4 ASN.1 Miscellaneous Utilities
4.1 ASN.1 Bit String Utilities
| (require asn1/util/bit-string) | package: asn1-lib |
Added in version 1.2 of package asn1-lib.
procedure
(bit-string-length bs) → exact-nonnegative-integer?
bs : bit-string?
Returns the number of bits in bs.
procedure
(bit-string-ref bs index) → boolean?
bs : bit-string? index : exact-nonnegative-integer?
Returns the bit stored in bs at the given index as a
boolean. Note that in ASN.1, the first bit of a bit string is stored
as the high bit of the first byte.
4.2 ASN.1 Named Value Utilities
| (require asn1/util/names) | package: asn1-lib |
Added in version 1.2 of package asn1-lib.
procedure
(WRAP-NAMES type named-values) → asn1-type?
type : (or/c ENUMERATED BIT-STRING) named-values : (listof (cons/c symbol? any/c))
Wraps type with decode and encode hooks to translate to and from named
values.
If type is ENUMERATED, then the corresponding Racket values
are symbols from named-values and exact integers for values not in the
list.
Examples:
> (define xyz (WRAP-NAMES ENUMERATED '((x . 0) (y . 1) (z . 2)))) > (bytes->asn1 xyz (asn1->bytes ENUMERATED 2)) 'z
> (bytes->asn1 xyz (asn1->bytes ENUMERATED 5)) 5
If type is BIT-STRING, then the corresponding Racket values
are lists of symbols from named-values and exact integers for values
not in the list.
Examples:
> (define abc (WRAP-NAMES BIT-STRING '((a . 0) (b . 1) (c . 2)))) > (bytes->asn1 abc (asn1->bytes BIT-STRING (bit-string (bytes #b10100000) 0))) '(a c)
> (bytes->asn1 abc (asn1->bytes BIT-STRING (bit-string (bytes #b10100010) 0))) '(a c 6)
4.3 ASN.1 Time Utilities
| (require asn1/util/time) | package: asn1-lib |
Added in version 1.2 of package asn1-lib.
procedure
s : asn1-utc-time?
procedure
s : asn1-generalized-time?
Interprets s as a date and time and returns it as a number of seconds
since midnight UTC, January 1, 1970 (like current-seconds,
seconds->date, etc). If s omits minutes, seconds, or
fractional seconds, they are treated as 0. If s omits the UTC specifier
(Z) or timezone offset, the time is interpreted as local time.
The two-digit years of UTCTime are interpreted in the range 1950 to 2049; this is consistent with X.509 but not all other ASN.1 applications.
Examples:
> (asn1-utc-time->seconds "20110220-07") 1604337120
> (asn1-generalized-time->seconds "19700101010203Z") 3723