blocktrail-sdk/vendor/asmcrypto.js/src/utils.js

BlockTrail's Developer Friendly API binding for NodeJS

var FloatArray = global.Float64Array || global.Float32Array; // make PhantomJS happy

function string_to_bytes ( str, utf8 ) {
    utf8 = !!utf8;

    var len = str.length,
        bytes = new Uint8Array( utf8 ? 4*len : len );

    for ( var i = 0, j = 0; i < len; i++ ) {
        var c = str.charCodeAt(i);

        if ( utf8 && 0xd800 <= c && c <= 0xdbff ) {
            if ( ++i >= len ) throw new Error( "Malformed string, low surrogate expected at position " + i );
            c = ( (c ^ 0xd800) << 10 ) | 0x10000 | ( str.charCodeAt(i) ^ 0xdc00 );
        }
        else if ( !utf8 && c >>> 8 ) {
            throw new Error("Wide characters are not allowed.");
        }

        if ( !utf8 || c <= 0x7f ) {
            bytes[j++] = c;
        }
        else if ( c <= 0x7ff ) {
            bytes[j++] = 0xc0 | (c >> 6);
            bytes[j++] = 0x80 | (c & 0x3f);
        }
        else if ( c <= 0xffff ) {
            bytes[j++] = 0xe0 | (c >> 12);
            bytes[j++] = 0x80 | (c >> 6 & 0x3f);
            bytes[j++] = 0x80 | (c & 0x3f);
        }
        else {
            bytes[j++] = 0xf0 | (c >> 18);
            bytes[j++] = 0x80 | (c >> 12 & 0x3f);
            bytes[j++] = 0x80 | (c >> 6 & 0x3f);
            bytes[j++] = 0x80 | (c & 0x3f);
        }
    }

    return bytes.subarray(0, j);
}

function hex_to_bytes ( str ) {
    var len = str.length;
    if ( len & 1 ) {
        str = '0'+str;
        len++;
    }
    var bytes = new Uint8Array(len>>1);
    for ( var i = 0; i < len; i += 2 ) {
        bytes[i>>1] = parseInt( str.substr( i, 2), 16 );
    }
    return bytes;
}

function base64_to_bytes ( str ) {
    return string_to_bytes( atob( str ) );
}

function bytes_to_string ( bytes, utf8 ) {
    utf8 = !!utf8;

    var len = bytes.length,
        chars = new Array(len);

    for ( var i = 0, j = 0; i < len; i++ ) {
        var b = bytes[i];
        if ( !utf8 || b < 128 ) {
            chars[j++] = b;
        }
        else if ( b >= 192 && b < 224 && i+1 < len ) {
            chars[j++] = ( (b & 0x1f) << 6 ) | (bytes[++i] & 0x3f);
        }
        else if ( b >= 224 && b < 240 && i+2 < len ) {
            chars[j++] = ( (b & 0xf) << 12 ) | ( (bytes[++i] & 0x3f) << 6 ) | (bytes[++i] & 0x3f);
        }
        else if ( b >= 240 && b < 248 && i+3 < len ) {
            var c = ( (b & 7) << 18 ) | ( (bytes[++i] & 0x3f) << 12 ) | ( (bytes[++i] & 0x3f) << 6 ) | (bytes[++i] & 0x3f);
            if ( c <= 0xffff ) {
                chars[j++] = c;
            }
            else {
                c ^= 0x10000;
                chars[j++] = 0xd800 | (c >> 10);
                chars[j++] = 0xdc00 | (c & 0x3ff);
            }
        }
        else {
            throw new Error("Malformed UTF8 character at byte offset " + i);
        }
    }

    var str = '',
        bs = 16384;
    for ( var i = 0; i < j; i += bs ) {
        str += String.fromCharCode.apply( String, chars.slice( i, i+bs <= j ? i+bs : j ) );
    }

    return str;
}

function bytes_to_hex ( arr ) {
    var str = '';
    for ( var i = 0; i < arr.length; i++ ) {
        var h = ( arr[i] & 0xff ).toString(16);
        if ( h.length < 2 ) str += '0';
        str += h;
    }
    return str;
}

function bytes_to_base64 ( arr ) {
    return btoa( bytes_to_string(arr) );
}

function pow2_ceil ( a ) {
    a -= 1;
    a |= a >>> 1;
    a |= a >>> 2;
    a |= a >>> 4;
    a |= a >>> 8;
    a |= a >>> 16;
    a += 1;
    return a;
}

function is_number ( a ) {
    return ( typeof a === 'number' );
}

function is_string ( a ) {
    return ( typeof a === 'string' );
}

function is_buffer ( a ) {
    return ( a instanceof ArrayBuffer );
}

function is_bytes ( a ) {
    return ( a instanceof Uint8Array );
}

function is_typed_array ( a ) {
    return ( a instanceof Int8Array ) || ( a instanceof Uint8Array )
        || ( a instanceof Int16Array ) || ( a instanceof Uint16Array )
        || ( a instanceof Int32Array ) || ( a instanceof Uint32Array )
        || ( a instanceof Float32Array )
        || ( a instanceof Float64Array );
}

function _heap_init ( constructor, options ) {
    var heap = options.heap,
        size = heap ? heap.byteLength : options.heapSize || 65536;

    if ( size & 0xfff || size <= 0 )
        throw new Error("heap size must be a positive integer and a multiple of 4096");

    heap = heap || new constructor( new ArrayBuffer(size) );

    return heap;
}

function _heap_write ( heap, hpos, data, dpos, dlen ) {
    var hlen = heap.length - hpos,
        wlen = ( hlen < dlen ) ? hlen : dlen;

    heap.set( data.subarray( dpos, dpos+wlen ), hpos );

    return wlen;
}