Realization while thinking about the recently added truncate: in a STL

container like vector, truncate is simply resize, but what
MemoryRegion called resize will zap the entire contents, and then what
was resize was called grow_to. This is really problematic in terms of
the goal of replacing MemoryRegion with a vector with a custom
allocator.

In this checkin:
  - Remove MemoryRegion::grow_to and MemoryRegion::truncate

  - Change the semantics of MemoryRegion::resize to change the size
    while keeping any current contents intact (up to the new size),
    zero initializing any new values.

Unrelated, just noticed the lack while I was in there, add a version
of CryptoBox::decrypt taking a std::string for the input.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/math/bigint/bigint.cpp b/src/math/bigint/bigint.cpp
index 7feec4d59..1ae8be130 100644
--- a/src/math/bigint/bigint.cpp
+++ b/src/math/bigint/bigint.cpp
@@ -114,7 +114,7 @@ void BigInt::swap(BigInt& other)
 */
 void BigInt::grow_reg(u32bit n)
    {
-   reg.grow_to(round_up<u32bit>(size() + n, 8));
+   reg.resize(round_up<u32bit>(size() + n, 8));
    }
 
 /*
@@ -123,7 +123,7 @@ void BigInt::grow_reg(u32bit n)
 void BigInt::grow_to(u32bit n)
    {
    if(n > size())
-      reg.grow_to(round_up<u32bit>(n, 8));
+      reg.resize(round_up<u32bit>(n, 8));
    }
 
 /*
@@ -348,6 +348,7 @@ void BigInt::binary_decode(const byte buf[], u32bit length)
    {
    const u32bit WORD_BYTES = sizeof(word);
 
+   reg.clear();
    reg.resize(round_up<u32bit>((length / WORD_BYTES) + 1, 8));
 
    for(u32bit j = 0; j != length / WORD_BYTES; ++j)