[exim.git] / src / src / auths / spa.c

/*************************************************
*     Exim - an Internet mail transport agent    *
*************************************************/

/* Copyright (c) University of Cambridge 1995 - 2009 */
/* See the file NOTICE for conditions of use and distribution. */

/* This file, which provides support for Microsoft's Secure Password
Authentication, was contributed by Marc Prud'hommeaux. Tom Kistner added SPA
server support. I (PH) have only modified it in very trivial ways.

References:
  http://www.innovation.ch/java/ntlm.html
  http://www.kuro5hin.org/story/2002/4/28/1436/66154
  http://download.microsoft.com/download/9/5/e/95ef66af-9026-4bb0-a41d-a4f81802d92c/%5bMS-SMTP%5d.pdf

 * It seems that some systems have existing but different definitions of some
 * of the following types. I received a complaint about "int16" causing
 * compilation problems. So I (PH) have renamed them all, to be on the safe
 * side, by adding 'x' on the end. See auths/auth-spa.h.

 * typedef signed short int16;
 * typedef unsigned short uint16;
 * typedef unsigned uint32;
 * typedef unsigned char  uint8;

07-August-2003:  PH: Patched up the code to avoid assert bombouts for stupid
                     input data. Find appropriate comment by grepping for "PH".
16-October-2006: PH: Added a call to auth_check_serv_cond() at the end
05-June-2010:    PP: handle SASL initial response
*/


#include "../exim.h"
#include "spa.h"

/* #define DEBUG_SPA */

#ifdef DEBUG_SPA
#define DSPA(x,y,z)   debug_printf(x,y,z)
#else
#define DSPA(x,y,z)
#endif

/* Options specific to the spa authentication mechanism. */

optionlist auth_spa_options[] = {
  { "client_domain",             opt_stringptr,
      (void *)(offsetof(auth_spa_options_block, spa_domain)) },
  { "client_password",           opt_stringptr,
      (void *)(offsetof(auth_spa_options_block, spa_password)) },
  { "client_username",           opt_stringptr,
      (void *)(offsetof(auth_spa_options_block, spa_username)) },
  { "server_password",           opt_stringptr,
      (void *)(offsetof(auth_spa_options_block, spa_serverpassword)) }
};

/* Size of the options list. An extern variable has to be used so that its
address can appear in the tables drtables.c. */

int auth_spa_options_count =
  sizeof(auth_spa_options)/sizeof(optionlist);

/* Default private options block for the contidion authentication method. */

auth_spa_options_block auth_spa_option_defaults = {
  NULL,              /* spa_password */
  NULL,              /* spa_username */
  NULL,              /* spa_domain */
  NULL               /* spa_serverpassword (for server side use) */
};


/*************************************************
*          Initialization entry point            *
*************************************************/

/* Called for each instance, after its options have been read, to
enable consistency checks to be done, or anything else that needs
to be set up. */

void
auth_spa_init(auth_instance *ablock)
{
auth_spa_options_block *ob =
  (auth_spa_options_block *)(ablock->options_block);

/* The public name defaults to the authenticator name */

if (ablock->public_name == NULL) ablock->public_name = ablock->name;

/* Both username and password must be set for a client */

if ((ob->spa_username == NULL) != (ob->spa_password == NULL))
  log_write(0, LOG_PANIC_DIE|LOG_CONFIG_FOR, "%s authenticator:\n  "
      "one of client_username and client_password cannot be set without "
      "the other", ablock->name);
ablock->client = ob->spa_username != NULL;

/* For a server we have just one option */

ablock->server = ob->spa_serverpassword != NULL;
}


/*************************************************
*             Server entry point                 *
*************************************************/

/* For interface, see auths/README */

#define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
#define PVAL(buf,pos) ((unsigned)CVAL(buf,pos))
#define SVAL(buf,pos) (PVAL(buf,pos)|PVAL(buf,(pos)+1)<<8)
#define IVAL(buf,pos) (SVAL(buf,pos)|SVAL(buf,(pos)+2)<<16)

int
auth_spa_server(auth_instance *ablock, uschar *data)
{
auth_spa_options_block *ob = (auth_spa_options_block *)(ablock->options_block);
uint8x lmRespData[24];
uint8x ntRespData[24];
SPAAuthRequest request;
SPAAuthChallenge challenge;
SPAAuthResponse  response;
SPAAuthResponse  *responseptr = &response;
uschar msgbuf[2048];
uschar *clearpass;

/* send a 334, MS Exchange style, and grab the client's request,
unless we already have it via an initial response. */

if ((*data == '\0') &&
    (auth_get_no64_data(&data, US"NTLM supported") != OK))
  {
  /* something borked */
  return FAIL;
  }

if (spa_base64_to_bits((char *)(&request), sizeof(request), (const char *)(data)) < 0)
  {
  DEBUG(D_auth) debug_printf("auth_spa_server(): bad base64 data in "
  "request: %s\n", data);
  return FAIL;
  }

/* create a challenge and send it back */

spa_build_auth_challenge(&request,&challenge);
spa_bits_to_base64 (msgbuf, (unsigned char*)&challenge,
    spa_request_length(&challenge));

if (auth_get_no64_data(&data, msgbuf) != OK)
  {
  /* something borked */
  return FAIL;
  }

/* dump client response */
if (spa_base64_to_bits((char *)(&response), sizeof(response), (const char *)(data)) < 0)
  {
  DEBUG(D_auth) debug_printf("auth_spa_server(): bad base64 data in "
  "response: %s\n", data);
  return FAIL;
  }

/***************************************************************
PH 07-Aug-2003: The original code here was this:

Ustrcpy(msgbuf, unicodeToString(((char*)responseptr) +
  IVAL(&responseptr->uUser.offset,0),
  SVAL(&responseptr->uUser.len,0)/2) );

However, if the response data is too long, unicodeToString bombs out on
an assertion failure. It uses a 1024 fixed buffer. Bombing out is not a good
idea. It's too messy to try to rework that function to return an error because
it is called from a number of other places in the auth-spa.c module. Instead,
since it is a very small function, I reproduce its code here, with a size check
that causes failure if the size of msgbuf is exceeded. ****/

  {
  int i;
  char *p = ((char*)responseptr) + IVAL(&responseptr->uUser.offset,0);
  int len = SVAL(&responseptr->uUser.len,0)/2;

  if (len + 1 >= sizeof(msgbuf)) return FAIL;
  for (i = 0; i < len; ++i)
    {
    msgbuf[i] = *p & 0x7f;
    p += 2;
    }
  msgbuf[i] = 0;
  }

/***************************************************************/

/* Put the username in $auth1 and $1. The former is now the preferred variable;
the latter is the original variable. */

auth_vars[0] = expand_nstring[1] = msgbuf;
expand_nlength[1] = Ustrlen(msgbuf);
expand_nmax = 1;

/* clean up globals which aren't referenced, but still shouldn't be left
pointing to stack memory */
#define CLEANUP_RETURN(Code) do { auth_vars[0] = expand_nstring[1] = NULL; \
  expand_nlength[1] = expand_nmax = 0; return (Code); } while (0);

debug_print_string(ablock->server_debug_string);    /* customized debug */

/* look up password */

clearpass = expand_string(ob->spa_serverpassword);
if (clearpass == NULL)
  {
  if (expand_string_forcedfail)
    {
    DEBUG(D_auth) debug_printf("auth_spa_server(): forced failure while "
      "expanding spa_serverpassword\n");
    CLEANUP_RETURN(FAIL);
    }
  else
    {
    DEBUG(D_auth) debug_printf("auth_spa_server(): error while expanding "
      "spa_serverpassword: %s\n", expand_string_message);
    CLEANUP_RETURN(DEFER);
    }
  }

/* create local hash copy */

spa_smb_encrypt (clearpass, challenge.challengeData, lmRespData);
spa_smb_nt_encrypt (clearpass, challenge.challengeData, ntRespData);

/* compare NT hash (LM may not be available) */

if (memcmp(ntRespData,
      ((unsigned char*)responseptr)+IVAL(&responseptr->ntResponse.offset,0),
      24) == 0)
  /* success. we have a winner. */
  {
  int rc = auth_check_serv_cond(ablock);
  CLEANUP_RETURN(rc);
  }

  /* Expand server_condition as an authorization check (PH) */

CLEANUP_RETURN(FAIL);
}


/*************************************************
*              Client entry point                *
*************************************************/

/* For interface, see auths/README */

int
auth_spa_client(
  auth_instance *ablock,                 /* authenticator block */
  smtp_inblock *inblock,                 /* connection inblock */
  smtp_outblock *outblock,               /* connection outblock */
  int timeout,                           /* command timeout */
  uschar *buffer,                        /* buffer for reading response */
  int buffsize)                          /* size of buffer */
{
       auth_spa_options_block *ob =
               (auth_spa_options_block *)(ablock->options_block);
       SPAAuthRequest   request;
       SPAAuthChallenge challenge;
       SPAAuthResponse  response;
       char msgbuf[2048];
       char *domain = NULL;
       char *username, *password;

       /* Code added by PH to expand the options */

       *buffer = 0;    /* Default no message when cancelled */

       username = CS expand_string(ob->spa_username);
       if (username == NULL)
         {
         if (expand_string_forcedfail) return CANCELLED;
         string_format(buffer, buffsize, "expansion of \"%s\" failed in %s "
           "authenticator: %s", ob->spa_username, ablock->name,
           expand_string_message);
         return ERROR;
         }

       password = CS expand_string(ob->spa_password);
       if (password == NULL)
         {
         if (expand_string_forcedfail) return CANCELLED;
         string_format(buffer, buffsize, "expansion of \"%s\" failed in %s "
           "authenticator: %s", ob->spa_password, ablock->name,
           expand_string_message);
         return ERROR;
         }

       if (ob->spa_domain != NULL)
         {
         domain = CS expand_string(ob->spa_domain);
         if (domain == NULL)
           {
           if (expand_string_forcedfail) return CANCELLED;
           string_format(buffer, buffsize, "expansion of \"%s\" failed in %s "
             "authenticator: %s", ob->spa_domain, ablock->name,
             expand_string_message);
           return ERROR;
           }
         }

       /* Original code */

    if (smtp_write_command(outblock, FALSE, "AUTH %s\r\n",
         ablock->public_name) < 0)
               return FAIL_SEND;

       /* wait for the 3XX OK message */
       if (!smtp_read_response(inblock, (uschar *)buffer, buffsize, '3', timeout))
               return FAIL;

       DSPA("\n\n%s authenticator: using domain %s\n\n",
               ablock->name, domain);

       spa_build_auth_request (&request, CS username, domain);
       spa_bits_to_base64 (US msgbuf, (unsigned char*)&request,
               spa_request_length(&request));

       DSPA("\n\n%s authenticator: sending request (%s)\n\n", ablock->name,
               msgbuf);

       /* send the encrypted password */
       if (smtp_write_command(outblock, FALSE, "%s\r\n", msgbuf) < 0)
               return FAIL_SEND;

       /* wait for the auth challenge */
       if (!smtp_read_response(inblock, (uschar *)buffer, buffsize, '3', timeout))
               return FAIL;

       /* convert the challenge into the challenge struct */
       DSPA("\n\n%s authenticator: challenge (%s)\n\n",
               ablock->name, buffer + 4);
       spa_base64_to_bits ((char *)(&challenge), sizeof(challenge), (const char *)(buffer + 4));

       spa_build_auth_response (&challenge, &response,
               CS username, CS password);
       spa_bits_to_base64 (US msgbuf, (unsigned char*)&response,
               spa_request_length(&response));
       DSPA("\n\n%s authenticator: challenge response (%s)\n\n", ablock->name,
               msgbuf);

       /* send the challenge response */
       if (smtp_write_command(outblock, FALSE, "%s\r\n", msgbuf) < 0)
               return FAIL_SEND;

       /* If we receive a success response from the server, authentication
       has succeeded. There may be more data to send, but is there any point
       in provoking an error here? */
       if (smtp_read_response(inblock, US buffer, buffsize, '2', timeout))
               return OK;

       /* Not a success response. If errno != 0 there is some kind of transmission
       error. Otherwise, check the response code in the buffer. If it starts with
       '3', more data is expected. */
       if (errno != 0 || buffer[0] != '3')
               return FAIL;

       return FAIL;
}

/* End of spa.c */
Commit	Line	Data
0756eb3c PH	1	/*************************************************
	2	* Exim - an Internet mail transport agent *
	3	*************************************************/
	4
0a49a7a4	5	/* Copyright (c) University of Cambridge 1995 - 2009 */
0756eb3c PH	6	/* See the file NOTICE for conditions of use and distribution. */
	7
	8	/* This file, which provides support for Microsoft's Secure Password
	9	Authentication, was contributed by Marc Prud'hommeaux. Tom Kistner added SPA
	10	server support. I (PH) have only modified it in very trivial ways.
	11
	12	References:
	13	http://www.innovation.ch/java/ntlm.html
	14	http://www.kuro5hin.org/story/2002/4/28/1436/66154
55c75993	15	http://download.microsoft.com/download/9/5/e/95ef66af-9026-4bb0-a41d-a4f81802d92c/%5bMS-SMTP%5d.pdf
0756eb3c PH	16
	17	* It seems that some systems have existing but different definitions of some
	18	* of the following types. I received a complaint about "int16" causing
	19	* compilation problems. So I (PH) have renamed them all, to be on the safe
	20	* side, by adding 'x' on the end. See auths/auth-spa.h.
	21
	22	* typedef signed short int16;
	23	* typedef unsigned short uint16;
	24	* typedef unsigned uint32;
	25	* typedef unsigned char uint8;
	26
16ff981e PH	27	07-August-2003: PH: Patched up the code to avoid assert bombouts for stupid
	28	input data. Find appropriate comment by grepping for "PH".
	29	16-October-2006: PH: Added a call to auth_check_serv_cond() at the end
55c75993	30	05-June-2010: PP: handle SASL initial response
0756eb3c PH	31	*/
	32
	33
	34	#include "../exim.h"
	35	#include "spa.h"
	36
	37	/* #define DEBUG_SPA */
	38
	39	#ifdef DEBUG_SPA
	40	#define DSPA(x,y,z) debug_printf(x,y,z)
	41	#else
	42	#define DSPA(x,y,z)
	43	#endif
	44
	45	/* Options specific to the spa authentication mechanism. */
	46
	47	optionlist auth_spa_options[] = {
	48	{ "client_domain", opt_stringptr,
	49	(void *)(offsetof(auth_spa_options_block, spa_domain)) },
	50	{ "client_password", opt_stringptr,
	51	(void *)(offsetof(auth_spa_options_block, spa_password)) },
	52	{ "client_username", opt_stringptr,
	53	(void *)(offsetof(auth_spa_options_block, spa_username)) },
	54	{ "server_password", opt_stringptr,
	55	(void *)(offsetof(auth_spa_options_block, spa_serverpassword)) }
	56	};
	57
	58	/* Size of the options list. An extern variable has to be used so that its
	59	address can appear in the tables drtables.c. */
	60
	61	int auth_spa_options_count =
	62	sizeof(auth_spa_options)/sizeof(optionlist);
	63
	64	/* Default private options block for the contidion authentication method. */
	65
	66	auth_spa_options_block auth_spa_option_defaults = {
	67	NULL, /* spa_password */
	68	NULL, /* spa_username */
	69	NULL, /* spa_domain */
	70	NULL /* spa_serverpassword (for server side use) */
	71	};
	72
	73
	74	/*************************************************
	75	* Initialization entry point *
	76	*************************************************/
	77
	78	/* Called for each instance, after its options have been read, to
	79	enable consistency checks to be done, or anything else that needs
	80	to be set up. */
	81
	82	void
	83	auth_spa_init(auth_instance *ablock)
	84	{
	85	auth_spa_options_block *ob =
	86	(auth_spa_options_block *)(ablock->options_block);
	87
	88	/* The public name defaults to the authenticator name */
	89
	90	if (ablock->public_name == NULL) ablock->public_name = ablock->name;
	91
	92	/* Both username and password must be set for a client */
	93
	94	if ((ob->spa_username == NULL) != (ob->spa_password == NULL))
95	log_write(0, LOG_PANIC_DIE\|LOG_CONFIG_FOR, "%s authenticator:\n "
96	"one of client_username and client_password cannot be set without "
97	"the other", ablock->name);
98	ablock->client = ob->spa_username != NULL;
99
100	/* For a server we have just one option */
101
102	ablock->server = ob->spa_serverpassword != NULL;
103	}
104
105
106
107	/*************************************************
108	* Server entry point *
109	*************************************************/
110
111	/* For interface, see auths/README */
112
113	#define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
114	#define PVAL(buf,pos) ((unsigned)CVAL(buf,pos))
115	#define SVAL(buf,pos) (PVAL(buf,pos)\|PVAL(buf,(pos)+1)<<8)
116	#define IVAL(buf,pos) (SVAL(buf,pos)\|SVAL(buf,(pos)+2)<<16)
117
118	int
119	auth_spa_server(auth_instance ablock, uschar data)
120	{
121	auth_spa_options_block ob = (auth_spa_options_block )(ablock->options_block);
122	uint8x lmRespData[24];
123	uint8x ntRespData[24];
124	SPAAuthRequest request;
125	SPAAuthChallenge challenge;
126	SPAAuthResponse response;
127	SPAAuthResponse *responseptr = &response;
128	uschar msgbuf[2048];
129	uschar *clearpass;
130
55c75993 PP	131	/* send a 334, MS Exchange style, and grab the client's request,
55c75993 PP	132	unless we already have it via an initial response. */
0756eb3c	133
55c75993 PP	134	if ((*data == '\0') &&
55c75993 PP	135	(auth_get_no64_data(&data, US"NTLM supported") != OK))
0756eb3c PH	136	{
	137	/* something borked */
	138	return FAIL;
	139	}
	140
85b87bc2	141	if (spa_base64_to_bits((char )(&request), sizeof(request), (const char )(data)) < 0)
0756eb3c PH	142	{
	143	DEBUG(D_auth) debug_printf("auth_spa_server(): bad base64 data in "
	144	"request: %s\n", data);
	145	return FAIL;
	146	}
	147
	148	/* create a challenge and send it back */
	149
	150	spa_build_auth_challenge(&request,&challenge);
	151	spa_bits_to_base64 (msgbuf, (unsigned char*)&challenge,
	152	spa_request_length(&challenge));
	153
	154	if (auth_get_no64_data(&data, msgbuf) != OK)
	155	{
	156	/* something borked */
	157	return FAIL;
	158	}
	159
	160	/* dump client response */
85b87bc2	161	if (spa_base64_to_bits((char )(&response), sizeof(response), (const char )(data)) < 0)
0756eb3c PH	162	{
	163	DEBUG(D_auth) debug_printf("auth_spa_server(): bad base64 data in "
	164	"response: %s\n", data);
	165	return FAIL;
	166	}
	167
0756eb3c PH	168	/***************************************************************
	169	PH 07-Aug-2003: The original code here was this:
	170
	171	Ustrcpy(msgbuf, unicodeToString(((char*)responseptr) +
	172	IVAL(&responseptr->uUser.offset,0),
	173	SVAL(&responseptr->uUser.len,0)/2) );
	174
	175	However, if the response data is too long, unicodeToString bombs out on
	176	an assertion failure. It uses a 1024 fixed buffer. Bombing out is not a good
	177	idea. It's too messy to try to rework that function to return an error because
	178	it is called from a number of other places in the auth-spa.c module. Instead,
	179	since it is a very small function, I reproduce its code here, with a size check
	180	that causes failure if the size of msgbuf is exceeded. ****/
	181
	182	{
	183	int i;
	184	char p = ((char)responseptr) + IVAL(&responseptr->uUser.offset,0);
	185	int len = SVAL(&responseptr->uUser.len,0)/2;
	186
	187	if (len + 1 >= sizeof(msgbuf)) return FAIL;
	188	for (i = 0; i < len; ++i)
	189	{
	190	msgbuf[i] = *p & 0x7f;
	191	p += 2;
	192	}
	193	msgbuf[i] = 0;
	194	}
	195
	196	/***************************************************************/
	197
f78eb7c6 PH	198	/* Put the username in $auth1 and $1. The former is now the preferred variable;
	199	the latter is the original variable. */
	200
	201	auth_vars[0] = expand_nstring[1] = msgbuf;
0756eb3c PH	202	expand_nlength[1] = Ustrlen(msgbuf);
	203	expand_nmax = 1;
	204
08488c86 PP	205	/* clean up globals which aren't referenced, but still shouldn't be left
	206	pointing to stack memory */
	207	#define CLEANUP_RETURN(Code) do { auth_vars[0] = expand_nstring[1] = NULL; \
	208	expand_nlength[1] = expand_nmax = 0; return (Code); } while (0);
	209
f78eb7c6 PH	210	debug_print_string(ablock->server_debug_string); /* customized debug */
f78eb7c6 PH	211
0756eb3c PH	212	/* look up password */
	213
	214	clearpass = expand_string(ob->spa_serverpassword);
	215	if (clearpass == NULL)
	216	{
	217	if (expand_string_forcedfail)
	218	{
	219	DEBUG(D_auth) debug_printf("auth_spa_server(): forced failure while "
	220	"expanding spa_serverpassword\n");
08488c86	221	CLEANUP_RETURN(FAIL);
0756eb3c PH	222	}
	223	else
	224	{
	225	DEBUG(D_auth) debug_printf("auth_spa_server(): error while expanding "
	226	"spa_serverpassword: %s\n", expand_string_message);
08488c86	227	CLEANUP_RETURN(DEFER);
0756eb3c PH	228	}
	229	}
	230
	231	/* create local hash copy */
	232
	233	spa_smb_encrypt (clearpass, challenge.challengeData, lmRespData);
	234	spa_smb_nt_encrypt (clearpass, challenge.challengeData, ntRespData);
	235
	236	/* compare NT hash (LM may not be available) */
	237
	238	if (memcmp(ntRespData,
	239	((unsigned char*)responseptr)+IVAL(&responseptr->ntResponse.offset,0),
	240	24) == 0)
	241	/* success. we have a winner. */
08488c86 PP	242	{
	243	int rc = auth_check_serv_cond(ablock);
	244	CLEANUP_RETURN(rc);
	245	}
16ff981e PH	246
16ff981e PH	247	/* Expand server_condition as an authorization check (PH) */
0756eb3c	248
08488c86	249	CLEANUP_RETURN(FAIL);
0756eb3c PH	250	}
	251
	252
	253	/*************************************************
	254	* Client entry point *
	255	*************************************************/
	256
	257	/* For interface, see auths/README */
	258
	259	int
	260	auth_spa_client(
	261	auth_instance ablock, / authenticator block */
	262	smtp_inblock inblock, / connection inblock */
	263	smtp_outblock outblock, / connection outblock */
	264	int timeout, /* command timeout */
	265	uschar buffer, / buffer for reading response */
	266	int buffsize) /* size of buffer */
	267	{
	268	auth_spa_options_block *ob =
	269	(auth_spa_options_block *)(ablock->options_block);
	270	SPAAuthRequest request;
	271	SPAAuthChallenge challenge;
	272	SPAAuthResponse response;
	273	char msgbuf[2048];
	274	char *domain = NULL;
	275	char username, password;
	276
0756eb3c PH	277	/* Code added by PH to expand the options */
0756eb3c PH	278
4730f942 PH	279	buffer = 0; / Default no message when cancelled */
4730f942 PH	280
0756eb3c PH	281	username = CS expand_string(ob->spa_username);
	282	if (username == NULL)
	283	{
b1206957	284	if (expand_string_forcedfail) return CANCELLED;
0756eb3c PH	285	string_format(buffer, buffsize, "expansion of \"%s\" failed in %s "
	286	"authenticator: %s", ob->spa_username, ablock->name,
	287	expand_string_message);
	288	return ERROR;
	289	}
	290
	291	password = CS expand_string(ob->spa_password);
	292	if (password == NULL)
	293	{
b1206957	294	if (expand_string_forcedfail) return CANCELLED;
0756eb3c PH	295	string_format(buffer, buffsize, "expansion of \"%s\" failed in %s "
	296	"authenticator: %s", ob->spa_password, ablock->name,
	297	expand_string_message);
	298	return ERROR;
	299	}
	300
	301	if (ob->spa_domain != NULL)
	302	{
	303	domain = CS expand_string(ob->spa_domain);
	304	if (domain == NULL)
	305	{
b1206957	306	if (expand_string_forcedfail) return CANCELLED;
0756eb3c PH	307	string_format(buffer, buffsize, "expansion of \"%s\" failed in %s "
	308	"authenticator: %s", ob->spa_domain, ablock->name,
	309	expand_string_message);
	310	return ERROR;
	311	}
	312	}
	313
	314	/* Original code */
	315
b1206957 PH	316	if (smtp_write_command(outblock, FALSE, "AUTH %s\r\n",
	317	ablock->public_name) < 0)
	318	return FAIL_SEND;
	319
	320	/* wait for the 3XX OK message */
	321	if (!smtp_read_response(inblock, (uschar *)buffer, buffsize, '3', timeout))
	322	return FAIL;
	323
0756eb3c PH	324	DSPA("\n\n%s authenticator: using domain %s\n\n",
	325	ablock->name, domain);
	326
	327	spa_build_auth_request (&request, CS username, domain);
	328	spa_bits_to_base64 (US msgbuf, (unsigned char*)&request,
	329	spa_request_length(&request));
	330
	331	DSPA("\n\n%s authenticator: sending request (%s)\n\n", ablock->name,
	332	msgbuf);
	333
	334	/* send the encrypted password */
	335	if (smtp_write_command(outblock, FALSE, "%s\r\n", msgbuf) < 0)
	336	return FAIL_SEND;
	337
	338	/* wait for the auth challenge */
	339	if (!smtp_read_response(inblock, (uschar *)buffer, buffsize, '3', timeout))
	340	return FAIL;
	341
	342	/* convert the challenge into the challenge struct */
	343	DSPA("\n\n%s authenticator: challenge (%s)\n\n",
	344	ablock->name, buffer + 4);
85b87bc2	345	spa_base64_to_bits ((char )(&challenge), sizeof(challenge), (const char )(buffer + 4));
0756eb3c PH	346
	347	spa_build_auth_response (&challenge, &response,
	348	CS username, CS password);
	349	spa_bits_to_base64 (US msgbuf, (unsigned char*)&response,
	350	spa_request_length(&response));
	351	DSPA("\n\n%s authenticator: challenge response (%s)\n\n", ablock->name,
	352	msgbuf);
	353
	354	/* send the challenge response */
	355	if (smtp_write_command(outblock, FALSE, "%s\r\n", msgbuf) < 0)
	356	return FAIL_SEND;
	357
	358	/* If we receive a success response from the server, authentication
	359	has succeeded. There may be more data to send, but is there any point
	360	in provoking an error here? */
	361	if (smtp_read_response(inblock, US buffer, buffsize, '2', timeout))
	362	return OK;
	363
	364	/* Not a success response. If errno != 0 there is some kind of transmission
	365	error. Otherwise, check the response code in the buffer. If it starts with
	366	'3', more data is expected. */
	367	if (errno != 0 \|\| buffer[0] != '3')
	368	return FAIL;
	369
	370	return FAIL;
	371	}
	372
	373	/* End of spa.c */