r839: password set/change in the samr server is complex enough that it

deserves its own C module
(This used to be commit 2ba7ff824c32b3db037263ddcff9c876293ea284)

1 files changed, 508 insertions, 0 deletions

diff --git a/source4/rpc_server/samr/samr_password.c b/source4/rpc_server/samr/samr_password.c
new file mode 100644
index 0000000000..bc31d82a6a
--- /dev/null
+++ b/source4/rpc_server/samr/samr_password.c
@@ -0,0 +1,508 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   samr server password set/change handling
+
+   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"
+#include "rpc_server/common/common.h"
+#include "rpc_server/samr/dcesrv_samr.h"
+
+/* 
+  samr_ChangePasswordUser 
+*/
+NTSTATUS samr_ChangePasswordUser(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
+				 struct samr_ChangePasswordUser *r)
+{
+	struct dcesrv_handle *h;
+	struct samr_account_state *a_state;
+	struct ldb_message **res, mod, *msg;
+	int ret;
+	struct samr_Hash *lmPwdHash=NULL, *ntPwdHash=NULL;
+	struct samr_Hash new_lmPwdHash, new_ntPwdHash, checkHash;
+	NTSTATUS status = NT_STATUS_OK;
+	const char * const attrs[] = { "lmPwdHash", "ntPwdHash" , NULL };
+
+	DCESRV_PULL_HANDLE(h, r->in.handle, SAMR_HANDLE_USER);
+
+	a_state = h->data;
+
+	/* fetch the old hashes */
+	ret = samdb_search(a_state->sam_ctx, mem_ctx, NULL, &res, attrs,
+			   "dn=%s", a_state->account_dn);
+	if (ret != 1) {
+		return NT_STATUS_INTERNAL_DB_CORRUPTION;
+	}
+	msg = res[0];
+
+	/* basic sanity checking on parameters */
+	if (!r->in.lm_present || !r->in.nt_present ||
+	    !r->in.old_lm_crypted || !r->in.new_lm_crypted ||
+	    !r->in.old_nt_crypted || !r->in.new_nt_crypted) {
+		/* we should really handle a change with lm not
+		   present */
+		return NT_STATUS_INVALID_PARAMETER_MIX;
+	}
+	if (!r->in.cross1_present || !r->in.nt_cross) {
+		return NT_STATUS_NT_CROSS_ENCRYPTION_REQUIRED;
+	}
+	if (!r->in.cross2_present || !r->in.lm_cross) {
+		return NT_STATUS_LM_CROSS_ENCRYPTION_REQUIRED;
+	}
+
+	ret = samdb_result_hashes(mem_ctx, msg, "lmPwdHash", &lmPwdHash);
+	if (ret != 1) {
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+	ret = samdb_result_hashes(mem_ctx, msg, "ntPwdHash", &ntPwdHash);
+	if (ret != 1) {
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+
+	/* decrypt and check the new lm hash */
+	D_P16(lmPwdHash->hash, r->in.new_lm_crypted->hash, new_lmPwdHash.hash);
+	D_P16(new_lmPwdHash.hash, r->in.old_lm_crypted->hash, checkHash.hash);
+	if (memcmp(checkHash.hash, lmPwdHash->hash, 16) != 0) {
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+
+	/* decrypt and check the new nt hash */
+	D_P16(ntPwdHash->hash, r->in.new_nt_crypted->hash, new_ntPwdHash.hash);
+	D_P16(new_ntPwdHash.hash, r->in.old_nt_crypted->hash, checkHash.hash);
+	if (memcmp(checkHash.hash, ntPwdHash->hash, 16) != 0) {
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+	
+	/* check the nt cross hash */
+	D_P16(lmPwdHash->hash, r->in.nt_cross->hash, checkHash.hash);
+	if (memcmp(checkHash.hash, new_ntPwdHash.hash, 16) != 0) {
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+
+	/* check the lm cross hash */
+	D_P16(ntPwdHash->hash, r->in.lm_cross->hash, checkHash.hash);
+	if (memcmp(checkHash.hash, new_lmPwdHash.hash, 16) != 0) {
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+
+	ZERO_STRUCT(mod);
+	mod.dn = talloc_strdup(mem_ctx, a_state->account_dn);
+	if (!mod.dn) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	status = samdb_set_password(a_state->sam_ctx, mem_ctx,
+				    a_state->account_dn, a_state->domain_state->domain_dn,
+				    &mod, NULL, &new_lmPwdHash, &new_ntPwdHash, True);
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+
+	/* modify the samdb record */
+	ret = samdb_replace(a_state->sam_ctx, mem_ctx, &mod);
+	if (ret != 0) {
+		return NT_STATUS_UNSUCCESSFUL;
+	}
+
+	return NT_STATUS_OK;
+}
+
+/* 
+  samr_OemChangePasswordUser2 
+*/
+NTSTATUS samr_OemChangePasswordUser2(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
+				     struct samr_OemChangePasswordUser2 *r)
+{
+	NTSTATUS status;
+	char new_pass[512];
+	uint32 new_pass_len;
+	struct samr_CryptPassword *pwbuf = r->in.password;
+	void *sam_ctx;
+	const char *user_dn, *domain_dn;
+	int ret;
+	struct ldb_message **res, mod;
+	const char * const attrs[] = { "objectSid", "lmPwdHash", NULL };
+	const char *domain_sid;
+	struct samr_Hash *lmPwdHash;
+
+	if (pwbuf == NULL) {
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+
+	/* this call doesn't take a policy handle, so we need to open
+	   the sam db from scratch */
+	sam_ctx = samdb_connect();
+	if (sam_ctx == NULL) {
+		return NT_STATUS_INVALID_SYSTEM_SERVICE;
+	}
+
+	/* we need the users dn and the domain dn (derived from the
+	   user SID). We also need the current lm password hash in
+	   order to decrypt the incoming password */
+	ret = samdb_search(sam_ctx, 
+			   mem_ctx, NULL, &res, attrs,
+			   "(&(sAMAccountName=%s)(objectclass=user))",
+			   r->in.account->name);
+	if (ret != 1) {
+		samdb_close(sam_ctx);
+		return NT_STATUS_NO_SUCH_USER;
+	}
+
+	user_dn = res[0]->dn;
+
+	ret = samdb_result_hashes(mem_ctx, res[0], "lmPwdHash", &lmPwdHash);
+	if (ret != 1) {
+		samdb_close(sam_ctx);
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+
+	/* decrypt the password we have been given */
+	SamOEMhash(pwbuf->data, lmPwdHash->hash, 516);
+
+	if (!decode_pw_buffer(pwbuf->data, new_pass, sizeof(new_pass),
+			      &new_pass_len, STR_ASCII)) {
+		DEBUG(3,("samr: failed to decode password buffer\n"));
+		samdb_close(sam_ctx);
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+
+	/* work out the domain dn */
+	domain_sid = samdb_result_sid_prefix(mem_ctx, res[0], "objectSid");
+	if (domain_sid == NULL) {
+		samdb_close(sam_ctx);
+		return NT_STATUS_NO_SUCH_USER;
+	}
+
+	domain_dn = samdb_search_string(sam_ctx, mem_ctx, NULL, "dn",
+					"(objectSid=%s)", domain_sid);
+	if (!domain_dn) {
+		samdb_close(sam_ctx);
+		return NT_STATUS_INTERNAL_DB_CORRUPTION;
+	}
+
+
+	ZERO_STRUCT(mod);
+	mod.dn = talloc_strdup(mem_ctx, user_dn);
+	if (!mod.dn) {
+		samdb_close(sam_ctx);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	/* set the password - samdb needs to know both the domain and user DNs,
+	   so the domain password policy can be used */
+	status = samdb_set_password(sam_ctx, mem_ctx,
+				    user_dn, domain_dn, 
+				    &mod, new_pass, 
+				    NULL, NULL,
+				    True);
+	if (!NT_STATUS_IS_OK(status)) {
+		samdb_close(sam_ctx);
+		return status;
+	}
+
+	/* modify the samdb record */
+	ret = samdb_replace(sam_ctx, mem_ctx, &mod);
+	if (ret != 0) {
+		samdb_close(sam_ctx);
+		return NT_STATUS_UNSUCCESSFUL;
+	}
+
+	samdb_close(sam_ctx);
+	return NT_STATUS_OK;
+}
+
+
+/* 
+  samr_ChangePasswordUser2 
+*/
+NTSTATUS samr_ChangePasswordUser2(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
+				  struct samr_ChangePasswordUser2 *r)
+{
+	DCESRV_FAULT(DCERPC_FAULT_OP_RNG_ERROR);
+}
+
+
+/* 
+  samr_ChangePasswordUser3 
+*/
+NTSTATUS samr_ChangePasswordUser3(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
+				  struct samr_ChangePasswordUser3 *r)
+{
+	DCESRV_FAULT(DCERPC_FAULT_OP_RNG_ERROR);
+}
+
+
+
+
+/*
+  check that a password is sufficiently complex
+*/
+BOOL samdb_password_complexity_ok(const char *pass)
+{
+	return check_password_quality(pass);
+}
+
+/*
+  set the user password using plaintext, obeying any user or domain
+  password restrictions
+*/
+NTSTATUS samdb_set_password(void *ctx, TALLOC_CTX *mem_ctx,
+				   const char *user_dn, const char *domain_dn,
+				   struct ldb_message *mod,
+ 				   const char *new_pass,
+				   struct samr_Hash *lmNewHash, 
+				   struct samr_Hash *ntNewHash,
+				   BOOL user_change)
+{
+	const char * const user_attrs[] = { "userAccountControl", "lmPwdHistory", 
+					    "ntPwdHistory", "unicodePwd", 
+					    "lmPwdHash", "ntPwdHash", "badPwdCount", 
+					    NULL };
+	const char * const domain_attrs[] = { "pwdProperties", "pwdHistoryLength", 
+					      "maxPwdAge", "minPwdAge", 
+					      "minPwdLength", "pwdLastSet", NULL };
+	const char *unicodePwd;
+	double minPwdAge, pwdLastSet;
+	uint_t minPwdLength, pwdProperties, pwdHistoryLength;
+	uint_t userAccountControl, badPwdCount;
+	struct samr_Hash *lmPwdHistory, *ntPwdHistory, lmPwdHash, ntPwdHash;
+	struct samr_Hash *new_lmPwdHistory, *new_ntPwdHistory;
+	struct samr_Hash local_lmNewHash, local_ntNewHash;
+	int lmPwdHistory_len, ntPwdHistory_len;
+	struct ldb_message **res;
+	int count;
+	time_t now = time(NULL);
+	NTTIME now_nt;
+	double now_double;
+	int i;
+
+	/* we need to know the time to compute password age */
+	unix_to_nt_time(&now_nt, now);
+	now_double = nttime_to_double_nt(now_nt);
+
+	/* pull all the user parameters */
+	count = samdb_search(ctx, mem_ctx, NULL, &res, user_attrs, "dn=%s", user_dn);
+	if (count != 1) {
+		return NT_STATUS_INTERNAL_DB_CORRUPTION;
+	}
+	unicodePwd =         samdb_result_string(res[0], "unicodePwd", NULL);
+	userAccountControl = samdb_result_uint(res[0],   "userAccountControl", 0);
+	badPwdCount =        samdb_result_uint(res[0],   "badPwdCount", 0);
+	lmPwdHistory_len =   samdb_result_hashes(mem_ctx, res[0], 
+						 "lmPwdHistory", &lmPwdHistory);
+	ntPwdHistory_len =   samdb_result_hashes(mem_ctx, res[0], 
+						 "ntPwdHistory", &ntPwdHistory);
+	lmPwdHash =          samdb_result_hash(res[0],   "lmPwdHash");
+	ntPwdHash =          samdb_result_hash(res[0],   "ntPwdHash");
+	pwdLastSet =         samdb_result_double(res[0], "pwdLastSet", 0);
+
+	/* pull the domain parameters */
+	count = samdb_search(ctx, mem_ctx, NULL, &res, domain_attrs, "dn=%s", domain_dn);
+	if (count != 1) {
+		return NT_STATUS_INTERNAL_DB_CORRUPTION;
+	}
+	pwdProperties =    samdb_result_uint(res[0],   "pwdProperties", 0);
+	pwdHistoryLength = samdb_result_uint(res[0],   "pwdHistoryLength", 0);
+	minPwdLength =     samdb_result_uint(res[0],   "minPwdLength", 0);
+	minPwdAge =        samdb_result_double(res[0], "minPwdAge", 0);
+
+	if (new_pass) {
+		/* check the various password restrictions */
+		if (minPwdLength > str_charnum(new_pass)) {
+			return NT_STATUS_PASSWORD_RESTRICTION;
+		}
+		
+		/* possibly check password complexity */
+		if (pwdProperties & DOMAIN_PASSWORD_COMPLEX &&
+		    !samdb_password_complexity_ok(new_pass)) {
+			return NT_STATUS_PASSWORD_RESTRICTION;
+		}
+		
+		/* compute the new nt and lm hashes */
+		if (E_deshash(new_pass, local_lmNewHash.hash)) {
+			lmNewHash = &local_lmNewHash;
+		}
+		E_md4hash(new_pass, local_ntNewHash.hash);
+		ntNewHash = &local_ntNewHash;
+	}
+
+	if (user_change) {
+		/* are all password changes disallowed? */
+		if (pwdProperties & DOMAIN_REFUSE_PASSWORD_CHANGE) {
+			return NT_STATUS_PASSWORD_RESTRICTION;
+		}
+		
+		/* can this user change password? */
+		if (userAccountControl & UF_PASSWD_CANT_CHANGE) {
+			return NT_STATUS_PASSWORD_RESTRICTION;
+		}
+		
+		/* yes, this is a minus. The ages are in negative 100nsec units! */
+		if (pwdLastSet - minPwdAge > now_double) {
+			return NT_STATUS_PASSWORD_RESTRICTION;
+		}
+
+		/* check the immediately past password */
+		if (pwdHistoryLength > 0) {
+			if (lmNewHash && memcmp(lmNewHash->hash, lmPwdHash.hash, 16) == 0) {
+				return NT_STATUS_PASSWORD_RESTRICTION;
+			}
+			if (ntNewHash && memcmp(ntNewHash->hash, ntPwdHash.hash, 16) == 0) {
+				return NT_STATUS_PASSWORD_RESTRICTION;
+			}
+		}
+		
+		/* check the password history */
+		lmPwdHistory_len = MIN(lmPwdHistory_len, pwdHistoryLength);
+		ntPwdHistory_len = MIN(ntPwdHistory_len, pwdHistoryLength);
+		
+		if (pwdHistoryLength > 0) {
+			if (unicodePwd && new_pass && strcmp(unicodePwd, new_pass) == 0) {
+				return NT_STATUS_PASSWORD_RESTRICTION;
+			}
+			if (lmNewHash && memcmp(lmNewHash->hash, lmPwdHash.hash, 16) == 0) {
+				return NT_STATUS_PASSWORD_RESTRICTION;
+			}
+			if (ntNewHash && memcmp(ntNewHash->hash, ntPwdHash.hash, 16) == 0) {
+				return NT_STATUS_PASSWORD_RESTRICTION;
+			}
+		}
+		
+		for (i=0; lmNewHash && i<lmPwdHistory_len;i++) {
+			if (memcmp(lmNewHash->hash, lmPwdHistory[i].hash, 16) == 0) {
+				return NT_STATUS_PASSWORD_RESTRICTION;
+			}
+		}
+		for (i=0; ntNewHash && i<ntPwdHistory_len;i++) {
+			if (memcmp(ntNewHash->hash, ntPwdHistory[i].hash, 16) == 0) {
+				return NT_STATUS_PASSWORD_RESTRICTION;
+			}
+		}
+	}
+
+#define CHECK_RET(x) do { if (x != 0) return NT_STATUS_NO_MEMORY; } while(0)
+
+	/* the password is acceptable. Start forming the new fields */
+	if (lmNewHash) {
+		CHECK_RET(samdb_msg_add_hash(ctx, mem_ctx, mod, "lmPwdHash", *lmNewHash));
+	} else {
+		CHECK_RET(samdb_msg_add_delete(ctx, mem_ctx, mod, "lmPwdHash"));
+	}
+
+	if (ntNewHash) {
+		CHECK_RET(samdb_msg_add_hash(ctx, mem_ctx, mod, "ntPwdHash", *ntNewHash));
+	} else {
+		CHECK_RET(samdb_msg_add_delete(ctx, mem_ctx, mod, "ntPwdHash"));
+	}
+
+	if (new_pass && (pwdProperties & DOMAIN_PASSWORD_STORE_CLEARTEXT) &&
+	    (userAccountControl & UF_ENCRYPTED_TEXT_PASSWORD_ALLOWED)) {
+		CHECK_RET(samdb_msg_add_string(ctx, mem_ctx, mod, 
+					       "unicodePwd", new_pass));
+	} else {
+		CHECK_RET(samdb_msg_add_delete(ctx, mem_ctx, mod, "unicodePwd"));
+	}
+
+	CHECK_RET(samdb_msg_add_double(ctx, mem_ctx, mod, "pwdLastSet", now_double));
+	
+	if (pwdHistoryLength == 0) {
+		CHECK_RET(samdb_msg_add_delete(ctx, mem_ctx, mod, "lmPwdHistory"));
+		CHECK_RET(samdb_msg_add_delete(ctx, mem_ctx, mod, "ntPwdHistory"));
+		return NT_STATUS_OK;
+	}
+	
+	/* store the password history */
+	new_lmPwdHistory = talloc_array_p(mem_ctx, struct samr_Hash, 
+					  pwdHistoryLength);
+	if (!new_lmPwdHistory) {
+		return NT_STATUS_NO_MEMORY;
+	}
+	new_ntPwdHistory = talloc_array_p(mem_ctx, struct samr_Hash, 
+					  pwdHistoryLength);
+	if (!new_ntPwdHistory) {
+		return NT_STATUS_NO_MEMORY;
+	}
+	for (i=0;i<MIN(pwdHistoryLength-1, lmPwdHistory_len);i++) {
+		new_lmPwdHistory[i+1] = lmPwdHistory[i];
+	}
+	for (i=0;i<MIN(pwdHistoryLength-1, ntPwdHistory_len);i++) {
+		new_ntPwdHistory[i+1] = ntPwdHistory[i];
+	}
+
+	/* Don't store 'long' passwords in the LM history, 
+	   but make sure to 'expire' one password off the other end */
+	if (lmNewHash) {
+		new_lmPwdHistory[0] = *lmNewHash;
+	} else {
+		ZERO_STRUCT(new_lmPwdHistory[0]);
+	}
+	lmPwdHistory_len = MIN(lmPwdHistory_len + 1, pwdHistoryLength);
+
+	if (ntNewHash) {
+		new_ntPwdHistory[0] = *ntNewHash;
+	} else {
+		ZERO_STRUCT(new_ntPwdHistory[0]);
+	}
+	ntPwdHistory_len = MIN(ntPwdHistory_len + 1, pwdHistoryLength);
+	
+	CHECK_RET(samdb_msg_add_hashes(ctx, mem_ctx, mod, 
+				       "lmPwdHistory", 
+				       new_lmPwdHistory, 
+				       lmPwdHistory_len));
+
+	CHECK_RET(samdb_msg_add_hashes(ctx, mem_ctx, mod, 
+				       "ntPwdHistory", 
+				       new_ntPwdHistory, 
+				       ntPwdHistory_len));
+	return NT_STATUS_OK;
+}
+
+/*
+  set password via a samr_CryptPassword buffer
+  this will in the 'msg' with modify operations that will update the user
+  password when applied
+*/
+NTSTATUS samr_set_password(struct dcesrv_call_state *dce_call,
+			   void *sam_ctx,
+			   const char *account_dn, const char *domain_dn,
+			   TALLOC_CTX *mem_ctx,
+			   struct ldb_message *msg, 
+			   struct samr_CryptPassword *pwbuf)
+{
+	char new_pass[512];
+	uint32 new_pass_len;
+	DATA_BLOB session_key = dce_call->conn->session_key;
+
+	SamOEMhashBlob(pwbuf->data, 516, &session_key);
+
+	if (!decode_pw_buffer(pwbuf->data, new_pass, sizeof(new_pass),
+			      &new_pass_len, STR_UNICODE)) {
+		DEBUG(3,("samr: failed to decode password buffer\n"));
+		return NT_STATUS_WRONG_PASSWORD;
+	}
+
+	/* set the password - samdb needs to know both the domain and user DNs,
+	   so the domain password policy can be used */
+	return samdb_set_password(sam_ctx, mem_ctx,
+				  account_dn, domain_dn, 
+				  msg, new_pass, 
+				  NULL, NULL,
+				  False /* This is a password set, not change */);
+}
+