diff options
Diffstat (limited to 'source4/auth/ntlmssp/ntlmssp_sign.c')
| -rw-r--r-- | source4/auth/ntlmssp/ntlmssp_sign.c | 548 |
1 files changed, 548 insertions, 0 deletions
diff --git a/source4/auth/ntlmssp/ntlmssp_sign.c b/source4/auth/ntlmssp/ntlmssp_sign.c new file mode 100644 index 0000000000..063b16f539 --- /dev/null +++ b/source4/auth/ntlmssp/ntlmssp_sign.c @@ -0,0 +1,548 @@ +/* + * Unix SMB/CIFS implementation. + * Version 3.0 + * NTLMSSP Signing routines + * Copyright (C) Luke Kenneth Casson Leighton 1996-2001 + * Copyright (C) Andrew Bartlett <abartlet@samba.org> 2003-2005 + * + * 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 3 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, see <http://www.gnu.org/licenses/>. + */ + +#include "includes.h" +#include "auth/auth.h" +#include "auth/ntlmssp/ntlmssp.h" +#include "auth/ntlmssp/msrpc_parse.h" +#include "lib/crypto/crypto.h" +#include "auth/credentials/credentials.h" +#include "auth/gensec/gensec.h" +#include "param/param.h" + +#define CLI_SIGN "session key to client-to-server signing key magic constant" +#define CLI_SEAL "session key to client-to-server sealing key magic constant" +#define SRV_SIGN "session key to server-to-client signing key magic constant" +#define SRV_SEAL "session key to server-to-client sealing key magic constant" + +/** + * Some notes on the NTLM2 code: + * + * NTLM2 is a AEAD system. This means that the data encrypted is not + * all the data that is signed. In DCE-RPC case, the headers of the + * DCE-RPC packets are also signed. This prevents some of the + * fun-and-games one might have by changing them. + * + */ + +static void calc_ntlmv2_key(TALLOC_CTX *mem_ctx, + DATA_BLOB *subkey, + DATA_BLOB session_key, + const char *constant) +{ + struct MD5Context ctx3; + *subkey = data_blob_talloc(mem_ctx, NULL, 16); + MD5Init(&ctx3); + MD5Update(&ctx3, session_key.data, session_key.length); + MD5Update(&ctx3, (const uint8_t *)constant, strlen(constant)+1); + MD5Final(subkey->data, &ctx3); +} + +enum ntlmssp_direction { + NTLMSSP_SEND, + NTLMSSP_RECEIVE +}; + +static NTSTATUS ntlmssp_make_packet_signature(struct gensec_ntlmssp_state *gensec_ntlmssp_state, + TALLOC_CTX *sig_mem_ctx, + const uint8_t *data, size_t length, + const uint8_t *whole_pdu, size_t pdu_length, + enum ntlmssp_direction direction, + DATA_BLOB *sig, bool encrypt_sig) +{ + if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) { + + HMACMD5Context ctx; + uint8_t digest[16]; + uint8_t seq_num[4]; + + *sig = data_blob_talloc(sig_mem_ctx, NULL, NTLMSSP_SIG_SIZE); + if (!sig->data) { + return NT_STATUS_NO_MEMORY; + } + + switch (direction) { + case NTLMSSP_SEND: + SIVAL(seq_num, 0, gensec_ntlmssp_state->crypt.ntlm2.send_seq_num); + gensec_ntlmssp_state->crypt.ntlm2.send_seq_num++; + hmac_md5_init_limK_to_64(gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.data, + gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.length, &ctx); + break; + case NTLMSSP_RECEIVE: + SIVAL(seq_num, 0, gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num); + gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num++; + hmac_md5_init_limK_to_64(gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data, + gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.length, &ctx); + break; + } + hmac_md5_update(seq_num, sizeof(seq_num), &ctx); + hmac_md5_update(whole_pdu, pdu_length, &ctx); + hmac_md5_final(digest, &ctx); + + if (encrypt_sig && gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) { + switch (direction) { + case NTLMSSP_SEND: + arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, digest, 8); + break; + case NTLMSSP_RECEIVE: + arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, digest, 8); + break; + } + } + + SIVAL(sig->data, 0, NTLMSSP_SIGN_VERSION); + memcpy(sig->data + 4, digest, 8); + memcpy(sig->data + 12, seq_num, 4); + + DEBUG(10, ("NTLM2: created signature over %llu bytes of input:\n", (unsigned long long)pdu_length)); + dump_data(11, sig->data, sig->length); + + } else { + uint32_t crc; + crc = crc32_calc_buffer(data, length); + if (!msrpc_gen(sig_mem_ctx, + lp_iconv_convenience(gensec_ntlmssp_state->gensec_security->lp_ctx), + sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) { + return NT_STATUS_NO_MEMORY; + } + gensec_ntlmssp_state->crypt.ntlm.seq_num++; + + arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4); + + DEBUG(10, ("NTLM1: created signature over %llu bytes of input:\n", (unsigned long long)length)); + dump_data(11, sig->data, sig->length); + } + return NT_STATUS_OK; +} + +/* TODO: make this non-public */ +NTSTATUS gensec_ntlmssp_sign_packet(struct gensec_security *gensec_security, + TALLOC_CTX *sig_mem_ctx, + const uint8_t *data, size_t length, + const uint8_t *whole_pdu, size_t pdu_length, + DATA_BLOB *sig) +{ + struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data; + + return ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx, + data, length, + whole_pdu, pdu_length, + NTLMSSP_SEND, sig, true); +} + +/** + * Check the signature of an incoming packet + * + */ + +NTSTATUS gensec_ntlmssp_check_packet(struct gensec_security *gensec_security, + TALLOC_CTX *sig_mem_ctx, + const uint8_t *data, size_t length, + const uint8_t *whole_pdu, size_t pdu_length, + const DATA_BLOB *sig) +{ + struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data; + + DATA_BLOB local_sig; + NTSTATUS nt_status; + + if (!gensec_ntlmssp_state->session_key.length) { + DEBUG(3, ("NO session key, cannot check packet signature\n")); + return NT_STATUS_NO_USER_SESSION_KEY; + } + + nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx, + data, length, + whole_pdu, pdu_length, + NTLMSSP_RECEIVE, &local_sig, true); + + if (!NT_STATUS_IS_OK(nt_status)) { + DEBUG(0, ("NTLMSSP packet check failed with %s\n", nt_errstr(nt_status))); + return nt_status; + } + + if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) { + if (local_sig.length != sig->length || + memcmp(local_sig.data, + sig->data, sig->length) != 0) { + DEBUG(5, ("BAD SIG NTLM2: wanted signature over %llu bytes of input:\n", (unsigned long long)pdu_length)); + dump_data(5, local_sig.data, local_sig.length); + + DEBUG(5, ("BAD SIG: got signature over %llu bytes of input:\n", (unsigned long long)pdu_length)); + dump_data(5, sig->data, sig->length); + + DEBUG(1, ("NTLMSSP NTLM2 packet check failed due to invalid signature on %llu bytes of input!\n", (unsigned long long)pdu_length)); + return NT_STATUS_ACCESS_DENIED; + } + } else { + if (local_sig.length != sig->length || + memcmp(local_sig.data + 8, + sig->data + 8, sig->length - 8) != 0) { + DEBUG(5, ("BAD SIG NTLM1: wanted signature of %llu bytes of input:\n", (unsigned long long)length)); + dump_data(5, local_sig.data, local_sig.length); + + DEBUG(5, ("BAD SIG: got signature of %llu bytes of input:\n", (unsigned long long)length)); + dump_data(5, sig->data, sig->length); + + DEBUG(1, ("NTLMSSP NTLM1 packet check failed due to invalid signature on %llu bytes of input:\n", (unsigned long long)length)); + return NT_STATUS_ACCESS_DENIED; + } + } + dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length); + + return NT_STATUS_OK; +} + + +/** + * Seal data with the NTLMSSP algorithm + * + */ + +NTSTATUS gensec_ntlmssp_seal_packet(struct gensec_security *gensec_security, + TALLOC_CTX *sig_mem_ctx, + uint8_t *data, size_t length, + const uint8_t *whole_pdu, size_t pdu_length, + DATA_BLOB *sig) +{ + struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data; + NTSTATUS nt_status; + if (!gensec_ntlmssp_state->session_key.length) { + DEBUG(3, ("NO session key, cannot seal packet\n")); + return NT_STATUS_NO_USER_SESSION_KEY; + } + + DEBUG(10,("ntlmssp_seal_data: seal\n")); + dump_data_pw("ntlmssp clear data\n", data, length); + if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) { + /* The order of these two operations matters - we must first seal the packet, + then seal the sequence number - this is becouse the send_seal_hash is not + constant, but is is rather updated with each iteration */ + nt_status = ntlmssp_make_packet_signature(gensec_ntlmssp_state, sig_mem_ctx, + data, length, + whole_pdu, pdu_length, + NTLMSSP_SEND, sig, false); + arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, data, length); + if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_KEY_EXCH) { + arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, sig->data+4, 8); + } + } else { + uint32_t crc; + crc = crc32_calc_buffer(data, length); + if (!msrpc_gen(sig_mem_ctx, + lp_iconv_convenience(gensec_security->lp_ctx), + sig, "dddd", NTLMSSP_SIGN_VERSION, 0, crc, gensec_ntlmssp_state->crypt.ntlm.seq_num)) { + return NT_STATUS_NO_MEMORY; + } + + /* The order of these two operations matters - we must + first seal the packet, then seal the sequence + number - this is becouse the ntlmssp_hash is not + constant, but is is rather updated with each + iteration */ + + arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length); + arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, sig->data+4, sig->length-4); + /* increment counter on send */ + gensec_ntlmssp_state->crypt.ntlm.seq_num++; + nt_status = NT_STATUS_OK; + } + dump_data_pw("ntlmssp signature\n", sig->data, sig->length); + dump_data_pw("ntlmssp sealed data\n", data, length); + + + return nt_status; +} + +/** + * Unseal data with the NTLMSSP algorithm + * + */ + +/* + wrappers for the ntlmssp_*() functions +*/ +NTSTATUS gensec_ntlmssp_unseal_packet(struct gensec_security *gensec_security, + TALLOC_CTX *sig_mem_ctx, + uint8_t *data, size_t length, + const uint8_t *whole_pdu, size_t pdu_length, + const DATA_BLOB *sig) +{ + struct gensec_ntlmssp_state *gensec_ntlmssp_state = (struct gensec_ntlmssp_state *)gensec_security->private_data; + if (!gensec_ntlmssp_state->session_key.length) { + DEBUG(3, ("NO session key, cannot unseal packet\n")); + return NT_STATUS_NO_USER_SESSION_KEY; + } + + dump_data_pw("ntlmssp sealed data\n", data, length); + if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) { + arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, data, length); + } else { + arcfour_crypt_sbox(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, data, length); + } + dump_data_pw("ntlmssp clear data\n", data, length); + return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx, data, length, whole_pdu, pdu_length, sig); +} + +/** + Initialise the state for NTLMSSP signing. +*/ +/* TODO: make this non-public */ +NTSTATUS ntlmssp_sign_init(struct gensec_ntlmssp_state *gensec_ntlmssp_state) +{ + TALLOC_CTX *mem_ctx = talloc_new(gensec_ntlmssp_state); + + if (!mem_ctx) { + return NT_STATUS_NO_MEMORY; + } + + DEBUG(3, ("NTLMSSP Sign/Seal - Initialising with flags:\n")); + debug_ntlmssp_flags(gensec_ntlmssp_state->neg_flags); + + if (gensec_ntlmssp_state->session_key.length < 8) { + talloc_free(mem_ctx); + DEBUG(3, ("NO session key, cannot intialise signing\n")); + return NT_STATUS_NO_USER_SESSION_KEY; + } + + if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) + { + DATA_BLOB weak_session_key = gensec_ntlmssp_state->session_key; + const char *send_sign_const; + const char *send_seal_const; + const char *recv_sign_const; + const char *recv_seal_const; + + DATA_BLOB send_seal_key; + DATA_BLOB recv_seal_key; + + switch (gensec_ntlmssp_state->role) { + case NTLMSSP_CLIENT: + send_sign_const = CLI_SIGN; + send_seal_const = CLI_SEAL; + recv_sign_const = SRV_SIGN; + recv_seal_const = SRV_SEAL; + break; + case NTLMSSP_SERVER: + send_sign_const = SRV_SIGN; + send_seal_const = SRV_SEAL; + recv_sign_const = CLI_SIGN; + recv_seal_const = CLI_SEAL; + break; + default: + talloc_free(mem_ctx); + return NT_STATUS_INTERNAL_ERROR; + } + + gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state); + NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state); + gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state); + NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state); + + /** + Weaken NTLMSSP keys to cope with down-level + clients, servers and export restrictions. + + We probably should have some parameters to control + this, once we get NTLM2 working. + */ + + /* Key weakening was not performed on the master key + * for NTLM2 (in ntlmssp_weaken_keys()), but must be + * done on the encryption subkeys only. That is why + * we don't have this code for the ntlmv1 case. + */ + + if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_128) { + + } else if (gensec_ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_56) { + weak_session_key.length = 7; + } else { /* forty bits */ + weak_session_key.length = 5; + } + dump_data_pw("NTLMSSP weakend master key:\n", + weak_session_key.data, + weak_session_key.length); + + /* SEND: sign key */ + calc_ntlmv2_key(gensec_ntlmssp_state, + &gensec_ntlmssp_state->crypt.ntlm2.send_sign_key, + gensec_ntlmssp_state->session_key, send_sign_const); + dump_data_pw("NTLMSSP send sign key:\n", + gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.data, + gensec_ntlmssp_state->crypt.ntlm2.send_sign_key.length); + + /* SEND: seal ARCFOUR pad */ + calc_ntlmv2_key(mem_ctx, + &send_seal_key, + weak_session_key, send_seal_const); + dump_data_pw("NTLMSSP send seal key:\n", + send_seal_key.data, + send_seal_key.length); + arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state, + &send_seal_key); + dump_data_pw("NTLMSSP send sesl hash:\n", + gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox, + sizeof(gensec_ntlmssp_state->crypt.ntlm2.send_seal_arcfour_state->sbox)); + + /* RECV: sign key */ + calc_ntlmv2_key(gensec_ntlmssp_state, + &gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key, + gensec_ntlmssp_state->session_key, recv_sign_const); + dump_data_pw("NTLMSSP recv sign key:\n", + gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.data, + gensec_ntlmssp_state->crypt.ntlm2.recv_sign_key.length); + + /* RECV: seal ARCFOUR pad */ + calc_ntlmv2_key(mem_ctx, + &recv_seal_key, + weak_session_key, recv_seal_const); + dump_data_pw("NTLMSSP recv seal key:\n", + recv_seal_key.data, + recv_seal_key.length); + arcfour_init(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state, + &recv_seal_key); + dump_data_pw("NTLMSSP receive seal hash:\n", + gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox, + sizeof(gensec_ntlmssp_state->crypt.ntlm2.recv_seal_arcfour_state->sbox)); + + gensec_ntlmssp_state->crypt.ntlm2.send_seq_num = 0; + gensec_ntlmssp_state->crypt.ntlm2.recv_seq_num = 0; + + } else { + DATA_BLOB weak_session_key = ntlmssp_weakend_key(gensec_ntlmssp_state, mem_ctx); + DEBUG(5, ("NTLMSSP Sign/Seal - using NTLM1\n")); + + gensec_ntlmssp_state->crypt.ntlm.arcfour_state = talloc(gensec_ntlmssp_state, struct arcfour_state); + NT_STATUS_HAVE_NO_MEMORY(gensec_ntlmssp_state->crypt.ntlm.arcfour_state); + + arcfour_init(gensec_ntlmssp_state->crypt.ntlm.arcfour_state, + &weak_session_key); + dump_data_pw("NTLMSSP hash:\n", gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox, + sizeof(gensec_ntlmssp_state->crypt.ntlm.arcfour_state->sbox)); + + gensec_ntlmssp_state->crypt.ntlm.seq_num = 0; + } + + talloc_free(mem_ctx); + return NT_STATUS_OK; +} + +size_t gensec_ntlmssp_sig_size(struct gensec_security *gensec_security, size_t data_size) +{ + return NTLMSSP_SIG_SIZE; +} + +NTSTATUS gensec_ntlmssp_wrap(struct gensec_security *gensec_security, + TALLOC_CTX *sig_mem_ctx, + const DATA_BLOB *in, + DATA_BLOB *out) +{ + DATA_BLOB sig; + NTSTATUS nt_status; + + if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) { + + *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE); + if (!out->data) { + return NT_STATUS_NO_MEMORY; + } + memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length); + + nt_status = gensec_ntlmssp_seal_packet(gensec_security, sig_mem_ctx, + out->data + NTLMSSP_SIG_SIZE, + out->length - NTLMSSP_SIG_SIZE, + out->data + NTLMSSP_SIG_SIZE, + out->length - NTLMSSP_SIG_SIZE, + &sig); + + if (NT_STATUS_IS_OK(nt_status)) { + memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE); + } + return nt_status; + + } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) { + + *out = data_blob_talloc(sig_mem_ctx, NULL, in->length + NTLMSSP_SIG_SIZE); + if (!out->data) { + return NT_STATUS_NO_MEMORY; + } + memcpy(out->data + NTLMSSP_SIG_SIZE, in->data, in->length); + + nt_status = gensec_ntlmssp_sign_packet(gensec_security, sig_mem_ctx, + out->data + NTLMSSP_SIG_SIZE, + out->length - NTLMSSP_SIG_SIZE, + out->data + NTLMSSP_SIG_SIZE, + out->length - NTLMSSP_SIG_SIZE, + &sig); + + if (NT_STATUS_IS_OK(nt_status)) { + memcpy(out->data, sig.data, NTLMSSP_SIG_SIZE); + } + return nt_status; + + } else { + *out = *in; + return NT_STATUS_OK; + } +} + + +NTSTATUS gensec_ntlmssp_unwrap(struct gensec_security *gensec_security, + TALLOC_CTX *sig_mem_ctx, + const DATA_BLOB *in, + DATA_BLOB *out) +{ + DATA_BLOB sig; + + if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SEAL)) { + if (in->length < NTLMSSP_SIG_SIZE) { + return NT_STATUS_INVALID_PARAMETER; + } + sig.data = in->data; + sig.length = NTLMSSP_SIG_SIZE; + + *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE); + + return gensec_ntlmssp_unseal_packet(gensec_security, sig_mem_ctx, + out->data, out->length, + out->data, out->length, + &sig); + + } else if (gensec_have_feature(gensec_security, GENSEC_FEATURE_SIGN)) { + if (in->length < NTLMSSP_SIG_SIZE) { + return NT_STATUS_INVALID_PARAMETER; + } + sig.data = in->data; + sig.length = NTLMSSP_SIG_SIZE; + + *out = data_blob_talloc(sig_mem_ctx, in->data + NTLMSSP_SIG_SIZE, in->length - NTLMSSP_SIG_SIZE); + + return gensec_ntlmssp_check_packet(gensec_security, sig_mem_ctx, + out->data, out->length, + out->data, out->length, + &sig); + } else { + *out = *in; + return NT_STATUS_OK; + } +} + |