jwk_to_key.js 5.5 KB

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  1. import crypto from './webcrypto.js';
  2. import { JOSENotSupported } from '../util/errors.js';
  3. import { decode as base64url } from './base64url.js';
  4. function subtleMapping(jwk) {
  5. let algorithm;
  6. let keyUsages;
  7. switch (jwk.kty) {
  8. case 'oct': {
  9. switch (jwk.alg) {
  10. case 'HS256':
  11. case 'HS384':
  12. case 'HS512':
  13. algorithm = { name: 'HMAC', hash: `SHA-${jwk.alg.slice(-3)}` };
  14. keyUsages = ['sign', 'verify'];
  15. break;
  16. case 'A128CBC-HS256':
  17. case 'A192CBC-HS384':
  18. case 'A256CBC-HS512':
  19. throw new JOSENotSupported(`${jwk.alg} keys cannot be imported as CryptoKey instances`);
  20. case 'A128GCM':
  21. case 'A192GCM':
  22. case 'A256GCM':
  23. case 'A128GCMKW':
  24. case 'A192GCMKW':
  25. case 'A256GCMKW':
  26. algorithm = { name: 'AES-GCM' };
  27. keyUsages = ['encrypt', 'decrypt'];
  28. break;
  29. case 'A128KW':
  30. case 'A192KW':
  31. case 'A256KW':
  32. algorithm = { name: 'AES-KW' };
  33. keyUsages = ['wrapKey', 'unwrapKey'];
  34. break;
  35. case 'PBES2-HS256+A128KW':
  36. case 'PBES2-HS384+A192KW':
  37. case 'PBES2-HS512+A256KW':
  38. algorithm = { name: 'PBKDF2' };
  39. keyUsages = ['deriveBits'];
  40. break;
  41. default:
  42. throw new JOSENotSupported('Invalid or unsupported JWK "alg" (Algorithm) Parameter value');
  43. }
  44. break;
  45. }
  46. case 'RSA': {
  47. switch (jwk.alg) {
  48. case 'PS256':
  49. case 'PS384':
  50. case 'PS512':
  51. algorithm = { name: 'RSA-PSS', hash: `SHA-${jwk.alg.slice(-3)}` };
  52. keyUsages = jwk.d ? ['sign'] : ['verify'];
  53. break;
  54. case 'RS256':
  55. case 'RS384':
  56. case 'RS512':
  57. algorithm = { name: 'RSASSA-PKCS1-v1_5', hash: `SHA-${jwk.alg.slice(-3)}` };
  58. keyUsages = jwk.d ? ['sign'] : ['verify'];
  59. break;
  60. case 'RSA-OAEP':
  61. case 'RSA-OAEP-256':
  62. case 'RSA-OAEP-384':
  63. case 'RSA-OAEP-512':
  64. algorithm = {
  65. name: 'RSA-OAEP',
  66. hash: `SHA-${parseInt(jwk.alg.slice(-3), 10) || 1}`,
  67. };
  68. keyUsages = jwk.d ? ['decrypt', 'unwrapKey'] : ['encrypt', 'wrapKey'];
  69. break;
  70. default:
  71. throw new JOSENotSupported('Invalid or unsupported JWK "alg" (Algorithm) Parameter value');
  72. }
  73. break;
  74. }
  75. case 'EC': {
  76. switch (jwk.alg) {
  77. case 'ES256':
  78. algorithm = { name: 'ECDSA', namedCurve: 'P-256' };
  79. keyUsages = jwk.d ? ['sign'] : ['verify'];
  80. break;
  81. case 'ES384':
  82. algorithm = { name: 'ECDSA', namedCurve: 'P-384' };
  83. keyUsages = jwk.d ? ['sign'] : ['verify'];
  84. break;
  85. case 'ES512':
  86. algorithm = { name: 'ECDSA', namedCurve: 'P-521' };
  87. keyUsages = jwk.d ? ['sign'] : ['verify'];
  88. break;
  89. case 'ECDH-ES':
  90. case 'ECDH-ES+A128KW':
  91. case 'ECDH-ES+A192KW':
  92. case 'ECDH-ES+A256KW':
  93. algorithm = { name: 'ECDH', namedCurve: jwk.crv };
  94. keyUsages = jwk.d ? ['deriveBits'] : [];
  95. break;
  96. default:
  97. throw new JOSENotSupported('Invalid or unsupported JWK "alg" (Algorithm) Parameter value');
  98. }
  99. break;
  100. }
  101. case 'OKP': {
  102. switch (jwk.alg) {
  103. case 'EdDSA':
  104. algorithm = { name: jwk.crv };
  105. keyUsages = jwk.d ? ['sign'] : ['verify'];
  106. break;
  107. case 'ECDH-ES':
  108. case 'ECDH-ES+A128KW':
  109. case 'ECDH-ES+A192KW':
  110. case 'ECDH-ES+A256KW':
  111. algorithm = { name: jwk.crv };
  112. keyUsages = jwk.d ? ['deriveBits'] : [];
  113. break;
  114. default:
  115. throw new JOSENotSupported('Invalid or unsupported JWK "alg" (Algorithm) Parameter value');
  116. }
  117. break;
  118. }
  119. default:
  120. throw new JOSENotSupported('Invalid or unsupported JWK "kty" (Key Type) Parameter value');
  121. }
  122. return { algorithm, keyUsages };
  123. }
  124. const parse = async (jwk) => {
  125. var _a, _b;
  126. if (!jwk.alg) {
  127. throw new TypeError('"alg" argument is required when "jwk.alg" is not present');
  128. }
  129. const { algorithm, keyUsages } = subtleMapping(jwk);
  130. const rest = [
  131. algorithm,
  132. (_a = jwk.ext) !== null && _a !== void 0 ? _a : false,
  133. (_b = jwk.key_ops) !== null && _b !== void 0 ? _b : keyUsages,
  134. ];
  135. if (algorithm.name === 'PBKDF2') {
  136. return crypto.subtle.importKey('raw', base64url(jwk.k), ...rest);
  137. }
  138. const keyData = { ...jwk };
  139. delete keyData.alg;
  140. delete keyData.use;
  141. return crypto.subtle.importKey('jwk', keyData, ...rest);
  142. };
  143. export default parse;