// Sha1Checksum.cpp
// Declares the cSha1Checksum class representing the SHA-1 checksum calculator
#include "Globals.h"
#include "Sha1Checksum.h"
/*
// Self-test the hash formatting for known values:
// sha1(Notch) : 4ed1f46bbe04bc756bcb17c0c7ce3e4632f06a48
// sha1(jeb_) : -7c9d5b0044c130109a5d7b5fb5c317c02b4e28c1
// sha1(simon) : 88e16a1019277b15d58faf0541e11910eb756f6
static class Test
{
public:
Test(void)
{
AString DigestNotch, DigestJeb, DigestSimon;
Byte Digest[20];
cSha1Checksum Checksum;
Checksum.Update((const Byte *)"Notch", 5);
Checksum.Finalize(Digest);
cSha1Checksum::DigestToJava(Digest, DigestNotch);
Checksum.Restart();
Checksum.Update((const Byte *)"jeb_", 4);
Checksum.Finalize(Digest);
cSha1Checksum::DigestToJava(Digest, DigestJeb);
Checksum.Restart();
Checksum.Update((const Byte *)"simon", 5);
Checksum.Finalize(Digest);
cSha1Checksum::DigestToJava(Digest, DigestSimon);
printf("Notch: \"%s\"\n", DigestNotch.c_str());
printf("jeb_: \"%s\"\n", DigestJeb.c_str());
printf("simon: \"%s\"\n", DigestSimon.c_str());
assert(DigestNotch == "4ed1f46bbe04bc756bcb17c0c7ce3e4632f06a48");
assert(DigestJeb == "-7c9d5b0044c130109a5d7b5fb5c317c02b4e28c1");
assert(DigestSimon == "88e16a1019277b15d58faf0541e11910eb756f6");
}
} test;
*/
////////////////////////////////////////////////////////////////////////////////
// cSha1Checksum:
cSha1Checksum::cSha1Checksum(void) :
m_DoesAcceptInput(true)
{
mbedtls_sha1_starts(&m_Sha1);
}
void cSha1Checksum::Update(const Byte * a_Data, size_t a_Length)
{
ASSERT(m_DoesAcceptInput); // Not Finalize()-d yet, or Restart()-ed
mbedtls_sha1_update(&m_Sha1, a_Data, a_Length);
}
void cSha1Checksum::Finalize(cSha1Checksum::Checksum & a_Output)
{
ASSERT(m_DoesAcceptInput); // Not Finalize()-d yet, or Restart()-ed
mbedtls_sha1_finish(&m_Sha1, a_Output);
m_DoesAcceptInput = false;
}
void cSha1Checksum::DigestToJava(const Checksum & a_Digest, AString & a_Out)
{
Checksum Digest;
memcpy(Digest, a_Digest, sizeof(Digest));
bool IsNegative = (Digest[0] >= 0x80);
if (IsNegative)
{
// Two's complement:
bool carry = true; // Add one to the whole number
for (int i = 19; i >= 0; i--)
{
Digest[i] = ~Digest[i];
if (carry)
{
carry = (Digest[i] == 0xff);
Digest[i]++;
}
}
}
a_Out.clear();
a_Out.reserve(40);
for (int i = 0; i < 20; i++)
{
AppendPrintf(a_Out, "%02x", Digest[i]);
}
while ((a_Out.length() > 0) && (a_Out[0] == '0'))
{
a_Out.erase(0, 1);
}
if (IsNegative)
{
a_Out.insert(0, "-");
}
}
void cSha1Checksum::Restart(void)
{
mbedtls_sha1_starts(&m_Sha1);
m_DoesAcceptInput = true;
}
