diff options
Diffstat (limited to 'plugin/auth_gssapi/sspi_server.cc')
| -rw-r--r-- | plugin/auth_gssapi/sspi_server.cc | 463 |
1 files changed, 463 insertions, 0 deletions
diff --git a/plugin/auth_gssapi/sspi_server.cc b/plugin/auth_gssapi/sspi_server.cc new file mode 100644 index 00000000..4a195808 --- /dev/null +++ b/plugin/auth_gssapi/sspi_server.cc @@ -0,0 +1,463 @@ +/* Copyright (c) 2015, Shuang Qiu, Robbie Harwood, +Vladislav Vaintroub & MariaDB Corporation + +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + +1. Redistributions of source code must retain the above copyright notice, +this list of conditions and the following disclaimer. + +2. Redistributions in binary form must reproduce the above copyright notice, +this list of conditions and the following disclaimer in the documentation +and/or other materials provided with the distribution. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE +LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +POSSIBILITY OF SUCH DAMAGE. +*/ + +#include "sspi.h" +#include "common.h" +#include "server_plugin.h" +#include <mysql/plugin_auth.h> +#include <mysqld_error.h> +#include <sddl.h> + +/* This sends the error to the client */ +static void log_error(SECURITY_STATUS err, const char *msg) +{ + if (err) + { + char buf[1024]; + sspi_errmsg(err, buf, sizeof(buf)); + my_printf_error(ER_UNKNOWN_ERROR, "SSPI server error 0x%x - %s - %s", 0, err, msg, buf); + } + else + { + my_printf_error(ER_UNKNOWN_ERROR, "SSPI server error %s", 0, msg); + } + +} + +static char INVALID_KERBEROS_PRINCIPAL[] = "localhost"; + +static char *get_default_principal_name() +{ + static char default_principal[PRINCIPAL_NAME_MAX +1]; + ULONG size= sizeof(default_principal); + + if (GetUserNameEx(NameUserPrincipal,default_principal,&size)) + return default_principal; + + size= sizeof(default_principal); + if (GetUserNameEx(NameServicePrincipal,default_principal,&size)) + return default_principal; + + char domain[PRINCIPAL_NAME_MAX+1]; + char host[PRINCIPAL_NAME_MAX+1]; + size= sizeof(domain); + if (GetComputerNameEx(ComputerNameDnsDomain,domain,&size) && size > 0) + { + size= sizeof(host); + if (GetComputerNameEx(ComputerNameDnsHostname,host,&size)) + { + _snprintf(default_principal,sizeof(default_principal),"%s$@%s",host, domain); + return default_principal; + } + } + /* Unable to retrieve useful name, return something */ + return INVALID_KERBEROS_PRINCIPAL; +} + + +/* Extract client name from SSPI context */ +static int get_client_name_from_context(CtxtHandle *ctxt, + char *name, + size_t name_len, + int use_full_name) +{ + SecPkgContext_NativeNames native_names; + SECURITY_STATUS sspi_ret; + char *p; + + sspi_ret= QueryContextAttributes(ctxt, SECPKG_ATTR_NATIVE_NAMES, &native_names); + if (sspi_ret == SEC_E_OK) + { + /* Extract user from Kerberos principal name user@realm */ + if(!use_full_name) + { + p = strrchr(native_names.sClientName,'@'); + if(p) + *p = 0; + } + strncpy(name, native_names.sClientName, name_len); + + if (native_names.sClientName) + FreeContextBuffer(native_names.sClientName); + if (native_names.sServerName) + FreeContextBuffer(native_names.sServerName); + + return CR_OK; + } + + sspi_ret= ImpersonateSecurityContext(ctxt); + if (sspi_ret == SEC_E_OK) + { + ULONG len= (ULONG)name_len; + if (!GetUserNameEx(NameSamCompatible, name, &len)) + { + log_error(GetLastError(), "GetUserNameEx"); + RevertSecurityContext(ctxt); + return CR_ERROR; + } + RevertSecurityContext(ctxt); + + /* Extract user from Windows name realm\user */ + if (!use_full_name) + { + p = strrchr(name, '\\'); + if (p) + { + p++; + memmove(name, p, name + len + 1 - p); + } + } + return CR_OK; + } + + log_error(sspi_ret, "ImpersonateSecurityContext"); + return CR_ERROR; +} + + +/* + Check if username from SSPI context matches the name requested + in MYSQL_SERVER_AUTH_INFO + + There are 2 ways to specify SSPI username + username, of auth_string. + + if auth_string is used, we compare full name (i.e , with user+domain) + if not, we match just the user name. +*/ +static bool check_username_match(CtxtHandle *ctxt, + MYSQL_SERVER_AUTH_INFO *auth_info) +{ + char client_name[MYSQL_USERNAME_LENGTH + 1]; + const char *user= 0; + int compare_full_name;; + if (auth_info->auth_string_length > 0) + { + compare_full_name= 1; + user= auth_info->auth_string; + } + else + { + compare_full_name= 0; + user= auth_info->user_name; + } + if (get_client_name_from_context(ctxt, client_name, MYSQL_USERNAME_LENGTH, + compare_full_name) != CR_OK) + { + return false; + } + + /* Always compare case-insensitive on Windows. */ + if (_stricmp(client_name, user)) + { + my_printf_error(ER_ACCESS_DENIED_ERROR, + "GSSAPI name mismatch, requested '%s', actual name '%s'", 0, user, + client_name); + return false; + } + return true; +} + + +/* + Checks the security token extracted from SSPI context + for membership in specfied group. + + @param ctxt - SSPI context + @param group_name - group name to check membership against + NOTE: this can also be a user's name + + @param use_sid - whether name is SID + @last_error - will be set, if the function returns false, and + some of the API's have failed. + @failing_api - name of the API that has failed(for error logging) +*/ +static bool check_group_match(CtxtHandle *ctxt, const char *name, + bool name_is_sid) +{ + BOOL is_member= FALSE; + bool is_impersonating= false; + bool free_sid= false; + PSID sid= 0; + + +#define FAIL(msg) \ + do \ + { \ + log_error(GetLastError(), msg); \ + goto cleanup; \ + } while (0) + + /* Get the group SID.*/ + if (name_is_sid) + { + if (!ConvertStringSidToSidA(name, &sid)) + FAIL("ConvertStringSidToSid"); + free_sid= true; + } + else + { + /* Get the SID of the specified group via LookupAccountName().*/ + char sid_buf[SECURITY_MAX_SID_SIZE]; + char domain[256]; + DWORD sid_size= sizeof(sid_buf); + DWORD domain_size= sizeof(domain); + + SID_NAME_USE sid_name_use; + sid= (PSID) sid_buf; + + if (!LookupAccountName(0, name, sid, &sid_size, domain, + &domain_size, &sid_name_use)) + { + FAIL("LookupAccountName"); + } + } + + /* Impersonate, to check group membership */ + if (ImpersonateSecurityContext(ctxt)) + FAIL("ImpersonateSecurityContext"); + is_impersonating= true; + + if (!CheckTokenMembership(GetCurrentThreadToken(), sid, &is_member)) + FAIL("CheckTokenMembership"); + +cleanup: + if (is_impersonating) + RevertSecurityContext(ctxt); + if (free_sid) + LocalFree(sid); + return is_member; +} + +static SECURITY_STATUS sspi_get_context(MYSQL_PLUGIN_VIO *vio, + CtxtHandle *ctxt, CredHandle *cred) +{ + SECURITY_STATUS sspi_ret= SEC_E_OK; + ULONG attribs= 0; + TimeStamp lifetime; + SecBufferDesc inbuf_desc; + SecBuffer inbuf; + SecBufferDesc outbuf_desc; + SecBuffer outbuf; + void* out= NULL; + + SecInvalidateHandle(cred); + SecInvalidateHandle(ctxt); + + out= malloc(SSPI_MAX_TOKEN_SIZE); + if (!out) + { + log_error(SEC_E_OK, "memory allocation failed"); + sspi_ret= SEC_E_INSUFFICIENT_MEMORY; + goto cleanup; + } + sspi_ret= AcquireCredentialsHandle( + srv_principal_name, + (LPSTR)srv_mech_name, + SECPKG_CRED_INBOUND, + NULL, + NULL, + NULL, + NULL, + cred, + &lifetime); + + if (SEC_ERROR(sspi_ret)) + { + log_error(sspi_ret, "AcquireCredentialsHandle failed"); + goto cleanup; + } + + inbuf.cbBuffer= 0; + inbuf.BufferType= SECBUFFER_TOKEN; + inbuf.pvBuffer= NULL; + inbuf_desc.ulVersion= SECBUFFER_VERSION; + inbuf_desc.cBuffers= 1; + inbuf_desc.pBuffers= &inbuf; + + outbuf.BufferType= SECBUFFER_TOKEN; + outbuf.cbBuffer= SSPI_MAX_TOKEN_SIZE; + outbuf.pvBuffer= out; + + outbuf_desc.ulVersion= SECBUFFER_VERSION; + outbuf_desc.cBuffers= 1; + outbuf_desc.pBuffers= &outbuf; + + do + { + /* Read SSPI blob from client. */ + int len= vio->read_packet(vio, (unsigned char **)&inbuf.pvBuffer); + if (len < 0) + { + log_error(SEC_E_OK, "communication error(read)"); + goto cleanup; + } + inbuf.cbBuffer= len; + outbuf.cbBuffer= SSPI_MAX_TOKEN_SIZE; + sspi_ret= AcceptSecurityContext( + cred, + SecIsValidHandle(ctxt) ? ctxt : NULL, + &inbuf_desc, + attribs, + SECURITY_NATIVE_DREP, + ctxt, + &outbuf_desc, + &attribs, + &lifetime); + + if (SEC_ERROR(sspi_ret)) + { + log_error(sspi_ret, "AcceptSecurityContext"); + goto cleanup; + } + if (sspi_ret != SEC_E_OK && sspi_ret != SEC_I_CONTINUE_NEEDED) + { + log_error(sspi_ret, "AcceptSecurityContext unexpected return value"); + goto cleanup; + } + if (outbuf.cbBuffer) + { + /* Send generated blob to client. */ + if (vio->write_packet(vio, (unsigned char *)outbuf.pvBuffer, outbuf.cbBuffer)) + { + log_error(SEC_E_OK, "communicaton error(write)"); + goto cleanup; + } + } + } while (sspi_ret == SEC_I_CONTINUE_NEEDED); + +cleanup: + free(out); + return sspi_ret; +} + + +int auth_server(MYSQL_PLUGIN_VIO *vio, MYSQL_SERVER_AUTH_INFO *auth_info) +{ + int ret= CR_ERROR; + const char* group = 0; + bool use_sid = 0; + + CtxtHandle ctxt; + CredHandle cred; + if (sspi_get_context(vio, &ctxt, &cred) != SEC_E_OK) + goto cleanup; + + + /* + Authentication done, now test user name, or group + membership. + First, find out if matching group was requested. + */ + static struct + { + const char *str; + size_t len; + bool sid; + } prefixes[]= {{"GROUP:", sizeof("GROUP:") - 1, false}, + {"SID:", sizeof("SID:") - 1, true}}; + group= 0; + for (auto &prefix : prefixes) + { + if (auth_info->auth_string_length >= prefix.len && + !strncmp(auth_info->auth_string, prefix.str, prefix.len)) + { + group= auth_info->auth_string + prefix.len; + use_sid= prefix.sid; + break; + } + } + + if (group) + { + /* Test group membership.*/ + ret= check_group_match(&ctxt, group, use_sid) ? CR_OK : CR_ERROR; + } + else + { + /* Compare username. */ + ret= check_username_match(&ctxt, auth_info) ? CR_OK : CR_ERROR; + } + +cleanup: + if (SecIsValidHandle(&ctxt)) + DeleteSecurityContext(&ctxt); + + if (SecIsValidHandle(&cred)) + FreeCredentialsHandle(&cred); + + return ret; +} + +int plugin_init() +{ + CredHandle cred; + SECURITY_STATUS ret; + + /* + Use negotiate by default, which accepts raw kerberos + and also NTLM. + */ + if (srv_mech == PLUGIN_MECH_DEFAULT) + srv_mech= PLUGIN_MECH_SPNEGO; + + if(srv_mech == PLUGIN_MECH_KERBEROS) + srv_mech_name= "Kerberos"; + else if(srv_mech == PLUGIN_MECH_SPNEGO ) + srv_mech_name= "Negotiate"; + + if(!srv_principal_name[0]) + { + srv_principal_name= get_default_principal_name(); + } + my_printf_error(ER_UNKNOWN_ERROR, "SSPI: using principal name '%s', mech '%s'", + ME_ERROR_LOG | ME_NOTE, srv_principal_name, srv_mech_name); + + ret = AcquireCredentialsHandle( + srv_principal_name, + (LPSTR)srv_mech_name, + SECPKG_CRED_INBOUND, + NULL, + NULL, + NULL, + NULL, + &cred, + NULL); + if (SEC_ERROR(ret)) + { + log_error(ret, "AcquireCredentialsHandle"); + return -1; + } + FreeCredentialsHandle(&cred); + return 0; +} + +int plugin_deinit() +{ + return 0; +} |