OctetString type

class pyasn1.type.univ.OctetString(value=NoValue(), tagSet=TagSet(), subtypeSpec=ConstraintsIntersection(), encoding='iso-8859-1', binValue=NoValue(), hexValue=NoValue())

Create OctetString type or object.

OctetString objects are immutable and duck-type Python 2 str or Python 3 bytes. When used in Unicode context, OctetString type assumes “iso-8859-1” serialization.

Parameters:
  • value (str, bytes or OctetString object) – string (Python 2) or bytes (Python 3), alternatively unicode object (Python 2) or string (Python 3) representing character string to be serialized into octets (note encoding parameter) or OctetString object.
  • tagSet (TagSet) – Object representing non-default ASN.1 tag(s)
  • subtypeSpec (ConstraintsIntersection) – Object representing non-default ASN.1 subtype constraint(s)
  • encoding (str) – Unicode codec ID to encode/decode unicode (Python 2) or str (Python 3) the payload when OctetString object is used in text string context.
  • binValue (str) – Binary string initializer to use instead of the value. Example: ‘10110011’.
  • hexValue (str) – Hexadecimal string initializer to use instead of the value. Example: ‘DEADBEEF’.
Raises:

: :py:class:`pyasn1.error.PyAsn1Error` – On constraint violation or bad initializer.

Note

The OctetString type models an arbitrary string of octets (eight-bit numbers), not printable text string.

clone(value=NoValue(), tagSet=TagSet(), subtypeSpec=ConstraintsIntersection(), encoding='iso-8859-1')

Create a copy of a OctetString type or object.

Any parameters to the clone() method will replace corresponding properties of the OctetString object.

Parameters:
  • value (str, bytes or OctetString object) – Initialization value to pass to new ASN.1 object instead of inheriting one from the caller.
  • tagSet (TagSet) – Object representing ASN.1 tag(s) to use in new object instead of inheriting from the caller
  • subtypeSpec (ConstraintsIntersection) – Object representing ASN.1 subtype constraint(s) to use in new object instead of inheriting from the caller
  • encoding (str) – Unicode codec ID to encode/decode unicode (Python 2) or str (Python 3) the payload when OctetString object is used in string context.
  • binValue (str) – Binary string initializer. Example: ‘10110011’.
  • hexValue (str) – Hexadecimal string initializer. Example: ‘DEADBEEF’.
Returns:

new instance of OctetString type/value

subtype(value=NoValue(), implicitTag=Tag(), explicitTag=Tag(), subtypeSpec=ConstraintsIntersection(), encoding='iso-8859-1')

Create a copy of a OctetString type or object.

Any parameters to the subtype() method will be added to the corresponding properties of the OctetString object.

Parameters:
  • value (str, bytes or OctetString object) – Initialization value to pass to new ASN.1 object instead of inheriting one from the caller.
  • implicitTag (Tag) – Implicitly apply given ASN.1 tag object to OctetString object tag set TagSet, then use the result as new object’s ASN.1 tag(s).
  • explicitTag (Tag) – Explicitly apply given ASN.1 tag object to OctetString object tag set TagSet, then use the result as new object’s ASN.1 tag(s).
  • subtypeSpec (ConstraintsIntersection) – Add ASN.1 constraints object to one of the caller, then use the result as new object’s ASN.1 constraints.
  • encoding (str) – Unicode codec ID to encode/decode unicode (Python 2) or str (Python 3) the payload when OctetString object is used in string context.
  • binValue (str) – Binary string initializer. Example: ‘10110011’.
  • hexValue (str) – Hexadecimal string initializer. Example: ‘DEADBEEF’.
Returns:

new instance of OctetString type/value

tagSet = TagSet((), Tag(tagClass=0, tagFormat=0, tagId=4))

Set (on class, not on instance) or return a TagSet object representing ASN.1 tag(s) associated with OctetString type.

subtypeSpec = ConstraintsIntersection()

Set (on class, not on instance) or return a ConstraintsIntersection object imposing constraints on OctetString type initialization values.

static fromBinaryString(value)

Create a OctetString object initialized from a string of ‘0’ and ‘1’.

Parameters:value (str) – Text string like ‘1010111’
static fromHexString(value)

Create a OctetString object initialized from the hex string.

Parameters:value (str) – Text string like ‘DEADBEEF’
effectiveTagSet

For OctetString type is equivalent to tagSet

isSameTypeWith(other, matchTags=True, matchConstraints=True)

Examine OctetString type for equality with other ASN.1 type.

ASN.1 tags (tag) and constraints (constraint) are examined when carrying out ASN.1 types comparison.

No Python inheritance relationship between PyASN1 objects is considered.

Parameters:other (a pyasn1 type object) – Class instance representing ASN.1 type.
Returns:boolTrue if other is OctetString type, False otherwise.
isSuperTypeOf(other, matchTags=True, matchConstraints=True)

Examine OctetString type for subtype relationship with other ASN.1 type.

ASN.1 tags (tag) and constraints (constraint) are examined when carrying out ASN.1 types comparison.

No Python inheritance relationship between PyASN1 objects is considered.

Parameters:other (a pyasn1 type object) – Class instance representing ASN.1 type.
Returns:boolTrue if other is a subtype of OctetString type, False otherwise.
isValue

Indicate if OctetString object represents ASN.1 type or ASN.1 value.

In other words, if isValue is True, then the ASN.1 object is initialized.

Returns:boolTrue if object represents ASN.1 value and type, False if object represents just ASN.1 type.

Note

There is an important distinction between PyASN1 type and value objects. The PyASN1 type objects can only participate in ASN.1 type operations (subtyping, comparison etc) and serve as a blueprint for serialization codecs to resolve ambiguous types.

The PyASN1 value objects can additionally participate in most of built-in Python operations.

tagMap

Return a TagMap object mapping ASN.1 tags to ASN.1 objects within callee object.