PeculiarVentures/webcrypto

enable import/export raw ec-keys

armfazh opened this issue · 3 comments

armfazh commented

currently importKey and exportKey methods work only on public keys, but not on privateKeys.

microshine commented

Chrome doesn't support raw format for EC private key.
image

Script

var keys = await crypto.subtle.generateKey({name: "ECDSA", namedCurve: "P-256"}, true, ["sign", "verify"]);
var raw = await crypto.subtle.exportKey("raw", keys.privateKey); // Error

var raw = await crypto.subtle.exportKey("raw", keys.publicKey);
console.log(raw);

@peculiar/webcrypto throws AsnSchemaValidationError. Maybe it should be better to use a custom error for that.

AsnSchemaValidationError: Data does not match to PublicKeyInfo ASN1 schema. 
    at Function.fromASN (/Users/microshine/github/pv/webcrypto/node_modules/@peculiar/asn1-schema/build/cjs/parser.js:56:23)
    at Function.parse (/Users/microshine/github/pv/webcrypto/node_modules/@peculiar/asn1-schema/build/cjs/parser.js:29:26)
    at Function.exportKey (/Users/microshine/github/pv/webcrypto/build/webcrypto.js:1449:60)
    at EcdsaProvider.onExportKey (/Users/microshine/github/pv/webcrypto/build/webcrypto.js:1578:25)
    at EcdsaProvider.exportKey (/Users/microshine/github/pv/webcrypto/node_modules/webcrypto-core/build/webcrypto-core.js:203:33)
    at SubtleCrypto.exportKey (/Users/microshine/github/pv/webcrypto/node_modules/webcrypto-core/build/webcrypto-core.js:838:39)
    at main (/Users/microshine/github/pv/webcrypto/test.ts:7:35) {
  schemas: [ 'PublicKeyInfo' ]
}

@armfazh Do you have any ideas how EC private key raw must look like?

armfazh commented

Do you have any ideas how EC private key raw must look like?

For P-256, it's an arraybuffer of 32 bytes.

armfazh commented

after RTFM specification: https://www.w3.org/TR/WebCryptoAPI/#ecdsa-operations
Private keys cannot be exported in raw format, but they can be exported as jwk or pkcs8.
closing.