Simplify Base32 and Base64 conversions

This commit is contained in:
Pieter Wuille 2017-11-07 14:24:30 -08:00
parent 3296a3bb7f
commit b3ea8ccb7a
4 changed files with 60 additions and 245 deletions

View File

@ -43,6 +43,7 @@ public:
std::string operator()(const WitnessV0KeyHash& id) const std::string operator()(const WitnessV0KeyHash& id) const
{ {
std::vector<unsigned char> data = {0}; std::vector<unsigned char> data = {0};
data.reserve(33);
ConvertBits<8, 5, true>([&](unsigned char c) { data.push_back(c); }, id.begin(), id.end()); ConvertBits<8, 5, true>([&](unsigned char c) { data.push_back(c); }, id.begin(), id.end());
return bech32::Encode(m_params.Bech32HRP(), data); return bech32::Encode(m_params.Bech32HRP(), data);
} }
@ -50,6 +51,7 @@ public:
std::string operator()(const WitnessV0ScriptHash& id) const std::string operator()(const WitnessV0ScriptHash& id) const
{ {
std::vector<unsigned char> data = {0}; std::vector<unsigned char> data = {0};
data.reserve(53);
ConvertBits<8, 5, true>([&](unsigned char c) { data.push_back(c); }, id.begin(), id.end()); ConvertBits<8, 5, true>([&](unsigned char c) { data.push_back(c); }, id.begin(), id.end());
return bech32::Encode(m_params.Bech32HRP(), data); return bech32::Encode(m_params.Bech32HRP(), data);
} }
@ -60,6 +62,7 @@ public:
return {}; return {};
} }
std::vector<unsigned char> data = {(unsigned char)id.version}; std::vector<unsigned char> data = {(unsigned char)id.version};
data.reserve(1 + (id.length * 8 + 4) / 5);
ConvertBits<8, 5, true>([&](unsigned char c) { data.push_back(c); }, id.program, id.program + id.length); ConvertBits<8, 5, true>([&](unsigned char c) { data.push_back(c); }, id.program, id.program + id.length);
return bech32::Encode(m_params.Bech32HRP(), data); return bech32::Encode(m_params.Bech32HRP(), data);
} }
@ -94,6 +97,7 @@ CTxDestination DecodeDestination(const std::string& str, const CChainParams& par
// Bech32 decoding // Bech32 decoding
int version = bech.second[0]; // The first 5 bit symbol is the witness version (0-16) int version = bech.second[0]; // The first 5 bit symbol is the witness version (0-16)
// The rest of the symbols are converted witness program bytes. // The rest of the symbols are converted witness program bytes.
data.reserve(((bech.second.size() - 1) * 5) / 8);
if (ConvertBits<5, 8, false>([&](unsigned char c) { data.push_back(c); }, bech.second.begin() + 1, bech.second.end())) { if (ConvertBits<5, 8, false>([&](unsigned char c) { data.push_back(c); }, bech.second.begin() + 1, bech.second.end())) {
if (version == 0) { if (version == 0) {
{ {

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@ -16,9 +16,9 @@ BOOST_AUTO_TEST_CASE(base32_testvectors)
for (unsigned int i=0; i<sizeof(vstrIn)/sizeof(vstrIn[0]); i++) for (unsigned int i=0; i<sizeof(vstrIn)/sizeof(vstrIn[0]); i++)
{ {
std::string strEnc = EncodeBase32(vstrIn[i]); std::string strEnc = EncodeBase32(vstrIn[i]);
BOOST_CHECK(strEnc == vstrOut[i]); BOOST_CHECK_EQUAL(strEnc, vstrOut[i]);
std::string strDec = DecodeBase32(vstrOut[i]); std::string strDec = DecodeBase32(vstrOut[i]);
BOOST_CHECK(strDec == vstrIn[i]); BOOST_CHECK_EQUAL(strDec, vstrIn[i]);
} }
} }

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@ -16,9 +16,9 @@ BOOST_AUTO_TEST_CASE(base64_testvectors)
for (unsigned int i=0; i<sizeof(vstrIn)/sizeof(vstrIn[0]); i++) for (unsigned int i=0; i<sizeof(vstrIn)/sizeof(vstrIn[0]); i++)
{ {
std::string strEnc = EncodeBase64(vstrIn[i]); std::string strEnc = EncodeBase64(vstrIn[i]);
BOOST_CHECK(strEnc == vstrOut[i]); BOOST_CHECK_EQUAL(strEnc, vstrOut[i]);
std::string strDec = DecodeBase64(strEnc); std::string strDec = DecodeBase64(strEnc);
BOOST_CHECK(strDec == vstrIn[i]); BOOST_CHECK_EQUAL(strDec, vstrIn[i]);
} }
} }

View File

@ -127,46 +127,11 @@ std::string EncodeBase64(const unsigned char* pch, size_t len)
{ {
static const char *pbase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; static const char *pbase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
std::string strRet; std::string str;
strRet.reserve((len+2)/3*4); str.reserve(((len + 2) / 3) * 4);
ConvertBits<8, 6, true>([&](int v) { str += pbase64[v]; }, pch, pch + len);
int mode=0, left=0; while (str.size() % 4) str += '=';
const unsigned char *pchEnd = pch+len; return str;
while (pch<pchEnd)
{
int enc = *(pch++);
switch (mode)
{
case 0: // we have no bits
strRet += pbase64[enc >> 2];
left = (enc & 3) << 4;
mode = 1;
break;
case 1: // we have two bits
strRet += pbase64[left | (enc >> 4)];
left = (enc & 15) << 2;
mode = 2;
break;
case 2: // we have four bits
strRet += pbase64[left | (enc >> 6)];
strRet += pbase64[enc & 63];
mode = 0;
break;
}
}
if (mode)
{
strRet += pbase64[left];
strRet += '=';
if (mode == 1)
strRet += '=';
}
return strRet;
} }
std::string EncodeBase64(const std::string& str) std::string EncodeBase64(const std::string& str)
@ -193,68 +158,32 @@ std::vector<unsigned char> DecodeBase64(const char* p, bool* pfInvalid)
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
}; };
if (pfInvalid) const char* e = p;
*pfInvalid = false; std::vector<uint8_t> val;
val.reserve(strlen(p));
std::vector<unsigned char> vchRet; while (*p != 0) {
vchRet.reserve(strlen(p)*3/4); int x = decode64_table[(unsigned char)*p];
if (x == -1) break;
int mode = 0; val.push_back(x);
int left = 0; ++p;
while (1)
{
int dec = decode64_table[(unsigned char)*p];
if (dec == -1) break;
p++;
switch (mode)
{
case 0: // we have no bits and get 6
left = dec;
mode = 1;
break;
case 1: // we have 6 bits and keep 4
vchRet.push_back((left<<2) | (dec>>4));
left = dec & 15;
mode = 2;
break;
case 2: // we have 4 bits and get 6, we keep 2
vchRet.push_back((left<<4) | (dec>>2));
left = dec & 3;
mode = 3;
break;
case 3: // we have 2 bits and get 6
vchRet.push_back((left<<6) | dec);
mode = 0;
break;
}
} }
if (pfInvalid) std::vector<unsigned char> ret;
switch (mode) ret.reserve((val.size() * 3) / 4);
{ bool valid = ConvertBits<6, 8, false>([&](unsigned char c) { ret.push_back(c); }, val.begin(), val.end());
case 0: // 4n base64 characters processed: ok
break;
case 1: // 4n+1 base64 character processed: impossible const char* q = p;
*pfInvalid = true; while (valid && *p != 0) {
break; if (*p != '=') {
valid = false;
case 2: // 4n+2 base64 characters processed: require '==' break;
if (left || p[0] != '=' || p[1] != '=' || decode64_table[(unsigned char)p[2]] != -1)
*pfInvalid = true;
break;
case 3: // 4n+3 base64 characters processed: require '='
if (left || p[0] != '=' || decode64_table[(unsigned char)p[1]] != -1)
*pfInvalid = true;
break;
} }
++p;
}
valid = valid && (p - e) % 4 == 0 && p - q < 4;
if (pfInvalid) *pfInvalid = !valid;
return vchRet; return ret;
} }
std::string DecodeBase64(const std::string& str) std::string DecodeBase64(const std::string& str)
@ -267,59 +196,11 @@ std::string EncodeBase32(const unsigned char* pch, size_t len)
{ {
static const char *pbase32 = "abcdefghijklmnopqrstuvwxyz234567"; static const char *pbase32 = "abcdefghijklmnopqrstuvwxyz234567";
std::string strRet; std::string str;
strRet.reserve((len+4)/5*8); str.reserve(((len + 4) / 5) * 8);
ConvertBits<8, 5, true>([&](int v) { str += pbase32[v]; }, pch, pch + len);
int mode=0, left=0; while (str.size() % 8) str += '=';
const unsigned char *pchEnd = pch+len; return str;
while (pch<pchEnd)
{
int enc = *(pch++);
switch (mode)
{
case 0: // we have no bits
strRet += pbase32[enc >> 3];
left = (enc & 7) << 2;
mode = 1;
break;
case 1: // we have three bits
strRet += pbase32[left | (enc >> 6)];
strRet += pbase32[(enc >> 1) & 31];
left = (enc & 1) << 4;
mode = 2;
break;
case 2: // we have one bit
strRet += pbase32[left | (enc >> 4)];
left = (enc & 15) << 1;
mode = 3;
break;
case 3: // we have four bits
strRet += pbase32[left | (enc >> 7)];
strRet += pbase32[(enc >> 2) & 31];
left = (enc & 3) << 3;
mode = 4;
break;
case 4: // we have two bits
strRet += pbase32[left | (enc >> 5)];
strRet += pbase32[enc & 31];
mode = 0;
}
}
static const int nPadding[5] = {0, 6, 4, 3, 1};
if (mode)
{
strRet += pbase32[left];
for (int n=0; n<nPadding[mode]; n++)
strRet += '=';
}
return strRet;
} }
std::string EncodeBase32(const std::string& str) std::string EncodeBase32(const std::string& str)
@ -346,102 +227,32 @@ std::vector<unsigned char> DecodeBase32(const char* p, bool* pfInvalid)
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
}; };
if (pfInvalid) const char* e = p;
*pfInvalid = false; std::vector<uint8_t> val;
val.reserve(strlen(p));
std::vector<unsigned char> vchRet; while (*p != 0) {
vchRet.reserve((strlen(p))*5/8); int x = decode32_table[(unsigned char)*p];
if (x == -1) break;
int mode = 0; val.push_back(x);
int left = 0; ++p;
while (1)
{
int dec = decode32_table[(unsigned char)*p];
if (dec == -1) break;
p++;
switch (mode)
{
case 0: // we have no bits and get 5
left = dec;
mode = 1;
break;
case 1: // we have 5 bits and keep 2
vchRet.push_back((left<<3) | (dec>>2));
left = dec & 3;
mode = 2;
break;
case 2: // we have 2 bits and keep 7
left = left << 5 | dec;
mode = 3;
break;
case 3: // we have 7 bits and keep 4
vchRet.push_back((left<<1) | (dec>>4));
left = dec & 15;
mode = 4;
break;
case 4: // we have 4 bits, and keep 1
vchRet.push_back((left<<4) | (dec>>1));
left = dec & 1;
mode = 5;
break;
case 5: // we have 1 bit, and keep 6
left = left << 5 | dec;
mode = 6;
break;
case 6: // we have 6 bits, and keep 3
vchRet.push_back((left<<2) | (dec>>3));
left = dec & 7;
mode = 7;
break;
case 7: // we have 3 bits, and keep 0
vchRet.push_back((left<<5) | dec);
mode = 0;
break;
}
} }
if (pfInvalid) std::vector<unsigned char> ret;
switch (mode) ret.reserve((val.size() * 5) / 8);
{ bool valid = ConvertBits<5, 8, false>([&](unsigned char c) { ret.push_back(c); }, val.begin(), val.end());
case 0: // 8n base32 characters processed: ok
break;
case 1: // 8n+1 base32 characters processed: impossible const char* q = p;
case 3: // +3 while (valid && *p != 0) {
case 6: // +6 if (*p != '=') {
*pfInvalid = true; valid = false;
break; break;
case 2: // 8n+2 base32 characters processed: require '======'
if (left || p[0] != '=' || p[1] != '=' || p[2] != '=' || p[3] != '=' || p[4] != '=' || p[5] != '=' || decode32_table[(unsigned char)p[6]] != -1)
*pfInvalid = true;
break;
case 4: // 8n+4 base32 characters processed: require '===='
if (left || p[0] != '=' || p[1] != '=' || p[2] != '=' || p[3] != '=' || decode32_table[(unsigned char)p[4]] != -1)
*pfInvalid = true;
break;
case 5: // 8n+5 base32 characters processed: require '==='
if (left || p[0] != '=' || p[1] != '=' || p[2] != '=' || decode32_table[(unsigned char)p[3]] != -1)
*pfInvalid = true;
break;
case 7: // 8n+7 base32 characters processed: require '='
if (left || p[0] != '=' || decode32_table[(unsigned char)p[1]] != -1)
*pfInvalid = true;
break;
} }
++p;
}
valid = valid && (p - e) % 8 == 0 && p - q < 8;
if (pfInvalid) *pfInvalid = !valid;
return vchRet; return ret;
} }
std::string DecodeBase32(const std::string& str) std::string DecodeBase32(const std::string& str)