Initialization with parameters of RSA generated by Web Crypto API

[wybran]

Hi, I generate RSA-OAEP keys using SubtleCrypto interface of the Web Browser Crypto API:

window.crypto.subtle.generateKey({
      name: RSA_OAEP,
      modulusLength: 2048,
      publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
      hash: "SHA-512",
}, true, ["wrapKey", "unwrapKey"])

The generated RSA key pair is in JWK format so I need to use CryptoSwift with this constructor:
RSA.swift

public init(n: BigUInteger, e: BigUInteger, d: BigUInteger, p: BigUInteger, q: BigUInteger) throws {

Unfortunately, this line of the constructor throws an error for some of my key pairs:

let phi = (p - 1) * (q - 1)
guard d == e.inverse(phi) else { throw Error.invalidPrimes }

When I comment out this, the RSA correctly decrypts my data.
Does this inverse function calculate well?

Here is an example of my two RSA keys in JWK format generated by the same JS function, the left one works fine but the other one doesn't 😩

//Working
let nBase64 = "uMiALif7WXEPr2ExJdXQPPIhyloShAP56ArUqtpwLq3N6pLUG1vkJsHzLXmscTWDyb4YQPjxkY41bd9Gn8Y0nwSNY7d53vO3dboEp3o2BYAbDzoQTD5vYHtkxigpnlkKN9VGjz6B2XKCdaAoHMSeDwoqeqqHbyFoo1Wv1JWIiw29Uz6q1spetCG6c85nz2FMgVhBuWWVFiiFg9ysiOcvlcTADYowyFRBXB59u-hb8E0Y-P-vkhdLuyUt2RD8SQVtlZBE7gU4XBYzKz0IG8rbD_qfXFKWn-TGqbQTAWCF2BR1C9VKXV35hg2oqou32g227KT6D9TWZwbf54JmmqsPUQ"
let eBase64 = "AQAB"
let dBase64 = "DBK9nUZre8qRVcop5ej0dCb14jzEXO_NkkWy437mOYaNn7f8N9VnMMkXVG9QvwzaEYJkH0qkrff2sbkW6jWPFpy7iDpishiGciC3USIBCZb3LaWDjxe9OzaUvQW-wmPa8Q70T0OsRELhF0JhnI-ULDNj1yPxOWebaKCenmsuwrcEqFVDS0QN9yEpI_jpe5nnnZPyRwdapwpFdZITKfPqpTfo7ZysfVIQZJaxsuhOAKrOHZkwec-SGn0nCnIkvcuaMBbmAnzRSQBrsdbxon6Bih07zoYa-yEv_d_m0j__HynmdOMxM0OV0MF_jMzafJn0VXHWv8DnKHsH1xrDhol-YQ"
let pBase64 = "4hvu0URMSMIweTcNdvOPIOkXwK8Pbz7Zxy3Gy0MKJsRjm7IHJfC5aSpbXkmCjJ3jXaJuuRzgC-8HP5q7ViKee973oRjEz3mhcmV3SwvOdnFvGe7ILFLhBUeoc7gspGZ52pw1yu5qiizyrhiJDuZycnLpvzVDaBOd9HiD18pujy0"
let qBase64 = "0TYAW6ITWvxlsz1ZL7jS0KH2nkbccb6e8gAF0ErSHicyntN29a2437Az3EWtngA4TW3N8GtohG1Xl3Wf82VlJtIm7DWyA9vHGGbqPSfkPOKIxpuzN-NN8QctqHvaAFfV0DIQucGlh7hTCfohyna_rjYp8L6cBKmb1mGQ_moP9zU"
    
let n = BigUInteger(Data(base64urlEncoded: nBase64)!)
let e = BigUInteger(Data(base64urlEncoded: eBase64)!)
let d = BigUInteger(Data(base64urlEncoded: dBase64)!)
let p = BigUInteger(Data(base64urlEncoded: pBase64)!)
let q = BigUInteger(Data(base64urlEncoded: qBase64)!)

let rsa = try RSA(n: n, e: e, d: d, p: p, q: q)

//Not Working
let nBase64 = "zl3vzabNpwJZQ376h7s148jxH0ZTsseinCMR8QtDSa_DSzhvxY5JTvh86HUBvWM3W9vdx-v3dLNMgjRgHwAFHM89d6Gon0mU0zBG3Ut2f7QiYgo0Qr-zH5jeBINMYLqa2Rn9d7vT620Ak1438k0zyc6pXzX8Dc2Iakm_EZw8Lrqm1t4E7OxPF8fAxv1A7rOAa3zkjh843h5DXwiOcToMLwepwc8HRU5fTGmhBvyUXQp2ki1ikJ-cfcdjRHd9ZFW08-rq-qI_nhXaeOZYX9J5lexfHIZQrzlylzpm_av9LIUDRP2HCPXyGZMeBHJM7CFkROSva1OkYSZp-86yT7YOkw"
let eBase64 = "AQAB"
let dBase64 = "Bn7jBXT7ywcdnL7YKstGU4rjFToSnPFuApnckP99L9yVA2NmzvkabsMO_b2VrQGPDarc4WYYmaBY4nKYKs9Yx5CC9IIutt346UO2CZpOetjYrn-c3qYjN4f3IsZfO15_umpBTMSpU5Dixy5u5GK5tpYr18bMYELZEq0dSfQLR8QQpdmsCR96qDOY9mJnV_eGamnfA_Zisl3rSLzc_W0-Ar5ARdQXCy3XIvNVqO3_ESOD8pScIAXRay--YUZZJBr3Af9DEc8kqZZkR8a96_hKU6innFqAO22umrkgbuAFfwNUbSIgT_pCYColyWjdN4ER9ckXccDSm_wwkGV03HjnAQ"
let pBase64 = "8jojOD7A3ZEogh6LMPGfW0UXdeQHdpyWBO8CMF2DrHElH6ActHPjLBE43WWHq7BgRtc5YHS6l0UBqzVlZTn4b-sPT0B8SjK-qZVYhJdFgBRfq8RRdmQ0ebF65Bysmj0NYnR3ef8AImlGKEpfXWsYJtjfEEDA0vdrXM2UosqStFE"
let qBase64 = "2hnRZlvmC7uZSQyVhI-V-hPH96fcyGcuncVjHxrPeftVwV0mBJ6a_hbcBFetf6_j2L4BE0M5OrVLjWJN7gWL-GYcpWFfcmvQAnRpPNNEkeglnHS8TAM6wa0M12iHbLMWeXh8cJ_6oARpJ34bMLMHyCFTQwzl9I6c_JW5MgdUj6M"
    
let n = BigUInteger(Data(base64urlEncoded: nBase64)!)
let e = BigUInteger(Data(base64urlEncoded: eBase64)!)
let d = BigUInteger(Data(base64urlEncoded: dBase64)!)
let p = BigUInteger(Data(base64urlEncoded: pBase64)!)
let q = BigUInteger(Data(base64urlEncoded: qBase64)!)

let rsa = try RSA(n: n, e: e, d: d, p: p, q: q)

Does anyone know why guard d == e.inverse(phi) doesn't work for some keys?

[wybran]

I found the issue, RSA keys generated on safari using Web Crypto API work fine, but using any other browser the comparison:
guard d == e.inverse(phi) fails and throws the Error.invalidPrimes.

What do you think should be done to resolve this?