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gnupg/common/userids.c
2009-12-08 16:30:33 +00:00

323 lines
10 KiB
C

/* userids.c - Utility functions for user ids.
* Copyright (C) 2001, 2003, 2004, 2006,
* 2009 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 3 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, see <http://www.gnu.org/licenses/>.
*/
/* This file implements a few utility functions useful when working
with canonical encrypted S-expresions (i.e. not the S-exprssion
objects from libgcrypt). */
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "util.h"
#include "userids.h"
/* Parse the user-id NAME and build a search description for it.
* Returns 0 on succdess or an error code. DESC may be NULL to merely
* check the validity of a user-id.
*
* Some used rules:
* - If the username starts with 8,9,16 or 17 hex-digits (the first one
* must be in the range 0..9), this is considered a keyid; depending
* on the length a short or complete one.
* - If the username starts with 32,33,40 or 41 hex-digits (the first one
* must be in the range 0..9), this is considered a fingerprint.
* - If the username starts with a left angle, we assume it is a complete
* email address and look only at this part.
* - If the username starts with a colon we assume it is a unified
* key specfification.
* - If the username starts with a '.', we assume it is the ending
* part of an email address
* - If the username starts with an '@', we assume it is a part of an
* email address
* - If the userid start with an '=' an exact compare is done.
* - If the userid starts with a '*' a case insensitive substring search is
* done (This is the default).
* - If the userid starts with a '+' we will compare individual words
* and a match requires that all the words are in the userid.
* Words are delimited by white space or "()<>[]{}.@-+_,;/&!"
* (note that you can't search for these characters). Compare
* is not case sensitive.
* - If the userid starts with a '&' a 40 hex digits keygrip is expected.
*/
gpg_error_t
classify_user_id (const char *name, KEYDB_SEARCH_DESC *desc)
{
const char *s;
int hexprefix = 0;
int hexlength;
int mode = 0;
KEYDB_SEARCH_DESC dummy_desc;
if (!desc)
desc = &dummy_desc;
/* Clear the structure so that the mode field is set to zero unless
we set it to the correct value right at the end of this
function. */
memset (desc, 0, sizeof *desc);
/* Skip leading spaces. */
for(s = name; *s && spacep (s); s++ )
;
switch (*s)
{
case 0: /* Empty string is an error. */
return gpg_error (GPG_ERR_INV_USER_ID);
case '.': /* An email address, compare from end. Note that this
has not yet been implemented in the search code. */
mode = KEYDB_SEARCH_MODE_MAILEND;
s++;
desc->u.name = s;
break;
case '<': /* An email address. */
mode = KEYDB_SEARCH_MODE_MAIL;
s++;
desc->u.name = s;
break;
case '@': /* Part of an email address. */
mode = KEYDB_SEARCH_MODE_MAILSUB;
s++;
desc->u.name = s;
break;
case '=': /* Exact compare. */
mode = KEYDB_SEARCH_MODE_EXACT;
s++;
desc->u.name = s;
break;
case '*': /* Case insensitive substring search. */
mode = KEYDB_SEARCH_MODE_SUBSTR;
s++;
desc->u.name = s;
break;
case '+': /* Compare individual words. Note that this has not
yet been implemented in the search code. */
mode = KEYDB_SEARCH_MODE_WORDS;
s++;
desc->u.name = s;
break;
case '/': /* Subject's DN. */
s++;
if (!*s || spacep (s)) /* No DN or prefixed with a space. */
return gpg_error (GPG_ERR_INV_USER_ID);
desc->u.name = s;
mode = KEYDB_SEARCH_MODE_SUBJECT;
break;
case '#': /* S/N with optional issuer id or just issuer id. */
{
const char *si;
s++;
if ( *s == '/')
{ /* "#/" indicates an issuer's DN. */
s++;
if (!*s || spacep (s)) /* No DN or prefixed with a space. */
return gpg_error (GPG_ERR_INV_USER_ID);
desc->u.name = s;
mode = KEYDB_SEARCH_MODE_ISSUER;
}
else
{ /* Serialnumber + optional issuer ID. */
for (si=s; *si && *si != '/'; si++)
{
/* Check for an invalid digit in the serial number. */
if (!strchr("01234567890abcdefABCDEF", *si))
return gpg_error (GPG_ERR_INV_USER_ID);
}
desc->sn = (const unsigned char*)s;
desc->snlen = -1;
if (!*si)
mode = KEYDB_SEARCH_MODE_SN;
else
{
s = si+1;
if (!*s || spacep (s)) /* No DN or prefixed with a space. */
return gpg_error (GPG_ERR_INV_USER_ID);
desc->u.name = s;
mode = KEYDB_SEARCH_MODE_ISSUER_SN;
}
}
}
break;
case ':': /* Unified fingerprint. */
{
const char *se, *si;
int i;
se = strchr (++s,':');
if (!se)
return gpg_error (GPG_ERR_INV_USER_ID);
for (i=0,si=s; si < se; si++, i++ )
{
if (!strchr("01234567890abcdefABCDEF", *si))
return gpg_error (GPG_ERR_INV_USER_ID); /* Invalid digit. */
}
if (i != 32 && i != 40)
return gpg_error (GPG_ERR_INV_USER_ID); /* Invalid length of fpr. */
for (i=0,si=s; si < se; i++, si +=2)
desc->u.fpr[i] = hextobyte(si);
for (; i < 20; i++)
desc->u.fpr[i]= 0;
s = se + 1;
mode = KEYDB_SEARCH_MODE_FPR;
}
break;
case '&': /* Keygrip*/
{
if (hex2bin (s+1, desc->u.grip, 20) < 0)
return gpg_error (GPG_ERR_INV_USER_ID); /* Invalid. */
mode = KEYDB_SEARCH_MODE_KEYGRIP;
}
break;
default:
if (s[0] == '0' && s[1] == 'x')
{
hexprefix = 1;
s += 2;
}
hexlength = strspn(s, "0123456789abcdefABCDEF");
if (hexlength >= 8 && s[hexlength] =='!')
{
desc->exact = 1;
hexlength++; /* Just for the following check. */
}
/* Check if a hexadecimal number is terminated by EOS or blank. */
if (hexlength && s[hexlength] && !spacep (s+hexlength))
{
if (hexprefix) /* A "0x" prefix without a correct
termination is an error. */
return gpg_error (GPG_ERR_INV_USER_ID);
/* The first characters looked like a hex number, but the
entire string is not. */
hexlength = 0;
}
if (desc->exact)
hexlength--; /* Remove the bang. */
if (hexlength == 8
|| (!hexprefix && hexlength == 9 && *s == '0'))
{
/* Short keyid. */
if (hexlength == 9)
s++;
desc->u.kid[1] = strtoul( s, NULL, 16 );
mode = KEYDB_SEARCH_MODE_SHORT_KID;
}
else if (hexlength == 16
|| (!hexprefix && hexlength == 17 && *s == '0'))
{
/* Long keyid. */
char buf[9];
if (hexlength == 17)
s++;
mem2str (buf, s, 9);
desc->u.kid[0] = strtoul (buf, NULL, 16);
desc->u.kid[1] = strtoul (s+8, NULL, 16);
mode = KEYDB_SEARCH_MODE_LONG_KID;
}
else if (hexlength == 32
|| (!hexprefix && hexlength == 33 && *s == '0'))
{
/* MD5 fingerprint. */
int i;
if (hexlength == 33)
s++;
memset (desc->u.fpr+16, 0, 4);
for (i=0; i < 16; i++, s+=2)
{
int c = hextobyte(s);
if (c == -1)
return gpg_error (GPG_ERR_INV_USER_ID);
desc->u.fpr[i] = c;
}
mode = KEYDB_SEARCH_MODE_FPR16;
}
else if (hexlength == 40
|| (!hexprefix && hexlength == 41 && *s == '0'))
{
/* SHA1/RMD160 fingerprint. */
int i;
if (hexlength == 41)
s++;
for (i=0; i < 20; i++, s+=2)
{
int c = hextobyte(s);
if (c == -1)
return gpg_error (GPG_ERR_INV_USER_ID);
desc->u.fpr[i] = c;
}
mode = KEYDB_SEARCH_MODE_FPR20;
}
else if (!hexprefix)
{
/* The fingerprint in an X.509 listing is often delimited by
colons, so we try to single this case out. */
mode = 0;
hexlength = strspn (s, ":0123456789abcdefABCDEF");
if (hexlength == 59 && (!s[hexlength] || spacep (s+hexlength)))
{
int i;
for (i=0; i < 20; i++, s += 3)
{
int c = hextobyte(s);
if (c == -1 || (i < 19 && s[2] != ':'))
break;
desc->u.fpr[i] = c;
}
if (i == 20)
mode = KEYDB_SEARCH_MODE_FPR20;
}
if (!mode) /* Default to substring search. */
{
desc->exact = 0;
desc->u.name = s;
mode = KEYDB_SEARCH_MODE_SUBSTR;
}
}
else
{
/* Hex number with a prefix but with a wrong length. */
return gpg_error (GPG_ERR_INV_USER_ID);
}
}
desc->mode = mode;
return 0;
}