lapo.it
JavaScript generic ASN.1 parser (mirror)
Improve input checking. Avoid checking type on each single access.
+13
-2
+13
-2
asn1.js
+13
-2
asn1.js
···
60
60
* It uses an existing array or binary string and advances a position index. */
61
61
class Stream {
62
62
63
+
/**
64
+
* @param {Stream|array|string} enc data (will not be copied)
65
+
* @param {?number} pos starting position (mandatory when `end` is not a Stream)
66
+
*/
63
67
constructor(enc, pos) {
64
68
if (enc instanceof Stream) {
65
69
this.enc = enc.enc;
66
70
this.pos = enc.pos;
67
71
} else {
68
-
// enc should be an array or a binary string
69
72
this.enc = enc;
70
73
this.pos = pos;
71
74
}
75
+
if (typeof this.pos != 'number')
76
+
throw new Error('"pos" must be a numeric value');
77
+
if (typeof this.enc == 'string')
78
+
this.getRaw = pos => this.enc.charCodeAt(pos);
79
+
else if (typeof this.enc[0] == 'number')
80
+
this.getRaw = pos => this.enc[pos];
81
+
else
82
+
throw new Error('"enc" must be a numeric array or a string');
72
83
}
73
84
/** Get the byte at current position (and increment it) or at a specified position (and avoid moving current position).
74
85
* @param {?number} pos read position if specified, else current position (and increment it) */
···
77
88
pos = this.pos++;
78
89
if (pos >= this.enc.length)
79
90
throw new Error('Requesting byte offset ' + pos + ' on a stream of length ' + this.enc.length);
80
-
return (typeof this.enc == 'string') ? this.enc.charCodeAt(pos) : this.enc[pos];
91
+
return this.getRaw(pos);
81
92
}
82
93
/** Convert a single byte to an hexadcimal string (of length 2).
83
94
* @param {number} b */