ASN.1 - Revision history

Tom: /* Context */

2025-09-18T01:59:39Z

‎Context

Tom: /* Other Material */

2025-09-09T00:04:25Z

‎Other Material

Tom: /* Other Material */

2025-03-26T21:28:55Z

‎Other Material

Tom: /* Problems */

2025-01-05T06:08:43Z

‎Problems

Tom at 05:56, 5 January 2025

2025-01-05T05:56:11Z

Tom: /* Context */

2025-01-05T05:48:50Z

‎Context

Tom: /* Solution */

2021-08-26T22:49:30Z

‎Solution

Tom: /* Solution */

2021-08-26T22:49:01Z

‎Solution

Tom: /* Solution */

2021-08-25T19:56:03Z

‎Solution

Tom: /* Solution */

2021-08-25T03:33:22Z

‎Solution

← Older revision		Revision as of 01:59, 18 September 2025
Line 6:		Line 6:

	Abstract Syntax Notation One (ASN.1), which is defined in CCITT Recommendation X.208, is a way to specify abstract objects that will be serially transmitted. The set of ASN.1 rules for representing such objects as strings of ones and zeros is called the Distinguished Encoding Rules (DER), and is defined in CCITT Recommendation X.509, Section 8.7. These encoding methods are currently used to create the TLS certificates that are used to establish secure interchanges using HTTPS.		Abstract Syntax Notation One (ASN.1), which is defined in CCITT Recommendation X.208, is a way to specify abstract objects that will be serially transmitted. The set of ASN.1 rules for representing such objects as strings of ones and zeros is called the Distinguished Encoding Rules (DER), and is defined in CCITT Recommendation X.509, Section 8.7. These encoding methods are currently used to create the TLS certificates that are used to establish secure interchanges using HTTPS.
		+
		+	* [https://letsencrypt.org/docs/a-warm-welcome-to-asn1-and-der/ Simple description]

	==Problems==		==Problems==

@@ Line 133: / Line 133: @@
 [[Category:Glossary]]
 [[Category:Standard]]
 [[Category: Networking]]

@@ Line 127: / Line 127: @@
 <references />
 ===Other Material===
 * See the wiki page on [[Distinguished Encoding Rules]] for the most common encoding of ASN.1.
 * [https://letsencrypt.org/docs/a-warm-welcome-to-asn1-and-der/ Let's Encrypt web site description of ASN.1 and DER.]

@@ Line 8: / Line 8: @@
 ==Problems==
-# Bureaucracy
+# Bureaucracy = since the syntax is created by a CCITT (ITU) standard, it can only be updated by a new standard agreed by the entire organization.
-# Complexity
+# Complexity = the specifications can generate a wide range of outputs but the result cannot be decoded without knowing the standard and version used to create it.
 # Extensions were added in the PKI certificate version 3 that were beyond the ability of the schema.

@@ Line 1: / Line 1: @@
 ==Full Title==
-Abstract Syntax Notation version 1 = [[ASN.1]]. Since there is no version 2, ASN is the typical abbreviation here.
+Abstract Syntax Notation version 1 = [[ASN.1]]. Since there is no version 2, ASN is the typical abbreviation here.<ref>''OSS® ASN.1 Product Documentation'' https://www.oss.com/asn1/products/documentation/asn1-doc.html</ref>
 ==Context==
-In the time before internet there was the 7 layer ISO model and a bunch of PTOs (mostly government postal and telegraphy organizations) worried by this new technology that wanted to dominate the identity layer of communications. The result was a series of CCITT (now ITU-T) committees establish to translate the telephone industry white pages into the identity of every entity on the internet. This expanded to include X.400 series standards on electronic mail which went beyond that to create a security system base on [[ASN.1]] X.500 series standards. The only legacy of that is the use of [[Distinguished Name]]s in email directories, like Microsoft Outlook.
+In the time before the internet came to dominate the communications of humans using the World Wide Web, there was the 7 layer ISO model and a bunch of PTOs (mostly government postal and telegraphy organizations) worried by this new technology that wanted to dominate the identity layer of communications. The result was a series of CCITT (now ITU-T) committees establish to translate the telephone industry white pages into the identity of every entity on the internet. This expanded to include X.400 series standards on electronic mail which went beyond that to create a security system base on [[ASN.1]] X.500 series standards. The only legacy of that is the use of [[Distinguished Name]]s in email directories, like Microsoft Outlook.
 Abstract Syntax Notation One (ASN.1), which is defined in CCITT Recommendation X.208, is a way to specify abstract objects that will be serially transmitted. The set of ASN.1 rules for representing such objects as strings of ones and zeros is called the Distinguished Encoding Rules (DER), and is defined in CCITT Recommendation X.509, Section 8.7. These encoding methods are currently used to create the TLS certificates that are used to establish secure interchanges using HTTPS.
@@ Line 125: / Line 125: @@
 ==References==
 * See the wiki page on [[Distinguished Encoding Rules]] for the most common encoding of ASN.1.
 * [https://letsencrypt.org/docs/a-warm-welcome-to-asn1-and-der/ Let's Encrypt web site description of ASN.1 and DER.]
 [[Category:Glossary]]
 [[Category:Standard]]

@@ Line 33: / Line 33: @@
 00 Primitive
-20 Constructed. (and so A0 is context specific, Constructed.
+20 Constructed. (and so A0 is context specific, Constructed).
 Data Types

@@ Line 25: / Line 25: @@
 * Convert it all to json format so we don't need to spend so much effort understanding an syntax that was unnecessarily complex.
 * [https://asn1.io/asn1vsx/ Visual studio editing tool]
-Tags are the bottom 6 bits of the byte. The top two bits reference the class
+Tags are the bottom 5 bits of the byte. The top two bits reference the class and the next the constructed state
 <pre>
 00 Universal

@@ Line 51: / Line 51: @@
 ,48	10 & 30 *	SEQUENCE and SEQUENCE OF
 ,49	11 & 31 *	SET and SET OF
-	12	NumericString
+	12	NumericString (0-9 and space)
-	13	PrintableString (Upper and lower case letters, digits, space, apostrophe, left/right parenthesis, plus sign, comma, hyphen, full stop, slash, colon, equal sign, question mark)
+	13	PrintableString (A-Za-z0-9 space '()+,-./:=?)
 	14	Telex String (T61 - obsolete)
 	15	VideotexString

@@ Line 45: / Line 45: @@
 	06	OBJECT IDENTIFIER
        07      OBJECT DESCRIPTOR (Brief text description of an object) = string
 	09	REAL
 	0A	ENUMERATED