[secnet] / util.c

/*
 * util.c
 * - output and logging support
 * - program lifetime support
 * - IP address and subnet munging routines
 * - MPI convenience functions
 */
/*
 *  This file is
 *    Copyright (C) 1995--2001 Stephen Early <steve@greenend.org.uk>
 *
 *  It is part of secnet, which is
 *    Copyright (C) 1995--2001 Stephen Early <steve@greenend.org.uk>
 *    Copyright (C) 1998 Ross Anderson, Eli Biham, Lars Knudsen
 *  
 *  This program 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, or (at your option)
 *  any later version.
 *  
 *  This program 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 "secnet.h"
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <limits.h>
#include <assert.h>
#include <sys/wait.h>
#include "util.h"
#include "unaligned.h"

#define MIN_BUFFER_SIZE 64
#define DEFAULT_BUFFER_SIZE 4096
#define MAX_BUFFER_SIZE 131072

static const char *hexdigits="0123456789abcdef";

uint32_t current_phase=0;

struct phase_hook {
    hook_fn *fn;
    void *state;
    struct phase_hook *next;
};

static struct phase_hook *hooks[NR_PHASES]={NULL,};

char *safe_strdup(const char *s, const char *message)
{
    char *d;
    d=strdup(s);
    if (!d) {
	fatal_perror(message);
    }
    return d;
}

void *safe_malloc(size_t size, const char *message)
{
    void *r;
    r=malloc(size);
    if (!r) {
	fatal_perror(message);
    }
    return r;
}
void *safe_malloc_ary(size_t size, size_t count, const char *message) {
    if (count >= INT_MAX/size) {
	fatal("array allocation overflow: %s", message);
    }
    return safe_malloc(size*count, message);
}

/* Convert a buffer into its MP_INT representation */
void read_mpbin(MP_INT *a, uint8_t *bin, int binsize)
{
    char *buff;
    int i;

    buff=safe_malloc(binsize*2 + 1,"read_mpbin");

    for (i=0; i<binsize; i++) {
	buff[i*2]=hexdigits[(bin[i] & 0xf0) >> 4];
	buff[i*2+1]=hexdigits[(bin[i] & 0xf)];
    }
    buff[binsize*2]=0;

    mpz_set_str(a, buff, 16);
    free(buff);
}

/* Convert a MP_INT into a hex string */
char *write_mpstring(MP_INT *a)
{
    char *buff;

    buff=safe_malloc(mpz_sizeinbase(a,16)+2,"write_mpstring");
    mpz_get_str(buff, 16, a);
    return buff;
}

static uint8_t hexval(uint8_t c)
{
    switch (c) {
    case '0': return 0;
    case '1': return 1;
    case '2': return 2;
    case '3': return 3;
    case '4': return 4;
    case '5': return 5;
    case '6': return 6;
    case '7': return 7;
    case '8': return 8;
    case '9': return 9;
    case 'a': return 10;
    case 'A': return 10;
    case 'b': return 11;
    case 'B': return 11;
    case 'c': return 12;
    case 'C': return 12;
    case 'd': return 13;
    case 'D': return 13;
    case 'e': return 14;
    case 'E': return 14;
    case 'f': return 15;
    case 'F': return 15;
    }
    return -1;
}

/* Convert a MP_INT into a buffer; return length; truncate if necessary */
int32_t write_mpbin(MP_INT *a, uint8_t *buffer, int32_t buflen)
{
    char *hb;
    int i,j,l;
    
    if (buflen==0) return 0;
    hb=write_mpstring(a);
    
    l=strlen(hb);
    i=0; j=0;
    if (l&1) {
	/* The number starts with a half-byte */
	buffer[i++]=hexval(hb[j++]);
    }
    for (; hb[j] && i<buflen; i++) {
	buffer[i]=(hexval(hb[j])<<4)|hexval(hb[j+1]);
	j+=2;
    }
    free(hb);
    return i;
}

static const char *phases[NR_PHASES]={
    "PHASE_INIT",
    "PHASE_GETOPTS",
    "PHASE_READCONFIG",
    "PHASE_SETUP",
    "PHASE_DAEMONIZE",
    "PHASE_GETRESOURCES",
    "PHASE_DROPPRIV",
    "PHASE_RUN",
    "PHASE_SHUTDOWN"
};

void enter_phase(uint32_t new_phase)
{
    struct phase_hook *i;

    if (hooks[new_phase])
	Message(M_DEBUG_PHASE,"Running hooks for %s...\n", phases[new_phase]);
    current_phase=new_phase;

    for (i=hooks[new_phase]; i; i=i->next)
	i->fn(i->state, new_phase);
    Message(M_DEBUG_PHASE,"Now in %s\n",phases[new_phase]);
}

bool_t add_hook(uint32_t phase, hook_fn *fn, void *state)
{
    struct phase_hook *h;

    h=safe_malloc(sizeof(*h),"add_hook");
    h->fn=fn;
    h->state=state;
    h->next=hooks[phase];
    hooks[phase]=h;
    return True;
}

bool_t remove_hook(uint32_t phase, hook_fn *fn, void *state)
{
    fatal("remove_hook: not implemented");

    return False;
}

void vslilog(struct log_if *lf, int priority, const char *message, va_list ap)
{
    lf->vlog(lf->st,priority,message,ap);
}

void slilog(struct log_if *lf, int priority, const char *message, ...)
{
    va_list ap;
    
    va_start(ap,message);
    vslilog(lf,priority,message,ap);
    va_end(ap);
}

struct buffer {
    closure_t cl;
    struct buffer_if ops;
};

void buffer_assert_free(struct buffer_if *buffer, cstring_t file,
			int line)
{
    if (!buffer->free) {
	fprintf(stderr,"secnet: BUF_ASSERT_FREE, %s line %d, owned by %s",
		file,line,buffer->owner);
	assert(!"buffer_assert_free failure");
    }
}

void buffer_assert_used(struct buffer_if *buffer, cstring_t file,
			int line)
{
    if (buffer->free) {
	fprintf(stderr,"secnet: BUF_ASSERT_USED, %s line %d, last owned by %s",
		file,line,buffer->owner);
	assert(!"buffer_assert_used failure");
    }
}

void buffer_init(struct buffer_if *buffer, int32_t max_start_pad)
{
    buffer->start=buffer->base+max_start_pad;
    buffer->size=0;
}

void *buf_append(struct buffer_if *buf, int32_t amount) {
    void *p;
    assert(buf->size <= buf->len - amount);
    p=buf->start + buf->size;
    buf->size+=amount;
    return p;
}

void *buf_prepend(struct buffer_if *buf, int32_t amount) {
    assert(amount <= buf->start - buf->base);
    buf->size+=amount;
    return buf->start-=amount;
}

void *buf_unappend(struct buffer_if *buf, int32_t amount) {
    if (buf->size < amount) return 0;
    return buf->start+(buf->size-=amount);
}

void *buf_unprepend(struct buffer_if *buf, int32_t amount) {
    void *p;
    if (buf->size < amount) return 0;
    p=buf->start;
    buf->start+=amount;
    buf->size-=amount;
    return p;
}

/* Append a two-byte length and the string to the buffer. Length is in
   network byte order. */
void buf_append_string(struct buffer_if *buf, cstring_t s)
{
    size_t len;

    len=strlen(s);
    /* fixme: if string is longer than 65535, result is a corrupted packet */
    buf_append_uint16(buf,len);
    memcpy(buf_append(buf,len),s,len);
}

void buffer_new(struct buffer_if *buf, int32_t len)
{
    buf->free=True;
    buf->owner=NULL;
    buf->flags=0;
    buf->loc.file=NULL;
    buf->loc.line=0;
    buf->size=0;
    buf->len=len;
    buf->start=NULL;
    buf->base=safe_malloc(len,"buffer_new");
}

void buffer_readonly_view(struct buffer_if *buf, const void *data, int32_t len)
{
    buf->free=False;
    buf->owner="READONLY";
    buf->flags=0;
    buf->loc.file=NULL;
    buf->loc.line=0;
    buf->size=buf->len=len;
    buf->base=buf->start=(uint8_t*)data;
}

void buffer_readonly_clone(struct buffer_if *out, const struct buffer_if *in)
{
    buffer_readonly_view(out,in->start,in->size);
}

void buffer_copy(struct buffer_if *dst, const struct buffer_if *src)
{
    if (dst->len < src->len) {
	dst->base=realloc(dst->base,src->len);
	if (!dst->base) fatal_perror("buffer_copy");
	dst->len = src->len;
    }
    dst->start = dst->base + (src->start - src->base);
    dst->size = src->size;
    memcpy(dst->start, src->start, dst->size);
}

static list_t *buffer_apply(closure_t *self, struct cloc loc, dict_t *context,
			    list_t *args)
{
    struct buffer *st;
    item_t *item;
    dict_t *dict;
    bool_t lockdown=False;
    uint32_t len=DEFAULT_BUFFER_SIZE;
    
    st=safe_malloc(sizeof(*st),"buffer_apply");
    st->cl.description="buffer";
    st->cl.type=CL_BUFFER;
    st->cl.apply=NULL;
    st->cl.interface=&st->ops;

    /* First argument, if present, is buffer length */
    item=list_elem(args,0);
    if (item) {
	if (item->type!=t_number) {
	    cfgfatal(st->ops.loc,"buffer","first parameter must be a "
		     "number (buffer size)\n");
	}
	len=item->data.number;
	if (len<MIN_BUFFER_SIZE) {
	    cfgfatal(st->ops.loc,"buffer","ludicrously small buffer size\n");
	}
	if (len>MAX_BUFFER_SIZE) {
	    cfgfatal(st->ops.loc,"buffer","ludicrously large buffer size\n");
	}
    }
    /* Second argument, if present, is a dictionary */
    item=list_elem(args,1);
    if (item) {
	if (item->type!=t_dict) {
	    cfgfatal(st->ops.loc,"buffer","second parameter must be a "
		     "dictionary\n");
	}
	dict=item->data.dict;
	lockdown=dict_read_bool(dict,"lockdown",False,"buffer",st->ops.loc,
				False);
    }

    buffer_new(&st->ops,len);
    if (lockdown) {
	/* XXX mlock the buffer if possible */
    }
    
    return new_closure(&st->cl);
}

int consttime_memeq(const void *s1in, const void *s2in, size_t n)
{
    const uint8_t *s1=s1in, *s2=s2in;
    register volatile uint8_t accumulator=0;

    while (n-- > 0) {
	accumulator |= (*s1++ ^ *s2++);
    }
    accumulator |= accumulator >> 4; /* constant-time             */
    accumulator |= accumulator >> 2; /*  boolean canonicalisation */
    accumulator |= accumulator >> 1;
    accumulator &= 1;
    accumulator ^= 1;
    return accumulator;
}

void util_module(dict_t *dict)
{
    add_closure(dict,"sysbuffer",buffer_apply);
}
Commit	Line	Data
b2a56f7c SE	1	/*
	2	* util.c
	3	* - output and logging support
	4	* - program lifetime support
	5	* - IP address and subnet munging routines
	6	* - MPI convenience functions
	7	*/
	8	/*
	9	* This file is
	10	* Copyright (C) 1995--2001 Stephen Early <steve@greenend.org.uk>
2fe58dfd	11	*
b2a56f7c SE	12	* It is part of secnet, which is
	13	* Copyright (C) 1995--2001 Stephen Early <steve@greenend.org.uk>
	14	* Copyright (C) 1998 Ross Anderson, Eli Biham, Lars Knudsen
	15	*
	16	* This program is free software; you can redistribute it and/or modify
	17	* it under the terms of the GNU General Public License as published by
	18	* the Free Software Foundation; either version 2, or (at your option)
	19	* any later version.
	20	*
	21	* This program is distributed in the hope that it will be useful,
	22	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	23	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	24	* GNU General Public License for more details.
	25	*
	26	* You should have received a copy of the GNU General Public License
	27	* along with this program; if not, write to the Free Software Foundation,
	28	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
2fe58dfd SE	29	*/
2fe58dfd SE	30
8689b3a9	31	#include "secnet.h"
2fe58dfd	32	#include <stdio.h>
2fe58dfd SE	33	#include <string.h>
2fe58dfd SE	34	#include <errno.h>
2fe58dfd	35	#include <unistd.h>
59635212	36	#include <limits.h>
2fe58dfd	37	#include <assert.h>
4efd681a	38	#include <sys/wait.h>
2fe58dfd	39	#include "util.h"
59635212	40	#include "unaligned.h"
2fe58dfd SE	41
	42	#define MIN_BUFFER_SIZE 64
	43	#define DEFAULT_BUFFER_SIZE 4096
	44	#define MAX_BUFFER_SIZE 131072
	45
fe5e9cc4	46	static const char *hexdigits="0123456789abcdef";
2fe58dfd	47
7138d0c5	48	uint32_t current_phase=0;
2fe58dfd SE	49
	50	struct phase_hook {
	51	hook_fn *fn;
	52	void *state;
	53	struct phase_hook *next;
	54	};
	55
	56	static struct phase_hook *hooks[NR_PHASES]={NULL,};
	57
fe5e9cc4	58	char safe_strdup(const char s, const char *message)
2fe58dfd SE	59	{
	60	char *d;
	61	d=strdup(s);
	62	if (!d) {
	63	fatal_perror(message);
	64	}
	65	return d;
	66	}
	67
fe5e9cc4	68	void safe_malloc(size_t size, const char message)
2fe58dfd SE	69	{
	70	void *r;
	71	r=malloc(size);
	72	if (!r) {
	73	fatal_perror(message);
	74	}
	75	return r;
	76	}
bb9d0561 IJ	77	void safe_malloc_ary(size_t size, size_t count, const char message) {
	78	if (count >= INT_MAX/size) {
	79	fatal("array allocation overflow: %s", message);
	80	}
	81	return safe_malloc(size*count, message);
	82	}
2fe58dfd SE	83
	84	/* Convert a buffer into its MP_INT representation */
	85	void read_mpbin(MP_INT a, uint8_t bin, int binsize)
	86	{
	87	char *buff;
	88	int i;
	89
	90	buff=safe_malloc(binsize*2 + 1,"read_mpbin");
	91
	92	for (i=0; i<binsize; i++) {
	93	buff[i*2]=hexdigits[(bin[i] & 0xf0) >> 4];
	94	buff[i*2+1]=hexdigits[(bin[i] & 0xf)];
	95	}
	96	buff[binsize*2]=0;
	97
	98	mpz_set_str(a, buff, 16);
	99	free(buff);
	100	}
	101
	102	/* Convert a MP_INT into a hex string */
	103	char write_mpstring(MP_INT a)
	104	{
	105	char *buff;
	106
	107	buff=safe_malloc(mpz_sizeinbase(a,16)+2,"write_mpstring");
	108	mpz_get_str(buff, 16, a);
	109	return buff;
	110	}
	111
	112	static uint8_t hexval(uint8_t c)
	113	{
	114	switch (c) {
	115	case '0': return 0;
	116	case '1': return 1;
	117	case '2': return 2;
	118	case '3': return 3;
	119	case '4': return 4;
	120	case '5': return 5;
	121	case '6': return 6;
	122	case '7': return 7;
	123	case '8': return 8;
	124	case '9': return 9;
	125	case 'a': return 10;
	126	case 'A': return 10;
	127	case 'b': return 11;
	128	case 'B': return 11;
	129	case 'c': return 12;
	130	case 'C': return 12;
	131	case 'd': return 13;
	132	case 'D': return 13;
	133	case 'e': return 14;
	134	case 'E': return 14;
	135	case 'f': return 15;
	136	case 'F': return 15;
	137	}
	138	return -1;
	139	}
	140
	141	/* Convert a MP_INT into a buffer; return length; truncate if necessary */
1caa23ff	142	int32_t write_mpbin(MP_INT a, uint8_t buffer, int32_t buflen)
2fe58dfd SE	143	{
	144	char *hb;
	145	int i,j,l;
	146
	147	if (buflen==0) return 0;
	148	hb=write_mpstring(a);
	149
	150	l=strlen(hb);
	151	i=0; j=0;
	152	if (l&1) {
	153	/* The number starts with a half-byte */
	154	buffer[i++]=hexval(hb[j++]);
	155	}
	156	for (; hb[j] && i<buflen; i++) {
	157	buffer[i]=(hexval(hb[j])<<4)\|hexval(hb[j+1]);
	158	j+=2;
	159	}
	160	free(hb);
	161	return i;
	162	}
	163
fe5e9cc4	164	static const char *phases[NR_PHASES]={
2fe58dfd SE	165	"PHASE_INIT",
	166	"PHASE_GETOPTS",
	167	"PHASE_READCONFIG",
	168	"PHASE_SETUP",
7b1a9fb7	169	"PHASE_DAEMONIZE",
baa06aeb	170	"PHASE_GETRESOURCES",
2fe58dfd SE	171	"PHASE_DROPPRIV",
	172	"PHASE_RUN",
	173	"PHASE_SHUTDOWN"
	174	};
	175
	176	void enter_phase(uint32_t new_phase)
	177	{
	178	struct phase_hook *i;
	179
baa06aeb SE	180	if (hooks[new_phase])
baa06aeb SE	181	Message(M_DEBUG_PHASE,"Running hooks for %s...\n", phases[new_phase]);
2fe58dfd SE	182	current_phase=new_phase;
	183
	184	for (i=hooks[new_phase]; i; i=i->next)
	185	i->fn(i->state, new_phase);
baa06aeb	186	Message(M_DEBUG_PHASE,"Now in %s\n",phases[new_phase]);
2fe58dfd SE	187	}
	188
	189	bool_t add_hook(uint32_t phase, hook_fn fn, void state)
	190	{
	191	struct phase_hook *h;
	192
	193	h=safe_malloc(sizeof(*h),"add_hook");
	194	h->fn=fn;
	195	h->state=state;
	196	h->next=hooks[phase];
	197	hooks[phase]=h;
	198	return True;
	199	}
	200
	201	bool_t remove_hook(uint32_t phase, hook_fn fn, void state)
	202	{
4f5e39ec	203	fatal("remove_hook: not implemented");
2fe58dfd SE	204
	205	return False;
	206	}
	207
59938e0e IJ	208	void vslilog(struct log_if lf, int priority, const char message, va_list ap)
	209	{
	210	lf->vlog(lf->st,priority,message,ap);
	211	}
	212
040ee979	213	void slilog(struct log_if lf, int priority, const char message, ...)
2fe58dfd SE	214	{
	215	va_list ap;
	216
	217	va_start(ap,message);
59938e0e	218	vslilog(lf,priority,message,ap);
2fe58dfd SE	219	va_end(ap);
	220	}
	221
	222	struct buffer {
	223	closure_t cl;
	224	struct buffer_if ops;
	225	};
	226
fe5e9cc4	227	void buffer_assert_free(struct buffer_if *buffer, cstring_t file,
1caa23ff	228	int line)
2fe58dfd SE	229	{
2fe58dfd SE	230	if (!buffer->free) {
28db900b IJ	231	fprintf(stderr,"secnet: BUF_ASSERT_FREE, %s line %d, owned by %s",
	232	file,line,buffer->owner);
	233	assert(!"buffer_assert_free failure");
2fe58dfd SE	234	}
	235	}
	236
fe5e9cc4	237	void buffer_assert_used(struct buffer_if *buffer, cstring_t file,
1caa23ff	238	int line)
2fe58dfd SE	239	{
2fe58dfd SE	240	if (buffer->free) {
28db900b IJ	241	fprintf(stderr,"secnet: BUF_ASSERT_USED, %s line %d, last owned by %s",
	242	file,line,buffer->owner);
	243	assert(!"buffer_assert_used failure");
2fe58dfd SE	244	}
	245	}
	246
1caa23ff	247	void buffer_init(struct buffer_if *buffer, int32_t max_start_pad)
2fe58dfd SE	248	{
	249	buffer->start=buffer->base+max_start_pad;
	250	buffer->size=0;
	251	}
	252
1caa23ff	253	void buf_append(struct buffer_if buf, int32_t amount) {
2fe58dfd	254	void *p;
59230b9b	255	assert(buf->size <= buf->len - amount);
2fe58dfd SE	256	p=buf->start + buf->size;
	257	buf->size+=amount;
	258	return p;
	259	}
	260
1caa23ff	261	void buf_prepend(struct buffer_if buf, int32_t amount) {
59230b9b	262	assert(amount <= buf->start - buf->base);
2fe58dfd SE	263	buf->size+=amount;
	264	return buf->start-=amount;
	265	}
	266
1caa23ff	267	void buf_unappend(struct buffer_if buf, int32_t amount) {
2fe58dfd SE	268	if (buf->size < amount) return 0;
	269	return buf->start+(buf->size-=amount);
	270	}
	271
1caa23ff	272	void buf_unprepend(struct buffer_if buf, int32_t amount) {
2fe58dfd	273	void *p;
20138876	274	if (buf->size < amount) return 0;
2fe58dfd SE	275	p=buf->start;
	276	buf->start+=amount;
	277	buf->size-=amount;
	278	return p;
	279	}
	280
	281	/* Append a two-byte length and the string to the buffer. Length is in
	282	network byte order. */
fe5e9cc4	283	void buf_append_string(struct buffer_if *buf, cstring_t s)
2fe58dfd	284	{
1caa23ff	285	size_t len;
2fe58dfd SE	286
2fe58dfd SE	287	len=strlen(s);
59230b9b	288	/* fixme: if string is longer than 65535, result is a corrupted packet */
59635212	289	buf_append_uint16(buf,len);
2fe58dfd SE	290	memcpy(buf_append(buf,len),s,len);
	291	}
	292
1caa23ff	293	void buffer_new(struct buffer_if *buf, int32_t len)
2fe58dfd SE	294	{
	295	buf->free=True;
	296	buf->owner=NULL;
	297	buf->flags=0;
	298	buf->loc.file=NULL;
	299	buf->loc.line=0;
	300	buf->size=0;
	301	buf->len=len;
	302	buf->start=NULL;
	303	buf->base=safe_malloc(len,"buffer_new");
	304	}
	305
28db900b IJ	306	void buffer_readonly_view(struct buffer_if buf, const void data, int32_t len)
	307	{
	308	buf->free=False;
	309	buf->owner="READONLY";
	310	buf->flags=0;
	311	buf->loc.file=NULL;
	312	buf->loc.line=0;
	313	buf->size=buf->len=len;
	314	buf->base=buf->start=(uint8_t*)data;
	315	}
	316
	317	void buffer_readonly_clone(struct buffer_if out, const struct buffer_if in)
	318	{
	319	buffer_readonly_view(out,in->start,in->size);
	320	}
	321
05f39b4d IJ	322	void buffer_copy(struct buffer_if dst, const struct buffer_if src)
	323	{
	324	if (dst->len < src->len) {
	325	dst->base=realloc(dst->base,src->len);
	326	if (!dst->base) fatal_perror("buffer_copy");
	327	dst->len = src->len;
	328	}
	329	dst->start = dst->base + (src->start - src->base);
	330	dst->size = src->size;
	331	memcpy(dst->start, src->start, dst->size);
	332	}
	333
2fe58dfd SE	334	static list_t buffer_apply(closure_t self, struct cloc loc, dict_t *context,
	335	list_t *args)
	336	{
	337	struct buffer *st;
	338	item_t *item;
	339	dict_t *dict;
	340	bool_t lockdown=False;
4efd681a	341	uint32_t len=DEFAULT_BUFFER_SIZE;
2fe58dfd SE	342
	343	st=safe_malloc(sizeof(*st),"buffer_apply");
	344	st->cl.description="buffer";
	345	st->cl.type=CL_BUFFER;
	346	st->cl.apply=NULL;
	347	st->cl.interface=&st->ops;
2fe58dfd SE	348
	349	/* First argument, if present, is buffer length */
	350	item=list_elem(args,0);
	351	if (item) {
	352	if (item->type!=t_number) {
	353	cfgfatal(st->ops.loc,"buffer","first parameter must be a "
	354	"number (buffer size)\n");
	355	}
4efd681a SE	356	len=item->data.number;
4efd681a SE	357	if (len<MIN_BUFFER_SIZE) {
2fe58dfd SE	358	cfgfatal(st->ops.loc,"buffer","ludicrously small buffer size\n");
2fe58dfd SE	359	}
4efd681a	360	if (len>MAX_BUFFER_SIZE) {
2fe58dfd SE	361	cfgfatal(st->ops.loc,"buffer","ludicrously large buffer size\n");
	362	}
	363	}
	364	/* Second argument, if present, is a dictionary */
	365	item=list_elem(args,1);
	366	if (item) {
	367	if (item->type!=t_dict) {
	368	cfgfatal(st->ops.loc,"buffer","second parameter must be a "
	369	"dictionary\n");
	370	}
	371	dict=item->data.dict;
	372	lockdown=dict_read_bool(dict,"lockdown",False,"buffer",st->ops.loc,
	373	False);
	374	}
	375
4efd681a	376	buffer_new(&st->ops,len);
2fe58dfd	377	if (lockdown) {
70dc107b	378	/* XXX mlock the buffer if possible */
2fe58dfd SE	379	}
	380
	381	return new_closure(&st->cl);
	382	}
	383
5ad34db2 IJ	384	int consttime_memeq(const void s1in, const void s2in, size_t n)
	385	{
	386	const uint8_t s1=s1in, s2=s2in;
	387	register volatile uint8_t accumulator=0;
	388
	389	while (n-- > 0) {
	390	accumulator \|= (s1++ ^ s2++);
	391	}
	392	accumulator \|= accumulator >> 4; /* constant-time */
	393	accumulator \|= accumulator >> 2; /* boolean canonicalisation */
	394	accumulator \|= accumulator >> 1;
	395	accumulator &= 1;
	396	accumulator ^= 1;
	397	return accumulator;
	398	}
	399
2fe58dfd SE	400	void util_module(dict_t *dict)
2fe58dfd SE	401	{
2fe58dfd SE	402	add_closure(dict,"sysbuffer",buffer_apply);
2fe58dfd SE	403	}