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authorDavid Thompson <dthompson2@worcester.edu>2015-12-07 08:53:58 -0500
committerDavid Thompson <dthompson2@worcester.edu>2015-12-09 08:42:57 -0500
commit7f59af4cdf071dc133ae3ed04b3a3c146a3d8429 (patch)
treef1d59412de994d00498d87e85eb787e1307493ed /web
parent1774770170531197d906194c6de806af62b1b516 (diff)
Move base64 and SHA-1 modules to (web socket) namespace.
Diffstat (limited to 'web')
-rw-r--r--web/socket/base64.scm285
-rw-r--r--web/socket/server.scm4
-rw-r--r--web/socket/sha-1.scm300
3 files changed, 587 insertions, 2 deletions
diff --git a/web/socket/base64.scm b/web/socket/base64.scm
new file mode 100644
index 0000000..69d45b7
--- /dev/null
+++ b/web/socket/base64.scm
@@ -0,0 +1,285 @@
+;; -*- mode: scheme; coding: utf-8 -*-
+;; Copyright © 2009, 2010, 2012, 2013 Göran Weinholt <goran@weinholt.se>
+
+;; Permission is hereby granted, free of charge, to any person obtaining a
+;; copy of this software and associated documentation files (the "Software"),
+;; to deal in the Software without restriction, including without limitation
+;; the rights to use, copy, modify, merge, publish, distribute, sublicense,
+;; and/or sell copies of the Software, and to permit persons to whom the
+;; Software is furnished to do so, subject to the following conditions:
+
+;; The above copyright notice and this permission notice shall be included in
+;; all copies or substantial portions of the Software.
+
+;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+;; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+;; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+;; THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+;; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+;; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+;; DEALINGS IN THE SOFTWARE.
+#!r6rs
+
+;; RFC 4648 Base-N Encodings
+
+(library (web socket base64)
+ (export base64-encode
+ base64-decode
+ base64-alphabet
+ base64url-alphabet
+ get-delimited-base64
+ put-delimited-base64)
+ (import (rnrs)
+ (only (srfi :13 strings)
+ string-index
+ string-prefix? string-suffix?
+ string-concatenate string-trim-both))
+
+ (define base64-alphabet
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/")
+
+ (define base64url-alphabet
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_")
+
+ (define base64-encode
+ (case-lambda
+ ;; Simple interface. Returns a string containing the canonical
+ ;; base64 representation of the given bytevector.
+ ((bv)
+ (base64-encode bv 0 (bytevector-length bv) #f #f base64-alphabet #f))
+ ((bv start)
+ (base64-encode bv start (bytevector-length bv) #f #f base64-alphabet #f))
+ ((bv start end)
+ (base64-encode bv start end #f #f base64-alphabet #f))
+ ((bv start end line-length)
+ (base64-encode bv start end line-length #f base64-alphabet #f))
+ ((bv start end line-length no-padding)
+ (base64-encode bv start end line-length no-padding base64-alphabet #f))
+ ((bv start end line-length no-padding alphabet)
+ (base64-encode bv start end line-length no-padding alphabet #f))
+ ;; Base64 encodes the bytes [start,end[ in the given bytevector.
+ ;; Lines are limited to line-length characters (unless #f),
+ ;; which must be a multiple of four. To omit the padding
+ ;; characters (#\=) set no-padding to a true value. If port is
+ ;; #f, returns a string.
+ ((bv start end line-length no-padding alphabet port)
+ (assert (or (not line-length) (zero? (mod line-length 4))))
+ (let-values (((p extract) (if port
+ (values port (lambda () (values)))
+ (open-string-output-port))))
+ (letrec ((put (if line-length
+ (let ((chars 0))
+ (lambda (p c)
+ (when (fx=? chars line-length)
+ (set! chars 0)
+ (put-char p #\linefeed))
+ (set! chars (fx+ chars 1))
+ (put-char p c)))
+ put-char)))
+ (let lp ((i start))
+ (cond ((= i end))
+ ((<= (+ i 3) end)
+ (let ((x (bytevector-uint-ref bv i (endianness big) 3)))
+ (put p (string-ref alphabet (fxbit-field x 18 24)))
+ (put p (string-ref alphabet (fxbit-field x 12 18)))
+ (put p (string-ref alphabet (fxbit-field x 6 12)))
+ (put p (string-ref alphabet (fxbit-field x 0 6)))
+ (lp (+ i 3))))
+ ((<= (+ i 2) end)
+ (let ((x (fxarithmetic-shift-left (bytevector-u16-ref bv i (endianness big)) 8)))
+ (put p (string-ref alphabet (fxbit-field x 18 24)))
+ (put p (string-ref alphabet (fxbit-field x 12 18)))
+ (put p (string-ref alphabet (fxbit-field x 6 12)))
+ (unless no-padding
+ (put p #\=))))
+ (else
+ (let ((x (fxarithmetic-shift-left (bytevector-u8-ref bv i) 16)))
+ (put p (string-ref alphabet (fxbit-field x 18 24)))
+ (put p (string-ref alphabet (fxbit-field x 12 18)))
+ (unless no-padding
+ (put p #\=)
+ (put p #\=)))))))
+ (extract)))))
+
+ ;; Create a lookup table for the alphabet and remember the latest table.
+ (define get-decode-table
+ (let ((ascii-table #f)
+ (extra-table '()) ;in the unlikely case of unicode chars
+ (table-alphabet #f))
+ (lambda (alphabet)
+ (unless (eq? alphabet table-alphabet)
+ ;; Rebuild the table.
+ (do ((ascii (make-vector 128 #f))
+ (extra '())
+ (i 0 (+ i 1)))
+ ((= i (string-length alphabet))
+ (set! ascii-table ascii)
+ (set! extra-table extra))
+ (let ((c (char->integer (string-ref alphabet i))))
+ (if (fx<=? c 127)
+ (vector-set! ascii c i)
+ (set! extra (cons (cons c i) extra)))))
+ (set! table-alphabet alphabet))
+ (values ascii-table extra-table))))
+
+ ;; Decodes a correctly padded base64 string, optionally ignoring
+ ;; non-alphabet characters.
+ (define base64-decode
+ (case-lambda
+ ((str)
+ (base64-decode str base64-alphabet #f))
+ ((str alphabet)
+ (base64-decode str alphabet #f))
+ ((str alphabet port)
+ (base64-decode str alphabet port #t))
+ ((str alphabet port strict?)
+ (define (pad? c) (eqv? c (char->integer #\=)))
+ (let-values (((p extract) (if port
+ (values port (lambda () (values)))
+ (open-bytevector-output-port)))
+ ((ascii extra) (get-decode-table alphabet)))
+ (define-syntax lookup
+ (syntax-rules ()
+ ((_ c) (or (and (fx<=? c 127) (vector-ref ascii c))
+ (cond ((assv c extra) => cdr)
+ (else #f))))))
+ (let* ((len (if strict?
+ (string-length str)
+ (let lp ((i (fx- (string-length str) 1)))
+ ;; Skip trailing invalid chars.
+ (cond ((fxzero? i) 0)
+ ((let ((c (char->integer (string-ref str i))))
+ (or (lookup c) (pad? c)))
+ (fx+ i 1))
+ (else (lp (fx- i 1))))))))
+ (let lp ((i 0))
+ (cond
+ ((fx=? i len)
+ (extract))
+ ((fx<=? i (fx- len 4))
+ (let lp* ((c1 (char->integer (string-ref str i)))
+ (c2 (char->integer (string-ref str (fx+ i 1))))
+ (c3 (char->integer (string-ref str (fx+ i 2))))
+ (c4 (char->integer (string-ref str (fx+ i 3))))
+ (i i))
+ (let ((i1 (lookup c1)) (i2 (lookup c2))
+ (i3 (lookup c3)) (i4 (lookup c4)))
+ (cond
+ ((and i1 i2 i3 i4)
+ ;; All characters present and accounted for.
+ ;; The most common case.
+ (let ((x (fxior (fxarithmetic-shift-left i1 18)
+ (fxarithmetic-shift-left i2 12)
+ (fxarithmetic-shift-left i3 6)
+ i4)))
+ (put-u8 p (fxbit-field x 16 24))
+ (put-u8 p (fxbit-field x 8 16))
+ (put-u8 p (fxbit-field x 0 8))
+ (lp (fx+ i 4))))
+ ((and i1 i2 i3 (pad? c4) (= i (- len 4)))
+ ;; One padding character at the end of the input.
+ (let ((x (fxior (fxarithmetic-shift-left i1 18)
+ (fxarithmetic-shift-left i2 12)
+ (fxarithmetic-shift-left i3 6))))
+ (put-u8 p (fxbit-field x 16 24))
+ (put-u8 p (fxbit-field x 8 16))
+ (lp (fx+ i 4))))
+ ((and i1 i2 (pad? c3) (pad? c4) (= i (- len 4)))
+ ;; Two padding characters.
+ (let ((x (fxior (fxarithmetic-shift-left i1 18)
+ (fxarithmetic-shift-left i2 12))))
+ (put-u8 p (fxbit-field x 16 24))
+ (lp (fx+ i 4))))
+ ((not strict?)
+ ;; Non-alphabet characters.
+ (let lp ((i i) (c* '()) (n 4))
+ (cond ((fxzero? n)
+ ;; Found four valid characters.
+ (lp* (cadddr c*) (caddr c*) (cadr c*) (car c*)
+ (fx- i 4)))
+ ((fx=? i len)
+ (error 'base64-decode
+ "Invalid input in non-strict mode."
+ i c*))
+ (else
+ ;; Gather alphabetic (or valid
+ ;; padding) characters.
+ (let ((c (char->integer (string-ref str i))))
+ (cond ((or (lookup c)
+ (and (pad? c)
+ (fx<=? n 2)
+ (fx=? i (fx- len n))))
+ (lp (fx+ i 1) (cons c c*) (fx- n 1)))
+ (else
+ (lp (fx+ i 1) c* n))))))))
+ (else
+ (error 'base64-decode
+ "Invalid input in strict mode."
+ c1 c2 c3 c4))))))
+ (else
+ (error 'base64-decode
+ "The input is too short, it may be missing padding."
+ i)))))))))
+
+ (define (get-line-comp f port)
+ (if (port-eof? port)
+ (eof-object)
+ (f (get-line port))))
+
+ ;; Reads the common -----BEGIN/END type----- delimited format from
+ ;; the given port. Returns two values: a string with the type and a
+ ;; bytevector containing the base64 decoded data. The second value
+ ;; is the eof object if there is an eof before the BEGIN delimiter.
+ (define get-delimited-base64
+ (case-lambda
+ ((port)
+ (get-delimited-base64 port #t))
+ ((port strict)
+ (define (get-first-data-line port)
+ ;; Some MIME data has header fields in the same format as mail
+ ;; or http. These are ignored.
+ (let ((line (get-line-comp string-trim-both port)))
+ (cond ((eof-object? line) line)
+ ((string-index line #\:)
+ (let lp () ;read until empty line
+ (let ((line (get-line-comp string-trim-both port)))
+ (if (string=? line "")
+ (get-line-comp string-trim-both port)
+ (lp)))))
+ (else line))))
+ (let ((line (get-line-comp string-trim-both port)))
+ (cond ((eof-object? line)
+ (values "" (eof-object)))
+ ((string=? line "")
+ (get-delimited-base64 port))
+ ((and (string-prefix? "-----BEGIN " line)
+ (string-suffix? "-----" line))
+ (let* ((type (substring line 11 (- (string-length line) 5)))
+ (endline (string-append "-----END " type "-----")))
+ (let-values (((outp extract) (open-bytevector-output-port)))
+ (let lp ((line (get-first-data-line port)))
+ (cond ((eof-object? line)
+ (error 'get-delimited-base64
+ "unexpected end of file"))
+ ((string-prefix? "-" line)
+ (unless (string=? line endline)
+ (error 'get-delimited-base64
+ "bad end delimiter" type line))
+ (values type (extract)))
+ (else
+ (unless (and (= (string-length line) 5)
+ (string-prefix? "=" line)) ;Skip Radix-64 checksum
+ (base64-decode line base64-alphabet outp))
+ (lp (get-line-comp string-trim-both port))))))))
+ (else ;skip garbage (like in openssl x509 -in foo -text output).
+ (get-delimited-base64 port)))))))
+
+ (define put-delimited-base64
+ (case-lambda
+ ((port type bv line-length)
+ (display (string-append "-----BEGIN " type "-----\n") port)
+ (base64-encode bv 0 (bytevector-length bv)
+ line-length #f base64-alphabet port)
+ (display (string-append "\n-----END " type "-----\n") port))
+ ((port type bv)
+ (put-delimited-base64 port type bv 76)))))
diff --git a/web/socket/server.scm b/web/socket/server.scm
index 85395a3..7b6463e 100644
--- a/web/socket/server.scm
+++ b/web/socket/server.scm
@@ -26,12 +26,12 @@
(define-module (web socket server)
#:use-module (ice-9 match)
#:use-module (rnrs bytevectors)
- #:use-module (base64)
- #:use-module (sha-1)
#:use-module (web request)
#:use-module (web response)
#:use-module (web uri)
+ #:use-module (web socket base64)
#:use-module (web socket frame)
+ #:use-module (web socket sha-1)
#:export (make-server-socket
run-server))
diff --git a/web/socket/sha-1.scm b/web/socket/sha-1.scm
new file mode 100644
index 0000000..95a13aa
--- /dev/null
+++ b/web/socket/sha-1.scm
@@ -0,0 +1,300 @@
+;; -*- mode: scheme; coding: utf-8 -*-
+;; Copyright © 2009, 2010, 2012 Göran Weinholt <goran@weinholt.se>
+
+;; Permission is hereby granted, free of charge, to any person obtaining a
+;; copy of this software and associated documentation files (the "Software"),
+;; to deal in the Software without restriction, including without limitation
+;; the rights to use, copy, modify, merge, publish, distribute, sublicense,
+;; and/or sell copies of the Software, and to permit persons to whom the
+;; Software is furnished to do so, subject to the following conditions:
+
+;; The above copyright notice and this permission notice shall be included in
+;; all copies or substantial portions of the Software.
+
+;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+;; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+;; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+;; THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+;; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+;; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+;; DEALINGS IN THE SOFTWARE.
+#!r6rs
+
+;; Byte-oriented SHA-1 from FIPS 180-3 and RFC 3174.
+
+;; The data being hashed will never be modified here.
+
+;; TODO: give an error if more than 2^64 bits are processed?
+;; TODO: Optimize. Should be simple enough with the help of a profiler.
+
+(library (web socket sha-1)
+ (export make-sha-1 sha-1-update! sha-1-finish! sha-1-clear!
+ sha-1 sha-1-copy sha-1-finish
+ sha-1-transform! ;for interested parties only
+ sha-1-length
+ sha-1-copy-hash! sha-1-96-copy-hash!
+ sha-1->bytevector sha-1->string
+ sha-1-hash=? sha-1-96-hash=?
+ hmac-sha-1)
+ (import (except (rnrs) bitwise-rotate-bit-field))
+
+ (define (sha-1-length) 20)
+
+ (define (vector-copy x) (vector-map (lambda (i) i) x))
+
+ (define (rol32 n count)
+ (let ((field1 (bitwise-and #xffffffff (bitwise-arithmetic-shift-left n count)))
+ (field2 (bitwise-arithmetic-shift-right n (- 32 count))))
+ (bitwise-ior field1 field2)))
+
+ (define-record-type sha1state
+ (fields (immutable H) ;Hash
+ (immutable W) ;temporary data
+ (immutable m) ;unprocessed data
+ (mutable pending) ;length of unprocessed data
+ (mutable processed))) ;length of processed data
+
+ (define (make-sha-1)
+ (let ((H (list->vector initial-hash))
+ (W (make-bytevector (* 4 80)))
+ (m (make-bytevector (* 4 16))))
+ (make-sha1state H W m 0 0)))
+
+ (define (sha-1-copy state)
+ (let ((H (vector-copy (sha1state-H state)))
+ (W (make-bytevector (* 4 80)))
+ (m (bytevector-copy (sha1state-m state))))
+ (make-sha1state H W m
+ (sha1state-pending state)
+ (sha1state-processed state))))
+
+ (define (sha-1-clear! state)
+ (for-each (lambda (i v)
+ (vector-set! (sha1state-H state) i v))
+ '(0 1 2 3 4)
+ initial-hash)
+ (bytevector-fill! (sha1state-W state) 0)
+ (bytevector-fill! (sha1state-m state) 0)
+ (sha1state-pending-set! state 0)
+ (sha1state-processed-set! state 0))
+
+ (define initial-hash '(#x67452301 #xefcdab89 #x98badcfe #x10325476 #xc3d2e1f0))
+
+ (define (Ch x y z)
+ (bitwise-xor (bitwise-and x y)
+ (bitwise-and (bitwise-not x) z)))
+
+ (define Parity bitwise-xor)
+
+ (define (Maj x y z)
+ (bitwise-xor (bitwise-and x y)
+ (bitwise-and x z)
+ (bitwise-and y z)))
+
+ (define k1 #x5a827999)
+ (define k2 #x6ed9eba1)
+ (define k3 #x8f1bbcdc)
+ (define k4 #xca62c1d6)
+
+ (define (f t B C D)
+ ((cond ((<= 0 t 19) Ch)
+ ((<= 20 t 39) Parity)
+ ((<= 40 t 59) Maj)
+ (else Parity))
+ B C D))
+
+ (define (K t)
+ (cond ((<= 0 t 19) k1)
+ ((<= 20 t 39) k2)
+ ((<= 40 t 59) k3)
+ (else k4)))
+
+ ;; This function transforms a whole 512 bit block.
+ (define (sha-1-transform! H W m offset)
+ ;; Copy the message block
+ (do ((t 0 (+ t 4)))
+ ((= t (* 4 16)))
+ (bytevector-u32-native-set! W t (bytevector-u32-ref m (+ t offset) (endianness big))))
+ ;; Initialize W[16..79]
+ (do ((t (* 4 16) (+ t 4)))
+ ((= t (* 4 80)))
+ (bytevector-u32-native-set! W t (rol32
+ (bitwise-xor (bytevector-u32-native-ref W (- t (* 4 3)))
+ (bytevector-u32-native-ref W (- t (* 4 8)))
+ (bytevector-u32-native-ref W (- t (* 4 14)))
+ (bytevector-u32-native-ref W (- t (* 4 16))))
+ 1)))
+ ;; Do the hokey pokey
+ (let lp ((A (vector-ref H 0))
+ (B (vector-ref H 1))
+ (C (vector-ref H 2))
+ (D (vector-ref H 3))
+ (E (vector-ref H 4))
+ (t 0))
+ (cond ((= t 80)
+ (vector-set! H 0 (bitwise-and #xffffffff (+ A (vector-ref H 0))))
+ (vector-set! H 1 (bitwise-and #xffffffff (+ B (vector-ref H 1))))
+ (vector-set! H 2 (bitwise-and #xffffffff (+ C (vector-ref H 2))))
+ (vector-set! H 3 (bitwise-and #xffffffff (+ D (vector-ref H 3))))
+ (vector-set! H 4 (bitwise-and #xffffffff (+ E (vector-ref H 4)))))
+ (else
+ (lp (bitwise-and #xffffffff
+ (+ (rol32 A 5)
+ (f t B C D)
+ E
+ (bytevector-u32-native-ref W (* 4 t))
+ (K t)))
+ A
+ (rol32 B 30)
+ C
+ D
+ (+ t 1))))))
+
+ ;; Add a bytevector to the state. Align your data to whole blocks if
+ ;; you want this to go a little faster.
+ (define sha-1-update!
+ (case-lambda
+ ((state data start end)
+ (let ((m (sha1state-m state)) ;unprocessed data
+ (H (sha1state-H state))
+ (W (sha1state-W state)))
+ (let lp ((offset start))
+ (cond ((= (sha1state-pending state) 64)
+ ;; A whole block is pending
+ (sha-1-transform! H W m 0)
+ (sha1state-pending-set! state 0)
+ (sha1state-processed-set! state (+ 64 (sha1state-processed state)))
+ (lp offset))
+ ((= offset end)
+ (values))
+ ((or (> (sha1state-pending state) 0)
+ (> (+ offset 64) end))
+ ;; Pending data exists or less than a block remains.
+ ;; Add more pending data.
+ (let ((added (min (- 64 (sha1state-pending state))
+ (- end offset))))
+ (bytevector-copy! data offset
+ m (sha1state-pending state)
+ added)
+ (sha1state-pending-set! state (+ added (sha1state-pending state)))
+ (lp (+ offset added))))
+ (else
+ ;; Consume a whole block
+ (sha-1-transform! H W data offset)
+ (sha1state-processed-set! state (+ 64 (sha1state-processed state)))
+ (lp (+ offset 64)))))))
+ ((state data)
+ (sha-1-update! state data 0 (bytevector-length data)))))
+
+ (define zero-block (make-bytevector 64 0))
+
+ ;; Finish the state by adding a 1, zeros and the counter.
+ (define (sha-1-finish! state)
+ (let ((m (sha1state-m state))
+ (pending (+ (sha1state-pending state) 1)))
+ (bytevector-u8-set! m (sha1state-pending state) #x80)
+ (cond ((> pending 56)
+ (bytevector-copy! zero-block 0
+ m pending
+ (- 64 pending))
+ (sha-1-transform! (sha1state-H state)
+ (sha1state-W state)
+ m
+ 0)
+ (bytevector-fill! m 0))
+ (else
+ (bytevector-copy! zero-block 0
+ m pending
+ (- 64 pending))))
+ ;; Number of bits in the data
+ (bytevector-u64-set! m 56
+ (* (+ (sha1state-processed state)
+ (- pending 1))
+ 8)
+ (endianness big))
+ (sha-1-transform! (sha1state-H state)
+ (sha1state-W state)
+ m
+ 0)))
+
+ (define (sha-1-finish state)
+ (let ((copy (sha-1-copy state)))
+ (sha-1-finish! copy)
+ copy))
+
+ ;; Find the SHA-1 of the concatenation of the given bytevectors.
+ (define (sha-1 . data)
+ (let ((state (make-sha-1)))
+ (for-each (lambda (d) (sha-1-update! state d))
+ data)
+ (sha-1-finish! state)
+ state))
+
+ (define (copy-hash! state bv off len)
+ (do ((i 0 (+ i 1)))
+ ((= i len))
+ (bytevector-u32-set! bv (+ off (* 4 i))
+ (vector-ref (sha1state-H state) i)
+ (endianness big))))
+
+ (define (sha-1-copy-hash! state bv off)
+ (copy-hash! state bv off 5))
+
+ (define (sha-1-96-copy-hash! state bv off)
+ (copy-hash! state bv off 3))
+
+ (define (sha-1->bytevector state)
+ (let ((ret (make-bytevector (* 4 5))))
+ (sha-1-copy-hash! state ret 0)
+ ret))
+
+ (define (sha-1->string state)
+ (apply string-append
+ (map (lambda (x)
+ (if (< x #x10)
+ (string-append "0" (number->string x 16))
+ (number->string x 16)))
+ (bytevector->u8-list (sha-1->bytevector state)))))
+
+ ;; Compare an SHA-1 state with a bytevector. It is supposed to not
+ ;; terminate early in order to not leak timing information. Assumes
+ ;; that the bytevector's length is ok.
+ (define (cmp state bv len)
+ (do ((i 0 (fx+ i 1))
+ (diff 0 (+ diff
+ (bitwise-xor
+ (bytevector-u32-ref bv (* 4 i) (endianness big))
+ (vector-ref (sha1state-H state) i)))))
+ ((fx=? i len)
+ (zero? diff))))
+
+ (define (sha-1-hash=? state bv) (cmp state bv 5))
+
+ (define (sha-1-96-hash=? state bv) (cmp state bv 3))
+
+;;; HMAC-SHA-1. RFC 2104.
+
+ ;; TODO: an API with make, update!, finish!, finish, clear!, copy, etc
+
+ (define (hmac-sha-1 secret . data)
+ ;; RFC 2104.
+ (if (> (bytevector-length secret) 64)
+ (apply hmac-sha-1 (sha-1->bytevector (sha-1 secret)) data)
+ (let ((k-ipad (make-bytevector 64 0))
+ (k-opad (make-bytevector 64 0)))
+ (bytevector-copy! secret 0 k-ipad 0 (bytevector-length secret))
+ (bytevector-copy! secret 0 k-opad 0 (bytevector-length secret))
+ (do ((i 0 (fx+ i 1)))
+ ((fx=? i 64))
+ (bytevector-u8-set! k-ipad i (fxxor #x36 (bytevector-u8-ref k-ipad i)))
+ (bytevector-u8-set! k-opad i (fxxor #x5c (bytevector-u8-ref k-opad i))))
+ (let ((state (make-sha-1)))
+ (sha-1-update! state k-ipad)
+ (for-each (lambda (d) (sha-1-update! state d)) data)
+ (sha-1-finish! state)
+ (let ((digest (sha-1->bytevector state)))
+ (sha-1-clear! state)
+ (sha-1-update! state k-opad)
+ (sha-1-update! state digest)
+ (sha-1-finish! state)
+ state))))))