11/*
22 * Copyright (c) Microsoft Corporation. All rights reserved.
33 * Licensed under the MIT License.
4+ *
45 */
56import { BrowserStringUtils } from "../utils/BrowserStringUtils" ;
67import { BrowserAuthError } from "../error/BrowserAuthError" ;
7-
8+ import { StringUtils } from "@azure/msal-common" ;
9+ /**
10+ * See here for more info on RsaHashedKeyGenParams: https://developer.mozilla.org/en-US/docs/Web/API/RsaHashedKeyGenParams
11+ */
12+ // RSA KeyGen Algorithm
13+ const PKCS1_V15_KEYGEN_ALG = "RSASSA-PKCS1-v1_5" ;
814// SHA-256 hashing algorithm
9- const HASH_ALG = "SHA-256" ;
15+ const S256_HASH_ALG = "SHA-256" ;
16+ // MOD length for PoP tokens
17+ const MODULUS_LENGTH = 2048 ;
18+ // Public Exponent
19+ const PUBLIC_EXPONENT : Uint8Array = new Uint8Array ( [ 0x01 , 0x00 , 0x01 ] ) ;
20+ // JWK Key Format string
21+ const KEY_FORMAT_JWK = "jwk" ;
1022
1123/**
1224 * This class implements functions used by the browser library to perform cryptography operations such as
1325 * hashing and encoding. It also has helper functions to validate the availability of specific APIs.
1426 */
1527export class BrowserCrypto {
1628
29+ private _keygenAlgorithmOptions : RsaHashedKeyGenParams ;
30+
1731 constructor ( ) {
1832 if ( ! ( this . hasCryptoAPI ( ) ) ) {
1933 throw BrowserAuthError . createCryptoNotAvailableError ( "Browser crypto or msCrypto object not available." ) ;
2034 }
35+
36+ this . _keygenAlgorithmOptions = {
37+ name : PKCS1_V15_KEYGEN_ALG ,
38+ hash : S256_HASH_ALG ,
39+ modulusLength : MODULUS_LENGTH ,
40+ publicExponent : PUBLIC_EXPONENT
41+ } ;
2142 }
2243
2344 /**
@@ -27,7 +48,7 @@ export class BrowserCrypto {
2748 async sha256Digest ( dataString : string ) : Promise < ArrayBuffer > {
2849 const data = BrowserStringUtils . stringToUtf8Arr ( dataString ) ;
2950
30- return this . hasIECrypto ( ) ? this . getMSCryptoDigest ( HASH_ALG , data ) : this . getSubtleCryptoDigest ( HASH_ALG , data ) ;
51+ return this . hasIECrypto ( ) ? this . getMSCryptoDigest ( S256_HASH_ALG , data ) : this . getSubtleCryptoDigest ( S256_HASH_ALG , data ) ;
3152 }
3253
3354 /**
@@ -43,17 +64,25 @@ export class BrowserCrypto {
4364 }
4465
4566 /**
46- * Checks whether IE crypto (AKA msCrypto) is available.
67+ * Generates a keypair based on current keygen algorithm config.
68+ * @param extractable
69+ * @param usages
4770 */
48- private hasIECrypto ( ) : boolean {
49- return ! ! window [ "msCrypto" ] ;
71+ async generateKeyPair ( extractable : boolean , usages : Array < KeyUsage > ) : Promise < CryptoKeyPair > {
72+ return (
73+ this . hasIECrypto ( ) ?
74+ this . msCryptoGenerateKey ( extractable , usages )
75+ : window . crypto . subtle . generateKey ( this . _keygenAlgorithmOptions , extractable , usages )
76+ ) as Promise < CryptoKeyPair > ;
5077 }
5178
5279 /**
53- * Check whether browser crypto is available.
80+ * Export key as given KeyFormat (see above)
81+ * @param key
82+ * @param format
5483 */
55- private hasBrowserCrypto ( ) : boolean {
56- return ! ! window . crypto ;
84+ async exportJwk ( key : CryptoKey ) : Promise < JsonWebKey > {
85+ return this . hasIECrypto ( ) ? this . msCryptoExportJwk ( key ) : window . crypto . subtle . exportKey ( KEY_FORMAT_JWK , key ) ;
5786 }
5887
5988 /**
@@ -63,17 +92,32 @@ export class BrowserCrypto {
6392 return this . hasIECrypto ( ) || this . hasBrowserCrypto ( ) ;
6493 }
6594
95+ /**
96+ * Checks whether IE crypto (AKA msCrypto) is available.
97+ */
98+ private hasIECrypto ( ) : boolean {
99+ return "msCrypto" in window ;
100+ }
101+
102+ /**
103+ * Check whether browser crypto is available.
104+ */
105+ private hasBrowserCrypto ( ) : boolean {
106+ return "crypto" in window ;
107+ }
108+
66109 /**
67110 * Helper function for SHA digest.
68111 * @param algorithm
69112 * @param data
70113 */
71114 private async getSubtleCryptoDigest ( algorithm : string , data : Uint8Array ) : Promise < ArrayBuffer > {
115+ console . log ( algorithm ) ;
72116 return window . crypto . subtle . digest ( algorithm , data ) ;
73117 }
74118
75119 /**
76- * Helper function for SHA digest.
120+ * IE Helper function for SHA digest.
77121 * @param algorithm
78122 * @param data
79123 */
@@ -88,4 +132,56 @@ export class BrowserCrypto {
88132 } ) ;
89133 } ) ;
90134 }
135+
136+ private async msCryptoGenerateKey ( extractable : boolean , usages : Array < KeyUsage > ) : Promise < CryptoKeyPair > {
137+ return new Promise ( ( resolve : any , reject : any ) => {
138+ const msGenerateKey = window [ "msCrypto" ] . subtle . generateKey ( this . _keygenAlgorithmOptions , extractable , usages ) ;
139+ msGenerateKey . addEventListener ( "complete" , ( e : { target : { result : CryptoKeyPair | PromiseLike < CryptoKeyPair > ; } ; } ) => {
140+ resolve ( e . target . result ) ;
141+ } ) ;
142+
143+ msGenerateKey . addEventListener ( "error" , ( error : any ) => {
144+ reject ( error ) ;
145+ } ) ;
146+ } ) ;
147+ }
148+
149+ /**
150+ * IE Helper function for exporting keys
151+ * @param key
152+ * @param format
153+ */
154+ private async msCryptoExportJwk ( key : CryptoKey ) : Promise < JsonWebKey > {
155+ return new Promise ( ( resolve : any , reject : any ) => {
156+ const msExportKey = window [ "msCrypto" ] . subtle . exportKey ( KEY_FORMAT_JWK , key ) ;
157+ msExportKey . addEventListener ( "complete" , ( e : { target : { result : ArrayBuffer ; } ; } ) => {
158+ const resultBuffer : ArrayBuffer = e . target . result ;
159+
160+ const resultString = BrowserStringUtils . utf8ArrToString ( new Uint8Array ( resultBuffer ) )
161+ . replace ( / \r / g, "" )
162+ . replace ( / \n / g, "" )
163+ . replace ( / \t / g, "" )
164+ . split ( " " ) . join ( "" )
165+ . replace ( "\u0000" , "" ) ;
166+
167+ try {
168+ resolve ( JSON . parse ( resultString ) ) ;
169+ } catch ( e ) {
170+ reject ( e ) ;
171+ }
172+ } ) ;
173+
174+ msExportKey . addEventListener ( "error" , ( error : any ) => {
175+ reject ( error ) ;
176+ } ) ;
177+ } ) ;
178+ }
179+
180+ /**
181+ * Returns stringified jwk.
182+ * @param jwk
183+ */
184+ static getJwkString ( jwk : JsonWebKey ) : string {
185+ return JSON . stringify ( jwk , Object . keys ( jwk ) . sort ( ) ) ;
186+ }
91187}
0 commit comments