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rfc.hmac
- HMAC keyed-hashingThis module implements HMAC algorithm, Keyed-hashing for message authentication, defined in RFC 2104.
For simple batched keyed hashing, you can use high-level API
hmac-digest
and hmac-digest-string
.
Or you can create <hmac>
object and update its state
as the data coming in.
Following is a typical way to digest a given string.
(use rfc.sha) ; import desired digest algorithm (use rfc.hmac) (hmac-message <sha256> "secret-key" "payload") ⇒ #u8(16 170 46 28 37 56 70 79 247 95 6 71 39 30 59 167 70 188 163 252 222 175 50 44 88 27 245 133 30 140 221 183) (hmac-message-to 'hex <sha256> "secret-key" "payload") ⇒ "10aa2e1c2538464ff75f0647271e3ba746bca3fcdeaf322c581bf5851e8cddb7"
{rfc.hmac} Read input data from the current input port, and compute HMAC digest with a hash algorithm hash-class and a key key.
The result is returned as an instance of class target, which
can be <u8vector>
or <string>
. Some symbols is also
allowed to specify encoding: base64
, base64url
,
base64url-nopad
, base32
, base32hex
, base16
,
and hex
. See util.digest
- Message digester framework for the details
of those encodings.
The hash-class argument must be a class implementing
<message-digest-algorithm>
, such as <sha256>
of rfc.sha
(see rfc.sha
- SHA message digest).
The key key may be a string or a u8vector.
{rfc.hmac} Returns an HMAC digest of message, computed with a hash algorithm hash-class, with a key key.
The hash-class argument must be a class inheriting
<message-digest-algorithm>
, e.g. <sha256>
class
from rfc.sha
(see rfc.sha
- SHA message digest).
You can pass both a stirng and a u8vector to key/message.
The target can be a class in which the result is returned,
either <u8vector>
or <string>, or a symbol specifying
the encoding: base64
, base64url
,
base64url-nopad
, base32, base32hex, base16
,
and hex
. See util.digest
- Message digester framework for the details
of those encodings.
{rfc.hmac}
A shortcut of (hmac-message-to <u8vector> hash-class key message)
.
(hmac-message <sha256> "secret" "Aloha, honua") ⇒ #u8(78 232 135 13 246 139 36 242 133 33 99 185 4 249 244 22 243 46 120 130 192 235 60 187 172 180 223 169 179 247 186 185)
{rfc.hmac}
Verify message by comparing its digest with the given digest.
Functionally it is (equal? digest (hmac-message hash-class key message))
,
but the digests are compared in a way that can avoid timing attack.
Hash-class is a class inherits <message-digest-algorithm>
such as <sha256>
.
Digest must be a u8vector. Either a string or a u8vector
is allowed for each of key and message.
Returns #t
if digest is valid digest for the message,
#f
if not.
(hmac-verify <sha256> '#u8(78 232 135 13 246 139 36 242 133 33 99 185 4 249 244 22 243 46 120 130 192 235 60 187 172 180 223 169 179 247 186 185) "secret" "Aloha, honua") ⇒ #t
{rfc.hmac}
Keeps state information of HMAC algorithm. This should not be
directly instantiated; use make-hmac
below.
{rfc.hmac}
Creates and returns a new <hmac>
object. The algorithm
argument is a class inheriting <message-digest-algorithm>
to
specify digest algorithm, for example, <sha256>
(see rfc.sha
- SHA message digest, for the details).
The key argument is a key, either a string or a u8vector.
When you use high-level APIs such as hmac-message
, you don’t
need to make an <hmac>
object since it is implicitly created.
You only need to create it explicitly to use the following
streaming update procedures.
{rfc.hmac} Updates the internal state of hmac by data, which must be represented by a (possibly incomplete) string.
{rfc.hmac}
Finalizes the internal state of hmac and returns the
digest in an instance of target, which must be
a <string>
or <u8vector>
class metaobject,
or a symbol to specify encoding. See hmac-to
above for the
details of target. The default is <string>
, for a
historical reason.
Once finalized, you can’t call hmac-update!
or hmac-final!
on hmac.
The following procedures are deprecated. You can use hmac-to
and hmac-message
instead.
{rfc.hmac}
Deprecated.
Creates an <hmac>
object and hash the data stream
from the current input port, then returns the hashed result
in an incomplete string.
{rfc.hmac}
Deprecated.
Creates an <hmac>
object and hash the data in string,
then returns the hashed result in an incomplete string.
Next: rfc.http
- HTTP client, Previous: rfc.ftp
- FTP client, Up: Library modules - Utilities [Contents][Index]