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-rw-r--r--src/crypto/ntlm.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/src/crypto/ntlm.c b/src/crypto/ntlm.c
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+++ b/src/crypto/ntlm.c
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+/*
+ * Copyright (C) 2017 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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 of the
+ * License, or 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * NT LAN Manager (NTLM) authentication
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+#include <byteswap.h>
+#include <ipxe/md4.h>
+#include <ipxe/md5.h>
+#include <ipxe/hmac.h>
+#include <ipxe/ntlm.h>
+
+/** Negotiate message
+ *
+ * This message content is fixed since there is no need to specify the
+ * calling workstation name or domain name, and the set of flags is
+ * mandated by the MS-NLMP specification.
+ */
+const struct ntlm_negotiate ntlm_negotiate = {
+ .header = {
+ .magic = NTLM_MAGIC,
+ .type = cpu_to_le32 ( NTLM_NEGOTIATE ),
+ },
+ .flags = cpu_to_le32 ( NTLM_NEGOTIATE_EXTENDED_SESSIONSECURITY |
+ NTLM_NEGOTIATE_ALWAYS_SIGN |
+ NTLM_NEGOTIATE_NTLM |
+ NTLM_REQUEST_TARGET |
+ NTLM_NEGOTIATE_UNICODE ),
+};
+
+/**
+ * Parse NTLM Challenge
+ *
+ * @v challenge Challenge message
+ * @v len Length of Challenge message
+ * @v info Challenge information to fill in
+ * @ret rc Return status code
+ */
+int ntlm_challenge ( struct ntlm_challenge *challenge, size_t len,
+ struct ntlm_challenge_info *info ) {
+ size_t offset;
+
+ DBGC ( challenge, "NTLM challenge message:\n" );
+ DBGC_HDA ( challenge, 0, challenge, len );
+
+ /* Sanity checks */
+ if ( len < sizeof ( *challenge ) ) {
+ DBGC ( challenge, "NTLM underlength challenge (%zd bytes)\n",
+ len );
+ return -EINVAL;
+ }
+
+ /* Extract nonce */
+ info->nonce = &challenge->nonce;
+ DBGC ( challenge, "NTLM challenge nonce:\n" );
+ DBGC_HDA ( challenge, 0, info->nonce, sizeof ( *info->nonce ) );
+
+ /* Extract target information */
+ info->len = le16_to_cpu ( challenge->info.len );
+ offset = le32_to_cpu ( challenge->info.offset );
+ if ( ( offset > len ) ||
+ ( info->len > ( len - offset ) ) ) {
+ DBGC ( challenge, "NTLM target information outside "
+ "challenge\n" );
+ DBGC_HDA ( challenge, 0, challenge, len );
+ return -EINVAL;
+ }
+ info->target = ( ( ( void * ) challenge ) + offset );
+ DBGC ( challenge, "NTLM challenge target information:\n" );
+ DBGC_HDA ( challenge, 0, info->target, info->len );
+
+ return 0;
+}
+
+/**
+ * Calculate NTLM verification key
+ *
+ * @v domain Domain name (or NULL)
+ * @v username User name (or NULL)
+ * @v password Password (or NULL)
+ * @v key Key to fill in
+ *
+ * This is the NTOWFv2() function as defined in MS-NLMP.
+ */
+void ntlm_key ( const char *domain, const char *username,
+ const char *password, struct ntlm_key *key ) {
+ struct digest_algorithm *md4 = &md4_algorithm;
+ struct digest_algorithm *md5 = &md5_algorithm;
+ union {
+ uint8_t md4[MD4_CTX_SIZE];
+ uint8_t md5[MD5_CTX_SIZE];
+ } ctx;
+ uint8_t digest[MD4_DIGEST_SIZE];
+ size_t digest_len;
+ uint8_t c;
+ uint16_t wc;
+
+ /* Use empty usernames/passwords if not specified */
+ if ( ! domain )
+ domain = "";
+ if ( ! username )
+ username = "";
+ if ( ! password )
+ password = "";
+
+ /* Construct MD4 digest of (Unicode) password */
+ digest_init ( md4, ctx.md4 );
+ while ( ( c = *(password++) ) ) {
+ wc = cpu_to_le16 ( c );
+ digest_update ( md4, ctx.md4, &wc, sizeof ( wc ) );
+ }
+ digest_final ( md4, ctx.md4, digest );
+
+ /* Construct HMAC-MD5 of (Unicode) upper-case username */
+ digest_len = sizeof ( digest );
+ hmac_init ( md5, ctx.md5, digest, &digest_len );
+ while ( ( c = *(username++) ) ) {
+ wc = cpu_to_le16 ( toupper ( c ) );
+ hmac_update ( md5, ctx.md5, &wc, sizeof ( wc ) );
+ }
+ while ( ( c = *(domain++) ) ) {
+ wc = cpu_to_le16 ( c );
+ hmac_update ( md5, ctx.md5, &wc, sizeof ( wc ) );
+ }
+ hmac_final ( md5, ctx.md5, digest, &digest_len, key->raw );
+ DBGC ( key, "NTLM key:\n" );
+ DBGC_HDA ( key, 0, key, sizeof ( *key ) );
+}
+
+/**
+ * Construct NTLM responses
+ *
+ * @v info Challenge information
+ * @v key Verification key
+ * @v nonce Nonce, or NULL to use a random nonce
+ * @v lm LAN Manager response to fill in
+ * @v nt NT response to fill in
+ */
+void ntlm_response ( struct ntlm_challenge_info *info, struct ntlm_key *key,
+ struct ntlm_nonce *nonce, struct ntlm_lm_response *lm,
+ struct ntlm_nt_response *nt ) {
+ struct digest_algorithm *md5 = &md5_algorithm;
+ struct ntlm_nonce tmp_nonce;
+ uint8_t ctx[MD5_CTX_SIZE];
+ size_t key_len = sizeof ( *key );
+ unsigned int i;
+
+ /* Generate random nonce, if needed */
+ if ( ! nonce ) {
+ for ( i = 0 ; i < sizeof ( tmp_nonce ) ; i++ )
+ tmp_nonce.raw[i] = random();
+ nonce = &tmp_nonce;
+ }
+
+ /* Construct LAN Manager response */
+ memcpy ( &lm->nonce, nonce, sizeof ( lm->nonce ) );
+ hmac_init ( md5, ctx, key->raw, &key_len );
+ hmac_update ( md5, ctx, info->nonce, sizeof ( *info->nonce ) );
+ hmac_update ( md5, ctx, &lm->nonce, sizeof ( lm->nonce ) );
+ hmac_final ( md5, ctx, key->raw, &key_len, lm->digest );
+ DBGC ( key, "NTLM LAN Manager response:\n" );
+ DBGC_HDA ( key, 0, lm, sizeof ( *lm ) );
+
+ /* Construct NT response */
+ memset ( nt, 0, sizeof ( *nt ) );
+ nt->version = NTLM_VERSION_NTLMV2;
+ nt->high = NTLM_VERSION_NTLMV2;
+ memcpy ( &nt->nonce, nonce, sizeof ( nt->nonce ) );
+ hmac_init ( md5, ctx, key->raw, &key_len );
+ hmac_update ( md5, ctx, info->nonce, sizeof ( *info->nonce ) );
+ hmac_update ( md5, ctx, &nt->version,
+ ( sizeof ( *nt ) -
+ offsetof ( typeof ( *nt ), version ) ) );
+ hmac_update ( md5, ctx, info->target, info->len );
+ hmac_update ( md5, ctx, &nt->zero, sizeof ( nt->zero ) );
+ hmac_final ( md5, ctx, key->raw, &key_len, nt->digest );
+ DBGC ( key, "NTLM NT response prefix:\n" );
+ DBGC_HDA ( key, 0, nt, sizeof ( *nt ) );
+}
+
+/**
+ * Append data to NTLM message
+ *
+ * @v header Message header, or NULL to only calculate next payload
+ * @v data Data descriptor
+ * @v payload Data payload
+ * @v len Length of data
+ * @ret payload Next data payload
+ */
+static void * ntlm_append ( struct ntlm_header *header, struct ntlm_data *data,
+ void *payload, size_t len ) {
+
+ /* Populate data descriptor */
+ if ( header ) {
+ data->offset = cpu_to_le32 ( payload - ( ( void * ) header ) );
+ data->len = data->max_len = cpu_to_le16 ( len );
+ }
+
+ return ( payload + len );
+}
+
+/**
+ * Append Unicode string data to NTLM message
+ *
+ * @v header Message header, or NULL to only calculate next payload
+ * @v data Data descriptor
+ * @v payload Data payload
+ * @v string String to append, or NULL
+ * @ret payload Next data payload
+ */
+static void * ntlm_append_string ( struct ntlm_header *header,
+ struct ntlm_data *data, void *payload,
+ const char *string ) {
+ uint16_t *tmp = payload;
+ uint8_t c;
+
+ /* Convert string to Unicode */
+ for ( tmp = payload ; ( string && ( c = *(string++) ) ) ; tmp++ ) {
+ if ( header )
+ *tmp = cpu_to_le16 ( c );
+ }
+
+ /* Append string data */
+ return ntlm_append ( header, data, payload,
+ ( ( ( void * ) tmp ) - payload ) );
+}
+
+/**
+ * Construct NTLM Authenticate message
+ *
+ * @v info Challenge information
+ * @v domain Domain name, or NULL
+ * @v username User name, or NULL
+ * @v workstation Workstation name, or NULL
+ * @v lm LAN Manager response
+ * @v nt NT response
+ * @v auth Message to fill in, or NULL to only calculate length
+ * @ret len Length of message
+ */
+size_t ntlm_authenticate ( struct ntlm_challenge_info *info, const char *domain,
+ const char *username, const char *workstation,
+ struct ntlm_lm_response *lm,
+ struct ntlm_nt_response *nt,
+ struct ntlm_authenticate *auth ) {
+ void *tmp;
+ size_t nt_len;
+ size_t len;
+
+ /* Construct response header */
+ if ( auth ) {
+ memset ( auth, 0, sizeof ( *auth ) );
+ memcpy ( auth->header.magic, ntlm_negotiate.header.magic,
+ sizeof ( auth->header.magic ) );
+ auth->header.type = cpu_to_le32 ( NTLM_AUTHENTICATE );
+ auth->flags = ntlm_negotiate.flags;
+ }
+ tmp = ( ( ( void * ) auth ) + sizeof ( *auth ) );
+
+ /* Construct LAN Manager response */
+ if ( auth )
+ memcpy ( tmp, lm, sizeof ( *lm ) );
+ tmp = ntlm_append ( &auth->header, &auth->lm, tmp, sizeof ( *lm ) );
+
+ /* Construct NT response */
+ nt_len = ( sizeof ( *nt ) + info->len + sizeof ( nt->zero ) );
+ if ( auth ) {
+ memcpy ( tmp, nt, sizeof ( *nt ) );
+ memcpy ( ( tmp + sizeof ( *nt ) ), info->target, info->len );
+ memset ( ( tmp + sizeof ( *nt ) + info->len ), 0,
+ sizeof ( nt->zero ) );
+ }
+ tmp = ntlm_append ( &auth->header, &auth->nt, tmp, nt_len );
+
+ /* Populate domain, user, and workstation names */
+ tmp = ntlm_append_string ( &auth->header, &auth->domain, tmp, domain );
+ tmp = ntlm_append_string ( &auth->header, &auth->user, tmp, username );
+ tmp = ntlm_append_string ( &auth->header, &auth->workstation, tmp,
+ workstation );
+
+ /* Calculate length */
+ len = ( tmp - ( ( void * ) auth ) );
+ if ( auth ) {
+ DBGC ( auth, "NTLM authenticate message:\n" );
+ DBGC_HDA ( auth, 0, auth, len );
+ }
+
+ return len;
+}
+
+/**
+ * Calculate NTLM Authenticate message length
+ *
+ * @v info Challenge information
+ * @v domain Domain name, or NULL
+ * @v username User name, or NULL
+ * @v workstation Workstation name, or NULL
+ * @ret len Length of Authenticate message
+ */
+size_t ntlm_authenticate_len ( struct ntlm_challenge_info *info,
+ const char *domain, const char *username,
+ const char *workstation ) {
+
+ return ntlm_authenticate ( info, domain, username, workstation,
+ NULL, NULL, NULL );
+}