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* $Id: x99_mac.c,v 1.6 2002/07/06 06:10:40 fcusack Exp $
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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* Copyright 2001,2002 Google, Inc.
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#include <openssl/des.h>
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static const char rcsid[] = "$Id: x99_mac.c,v 1.6 2002/07/06 06:10:40 fcusack Exp $";
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* The X9.9 MAC is used by tokens in the following manner:
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* 1. Possibly convert the challenge to ASCII (eg "12345" -> 0x3132333435).
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* Note that we do this unconditionally (we don't yet support tokens
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* that can use raw challenge bytes (SafeWord Gold/Platinum)).
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* 2. Use the possibly converted challenge as the plaintext input to
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* the X9.9 MAC algorithm.
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* 3. Convert the 32 bit MAC to ASCII (eg 0x1234567f -> "1234567f").
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* Note that some tokens (SafeWord Gold/Platinum) can display a 64 bit MAC;
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* we don't support those yet.
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* 4. Apply any vendor specific transformations on chars "a" thru "f".
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* 5. Use the result as the response.
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/* Returns 0 on success, non-zero otherwise. response sized as indicated. */
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x99_response(const char *challenge, char response[9],
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uint32_t card_id, des_cblock keyblock)
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const char *conversion;
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if (x99_mac(challenge, output, keyblock) != 0)
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if (card_id & X99_CF_DD) {
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if (card_id & X99_CF_CRYPTOCARD) {
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conversion = x99_cc_dec_conversion;
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/* This should not happen. */
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x99_log(X99_LOG_ERR, "x99_response: bad card mode/vendor");
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conversion = x99_hex_conversion;
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x99_keyblock_to_string(l_response, output, conversion);
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(void) memcpy(response, l_response, 8);
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if (card_id & X99_CF_R7) {
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if (card_id & X99_CF_CRYPTOCARD) {
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(void) memmove(&response[3], &response[4], 5);
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/* This should not happen. */
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x99_log(X99_LOG_ERR, "x99_response: bad card mode/vendor");
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* The ANSI X9.9 MAC algorithm is:
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* 1. Perform a CBC mode DES encryption of the plaintext. The last plaintext
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* block must be zero padded.
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* 2. The MAC is the most significant 32 bits of the last cipherblock.
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* Most tokens support a max of an 8 character challenge, but at least one
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* (CRYPTOCard RB-1) supports performing the full CBC mode encryption
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* of an arbitrary length challenge. So we don't limit ourselves
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* to just an ECB mode encryption.
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* This routine returns the entire 64 bit last cipherblock, at least one sync
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* mode needs this (and ANSI X9.9 states that the MAC can be 48 and 64 bit
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* MACs should be supported). Returns 0 on success, non-zero otherwise.
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x99_mac(const char *input, des_cblock output, des_cblock keyblock)
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des_cblock l_output[MAX_CHALLENGE_LEN / sizeof(des_cblock)];
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int chal_len = strlen(input);
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* Setup and verify the key.
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* This may be a bit expensive to do every time, but it
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* makes more sense for calling functions to deal with
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* the key itself, rather than the schedule. In practice,
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* I don't think this will amount to much, but I haven't
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* actually profiled it.
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if ((rc = des_set_key_checked((const_des_cblock *) keyblock, ks)) != 0) {
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x99_log(X99_LOG_ERR, "x99_mac: DES key %s",
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rc == -1 ? "has incorrect parity" : "is weak");
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(void) memset(ivec, 0, sizeof(ivec));
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des_cbc_encrypt(input, (unsigned char *) l_output, chal_len,
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ks, &ivec, DES_ENCRYPT);
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(void) memcpy(output, l_output[(chal_len - 1) / 8], 8);
added
removed
src/modules/rlm_x99_token/x99_mac.c
