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fixed two bugs in base64_encode, and added base64_decode
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@pkrumins
pkrumins committed Jul 10, 2010
1 parent 4925cc9 commit 4d8827c
Showing 1 changed file with 132 additions and 47 deletions.
179 changes: 132 additions & 47 deletions base64.cc
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@@ -1,78 +1,163 @@
#include <cctype>
#include <cstring>
#include <v8.h>
#include <node.h>
#include <node_buffer.h>

using namespace v8;
using namespace node;

static Handle<Value>
VException(const char *msg) {
HandleScope scope;
return ThrowException(Exception::Error(String::New(msg)));
}

static const char base64_chars[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";

static char *
base64_encode(const unsigned char *input, int length)
{
/* http://www.adp-gmbh.ch/cpp/common/base64.html */
int i=0, j=0, s=0;
unsigned char char_array_3[3], char_array_4[4];
/* http://www.adp-gmbh.ch/cpp/common/base64.html */
int i=0, j=0, s=0;
unsigned char char_array_3[3], char_array_4[4];

int b64len = (length+2 - ((length+2)%3))*4/3;
char *b64str = new char[b64len + 1];
int b64len = (length+2 - ((length+2)%3))*4/3;
char *b64str = new char[b64len + 1];

while (length--) {
char_array_3[i++] = *(input++);
if (i == 3) {
char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
char_array_4[3] = char_array_3[2] & 0x3f;
while (length--) {
char_array_3[i++] = *(input++);
if (i == 3) {
char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
char_array_4[3] = char_array_3[2] & 0x3f;

for (i = 0; i < 4; i++)
b64str[s++] = base64_chars[char_array_4[i]];
for (i = 0; i < 4; i++)
b64str[s++] = base64_chars[char_array_4[i]];

i = 0;
i = 0;
}
}
}
if (i) {
for (j = i; j < 3; j++)
char_array_3[j] = '\0';
if (i) {
for (j = i; j < 3; j++)
char_array_3[j] = '\0';

char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
char_array_4[3] = char_array_3[2] & 0x3f;
char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
char_array_4[3] = char_array_3[2] & 0x3f;

for (j = 0; j < i + 1; j++)
b64str[s++] = base64_chars[char_array_4[j]];
for (j = 0; j < i + 1; j++)
b64str[s++] = base64_chars[char_array_4[j]];

while (i++ < 3)
b64str[s++] = '=';
}
b64str[b64len] = '\0';

while (i++ < 3)
b64str[s++] = '=';
}
b64str[b64len] = '\0';
return b64str;
}

return b64str;
static inline bool is_base64(unsigned char c) {
return (isalnum(c) || (c == '+') || (c == '/'));
}

static unsigned char *
base64_decode(const char *input, int length, int *outlen)
{
int i = 0;
int j = 0;
int r = 0;
int idx = 0;
unsigned char char_array_4[4], char_array_3[3];
unsigned char *output = new unsigned char[length*3/4];

while (length-- && (input[idx] != '=') && is_base64(input[idx])) {
char_array_4[i++] = input[idx++];
if (i == 4) {
for (i = 0; i < 4; i++)
char_array_4[i] = strchr(base64_chars, char_array_4[i]) - base64_chars;

char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

for (i = 0; (i < 3); i++)
output[r++] = char_array_3[i];
i = 0;
}
}

if (i) {
for (j = i; j <4; j++)
char_array_4[j] = 0;

for (j = 0; j <4; j++)
char_array_4[j] = strchr(base64_chars, char_array_4[j]) - base64_chars;

char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

for (j = 0; (j < i - 1); j++)
output[r++] = char_array_3[j];
}

*outlen = r;

return output;
}

Handle<Value>
base64_encode_binding(const Arguments& args)
base64_encode_binding(const Arguments &args)
{
HandleScope scope;

if (!Buffer::HasInstance(args[0])) {
return ThrowException(Exception::TypeError(
String::New("Argument should be a buffer")));
}
Buffer *buffer = ObjectWrap::Unwrap<Buffer>(args[0]->ToObject());
char *str = base64_encode((unsigned char*)buffer->data(), buffer->length());
Local<String> ret = String::New(str);
delete str;
return ret;
HandleScope scope;

if (args.Length() != 1)
return VException("One argument required - buffer with data to encode");

if (!Buffer::HasInstance(args[0]))
return VException("Argument should be a buffer");

Buffer *buffer = ObjectWrap::Unwrap<Buffer>(args[0]->ToObject());
char *str = base64_encode((unsigned char *)buffer->data(), buffer->length());
Local<String> ret = String::New(str);
delete [] str;
return scope.Close(ret);
}

Handle<Value>
base64_decode_binding(const Arguments &args)
{
HandleScope scope;

if (args.Length() != 1)
return VException("One argument required - buffer or string with data to decode");

int outlen;
unsigned char *decoded;
if (Buffer::HasInstance(args[0])) { // buffer
Buffer *buffer = ObjectWrap::Unwrap<Buffer>(args[0]->ToObject());
decoded = base64_decode(buffer->data(), buffer->length(), &outlen);
}
else { // string
String::AsciiValue b64data(args[0]->ToString());
decoded = base64_decode(*b64data, b64data.length(), &outlen);
}

Local<Value> ret = Encode(decoded, outlen, BINARY);
delete [] decoded;
return scope.Close(ret);
}

extern "C" void init (Handle<Object> target)
{
HandleScope scope;
target->Set(String::New("encode"), FunctionTemplate::New(base64_encode_binding)->GetFunction());
HandleScope scope;
target->Set(String::New("encode"), FunctionTemplate::New(base64_encode_binding)->GetFunction());
target->Set(String::New("decode"), FunctionTemplate::New(base64_decode_binding)->GetFunction());
}

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