1 files changed, 49 insertions, 9 deletions

diff --git a/mailutils/sendmail.c b/mailutils/sendmail.c
index 0170f2870..32c50ba84 100644
--- 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 +250,8 @@ 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
+        //--- for -amMETHOD
+                OPT_am_plain = 1 << 9,  // AUTH PLAIN
         };
 
         // init global variables
@@ -286,9 +290,14 @@ 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 ((a[1] | 0x20) == 'p') // PLAIN
+                                opts |= OPT_am_plain;
+                        else if ((a[1] | 0x20) == 'l') // LOGIN
+                                ; /* do nothing (this is the default) */
+                        else
+                                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 +357,44 @@ 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
+                // 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_plain) {
+                        // C: AUTH PLAIN
+                        // S: 334
+                        // C: base64encoded(auth<NUL>user<NUL>pass)
+                        // S: 235 2.7.0 Authentication successful
+//Note: a shorter format is allowed:
+// C: AUTH PLAIN base64encoded(auth<NUL>user<NUL>pass)
+// S: 235 2.7.0 Authentication successful
+                        smtp_check("AUTH PLAIN", 334);
+                        {
+                                unsigned user_len = strlen(G.user);
+                                unsigned pass_len = strlen(G.pass);
+                                unsigned sz = 1 + user_len + 1 + pass_len;
+                                char plain_auth[sz + 1];
+                                // the format is:
+                                // "authorization identity<NUL>username<NUL>password"
+                                // authorization identity is empty.
+                                plain_auth[0] = '\0';
+                                strcpy(stpcpy(plain_auth + 1, G.user) + 1, G.pass);
+                                printbuf_base64(plain_auth, sz);
+                        }
+                } else {
+                        // C: AUTH LOGIN
+                        // S: 334 VXNlcm5hbWU6
+                        //        ^^^^^^^^^^^^ server says "Username:"
+                        // C: base64encoded(user)
+                        // S: 334 UGFzc3dvcmQ6
+                        //        ^^^^^^^^^^^^ server says "Password:"
+                        // C: base64encoded(pass)
+                        // S: 235 2.7.0 Authentication successful
+                        smtp_check("AUTH LOGIN", 334);
+                        printstr_base64(G.user);
+                        smtp_check("", 334);
+                        printstr_base64(G.pass);
+                }
                 smtp_check("", 235);
         }