Use variable-size (but in one case, fixed but larger) buffers for the SASL

exchange to deal with larger SASL messages (specifically, when doing GSSAPI
with certain ticket extensions).

diff --git a/mts/smtp/smtp.c b/mts/smtp/smtp.c
index e6ac1661dd84a197e74fdd8d0813a8405eae4dcf..65de0a7fe5364ae323f5e8f59e6739ec34ad9855 100644 (file)
--- a/mts/smtp/smtp.c
+++ b/mts/smtp/smtp.c
@@ -10,6 +10,7 @@
 #include "smtp.h"
 #include <h/mts.h>
 #include <h/signals.h>
+#include <h/utils.h>
 
 #ifdef CYRUS_SASL
 #include <sasl/sasl.h>
@@ -798,17 +799,26 @@ sm_end (int type)
  * completes successfully, then authentication is successful and we've
  * (optionally) negotiated a security layer.
  */
+
+#define CHECKB64SIZE(insize, outbuf, outsize) \
+    { size_t wantout = (((insize + 2) / 3) * 4) + 32; \
+      if (wantout > outsize) { \
+          outbuf = mh_xrealloc(outbuf, outsize = wantout); \
+      } \
+    }
+
 static int
 sm_auth_sasl(char *user, int saslssf, char *mechlist, char *inhost)
 {
     int result, status;
     unsigned int buflen, outlen;
-    char *buf, outbuf[BUFSIZ], host[NI_MAXHOST];
+    char *buf, *outbuf = NULL, host[NI_MAXHOST];
     const char *chosen_mech;
     sasl_security_properties_t secprops;
     sasl_ssf_t *ssf;
     int *outbufmax;
     struct nmh_creds creds = { 0, 0, 0 };
+    size_t outbufsize = 0;
 
     /*
      * Initialize the callback contexts
@@ -905,10 +915,13 @@ sm_auth_sasl(char *user, int saslssf, char *mechlist, char *inhost)
      */
 
     if (buflen) {
-       status = sasl_encode64(buf, buflen, outbuf, sizeof(outbuf), NULL);
+       CHECKB64SIZE(buflen, outbuf, outbufsize);
+       status = sasl_encode64(buf, buflen, outbuf, outbufsize, NULL);
        if (status != SASL_OK) {
            sm_ierror("SASL base64 encode failed: %s",
                      sasl_errstring(status, NULL, NULL));
+           if (outbuf)
+               free(outbuf);
            return NOTOK;
        }
 
@@ -935,8 +948,11 @@ sm_auth_sasl(char *user, int saslssf, char *mechlist, char *inhost)
 
        if (status == 235)
            break;
-       else if (status < 300 || status > 399)
+       else if (status < 300 || status > 399) {
+           if (outbuf)
+               free(outbuf);
            return RP_BHST;
+       }
        
        /*
         * Special case; a zero-length response from the SMTP server
@@ -947,12 +963,18 @@ sm_auth_sasl(char *user, int saslssf, char *mechlist, char *inhost)
        if (strcmp("=", sm_reply.text) == 0) {
            outlen = 0;
        } else {
+           if (sm_reply.length > (int) outbufsize) {
+               outbuf = mh_xrealloc(outbuf, outbufsize = sm_reply.length);
+           }
+
            result = sasl_decode64(sm_reply.text, sm_reply.length,
-                                  outbuf, sizeof(outbuf), &outlen);
+                                  outbuf, outbufsize, &outlen);
            if (result != SASL_OK) {
                smtalk(SM_AUTH, "*");
                sm_ierror("SASL base64 decode failed: %s",
                          sasl_errstring(result, NULL, NULL));
+               if (outbuf)
+                   free(outbuf);
                return NOTOK;
            }
        }
@@ -964,21 +986,29 @@ sm_auth_sasl(char *user, int saslssf, char *mechlist, char *inhost)
            smtalk(SM_AUTH, "*");
            sm_ierror("SASL client negotiation failed: %s",
                      sasl_errstring(result, NULL, NULL));
+           if (outbuf)
+               free(outbuf);
            return NOTOK;
        }
 
-       status = sasl_encode64(buf, buflen, outbuf, sizeof(outbuf), NULL);
+       CHECKB64SIZE(buflen, outbuf, outbufsize);
+       status = sasl_encode64(buf, buflen, outbuf, outbufsize, NULL);
 
        if (status != SASL_OK) {
            smtalk(SM_AUTH, "*");
            sm_ierror("SASL base64 encode failed: %s",
                      sasl_errstring(status, NULL, NULL));
+           if (outbuf)
+               free(outbuf);
            return NOTOK;
        }
        
        status = smtalk(SM_AUTH, outbuf);
     }
 
+    if (outbuf)
+       free(outbuf);
+
     /*
      * Make sure that we got the correct response
      */
@@ -1122,12 +1152,22 @@ smtalk (int time, char *fmt, ...)
 {
     va_list ap;
     int result;
-    char buffer[BUFSIZ];
+    char *buffer;
+    size_t bufsize = BUFSIZ;
+
+    buffer = mh_xmalloc(bufsize);
 
     va_start(ap, fmt);
-    vsnprintf (buffer, sizeof(buffer), fmt, ap);
+    result = vsnprintf (buffer, bufsize, fmt, ap);
     va_end(ap);
 
+    if (result > (int) bufsize) {
+       buffer = mh_xrealloc(buffer, bufsize = result + 1);
+       va_start(ap, fmt);
+       vsnprintf (buffer, bufsize, fmt, ap);
+       va_end(ap);
+    }
+
     if (sm_debug) {
        if (sasl_ssf)
                printf("(sasl-encrypted) ");
@@ -1143,6 +1183,8 @@ smtalk (int time, char *fmt, ...)
        result = smhear ();
     alarm (0);
 
+    free(buffer);
+
     return result;
 }
 

diff --git a/uip/popsbr.c b/uip/popsbr.c
index 2eb823cf91d095906b40b9fd9eef53833673e21f..479fdb1f6688a4425e1634513cffcf4beea16a66 100644 (file)
--- a/uip/popsbr.c
+++ b/uip/popsbr.c
@@ -89,12 +89,20 @@ static int putline (char *, FILE *);
  * layer.
  */
 
+#define CHECKB64SIZE(insize, outbuf, outsize) \
+    { size_t wantout = (((insize + 2) / 3) * 4) + 32; \
+      if (wantout > outsize) { \
+          outbuf = mh_xrealloc(outbuf, outsize = wantout); \
+      } \
+    }
+
 int
 pop_auth_sasl(char *user, char *host, char *mech)
 {
     int result, status, sasl_capability = 0;
     unsigned int buflen, outlen;
-    char server_mechs[256], *buf, outbuf[BUFSIZ];
+    char server_mechs[256], *buf, *outbuf = NULL;
+    size_t outbufsize = 0;
     const char *chosen_mech;
     sasl_security_properties_t secprops;
     struct pass_context p_context;
@@ -209,10 +217,13 @@ pop_auth_sasl(char *user, char *host, char *mech)
     }
 
     if (buflen) {
-       status = sasl_encode64(buf, buflen, outbuf, sizeof(outbuf), NULL);
+       CHECKB64SIZE(buflen, outbuf, outbufsize);
+       status = sasl_encode64(buf, buflen, outbuf, outbufsize, NULL);
        if (status != SASL_OK) {
            snprintf(response, sizeof(response), "SASL base64 encode "
                     "failed: %s", sasl_errstring(status, NULL, NULL));
+           if (outbuf)
+               free(outbuf);
            return NOTOK;
        }
 
@@ -221,8 +232,13 @@ pop_auth_sasl(char *user, char *host, char *mech)
        status = command("AUTH %s", chosen_mech);
 
     while (result == SASL_CONTINUE) {
-       if (status == NOTOK)
+       size_t inlen;
+
+       if (status == NOTOK) {
+           if (outbuf)
+               free(outbuf);
            return NOTOK;
+       }
        
        /*
         * If we get a "+OK" prefix to our response, then we should
@@ -241,16 +257,31 @@ pop_auth_sasl(char *user, char *host, char *mech)
            command("*");
            snprintf(response, sizeof(response),
                     "Malformed authentication message from server");
+           if (outbuf)
+               free(outbuf);
            return NOTOK;
        }
 
+       /*
+        * For decode, it will always be shorter, so just make sure
+        * that outbuf is as at least as big as the encoded response.
+        */
+
+       inlen = strlen(response + 2);
+
+       if (inlen > outbufsize) {
+           outbuf = mh_xrealloc(outbuf, outbufsize = inlen);
+       }
+
        result = sasl_decode64(response + 2, strlen(response + 2),
-                              outbuf, sizeof(outbuf), &outlen);
+                              outbuf, outbufsize, &outlen);
        
        if (result != SASL_OK) {
            command("*");
            snprintf(response, sizeof(response), "SASL base64 decode "
                     "failed: %s", sasl_errstring(result, NULL, NULL));
+           if (outbuf)
+               free(outbuf);
            return NOTOK;
        }
 
@@ -261,21 +292,30 @@ pop_auth_sasl(char *user, char *host, char *mech)
            command("*");
            snprintf(response, sizeof(response), "SASL client negotiaton "
                     "failed: %s", sasl_errdetail(conn));
+           if (outbuf)
+               free(outbuf);
            return NOTOK;
        }
 
-       status = sasl_encode64(buf, buflen, outbuf, sizeof(outbuf), NULL);
+       CHECKB64SIZE(buflen, outbuf, outbufsize);
+
+       status = sasl_encode64(buf, buflen, outbuf, outbufsize, NULL);
 
        if (status != SASL_OK) {
            command("*");
            snprintf(response, sizeof(response), "SASL base64 encode "
                     "failed: %s", sasl_errstring(status, NULL, NULL));
+           if (outbuf)
+               free(outbuf);
            return NOTOK;
        }
 
        status = command(outbuf);
     }
 
+    if (outbuf)
+       free(outbuf);
+
     /*
      * If we didn't get a positive final response, then error out
      * (that probably means we failed an authorization check).
@@ -753,9 +793,10 @@ command(const char *fmt, ...)
 static int
 vcommand (const char *fmt, va_list ap)
 {
-    char *cp, buffer[BUFSIZ];
+    char *cp, buffer[65536];
 
     vsnprintf (buffer, sizeof(buffer), fmt, ap);
+
     if (poprint) {
 #ifdef CYRUS_SASL
        if (sasl_ssf)