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Fix buffer length checking.

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git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@793 ec53bebd-3082-4978-b11e-865c3cabbd6b
This commit is contained in:
Johan Danielsson
1996-09-29 01:43:42 +00:00
parent 89c5cf1f40
commit d2c55ba4cc
1 changed files with 15 additions and 7 deletions
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22
appl/ftp/ftpd/kauth.c
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@@ -46,6 +46,7 @@ store_ticket(KTEXT cip)
char srealm[REALM_SZ]; char srealm[REALM_SZ];
unsigned char kvno; unsigned char kvno;
KTEXT_ST tkt; KTEXT_ST tkt;
int left = cip->length;
int kerror; int kerror;
@@ -56,42 +57,49 @@ store_ticket(KTEXT cip)
/* extract session key */ /* extract session key */
memmove(session, ptr, 8); memmove(session, ptr, 8);
ptr += 8; ptr += 8;
left -= 8;
if ((strlen(ptr) + (ptr - (char *) cip->dat)) > cip->length) if (strnlen(ptr, left) == left)
return(INTK_BADPW); return(INTK_BADPW);
/* extract server's name */ /* extract server's name */
strcpy(sname,ptr); strcpy(sname,ptr);
ptr += strlen(sname) + 1; ptr += strlen(sname) + 1;
left -= strlen(sname) + 1;
if ((strlen(ptr) + (ptr - (char *) cip->dat)) > cip->length) if (strnlen(ptr, left) == left)
return(INTK_BADPW); return(INTK_BADPW);
/* extract server's instance */ /* extract server's instance */
strcpy(sinst, ptr); strcpy(sinst, ptr);
ptr += strlen(sinst) + 1; ptr += strlen(sinst) + 1;
left -= strlen(sinst) + 1;
if ((strlen(ptr) + (ptr - (char *) cip->dat)) > cip->length) if (strnlen(ptr, left) == left)
return(INTK_BADPW); return(INTK_BADPW);
/* extract server's realm */ /* extract server's realm */
strcpy(srealm,ptr); strcpy(srealm,ptr);
ptr += strlen(srealm) + 1; ptr += strlen(srealm) + 1;
left -= strlen(srealm) + 1;
if(left < 3)
return INTK_BADPW;
/* extract ticket lifetime, server key version, ticket length */ /* extract ticket lifetime, server key version, ticket length */
/* be sure to avoid sign extension on lifetime! */ /* be sure to avoid sign extension on lifetime! */
lifetime = (unsigned char) ptr[0]; lifetime = (unsigned char) ptr[0];
kvno = (unsigned char) ptr[1]; kvno = (unsigned char) ptr[1];
tkt.length = (unsigned char) ptr[2]; tkt.length = (unsigned char) ptr[2];
ptr += 3; ptr += 3;
left -= 3;
if ((tkt.length < 0) || if (tkt.length > left)
((tkt.length + (ptr - (char *) cip->dat)) > cip->length))
return(INTK_BADPW); return(INTK_BADPW);
/* extract ticket itself */ /* extract ticket itself */
memmove(tkt.dat, ptr, tkt.length); memmove(tkt.dat, ptr, tkt.length);
ptr += tkt.length; ptr += tkt.length;
left -= tkt.length;
/* Here is where the time should be verified against the KDC. /* Here is where the time should be verified against the KDC.
* Unfortunately everything is sent in host byte order (receiver * Unfortunately everything is sent in host byte order (receiver
@@ -145,7 +153,7 @@ void kauth(char *principal, char *ticket)
return; return;
} }
if(realm[0] == 0) if(realm[0] == 0)
krb_get_lrealm(realm, 0); krb_get_lrealm(realm, 1);
if(ticket){ if(ticket){
cip.length = base64_decode(ticket, &cip.dat); cip.length = base64_decode(ticket, &cip.dat);