added DigestEngine::digestFromHex(const std::string& digest) method

This commit is contained in:
Marian Krivos 2012-04-28 09:32:25 +00:00
parent bd59670069
commit a4931bb9af
2 changed files with 232 additions and 193 deletions

View File

@ -85,6 +85,9 @@ public:
static std::string digestToHex(const Digest& bytes);
/// Converts a message digest into a string of hexadecimal numbers.
static Digest digestFromHex(const std::string& digest);
/// Converts a string created by digestToHex back to its Digest presentation
protected:
virtual void updateImpl(const void* data, unsigned length) = 0;
/// Updates the digest with the given data. Must be implemented

View File

@ -35,6 +35,7 @@
#include "Poco/DigestEngine.h"
#include "Poco/Exception.h"
namespace Poco {
@ -65,4 +66,39 @@ std::string DigestEngine::digestToHex(const Digest& bytes)
}
DigestEngine::Digest DigestEngine::digestFromHex(const std::string& digest)
{
if (digest.size() % 2 != 0)
throw DataFormatException();
Digest result;
result.reserve(digest.size()/2);
for (std::size_t i = 0; i < digest.size(); ++i)
{
int c = 0;
// first upper 4 bits
if (digest[i] >= '0' && digest[i] <= '9')
c = digest[i] - '0';
else if (digest[i] >= 'a' && digest[i] <= 'f')
c = digest[i] - 'a'+10;
else if (digest[i] >= 'A' && digest[i] <= 'F')
c = digest[i] - 'A'+10;
else
throw DataFormatException();
c <<= 4;
++i;
if (digest[i] >= '0' && digest[i] <= '9')
c += digest[i] - '0';
else if (digest[i] >= 'a' && digest[i] <= 'f')
c += digest[i] - 'a'+10;
else if (digest[i] >= 'A' && digest[i] <= 'F')
c += digest[i] - 'A'+10;
else
throw DataFormatException();
result.push_back(static_cast<unsigned char>(c));
}
return result;
}
} // namespace Poco