    j= val->nlimbs = nlimbs;
+    val->sign = 0;
+    for( ; j > 0; j-- ) {
+	a = 0;
+	for(; i < BYTES_PER_MPI_LIMB; i++ ) {
+	    if( ++nread > *ret_nread )
+		log_bug("mpi larger than buffer");
+	    a <<= 8;
+	    a |= *buffer++;
+	}
+	i = 0;
+	val->d[j-1] = a;
+    }
+
+  leave:
+    *ret_nread = nread;
+    return val;
+}
+
+
+/****************
+ * Make an mpi from a character string.
+ */
+int
+mpi_fromstr(MPI val, const char *str)
+{
+    int hexmode=0, sign=0, prepend_zero=0, i, j, c, c1, c2;
+    unsigned nbits, nbytes, nlimbs;
+    mpi_limb_t a;
+
+    if( *str == '-' ) {
+	sign = 1;
+	str++;
+    }
+    if( *str == '0' && str[1] == 'x' )
+	hexmode = 1;
+    else
+	return 1; /* other bases are not yet supported */
+    str += 2;
+
+    nbits = strlen(str)*4;
+    if( nbits % 8 )
+	prepend_zero = 1;
+    nbytes = (nbits+7) / 8;
+    nlimbs = (nbytes+BYTES_PER_MPI_LIMB-1) / BYTES_PER_MPI_LIMB;
+    if( val->alloced < nlimbs )
+	mpi_resize(val, nlimbs );
+    i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB;
+    i %= BYTES_PER_MPI_LIMB;
+    j= val->nlimbs = nlimbs;
+    val->sign = sign;
+    for( ; j > 0; j-- ) {
+	a = 0;
+	for(; i < BYTES_PER_MPI_LIMB; i++ ) {
+	    if( prepend_zero ) {
+		c1 = '0';
+		prepend_zero = 0;
+	    }
+	    else
+		c1 = *str++;
+	    assert(c1);
+	    c2 = *str++;
+	    assert(c2);
+	    if( c1 >= '0' && c1 <= '9' )
+		c = c1 - '0';
+	    else if( c1 >= 'a' && c1 <= 'f' )
+		c = c1 - 'a' + 10;
+	    else if( c1 >= 'A' && c1 <= 'F' )
+		c = c1 - 'A' + 10;
+	    else {
+		mpi_clear(val);
+		return 1;
+	    }
+	    c <<= 4;
+	    if( c2 >= '0' && c2 <= '9' )
+		c |= c2 - '0';
+	    else if( c2 >= 'a' && c2 <= 'f' )
+		c |= c2 - 'a' + 10;
+	    else if( c2 >= 'A' && c2 <= 'F' )
+		c |= c2 - 'A' + 10;
+	    else {
+		mpi_clear(val);
+		return 1;
+	    }
+	    a <<= 8;
+	    a |= c;
+	}
+	i = 0;
+	val->d[j-1] = a;
+    }
+
+    return 0;
+}
+
+
+/****************
+ * print an MPI to the given stream and return the number of characters
+ * printed.
+ */
+int
+mpi_print( FILE *fp, MPI a, int mode )
+{
+    int i, n=0;
+
+    if( a == MPI_NULL )
+	return fprintf(fp, "[MPI_NULL]");
+    if( !mode ) {
+	unsigned n1, n2;
+	n1 = mpi_get_nbits(a);
+	n2 = mpi_get_nbit_info(a);
+	if( n2 && n2 != n1 )
+	    n += fprintf(fp, "[%u bits (%u)]", n1, n2 );
+	else
+	    n += fprintf(fp, "[%u bits]", n1);
+    }
+    else {
+	if( a->sign )
+	    putc('-', fp);
+       #if BYTES_PER_MPI_LIMB == 2
+	  #define X "4"
+       #elif BYTES_PER_MPI_LIMB == 4
+	  #define X "8"
+       #elif BYTES_PER_MPI_LIMB == 8
+	  #define X "16"
+       #else
+	  #error please define the format here
+       #endif
+	for(i=a->nlimbs; i > 0 ; i-- ) {
+	    n += fprintf(fp, i!=a->nlimbs? "%0" X "lX":"%lX", (ulong)a->d[i-1]);
+       #undef X
+	}
+	if( !a->nlimbs )
+	    putc('0', fp );
+    }
+    return n;
+}
+
+
+void
+g10_log_mpidump( const char *text, MPI a )
+{
+    FILE *fp = log_stream();
+
+    g10_log_print_prefix(text);
+    mpi_print(fp, a, 1 );
+    fputc('\n', fp);
+}
+
+/****************
+ * Special function to get the low 8 bytes from an mpi.
+ * This can be used as a keyid; KEYID is an 2 element array.
+ * Return the low 4 bytes.
+ */
+u32
+mpi_get_keyid( MPI a, u32 *keyid )
+{
+#if BYTES_PER_MPI_LIMB == 4
+    if( keyid ) {
+	keyid[0] = a->nlimbs >= 2? a->d[1] : 0;
+	keyid[1] = a->nlimbs >= 1? a->d[0] : 0;
+    }
+    return a->nlimbs >= 1? a->d[0] : 0;
+#elif BYTES_PER_MPI_LIMB == 8
+    if( keyid ) {
+	keyid[0] = a->nlimbs? (u32)(a->d[0] >> 32) : 0;
+	keyid[1] = a->nlimbs? (u32)(a->d[0] & 0xffffffff) : 0;
+    }
+    return a->nlimbs? (u32)(a->d[0] & 0xffffffff) : 0;
+#else
+  #error Make this function work with other LIMB sizes
+#endif
+}
+
+
+/****************
+ * Return an m_alloced buffer with the MPI (msb first).
+ * NBYTES receives the length of this buffer. Caller must free the
+ * return string (This function does return a 0 byte buffer with NBYTES
+ * set to zero if the value of A is zero. If sign is not NULL, it will
+ * be set to the sign of the A.
+ */
+static byte *
+do_get_buffer( MPI a, unsigned *nbytes, int *sign, int force_secure )
+{
+    byte *p, *buffer;
+    mpi_limb_t alimb;
+    int i;
+
+    if( sign )
+	*sign = a->sign;
+    *nbytes = a->nlimbs * BYTES_PER_MPI_LIMB;
+    p = buffer = force_secure || mpi_is_secure(a) ? m_alloc_secure( *nbytes)
+						  : m_alloc( *nbytes );
+
+    for(i=a->nlimbs-1; i >= 0; i-- ) {
+	alimb = a->d[i];
+      #if BYTES_PER_MPI_LIMB == 4
+	*p++ = alimb >> 24;
+	*p++ = alimb >> 16;
+	*p++ = alimb >>  8;
+	*p++ = alimb	  ;
+      #elif BYTES_PER_MPI_LIMB == 8
+	*p++ = alimb >> 56;
+	*p++ = alimb >> 48;
+	*p++ = alimb >> 40;
+	*p++ = alimb >> 32;
+	*p++ = alimb >> 24;
+	*p++ = alimb >> 16;
+	*p++ = alimb >>  8;
+	*p++ = alimb	  ;
+      #else
+	#error please implement for this limb size.
+      #endif
+    }
+
+    /* this is sub-optimal but we need to do the shift oepration because
+     * the caller has to free the returned buffer */
+    for(p=buffer; !*p && *nbytes; p++, --*nbytes )
+	;
+    if( p != buffer )
+	memmove(buffer,p, *nbytes);
+    return buffer;
+}
+
+
+byte *
+mpi_get_buffer( MPI a, unsigned *nbytes, int *sign )
+{
+    return do_get_buffer( a, nbytes, sign, 0 );
+}
+
+byte *
+mpi_get_secure_buffer( MPI a, unsigned *nbytes, int *sign )
+{
+    return do_get_buffer( a, nbytes, sign, 1 );
+}
+
+/****************
+ * Use BUFFER to update MPI.
+ */
+void
+mpi_set_buffer( MPI a, const byte *buffer, unsigned nbytes, int sign )
+{
+    const byte *p;
+    mpi_limb_t alimb;
+    int nlimbs;
+    int i;
+
+    nlimbs = (nbytes + BYTES_PER_MPI_LIMB - 1) / BYTES_PER_MPI_LIMB;
+    RESIZE_IF_NEEDED(a, nlimbs);
+    a->sign = sign;
+
+    for(i=0, p = buffer+nbytes-1; p >= buffer+BYTES_PER_MPI_LIMB; ) {
+      #if BYTES_PER_MPI_LIMB == 4
+	alimb  = *p--	    ;
+	alimb |= *p-- <<  8 ;
+	alimb |= *p-- << 16 ;
+	alimb |= *p-- << 24 ;
+      #elif BYTES_PER_MPI_LIMB == 8
+	alimb  = (mpi_limb_t)*p--	;
+	alimb |= (mpi_limb_t)*p-- <<  8 ;
+	alimb |= (mpi_limb_t)*p-- << 16 ;
+	alimb |= (mpi_limb_t)*p-- << 24 ;
+	alimb |= (mpi_limb_t)*p-- << 32 ;
+	alimb |= (mpi_limb_t)*p-- << 40 ;
+	alimb |= (mpi_limb_t)*p-- << 48 ;
+	alimb |= (mpi_limb_t)*p-- << 56 ;
+      #else
+	#error please implement for this limb size.
+      #endif
+	a->d[i++] = alimb;
+    }
+    if( p >= buffer ) {
+      #if BYTES_PER_MPI_LIMB == 4
+	alimb  = *p--	    ;
+	if( p >= buffer ) alimb |= *p-- <<  8 ;
+	if( p >= buffer ) alimb |= *p-- << 16 ;
+	if( p >= buffer ) alimb |= *p-- << 24 ;
+      #elif BYTES_PER_MPI_LIMB == 8
+	alimb  = (mpi_limb_t)*p-- ;
+	if( p >= buffer ) alimb |= (mpi_limb_t)*p-- <<	8 ;
+	if( p >= buffer ) alimb |= (mpi_limb_t)*p-- << 16 ;
+	if( p >= buffer ) alimb |= (mpi_limb_t)*p-- << 24 ;
+	if( p >= buffer ) alimb |= (mpi_limb_t)*p-- << 32 ;
+	if( p >= buffer ) alimb |= (mpi_limb_t)*p-- << 40 ;
+	if( p >= buffer ) alimb |= (mpi_limb_t)*p-- << 48 ;
+	if( p >= buffer ) alimb |= (mpi_limb_t)*p-- << 56 ;
+      #else
+	#error please implement for this limb size.
+      #endif
+	a->d[i++] = alimb;
+    }
+    a->nlimbs = i;
+    assert( i == nlimbs );
+}
+