sendmail: support AUTH PLAIN in addition to AUTH LOGIN

Implement the -am argument to allow choosing an AUTH method.
For now only PLAIN and LOGIN are supported, but others can be added
easily in the future.

AUTH PLAIN required adding a new variant of encode_base64() capable of
handling NUL characters in the input string; the old function is now a
wrapper for the newer one.

function                                             old     new   delta
encode_n_base64                                        -     236    +236
sendmail_main                                       1199    1380    +181
packed_usage                                       32873   32877      +4
encode_base64                                        242      36    -206
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/1 up/down: 421/-206)          Total: 215 bytes

Signed-off-by: Raffaello D. Di Napoli <rafdev@dinapo.li>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/mailutils/mail.c b/mailutils/mail.c
index 7af7edd6c9e58cffdcf1f5344c3ce928fc5e7c6f..2ad959f7deff09d16e9358fe85a14bab74d4ab79 100644 (file)
--- a/mailutils/mail.c
+++ b/mailutils/mail.c
@@ -108,6 +108,17 @@ static char* FAST_FUNC parse_url(char *url, char **user, char **pass)
 */
 
 void FAST_FUNC encode_base64(char *fname, const char *text, const char *eol)
+{
+       size_t len = len;
+       if (text) {
+               // though we do not call uuencode(NULL, NULL) explicitly
+               // still we do not want to break things suddenly
+               len = strlen(text);
+       }
+       encode_n_base64(fname, text, len, eol);
+}
+
+void FAST_FUNC encode_n_base64(char *fname, const char *text, size_t len, const char *eol)
 {
        enum {
                SRC_BUF_SIZE = 57,  /* This *MUST* be a multiple of 3 */
@@ -116,17 +127,12 @@ void FAST_FUNC encode_base64(char *fname, const char *text, const char *eol)
 #define src_buf text
        char src[SRC_BUF_SIZE];
        FILE *fp = fp;
-       ssize_t len = len;
        char dst_buf[DST_BUF_SIZE + 1];
 
        if (fname) {
                fp = (NOT_LONE_DASH(fname)) ? xfopen_for_read(fname) : (FILE *)text;
                src_buf = src;
-       } else if (text) {
-               // though we do not call uuencode(NULL, NULL) explicitly
-               // still we do not want to break things suddenly
-               len = strlen(text);
-       } else
+       } else if (!text)
                return;
 
        while (1) {

diff --git a/mailutils/mail.h b/mailutils/mail.h
index fa0c5b3785be5a9345933828d4dbcbcb7e1d1280..4eb2bc2c0183cf3513add662a233a7f4a2241af2 100644 (file)
--- a/mailutils/mail.h
+++ b/mailutils/mail.h
@@ -35,3 +35,4 @@ void get_cred_or_die(int fd) FAST_FUNC;
 char *send_mail_command(const char *fmt, const char *param) FAST_FUNC;
 
 void encode_base64(char *fname, const char *text, const char *eol) FAST_FUNC;
+void encode_n_base64(char *fname, const char *text, size_t size, const char *eol) FAST_FUNC;

diff --git a/mailutils/sendmail.c b/mailutils/sendmail.c
index 0170f28703c4f3b99032e9dbb2800f02f4c1d2cb..1dbaf595cb257d119b50a00bf902e459bb4ac6a8 100644 (file)
--- a/mailutils/sendmail.c
+++ b/mailutils/sendmail.c
@@ -36,7 +36,9 @@
 //usage:     "\n               openssl s_client -quiet -tls1 -connect smtp.gmail.com:465"
 //usage:     "\n                       $SMTP_ANTISPAM_DELAY: seconds to wait after helper connect"
 //usage:     "\n       -S HOST[:PORT]  Server (default $SMTPHOST or 127.0.0.1)"
-//usage:     "\n       -amLOGIN        Log in using AUTH LOGIN (-amCRAM-MD5 not supported)"
+//usage:     "\n       -amLOGIN        Log in using AUTH LOGIN"
+//usage:     "\n       -amPLAIN        or AUTH PLAIN"
+//usage:     "\n                       (-amCRAM-MD5 not supported)"
 //usage:     "\n       -auUSER         Username for AUTH"
 //usage:     "\n       -apPASS         Password for AUTH"
 //usage:     "\n"
@@ -248,6 +250,10 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
                OPT_S = 1 << 6,         // specify connection string
                OPT_a = 1 << 7,         // authentication tokens
                OPT_v = 1 << 8,         // verbosity
+       //--- from -am
+               OPT_am_mask = 3 << 14,  // AUTH method
+               OPT_am_login = 0 << 14, // AUTH LOGIN (default)
+               OPT_am_plain = 1 << 14, // AUTH PLAIN
        };
 
        // init global variables
@@ -286,9 +292,12 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
                        G.user = xstrdup(a+1);
                if ('p' == a[0])
                        G.pass = xstrdup(a+1);
-               // N.B. we support only AUTH LOGIN so far
-               //if ('m' == a[0])
-               //      G.method = xstrdup(a+1);
+               if ('m' == a[0]) {
+                       if (strcasecmp("plain", a+1) == 0)
+                               opts |= OPT_am_plain;
+                       else if (strcasecmp("login", a+1) != 0)
+                               bb_error_msg_and_die("unsupported AUTH method %s", a+1);
+               }
        }
        // N.B. list == NULL here
        //bb_error_msg("OPT[%x] AU[%s], AP[%s], AM[%s], ARGV[%s]", opts, au, ap, am, *argv);
@@ -348,13 +357,28 @@ int sendmail_main(int argc UNUSED_PARAM, char **argv)
 
        // perform authentication
        if (opts & OPT_a) {
-               smtp_check("AUTH LOGIN", 334);
                // we must read credentials unless they are given via -a[up] options
                if (!G.user || !G.pass)
                        get_cred_or_die(4);
-               encode_base64(NULL, G.user, NULL);
-               smtp_check("", 334);
-               encode_base64(NULL, G.pass, NULL);
+               if ((opts & OPT_am_mask) == OPT_am_plain) {
+                       char *plain_auth;
+                       size_t user_len, pass_len;
+                       user_len = strlen(G.user);
+                       pass_len = strlen(G.pass);
+                       smtp_check("AUTH PLAIN", 334);
+                       // use \1 as placeholders for \0 (format string is NUL-terminated)
+                       plain_auth = xasprintf("\1%s\1%s", G.user, G.pass);
+                       // substitute placeholders
+                       plain_auth[0] = '\0';
+                       plain_auth[1 + user_len] = '\0';
+                       encode_n_base64(NULL, plain_auth, 1 + user_len + 1 + pass_len, NULL);
+                       free(plain_auth);
+               } else if ((opts & OPT_am_mask) == OPT_am_login) {
+                       smtp_check("AUTH LOGIN", 334);
+                       encode_base64(NULL, G.user, NULL);
+                       smtp_check("", 334);
+                       encode_base64(NULL, G.pass, NULL);
+               }
                smtp_check("", 235);
        }