From 32051f419344a4490e805ff462cd1184476b9fe5 Mon Sep 17 00:00:00 2001
From: Radovan Sroka <rsroka@redhat.com>
Date: Mon, 24 Jan 2022 11:27:48 +0100
Subject: [PATCH] Backport fix for CVE-2021-45417

Resolves: rhbz#2041950
---
 aide-0.16-CVE-2021-45417.patch | 123 +++++++++++++++++++++++++++++++++
 aide.spec                      |   8 ++-
 2 files changed, 130 insertions(+), 1 deletion(-)
 create mode 100644 aide-0.16-CVE-2021-45417.patch

diff --git a/aide-0.16-CVE-2021-45417.patch b/aide-0.16-CVE-2021-45417.patch
new file mode 100644
index 0000000..1752df3
--- /dev/null
+++ b/aide-0.16-CVE-2021-45417.patch
@@ -0,0 +1,123 @@
+diff --git a/include/base64.h b/include/base64.h
+index 0ff7116..381ef5d 100644
+--- a/include/base64.h
++++ b/include/base64.h
+@@ -36,7 +36,6 @@
+ #include <assert.h>
+ #include "types.h"
+ 
+-#define B64_BUF 16384
+ #define FAIL -1
+ #define SKIP -2
+ 
+diff --git a/src/base64.c b/src/base64.c
+index fd01bac..1b0f301 100644
+--- a/src/base64.c
++++ b/src/base64.c
+@@ -85,11 +85,9 @@ FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL
+ };
+ 
+ /* Returns NULL on error */
+-/* FIXME Possible buffer overflow on outputs larger than B64_BUF */
+ char* encode_base64(byte* src,size_t ssize)
+ {
+   char* outbuf;
+-  char* retbuf;
+   int pos;
+   int i, l, left;
+   unsigned long triple;
+@@ -101,7 +99,10 @@ char* encode_base64(byte* src,size_t ssize)
+     error(240,"\n");
+     return NULL;
+   }
+-  outbuf = (char *)malloc(sizeof(char)*B64_BUF);
++
++  /* length of encoded base64 string (padded) */
++  size_t length = sizeof(char)* ((ssize + 2) / 3) * 4;
++  outbuf = (char *)malloc(length + 1);
+   
+   /* Initialize working pointers */
+   inb = src;
+@@ -162,20 +163,14 @@ char* encode_base64(byte* src,size_t ssize)
+       inb++;
+   }
+   
+-  /* outbuf is not completely used so we use retbuf */
+-  retbuf=(char*)malloc(sizeof(char)*(pos+1));
+-  memcpy(retbuf,outbuf,pos);
+-  retbuf[pos]='\0';
+-  free(outbuf);
++  outbuf[pos]='\0';
+ 
+-  return retbuf;
++  return outbuf;
+ }
+ 
+-/* FIXME Possible buffer overflow on outputs larger than B64_BUF */
+ byte* decode_base64(char* src,size_t ssize, size_t *ret_len)
+ {
+   byte* outbuf;
+-  byte* retbuf;
+   char* inb;
+   int i;
+   int l;
+@@ -188,10 +183,18 @@ byte* decode_base64(char* src,size_t ssize, size_t *ret_len)
+   if (!ssize||src==NULL)
+     return NULL;
+ 
++  /* exit on unpadded input */
++  if (ssize % 4) {
++    error(3, "decode_base64: '%s' has invalid length (missing padding characters?)", src);
++    return NULL;
++  }
++
++  /* calculate length of decoded string, substract padding chars if any (ssize is >= 4) */
++  size_t length = sizeof(byte) * ((ssize / 4) * 3)- (src[ssize-1] == '=') - (src[ssize-2] == '=');
+ 
+   /* Initialize working pointers */
+   inb = src;
+-  outbuf = (byte *)malloc(sizeof(byte)*B64_BUF);
++  outbuf = (byte *)malloc(length + 1);
+ 
+   l = 0;
+   triple = 0;
+@@ -243,15 +246,11 @@ byte* decode_base64(char* src,size_t ssize, size_t *ret_len)
+       inb++;
+     }
+   
+-  retbuf=(byte*)malloc(sizeof(byte)*(pos+1));
+-  memcpy(retbuf,outbuf,pos);
+-  retbuf[pos]='\0';
+-  
+-  free(outbuf);
++  outbuf[pos]='\0';
+ 
+   if (ret_len) *ret_len = pos;
+   
+-  return retbuf;
++  return outbuf;
+ }
+ 
+ size_t length_base64(char* src,size_t ssize)
+diff --git a/src/db.c b/src/db.c
+index 858240d..62c4faa 100644
+--- a/src/db.c
++++ b/src/db.c
+@@ -664,13 +664,15 @@ db_line* db_char2line(char** ss,int db){
+ 
+ time_t base64totime_t(char* s){
+   
++  if(strcmp(s,"0")==0){
++      return 0;
++  }
+   byte* b=decode_base64(s,strlen(s),NULL);
+   char* endp;
+   
+-  if (b==NULL||strcmp(s,"0")==0) {
++  if (b==NULL) {
+     
+     /* Should we print error here? */
+-    free(b);
+     
+     return 0;
+   } else {
diff --git a/aide.spec b/aide.spec
index 5901c61..7bdd197 100644
--- a/aide.spec
+++ b/aide.spec
@@ -1,7 +1,7 @@
 Summary:        Intrusion detection environment
 Name:           aide
 Version:        0.16
-Release:        21%{?dist}
+Release:        100%{?dist}
 URL:            http://sourceforge.net/projects/aide
 License:        GPLv2+
 
@@ -39,6 +39,8 @@ Patch7: aide-0.16-crash-elf.patch
 Patch8: aide-configure.patch
 Patch9: aide-static-analysis.patch
 
+Patch10: aide-0.16-CVE-2021-45417.patch
+
 %description
 AIDE (Advanced Intrusion Detection Environment) is a file integrity
 checker and intrusion detection program.
@@ -84,6 +86,10 @@ mkdir -p -m0700 %{buildroot}%{_localstatedir}/lib/aide
 %dir %attr(0700,root,root) %{_localstatedir}/log/aide
 
 %changelog
+* Mon Jan 24 2022 Radovan Sroka <rsroka@redhat.com> - 0.16-100
+- backport fix for CVE-2021-45417
+  Resolves: rhbz#2041950
+
 * Mon Aug 09 2021 Mohan Boddu <mboddu@redhat.com> - 0.16-21
 - Rebuilt for IMA sigs, glibc 2.34, aarch64 flags
   Related: rhbz#1991688