Fix round_up

1. src/lib/codec/base64/base64.cpp:           :
(round_up<size_t>(input_length, 3) / 3) * 4;
2. src/lib/codec/base64/base64.cpp:           :
(round_up<size_t>(input_length, 4) * 3) / 4;
3. src/lib/filters/transform_filter.cpp:   return round_up(target_size,
update_granularity);
4. src/lib/math/bigint/bigint.cpp:
m_reg.resize(round_up<size_t>(size, 8));
5. src/lib/math/bigint/bigint.cpp:
m_reg.resize(round_up<size_t>((length / WORD_BYTES) + 1, 8));
6. src/lib/math/numbertheory/mp_numth.cpp:   BigInt z(BigInt::Positive,
round_up<size_t>(2*x_sw, 16));
7. src/lib/modes/cbc/cbc.cpp:   return round_up(input_length,
cipher().block_size());
8. src/lib/modes/ecb/ecb.cpp:   return round_up(input_length,
cipher().block_size());
9. src/lib/modes/xts/xts.cpp:   return round_up(input_length,
cipher().block_size());
10. src/lib/pbkdf/pbkdf2/pbkdf2.cpp:   const size_t blocks_needed =
round_up(out_len, prf_sz) / prf_sz;
11. src/lib/tls/tls_record.cpp:   const size_t buf_size = round_up(
12. src/lib/utils/rounding.h:inline T round_up(T n, T align_to)

1. Reason for change
2. Reason for change
3. first argument cannot be 0 (`target_size = 1024`)
4. Is a bug in the current implementation iff `size = 0`
5. first argument cannot be 0
6. round_up should return 0 if `x_sw = 0`
7. ?
8. ?
9. ?
10. first argument cannot be 0 (`if(out_len == 0) return 0;`)
11. first argument is unlikely to be 0 (`iv_size + msg_length + mac_size
+ (block_size ? 1 : 0)`)
12. Implementation

1 files changed, 5 insertions, 6 deletions

diff --git a/src/lib/utils/rounding.h b/src/lib/utils/rounding.h
index 02edb1929..8ad324225 100644
--- a/src/lib/utils/rounding.h
+++ b/src/lib/utils/rounding.h
@@ -9,22 +9,21 @@
 #define BOTAN_ROUNDING_H__
 
 #include <botan/types.h>
+#include <botan/assert.h>
 
 namespace Botan {
 
 /**
 * Round up
-* @param n an integer
+* @param n a non-negative integer
 * @param align_to the alignment boundary
 * @return n rounded up to a multiple of align_to
 */
-template<typename T>
-inline T round_up(T n, T align_to)
+inline size_t round_up(size_t n, size_t align_to)
    {
-   if(align_to == 0)
-      return n;
+   BOTAN_ASSERT(align_to != 0, "align_to must not be 0");
 
-   if(n % align_to || n == 0)
+   if(n % align_to)
       n += align_to - (n % align_to);
    return n;
    }