From 1aff05ea293463e829483b4d75a90e0a1fe07c74 Mon Sep 17 00:00:00 2001
From: Alexander Vdolainen <alex@vapaa.xyz>
Date: Tue, 6 Apr 2021 01:37:06 +0300
Subject: [PATCH] smtp fix;

---
 src/smtp.c | 28 ++++++++++++++++++++--------
 1 file changed, 20 insertions(+), 8 deletions(-)

diff --git a/src/smtp.c b/src/smtp.c
index 97617bc..33ef9f4 100644
--- a/src/smtp.c
+++ b/src/smtp.c
@@ -51,45 +51,57 @@ int smtp_checkuser(struct tlsport *p, struct ejabber_msg *m, const char *host)
   len = mlen = r = 0;
   memset(buf, 0, SMTPLINE_LENGTH);
 
+  /* read greetings, shall be 220 for error code */
+  len = tls_io(p, buf, SMTPLINE_LENGTH - sizeof(char), TLSIO_READ);
+  if(len < 3) return -1;
+  else if(strncmp(buf, "220", 3)) return -1;
+  memset(buf, 0, len + sizeof(char));
+
   /* start with hello */
-  mlen = strlen(host) + sizeof(char)*5;
+  mlen = strlen(host) + sizeof(char)*6;
   if(mlen > SMTPLINE_LENGTH - sizeof(char)) return -1; /* too long message */
-  snprintf(buf, mlen + sizeof(char), "HELO %s", host);
+  snprintf(buf, mlen + sizeof(char), "HELO %s\n", host);
   len = tls_io(p, buf, mlen, TLSIO_WRITE);
+
   if(len < 0) return -1;
   else memset(buf, 0, mlen);
+
   /* check the reply if any */
   len = tls_io(p, buf, SMTPLINE_LENGTH - sizeof(char), TLSIO_READ);
   if(len < 4) return -1;
   else if(strncmp(buf, "250 ", 4)) return -1;
+  memset(buf, 0, len + sizeof(char));
 
   /* set mail from */
-  mlen = strlen(m->user) + strlen(m->domain) + 15*sizeof(char);
+  mlen = strlen(m->user) + strlen(m->domain) + 14*sizeof(char);
   if(mlen > SMTPLINE_LENGTH - sizeof(char)) return -1; /* too long message */
-  snprintf(buf, mlen + sizeof(char), "mail from:<%s@%s>", m->user, m->domain);
+  snprintf(buf, mlen + sizeof(char), "mail from:<%s@%s>\n", m->user, m->domain);
   len = tls_io(p, buf, mlen, TLSIO_WRITE);
+
   if(len < 0) return -1;
   else memset(buf, 0, mlen);
   /* check the reply if any */
   len = tls_io(p, buf, SMTPLINE_LENGTH - sizeof(char), TLSIO_READ);
   if(len < 4) return -1;
   else if(strncmp(buf, "250 ", 4)) return -1;
+  memset(buf, 0, len + sizeof(char));
 
   /* set recepient, if it's ok - user exists, if it's not - no such user */
-  mlen = strlen(m->user) + strlen(m->domain) + 11*sizeof(char);
+  mlen = strlen(m->user) + strlen(m->domain) + 12*sizeof(char);
   if(mlen > SMTPLINE_LENGTH - sizeof(char)) return -1; /* too long message */
-  snprintf(buf, mlen + sizeof(char), "rcpt to:<%s@%s>", m->user, m->domain);
+  snprintf(buf, mlen + sizeof(char), "rcpt to:<%s@%s>\n", m->user, m->domain);
   len = tls_io(p, buf, mlen, TLSIO_WRITE);
   if(len < 0) return -1;
   else memset(buf, 0, mlen);
+
   /* check the reply if any */
   len = tls_io(p, buf, SMTPLINE_LENGTH - sizeof(char), TLSIO_READ);
   if(len < 4) return -1;
   else if(strncmp(buf, "250 ", 4)) r = -1;
 
   /* gracefully end smtp session */
-  mlen = strlen("quit");
-  snprintf(buf, mlen + sizeof(char), "quit");
+  mlen = strlen("quit\n");
+  snprintf(buf, mlen + sizeof(char), "quit\n");
   tls_io(p, buf, mlen, TLSIO_WRITE);
 
   return r;