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>
This commit is contained in:
Raffaello D. Di Napoli 2018-06-26 19:17:45 -04:00 committed by Denys Vlasenko
parent c16ae469ef
commit f28b8857a9
3 changed files with 45 additions and 14 deletions

View File

@ -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) {

View File

@ -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;

View File

@ -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);
}