sendmail: don't talk until 220 code is seen. Closes 3487

function old new delta sendmail_main 934 939 +5 smtp_checkp 167 165 -2 packed_usage 28634 28621 -13 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
author: Denys Vlasenko <vda.linux@googlemail.com> 2011-09-18 03:01:49 +0200
committer: Denys Vlasenko <vda.linux@googlemail.com> 2011-09-18 03:01:49 +0200
commit: 34c469ae0495bb010969eb920c63d31ed4a0e793 (patch)
tree: f9865b5433f2fc47f2d8006a7de1ef0bb06ebe76 /mailutils/sendmail.c
parent: 0851d125c33d65cc8a0655758f2928960077c20c (diff)
download: busybox-w32-34c469ae0495bb010969eb920c63d31ed4a0e793.tar.gz
busybox-w32-34c469ae0495bb010969eb920c63d31ed4a0e793.tar.bz2
busybox-w32-34c469ae0495bb010969eb920c63d31ed4a0e793.zip
1 files changed, 51 insertions, 39 deletions
diff --git a/mailutils/sendmail.c b/mailutils/sendmail.c
index e0aff20fb..dbd491002 100644
--- a/mailutils/sendmail.c
+++ b/mailutils/sendmail.c
@@ -26,18 +26,18 @@
 //usage:     "\n                        Examples:"
 //usage:     "\n                        -H 'exec openssl s_client -quiet -tls1 -starttls smtp"
 //usage:     "\n                                -connect smtp.gmail.com:25' <email.txt"
-//usage:     "\n                                [4<username_and_passwd.txt | -au<username> -ap<password>]"
+//usage:     "\n                                [4<username_and_passwd.txt | -auUSER -apPASS]"
 //usage:     "\n                        -H 'exec openssl s_client -quiet -tls1"
 //usage:     "\n                                -connect smtp.gmail.com:465' <email.txt"
-//usage:     "\n                                [4<username_and_passwd.txt | -au<username> -ap<password>]"
+//usage:     "\n                                [4<username_and_passwd.txt | -auUSER -apPASS]"
 //usage:     "\n        -S HOST[:PORT]  Server"
-//usage:     "\n        -au<username>   Username for AUTH LOGIN"
+//usage:     "\n        -auUSER         Username for AUTH LOGIN"
-//usage:     "\n        -ap<password>   Password for AUTH LOGIN"
+//usage:     "\n        -apPASS         Password for AUTH LOGIN"
-//usage:     "\n        -am<method>     Authentication method. Ignored. LOGIN is implied"
+////usage:     "\n      -amMETHOD       Authentication method. Ignored. LOGIN is implied"
 //usage:     "\n"
 //usage:     "\nOther options are silently ignored; -oi -t is implied"
 //usage:        IF_MAKEMIME(
-//usage:     "\nUse makemime applet to create message with attachments"
+//usage:     "\nUse makemime to create emails with attachments"
 //usage:        )
 #include "libbb.h"
@@ -66,7 +66,7 @@ static int smtp_checkp(const char *fmt, const char *param, int code)
        // if not equal -> die saying msg
        while ((answer = xmalloc_fgetline(stdin)) != NULL) {
                if (verbose)
-                        bb_error_msg("recv:'%.*s' %d", (int)(strchrnul(answer, '\r') - answer), answer, verbose);
+                        bb_error_msg("recv:'%.*s'", (int)(strchrnul(answer, '\r') - answer), answer);
                if (strlen(answer) <= 3 || '-' != answer[3])
                        break;
                free(answer);
@@ -75,10 +75,11 @@ static int smtp_checkp(const char *fmt, const char *param, int code)
                int n = atoi(answer);
                if (timeout)
                        alarm(0);
-                free(msg);
                free(answer);
-                if (-1 == code || n == code)
+                if (-1 == code || n == code) {
+                        free(msg);
                        return n;
+                }
        }
        bb_error_msg_and_die("%s failed", msg);
 }
@@ -176,11 +177,35 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
                const char *args[] = { "sh", "-c", opt_connect, NULL };
                // plug it in
                launch_helper(args);
-        // vanilla connection
+                // Now:
+                // our stdout will go to helper's stdin,
+                // helper's stdout will be available on our stdin.
+                // Wait for initial server message.
+                // If helper (such as openssl) invokes STARTTLS, the initial 220
+                // is swallowed by helper (and not repeated after TLS is initiated).
+                // We will send NOOP cmd to server and check the response.
+                // We should get 220+250 on plain connection, 250 on STARTTLSed session.
+                //
+                // The problem here is some servers delay initial 220 message,
+                // and consider client to be a spammer if it starts sending cmds
+                // before 220 reached it. The code below is unsafe in this regard:
+                // in non-STARTTLSed case, we potentially send NOOP before 220
+                // is sent by server.
+                // Ideas? (--delay SECS opt? --assume-starttls-helper opt?)
+                code = smtp_check("NOOP", -1);
+                if (code == 220)
+                        // we got 220 - this is not STARTTLSed connection,
+                        // eat 250 response to our NOOP
+                        smtp_check(NULL, 250);
+                else
+                if (code != 250)
+                        bb_error_msg_and_die("SMTP init failed");
        } else {
+                // vanilla connection
                int fd;
                // host[:port] not explicitly specified? -> use $SMTPHOST
-                // no $SMTPHOST ? -> use localhost
+                // no $SMTPHOST? -> use localhost
                if (!(opts & OPT_S)) {
                        opt_connect = getenv("SMTPHOST");
                        if (!opt_connect)
@@ -191,25 +216,14 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
                // and make ourselves a simple IO filter
                xmove_fd(fd, STDIN_FILENO);
                xdup2(STDIN_FILENO, STDOUT_FILENO);
-        }
-        // N.B. from now we know nothing about network :)
-        // wait for initial server OK
+                // Wait for initial server 220 message
-        // N.B. if we used openssl the initial 220 answer is already swallowed during openssl TLS init procedure
+                smtp_check(NULL, 220);
-        // so we need to kick the server to see whether we are ok
+        }
-        code = smtp_check("NOOP", -1);
-        // 220 on plain connection, 250 on openssl-helped TLS session
-        if (220 == code)
-                smtp_check(NULL, 250); // reread the code to stay in sync
-        else if (250 != code)
-                bb_error_msg_and_die("INIT failed");
        // we should start with modern EHLO
-        if (250 != smtp_checkp("EHLO %s", domain, -1)) {
+        if (250 != smtp_checkp("EHLO %s", domain, -1))
                smtp_checkp("HELO %s", domain, 250);
-        }
-        if (ENABLE_FEATURE_CLEAN_UP)
-                free(domain);
        // perform authentication
        if (opts & OPT_a) {
@@ -224,7 +238,7 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
        }
        // set sender
-        // N.B. we have here a very loosely defined algotythm
+        // N.B. we have here a very loosely defined algorythm
        // since sendmail historically offers no means to specify secrets on cmdline.
        // 1) server can require no authentication ->
        //      we must just provide a (possibly fake) reply address.
@@ -241,8 +255,6 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
        //      G.user = xuid2uname(getuid());
        //      opt_from = xasprintf("%s@%s", G.user, domain);
        //}
-        //if (ENABLE_FEATURE_CLEAN_UP)
-        //      free(domain);
        smtp_checkp("MAIL FROM:<%s>", opt_from, 250);
        // process message
@@ -272,26 +284,26 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
                if (0 == strncasecmp("To:", s, 3) || 0 == strncasecmp("Bcc:" + 1, s, 3)) {
                        rcptto(sane_address(s+3));
                        goto addheader;
+                }
                // Bcc: header adds blind copy (hidden) recipient
-                } else if (0 == strncasecmp("Bcc:", s, 4)) {
+                if (0 == strncasecmp("Bcc:", s, 4)) {
                        rcptto(sane_address(s+4));
                        free(s);
                        // N.B. Bcc: vanishes from headers!
+                } else
-                // other headers go verbatim
+                if (strchr(s, ':') || (list && skip_whitespace(s) != s)) {
+                        // other headers go verbatim
-                // N.B. RFC2822 2.2.3 "Long Header Fields" allows for headers to occupy several lines.
+                        // N.B. RFC2822 2.2.3 "Long Header Fields" allows for headers to occupy several lines.
-                // Continuation is denoted by prefixing additional lines with whitespace(s).
+                        // Continuation is denoted by prefixing additional lines with whitespace(s).
-                // Thanks (stefan.seyfried at googlemail.com) for pointing this out.
+                        // Thanks (stefan.seyfried at googlemail.com) for pointing this out.
-                } else if (strchr(s, ':') || (list && skip_whitespace(s) != s)) {
 addheader:
                        // N.B. we allow MAX_HEADERS generic headers at most to prevent attacks
                        if (MAX_HEADERS && ++nheaders >= MAX_HEADERS)
                                goto bail;
                        llist_add_to_end(&list, s);
-                // a line without ":" (an empty line too, by definition) doesn't look like a valid header
-                // so stop "analyze headers" mode
                } else {
+                        // a line without ":" (an empty line too, by definition) doesn't look like a valid header
+                        // so stop "analyze headers" mode
 reenter:
                        // put recipients specified on cmdline
                        while (*argv) {
author	Denys Vlasenko <vda.linux@googlemail.com>	2011-09-18 03:01:49 +0200
committer	Denys Vlasenko <vda.linux@googlemail.com>	2011-09-18 03:01:49 +0200
commit	34c469ae0495bb010969eb920c63d31ed4a0e793 (patch)
tree	f9865b5433f2fc47f2d8006a7de1ef0bb06ebe76 /mailutils/sendmail.c
parent	0851d125c33d65cc8a0655758f2928960077c20c (diff)
download	busybox-w32-34c469ae0495bb010969eb920c63d31ed4a0e793.tar.gz busybox-w32-34c469ae0495bb010969eb920c63d31ed4a0e793.tar.bz2 busybox-w32-34c469ae0495bb010969eb920c63d31ed4a0e793.zip

diff --git a/mailutils/sendmail.c b/mailutils/sendmail.c index e0aff20fb..dbd491002 100644 --- a/mailutils/sendmail.c +++ b/mailutils/sendmail.c
@@ -26,18 +26,18 @@
26	//usage: "\n Examples:"	26	//usage: "\n Examples:"
27	//usage: "\n -H 'exec openssl s_client -quiet -tls1 -starttls smtp"	27	//usage: "\n -H 'exec openssl s_client -quiet -tls1 -starttls smtp"
28	//usage: "\n -connect smtp.gmail.com:25' <email.txt"	28	//usage: "\n -connect smtp.gmail.com:25' <email.txt"
29	//usage: "\n [4<username_and_passwd.txt \| -au<username> -ap<password>]"	29	//usage: "\n [4<username_and_passwd.txt \| -auUSER -apPASS]"
30	//usage: "\n -H 'exec openssl s_client -quiet -tls1"	30	//usage: "\n -H 'exec openssl s_client -quiet -tls1"
31	//usage: "\n -connect smtp.gmail.com:465' <email.txt"	31	//usage: "\n -connect smtp.gmail.com:465' <email.txt"
32	//usage: "\n [4<username_and_passwd.txt \| -au<username> -ap<password>]"	32	//usage: "\n [4<username_and_passwd.txt \| -auUSER -apPASS]"
33	//usage: "\n -S HOST[:PORT] Server"	33	//usage: "\n -S HOST[:PORT] Server"
34	//usage: "\n -au<username> Username for AUTH LOGIN"	34	//usage: "\n -auUSER Username for AUTH LOGIN"
35	//usage: "\n -ap<password> Password for AUTH LOGIN"	35	//usage: "\n -apPASS Password for AUTH LOGIN"
36	//usage: "\n -am<method> Authentication method. Ignored. LOGIN is implied"	36	////usage: "\n -amMETHOD Authentication method. Ignored. LOGIN is implied"
37	//usage: "\n"	37	//usage: "\n"
38	//usage: "\nOther options are silently ignored; -oi -t is implied"	38	//usage: "\nOther options are silently ignored; -oi -t is implied"
39	//usage: IF_MAKEMIME(	39	//usage: IF_MAKEMIME(
40	//usage: "\nUse makemime applet to create message with attachments"	40	//usage: "\nUse makemime to create emails with attachments"
41	//usage: )	41	//usage: )
42		42
43	#include "libbb.h"	43	#include "libbb.h"
@@ -66,7 +66,7 @@ static int smtp_checkp(const char fmt, const char param, int code)
66	// if not equal -> die saying msg	66	// if not equal -> die saying msg
67	while ((answer = xmalloc_fgetline(stdin)) != NULL) {	67	while ((answer = xmalloc_fgetline(stdin)) != NULL) {
68	if (verbose)	68	if (verbose)
69	bb_error_msg("recv:'%.*s' %d", (int)(strchrnul(answer, '\r') - answer), answer, verbose);	69	bb_error_msg("recv:'%.*s'", (int)(strchrnul(answer, '\r') - answer), answer);
70	if (strlen(answer) <= 3 \|\| '-' != answer[3])	70	if (strlen(answer) <= 3 \|\| '-' != answer[3])
71	break;	71	break;
72	free(answer);	72	free(answer);
@@ -75,10 +75,11 @@ static int smtp_checkp(const char fmt, const char param, int code)
75	int n = atoi(answer);	75	int n = atoi(answer);
76	if (timeout)	76	if (timeout)
77	alarm(0);	77	alarm(0);
78	free(msg);
79	free(answer);	78	free(answer);
80	if (-1 == code \|\| n == code)	79	if (-1 == code \|\| n == code) {
		80	free(msg);
81	return n;	81	return n;
		82	}
82	}	83	}
83	bb_error_msg_and_die("%s failed", msg);	84	bb_error_msg_and_die("%s failed", msg);
84	}	85	}
@@ -176,11 +177,35 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
176	const char *args[] = { "sh", "-c", opt_connect, NULL };	177	const char *args[] = { "sh", "-c", opt_connect, NULL };
177	// plug it in	178	// plug it in
178	launch_helper(args);	179	launch_helper(args);
179	// vanilla connection	180	// Now:
		181	// our stdout will go to helper's stdin,
		182	// helper's stdout will be available on our stdin.
		183
		184	// Wait for initial server message.
		185	// If helper (such as openssl) invokes STARTTLS, the initial 220
		186	// is swallowed by helper (and not repeated after TLS is initiated).
		187	// We will send NOOP cmd to server and check the response.
		188	// We should get 220+250 on plain connection, 250 on STARTTLSed session.
		189	//
		190	// The problem here is some servers delay initial 220 message,
		191	// and consider client to be a spammer if it starts sending cmds
		192	// before 220 reached it. The code below is unsafe in this regard:
		193	// in non-STARTTLSed case, we potentially send NOOP before 220
		194	// is sent by server.
		195	// Ideas? (--delay SECS opt? --assume-starttls-helper opt?)
		196	code = smtp_check("NOOP", -1);
		197	if (code == 220)
		198	// we got 220 - this is not STARTTLSed connection,
		199	// eat 250 response to our NOOP
		200	smtp_check(NULL, 250);
		201	else
		202	if (code != 250)
		203	bb_error_msg_and_die("SMTP init failed");
180	} else {	204	} else {
		205	// vanilla connection
181	int fd;	206	int fd;
182	// host[:port] not explicitly specified? -> use $SMTPHOST	207	// host[:port] not explicitly specified? -> use $SMTPHOST
183	// no $SMTPHOST ? -> use localhost	208	// no $SMTPHOST? -> use localhost
184	if (!(opts & OPT_S)) {	209	if (!(opts & OPT_S)) {
185	opt_connect = getenv("SMTPHOST");	210	opt_connect = getenv("SMTPHOST");
186	if (!opt_connect)	211	if (!opt_connect)
@@ -191,25 +216,14 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
191	// and make ourselves a simple IO filter	216	// and make ourselves a simple IO filter
192	xmove_fd(fd, STDIN_FILENO);	217	xmove_fd(fd, STDIN_FILENO);
193	xdup2(STDIN_FILENO, STDOUT_FILENO);	218	xdup2(STDIN_FILENO, STDOUT_FILENO);
194	}
195	// N.B. from now we know nothing about network :)
196		219
197	// wait for initial server OK	220	// Wait for initial server 220 message
198	// N.B. if we used openssl the initial 220 answer is already swallowed during openssl TLS init procedure	221	smtp_check(NULL, 220);
199	// so we need to kick the server to see whether we are ok	222	}
200	code = smtp_check("NOOP", -1);
201	// 220 on plain connection, 250 on openssl-helped TLS session
202	if (220 == code)
203	smtp_check(NULL, 250); // reread the code to stay in sync
204	else if (250 != code)
205	bb_error_msg_and_die("INIT failed");
206		223
207	// we should start with modern EHLO	224	// we should start with modern EHLO
208	if (250 != smtp_checkp("EHLO %s", domain, -1)) {	225	if (250 != smtp_checkp("EHLO %s", domain, -1))
209	smtp_checkp("HELO %s", domain, 250);	226	smtp_checkp("HELO %s", domain, 250);
210	}
211	if (ENABLE_FEATURE_CLEAN_UP)
212	free(domain);
213		227
214	// perform authentication	228	// perform authentication
215	if (opts & OPT_a) {	229	if (opts & OPT_a) {
@@ -224,7 +238,7 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
224	}	238	}
225		239
226	// set sender	240	// set sender
227	// N.B. we have here a very loosely defined algotythm	241	// N.B. we have here a very loosely defined algorythm
228	// since sendmail historically offers no means to specify secrets on cmdline.	242	// since sendmail historically offers no means to specify secrets on cmdline.
229	// 1) server can require no authentication ->	243	// 1) server can require no authentication ->
230	// we must just provide a (possibly fake) reply address.	244	// we must just provide a (possibly fake) reply address.
@@ -241,8 +255,6 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
241	// G.user = xuid2uname(getuid());	255	// G.user = xuid2uname(getuid());
242	// opt_from = xasprintf("%s@%s", G.user, domain);	256	// opt_from = xasprintf("%s@%s", G.user, domain);
243	//}	257	//}
244	//if (ENABLE_FEATURE_CLEAN_UP)
245	// free(domain);
246	smtp_checkp("MAIL FROM:<%s>", opt_from, 250);	258	smtp_checkp("MAIL FROM:<%s>", opt_from, 250);
247		259
248	// process message	260	// process message
@@ -272,26 +284,26 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
272	if (0 == strncasecmp("To:", s, 3) \|\| 0 == strncasecmp("Bcc:" + 1, s, 3)) {	284	if (0 == strncasecmp("To:", s, 3) \|\| 0 == strncasecmp("Bcc:" + 1, s, 3)) {
273	rcptto(sane_address(s+3));	285	rcptto(sane_address(s+3));
274	goto addheader;	286	goto addheader;
		287	}
275	// Bcc: header adds blind copy (hidden) recipient	288	// Bcc: header adds blind copy (hidden) recipient
276	} else if (0 == strncasecmp("Bcc:", s, 4)) {	289	if (0 == strncasecmp("Bcc:", s, 4)) {
277	rcptto(sane_address(s+4));	290	rcptto(sane_address(s+4));
278	free(s);	291	free(s);
279	// N.B. Bcc: vanishes from headers!	292	// N.B. Bcc: vanishes from headers!
280		293	} else
281	// other headers go verbatim	294	if (strchr(s, ':') \|\| (list && skip_whitespace(s) != s)) {
282		295	// other headers go verbatim
283	// N.B. RFC2822 2.2.3 "Long Header Fields" allows for headers to occupy several lines.	296	// N.B. RFC2822 2.2.3 "Long Header Fields" allows for headers to occupy several lines.
284	// Continuation is denoted by prefixing additional lines with whitespace(s).	297	// Continuation is denoted by prefixing additional lines with whitespace(s).
285	// Thanks (stefan.seyfried at googlemail.com) for pointing this out.	298	// Thanks (stefan.seyfried at googlemail.com) for pointing this out.
286	} else if (strchr(s, ':') \|\| (list && skip_whitespace(s) != s)) {
287	addheader:	299	addheader:
288	// N.B. we allow MAX_HEADERS generic headers at most to prevent attacks	300	// N.B. we allow MAX_HEADERS generic headers at most to prevent attacks
289	if (MAX_HEADERS && ++nheaders >= MAX_HEADERS)	301	if (MAX_HEADERS && ++nheaders >= MAX_HEADERS)
290	goto bail;	302	goto bail;
291	llist_add_to_end(&list, s);	303	llist_add_to_end(&list, s);
292	// a line without ":" (an empty line too, by definition) doesn't look like a valid header
293	// so stop "analyze headers" mode
294	} else {	304	} else {
		305	// a line without ":" (an empty line too, by definition) doesn't look like a valid header
		306	// so stop "analyze headers" mode
295	reenter:	307	reenter:
296	// put recipients specified on cmdline	308	// put recipients specified on cmdline
297	while (*argv) {	309	while (*argv) {