- merge a fix from heimdal's 2010-03-21 advisory to add more paranoid

checking for underruns when decrypting packets.

ok beck@ "sure" deraadt@

1 files changed, 13 insertions, 0 deletions

diff --git a/kerberosV/src/lib/krb5/crypto.c b/kerberosV/src/lib/krb5/crypto.c
index dab6aa79956..94e87d5c769 100644
--- a/kerberosV/src/lib/krb5/crypto.c
+++ b/kerberosV/src/lib/krb5/crypto.c
@@ -3451,6 +3451,12 @@ decrypt_internal_derived(krb5_context context,
 	return KRB5_BAD_MSIZE;
     }
 
+    if (len < checksum_sz + et->confoundersize) {
+	krb5_set_error_string(context, "Encrypted data shorter then "
+				  "checksum + confunder");
+	return KRB5_BAD_MSIZE;
+    }
+
     p = malloc(len);
     if(len != 0 && p == NULL) {
 	krb5_set_error_string(context, "malloc: out of memory");
@@ -3525,6 +3531,13 @@ decrypt_internal(krb5_context context,
     }
 
     checksum_sz = CHECKSUMSIZE(et->checksum);
+
+    if (len < checksum_sz + et->confoundersize) {
+	krb5_set_error_string(context, "Encrypted data shorter then "
+				  "checksum + confunder");
+	return KRB5_BAD_MSIZE;
+    }
+
     p = malloc(len);
     if(len != 0 && p == NULL) {
 	krb5_set_error_string(context, "malloc: out of memory");