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

3 files changed, 3 insertions, 0 deletions

diff --git a/src/lib/modes/cbc/cbc.cpp b/src/lib/modes/cbc/cbc.cpp
index 27f2bce4a..dd6550fce 100644
--- a/src/lib/modes/cbc/cbc.cpp
+++ b/src/lib/modes/cbc/cbc.cpp
@@ -105,6 +105,7 @@ size_t CBC_Encryption::minimum_final_size() const
 
 size_t CBC_Encryption::output_length(size_t input_length) const
    {
+   BOTAN_ASSERT(input_length != 0, "CBC_Encryption::output_length() call");
    return round_up(input_length, cipher().block_size());
    }
 
diff --git a/src/lib/modes/ecb/ecb.cpp b/src/lib/modes/ecb/ecb.cpp
index 73a241394..6de00f18a 100644
--- a/src/lib/modes/ecb/ecb.cpp
+++ b/src/lib/modes/ecb/ecb.cpp
@@ -83,6 +83,7 @@ size_t ECB_Encryption::minimum_final_size() const
 
 size_t ECB_Encryption::output_length(size_t input_length) const
    {
+   BOTAN_ASSERT(input_length != 0, "ECB_Encryption::output_length() call");
    return round_up(input_length, cipher().block_size());
    }
 
diff --git a/src/lib/modes/xts/xts.cpp b/src/lib/modes/xts/xts.cpp
index cc0e6d54c..4eaf03fe5 100644
--- a/src/lib/modes/xts/xts.cpp
+++ b/src/lib/modes/xts/xts.cpp
@@ -135,6 +135,7 @@ void XTS_Mode::update_tweak(size_t which)
 
 size_t XTS_Encryption::output_length(size_t input_length) const
    {
+   BOTAN_ASSERT(input_length != 0, "XTS_Encryption::output_length() call");
    return round_up(input_length, cipher().block_size());
    }