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zcash-patched-for-explorer
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Simplify Base32 and Base64 conversions

This commit is contained in:
Pieter Wuille 2017-11-07 14:24:30 -08:00 committed by Jack Grigg
parent ac70f76c5d
commit 6a2cc8ddc0
No known key found for this signature in database
GPG Key ID: 1B8D649257DB0829
3 changed files with 56 additions and 245 deletions
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4
src/test/base32_tests.cpp
View File

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

4
src/test/base64_tests.cpp
View File

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

293
src/utilstrencodings.cpp
View File

@ -127,46 +127,11 @@ string EncodeBase64(const unsigned char* pch, size_t len)
{
static const char *pbase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
string strRet="";
strRet.reserve((len+2)/3*4);
int mode=0, left=0;
const unsigned char *pchEnd = pch+len;
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 str;
str.reserve(((len + 2) / 3) * 4);
ConvertBits<8, 6, true>([&](int v) { str += pbase64[v]; }, pch, pch + len);
while (str.size() % 4) str += '=';
return str;
}
string EncodeBase64(const string& str)
@ -193,68 +158,32 @@ 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
};
if (pfInvalid)
*pfInvalid = false;
vector<unsigned char> vchRet;
vchRet.reserve(strlen(p)*3/4);
int mode = 0;
int left = 0;
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;
}
const char* e = p;
std::vector<uint8_t> val;
val.reserve(strlen(p));
while (*p != 0) {
int x = decode64_table[(unsigned char)*p];
if (x == -1) break;
val.push_back(x);
++p;
}
if (pfInvalid)
switch (mode)
{
case 0: // 4n base64 characters processed: ok
break;
std::vector<unsigned char> ret;
ret.reserve((val.size() * 3) / 4);
bool valid = ConvertBits<6, 8, false>([&](unsigned char c) { ret.push_back(c); }, val.begin(), val.end());
case 1: // 4n+1 base64 character processed: impossible
*pfInvalid = true;
break;
case 2: // 4n+2 base64 characters processed: require '=='
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;
const char* q = p;
while (valid && *p != 0) {
if (*p != '=') {
valid = false;
break;
}
++p;
}
valid = valid && (p - e) % 4 == 0 && p - q < 4;
if (pfInvalid) *pfInvalid = !valid;
return vchRet;
return ret;
}
string DecodeBase64(const string& str)
@ -267,59 +196,11 @@ string EncodeBase32(const unsigned char* pch, size_t len)
{
static const char *pbase32 = "abcdefghijklmnopqrstuvwxyz234567";
string strRet="";
strRet.reserve((len+4)/5*8);
int mode=0, left=0;
const unsigned char *pchEnd = pch+len;
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 str;
str.reserve(((len + 4) / 5) * 8);
ConvertBits<8, 5, true>([&](int v) { str += pbase32[v]; }, pch, pch + len);
while (str.size() % 8) str += '=';
return str;
}
string EncodeBase32(const string& str)
@ -346,102 +227,32 @@ 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
};
if (pfInvalid)
*pfInvalid = false;
vector<unsigned char> vchRet;
vchRet.reserve((strlen(p))*5/8);
int mode = 0;
int left = 0;
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;
}
const char* e = p;
std::vector<uint8_t> val;
val.reserve(strlen(p));
while (*p != 0) {
int x = decode32_table[(unsigned char)*p];
if (x == -1) break;
val.push_back(x);
++p;
}
if (pfInvalid)
switch (mode)
{
case 0: // 8n base32 characters processed: ok
break;
std::vector<unsigned char> ret;
ret.reserve((val.size() * 5) / 8);
bool valid = ConvertBits<5, 8, false>([&](unsigned char c) { ret.push_back(c); }, val.begin(), val.end());
case 1: // 8n+1 base32 characters processed: impossible
case 3: // +3
case 6: // +6
*pfInvalid = true;
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;
const char* q = p;
while (valid && *p != 0) {
if (*p != '=') {
valid = false;
break;
}
++p;
}
valid = valid && (p - e) % 8 == 0 && p - q < 8;
if (pfInvalid) *pfInvalid = !valid;
return vchRet;
return ret;
}
string DecodeBase32(const string& str)