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-rw-r--r--source4/libcli/auth/schannel.c309
-rw-r--r--source4/libcli/auth/schannel.h35
2 files changed, 344 insertions, 0 deletions
diff --git a/source4/libcli/auth/schannel.c b/source4/libcli/auth/schannel.c
new file mode 100644
index 0000000000..e5a786ff24
--- /dev/null
+++ b/source4/libcli/auth/schannel.c
@@ -0,0 +1,309 @@
+/*
+ Unix SMB/CIFS implementation.
+
+ schannel library code
+
+ Copyright (C) Andrew Tridgell 2004
+
+ 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
+ (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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+
+/*******************************************************************
+ Encode or Decode the sequence number (which is symmetric)
+ ********************************************************************/
+static void netsec_deal_with_seq_num(struct schannel_state *state,
+ const uchar packet_digest[8],
+ uchar seq_num[8])
+{
+ static const uchar zeros[4];
+ uchar sequence_key[16];
+ uchar digest1[16];
+
+ hmac_md5(state->session_key, zeros, sizeof(zeros), digest1);
+ hmac_md5(digest1, packet_digest, 8, sequence_key);
+ SamOEMhash(seq_num, sequence_key, 8);
+
+ state->seq_num++;
+}
+
+
+/*******************************************************************
+ Calculate the key with which to encode the data payload
+ ********************************************************************/
+static void netsec_get_sealing_key(const uchar session_key[16],
+ const uchar seq_num[8],
+ uchar sealing_key[16])
+{
+ static const uchar zeros[4];
+ uchar digest2[16];
+ uchar sess_kf0[16];
+ int i;
+
+ for (i = 0; i < 16; i++) {
+ sess_kf0[i] = session_key[i] ^ 0xf0;
+ }
+
+ hmac_md5(sess_kf0, zeros, 4, digest2);
+ hmac_md5(digest2, seq_num, 8, sealing_key);
+}
+
+
+/*******************************************************************
+ Create a digest over the entire packet (including the data), and
+ MD5 it with the session key.
+ ********************************************************************/
+static void schannel_digest(const uchar sess_key[16],
+ const uchar netsec_sig[8],
+ const uchar *confounder,
+ const uchar *data, size_t data_len,
+ uchar digest_final[16])
+{
+ uchar packet_digest[16];
+ static const uchar zeros[4];
+ struct MD5Context ctx;
+
+ MD5Init(&ctx);
+ MD5Update(&ctx, zeros, 4);
+ MD5Update(&ctx, netsec_sig, 8);
+ if (confounder) {
+ MD5Update(&ctx, confounder, 8);
+ }
+ MD5Update(&ctx, data, data_len);
+ MD5Final(packet_digest, &ctx);
+
+ hmac_md5(sess_key, packet_digest, sizeof(packet_digest), digest_final);
+}
+
+
+/*
+ unseal a packet
+*/
+NTSTATUS schannel_unseal_packet(struct schannel_state *state,
+ uchar *data, size_t length,
+ DATA_BLOB *sig)
+{
+ uchar digest_final[16];
+ uchar confounder[8];
+ uchar seq_num[8];
+ uchar sealing_key[16];
+ static const uchar netsec_sig[8] = NETSEC_SEAL_SIGNATURE;
+
+ if (sig->length != 32) {
+ return NT_STATUS_ACCESS_DENIED;
+ }
+
+ memcpy(confounder, sig->data+24, 8);
+
+ RSIVAL(seq_num, 0, state->seq_num);
+ SIVAL(seq_num, 4, state->initiator?0:0x80);
+
+ netsec_get_sealing_key(state->session_key, seq_num, sealing_key);
+ SamOEMhash(confounder, sealing_key, 8);
+ SamOEMhash(data, sealing_key, length);
+
+ schannel_digest(state->session_key,
+ netsec_sig, confounder,
+ data, length, digest_final);
+
+ if (memcmp(digest_final, sig->data+16, 8) != 0) {
+ dump_data_pw("calc digest:", digest_final, 8);
+ dump_data_pw("wire digest:", sig->data+16, 8);
+ return NT_STATUS_ACCESS_DENIED;
+ }
+
+ netsec_deal_with_seq_num(state, digest_final, seq_num);
+
+ if (memcmp(seq_num, sig->data+8, 8) != 0) {
+ dump_data_pw("calc seq num:", seq_num, 8);
+ dump_data_pw("wire seq num:", sig->data+8, 8);
+ return NT_STATUS_ACCESS_DENIED;
+ }
+
+ return NT_STATUS_OK;
+}
+
+/*
+ check the signature on a packet
+*/
+NTSTATUS schannel_check_packet(struct schannel_state *state,
+ const uchar *data, size_t length,
+ const DATA_BLOB *sig)
+{
+ uchar digest_final[16];
+ uchar seq_num[8];
+ static const uchar netsec_sig[8] = NETSEC_SIGN_SIGNATURE;
+
+ if (sig->length != 32) {
+ return NT_STATUS_ACCESS_DENIED;
+ }
+
+ RSIVAL(seq_num, 0, state->seq_num);
+ SIVAL(seq_num, 4, state->initiator?0:0x80);
+
+ dump_data_pw("seq_num:\n", seq_num, 8);
+ dump_data_pw("sess_key:\n", state->session_key, 16);
+
+ schannel_digest(state->session_key,
+ netsec_sig, NULL,
+ data, length, digest_final);
+
+ netsec_deal_with_seq_num(state, digest_final, seq_num);
+
+ if (memcmp(seq_num, sig->data+8, 8) != 0) {
+ dump_data_pw("calc seq num:", seq_num, 8);
+ dump_data_pw("wire seq num:", sig->data+8, 8);
+ return NT_STATUS_ACCESS_DENIED;
+ }
+
+ if (memcmp(digest_final, sig->data+16, 8) != 0) {
+ dump_data_pw("calc digest:", digest_final, 8);
+ dump_data_pw("wire digest:", sig->data+16, 8);
+ return NT_STATUS_ACCESS_DENIED;
+ }
+
+ return NT_STATUS_OK;
+}
+
+
+/*
+ seal a packet
+*/
+NTSTATUS schannel_seal_packet(struct schannel_state *state,
+ uchar *data, size_t length,
+ DATA_BLOB *sig)
+{
+ uchar digest_final[16];
+ uchar confounder[8];
+ uchar seq_num[8];
+ uchar sealing_key[16];
+ static const uchar netsec_sig[8] = NETSEC_SEAL_SIGNATURE;
+
+ generate_random_buffer(confounder, 8, False);
+
+ RSIVAL(seq_num, 0, state->seq_num);
+ SIVAL(seq_num, 4, state->initiator?0x80:0);
+
+ schannel_digest(state->session_key,
+ netsec_sig, confounder,
+ data, length, digest_final);
+
+ netsec_get_sealing_key(state->session_key, seq_num, sealing_key);
+ SamOEMhash(confounder, sealing_key, 8);
+ SamOEMhash(data, sealing_key, length);
+
+ netsec_deal_with_seq_num(state, digest_final, seq_num);
+
+ if (!state->signature.data) {
+ state->signature = data_blob_talloc(state->mem_ctx, NULL, 32);
+ if (!state->signature.data) {
+ return NT_STATUS_NO_MEMORY;
+ }
+ }
+ (*sig) = state->signature;
+
+ memcpy(sig->data, netsec_sig, 8);
+ memcpy(sig->data+8, seq_num, 8);
+ memcpy(sig->data+16, digest_final, 8);
+ memcpy(sig->data+24, confounder, 8);
+
+ dump_data_pw("signature:", sig->data+ 0, 8);
+ dump_data_pw("seq_num :", sig->data+ 8, 8);
+ dump_data_pw("digest :", sig->data+16, 8);
+ dump_data_pw("confound :", sig->data+24, 8);
+
+ return NT_STATUS_OK;
+}
+
+
+/*
+ sign a packet
+*/
+NTSTATUS schannel_sign_packet(struct schannel_state *state,
+ const uchar *data, size_t length,
+ DATA_BLOB *sig)
+{
+ uchar digest_final[16];
+ uchar seq_num[8];
+ static const uchar netsec_sig[8] = NETSEC_SIGN_SIGNATURE;
+
+ RSIVAL(seq_num, 0, state->seq_num);
+ SIVAL(seq_num, 4, state->initiator?0x80:0);
+
+ schannel_digest(state->session_key,
+ netsec_sig, NULL,
+ data, length, digest_final);
+
+ netsec_deal_with_seq_num(state, digest_final, seq_num);
+
+ if (!state->signature.data) {
+ state->signature = data_blob_talloc(state->mem_ctx, NULL, 32);
+ if (!state->signature.data) {
+ return NT_STATUS_NO_MEMORY;
+ }
+ }
+ (*sig) = state->signature;
+
+ memcpy(sig->data, netsec_sig, 8);
+ memcpy(sig->data+8, seq_num, 8);
+ memcpy(sig->data+16, digest_final, 8);
+ memset(sig->data+24, 0, 8);
+
+ dump_data_pw("signature:", sig->data+ 0, 8);
+ dump_data_pw("seq_num :", sig->data+ 8, 8);
+ dump_data_pw("digest :", sig->data+16, 8);
+ dump_data_pw("confound :", sig->data+24, 8);
+
+ return NT_STATUS_OK;
+}
+
+/*
+ destroy an schannel context
+ */
+void schannel_end(struct schannel_state **state)
+{
+ talloc_destroy((*state)->mem_ctx);
+ (*state) = NULL;
+}
+
+/*
+ create an schannel context state
+*/
+NTSTATUS schannel_start(struct schannel_state **state,
+ uint8 session_key[16],
+ BOOL initiator)
+{
+ TALLOC_CTX *mem_ctx;
+
+ mem_ctx = talloc_init("schannel_state");
+ if (!mem_ctx) {
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ (*state) = talloc_p(mem_ctx, struct schannel_state);
+ if (!(*state)) {
+ talloc_destroy(mem_ctx);
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ (*state)->mem_ctx = mem_ctx;
+ memcpy((*state)->session_key, session_key, 16);
+ (*state)->initiator = initiator;
+ (*state)->signature = data_blob(NULL, 0);
+ (*state)->seq_num = 0;
+
+ return NT_STATUS_OK;
+}
diff --git a/source4/libcli/auth/schannel.h b/source4/libcli/auth/schannel.h
new file mode 100644
index 0000000000..7b710d7cb9
--- /dev/null
+++ b/source4/libcli/auth/schannel.h
@@ -0,0 +1,35 @@
+/*
+ Unix SMB/CIFS implementation.
+
+ schannel library code
+
+ Copyright (C) Andrew Tridgell 2004
+
+ 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
+ (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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+
+struct schannel_state {
+ TALLOC_CTX *mem_ctx;
+ uint8 session_key[16];
+ uint32 seq_num;
+ BOOL initiator;
+ DATA_BLOB signature;
+};
+
+#define NETSEC_SIGN_SIGNATURE { 0x77, 0x00, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00 }
+#define NETSEC_SEAL_SIGNATURE { 0x77, 0x00, 0x7a, 0x00, 0xff, 0xff, 0x00, 0x00 }
+
generated by cgit (git 2.34.1) at 2024-12-16 12:53:27 +0000