Signing JWT with RSA private key loaded from .env file

[PlasmaDischarge]

Hello,

I'd like to store my RSA private key in a .env file, and have it loaded into my node process via node-foreman, per best practice. The trouble is, the key format (PEM) spans multiple lines, which the .env file format doesn't allow. Based on workarounds posted by other folks, I've tried surrounding the key in double quotes and replacing line breaks with the line feed character ('\r'), but this results in an error:

.env

PRIVATE_KEY="-----BEGIN RSA PRIVATE KEY-----\rMIIEowIBAAKCAQEAz7pZEypvrFJCDshsbOamj9bmy/dXnUOyCo5b3xSvvTNIoFAC\r5ePXozCD/5Byih1JB6ZYE6OceEW6oArkPzZOl8bFBlqV9k30oerMtVei18+CfF/u\rFLWlJXs9FvXrRTKtsL43OmpLCH3LdzK9/+ZqhEx/TShp3JudUWuRW8ALqrBd8QW5\rCWJHYozYVaIpFzwJ9KW6fJ9GpZfcToCOquLWo8iINnAovXmvcAtdmzgIqoucD988\rf9oerll/CubJLy2rOiyeRvsAYouoefoyQZWN8IYPlnb5IB6Z7qnVL6rZz44dAjVw\rS3uARW3lxpfeZn3TN7wpPkBssGBF0OSEHNrXVwIDAQABAoIBAC8HHCVnpRKZKNVZ\r8JoS+cB0wZmJrK8w5TzYj9oIP+UQmC+bDZzoISiT0j5ogFXeXWs68JO5pbHg72hO\rLvBUpiRcXryag3rYmTqTArdHWNmM5BiuSyMrIHFE3ka1dAcdew8ZcT1rVQNeH1Mk\rDLnDe3fqLaPVM2o7XLlTJfxklP+WN6xWhBgDVgEawneo5svdgblYhg3u7cb4fsHg\rcAf0sCYraVuqcUHa/AUVOx7n5U39x3ShOvOQvFlWEDD6uN4Yg/twW2UyfFDWD57p\r2oPIEf06wOOu2XylPQwEU9w92Fr4yNqk0xksn8sOjbRyEPZncpDICsPTo1nsrz+R\r0AcwWUkCgYEA7DfUujbbg6WrfSOyS718kTeej0Il5z19JYu11g+Sis4r8RWbT92q\rweCp4dCGCpJrsPbs4+s4hT42sKfjUcUy5ZCGTDturQNbhH0RGxPp1KUTrytzdph8\r4mqpCVYcN1AmLCCA0WtFqJ53taWuipcLtU48ZRC4jHI+stUSNCtaE8UCgYEA4R+6\rx5mUjOWAK8GSTgHMWa72KqaxR/osYwmMPtHtjIFm1aOElQaXbGlZKd3dR5Tnw/4R\r8hO/gJc+eQeaPGhri0IVmG66JNTw8q0M0Qd+l0OrarYS5c09XzjAUdGOatstsaNE\rrhgRG90HvVYt0cHyKRa/C4+CnEBod/EoS/UnhGsCgYB5wT1Qzj3PWXFPCzs3du/i\rGf0Mclf/HN6In76WG2i5SxOzLCPlwqflTtvBnS25/Uas7FmmEPQNGcguvhqZZz+Y\rvCm82VVusDBX1e8fOeBozr2aqJbXJjoYqkl+mnfoutMyI37Ccrxw8V1ar4+Lt9c9\rGJpgrYGyQqC2pMTBRyci0QKBgHxc9uXE5ddgAQorCROm0qjIipzNMSo9/b9ISv15\rIu13nsNubZOV7JirKeKC+fbNP6t585fzaNs0sgJSPNYaKS7o9t0abiJisCifiHEA\r3uHZNBzjMFVaqAiuZS/NwAsvwXJca1hxWyI1XE0wCmfR6GDie+96/AAtZIi95DDx\r4T65AoGBAIE5LSP+glxJEd8jU/qc80D/dXf6icURyYDGARw8mziAgw6fL9cwbmqb\rIGDxP1ke2FA8OZ0W4VybRi9UcprenvADYpPb+CPZv4gxGoDFg0Bb/JcFUKL29hC1\rsteX0GR4TKYNeXLC+zz7Qr0DzhpqRswSyHG5GckkIRdgHx4l/Uza\r-----END RSA PRIVATE KEY-----"

(this key is not used in any live system)

app.js

var jwt = require('jsonwebtoken');

jwt.sign(data, process.env.PRIVATE_KEY, { 
    algorithm: 'RS256',
    expiresIn: '3 days'
}, function(token) {
    // process crashes before getting here
});

output

> nf start

[OKAY] Loaded ENV .env File as KEY=VALUE Format
[OKAY] Trimming display Output to 481 Columns
7:03:14 PM web.1 |  restify is listening on port http://[::]:5000
7:03:45 PM web.1 |  events.js:141
7:03:45 PM web.1 |        throw er; // Unhandled 'error' event
7:03:45 PM web.1 |        ^
7:03:45 PM web.1 |  Error: error:0906D06C:PEM routines:PEM_read_bio:no start line
7:03:45 PM web.1 |      at Error (native)
7:03:45 PM web.1 |      at Sign.sign (crypto.js:279:26)
7:03:45 PM web.1 |      at Object.sign (C:\example\node_modules\jsonwebtoken\node_modules\jws\node_modules\jwa\index.js:54:45)
7:03:45 PM web.1 |      at jwsSign (C:\example\node_modules\jsonwebtoken\node_modules\jws\lib\sign-stream.js:23:24)
7:03:45 PM web.1 |      at SignStream.sign (C:\example\node_modules\jsonwebtoken\node_modules\jws\lib\sign-stream.js:49:21)
7:03:45 PM web.1 |      at SignStream.<anonymous> (C:\example\node_modules\jsonwebtoken\node_modules\jws\lib\sign-stream.js:37:12)
7:03:45 PM web.1 |      at DataStream.g (events.js:260:16)
7:03:45 PM web.1 |      at emitNone (events.js:67:13)
7:03:45 PM web.1 |      at DataStream.emit (events.js:166:7)
7:03:45 PM web.1 |      at DataStream.<anonymous> (C:\example\node_modules\jsonwebtoken\node_modules\jws\lib\data-stream.js:32:12)
7:03:45 PM web.1 |      at doNTCallback0 (node.js:419:9)
7:03:45 PM web.1 |      at process._tickDomainCallback (node.js:389:13)
[DONE] Killing all processes with signal  null
7:03:45 PM web.1 Exited Abnormally

I've tried several permutations of this workaround without success. When loading the original private key file via the fs module and passing to this library, everything works perfectly as expected. Also, I've confirmed the key is being loaded into the process.env.PRIVATE_KEY variable in the exact same format as shown in the .env file.

So, how can I format the key in the .env file so that it will work as expected with this library?

Thanks in advance for your time.

[PlasmaDischarge]

The solution was to format my .env file as json using '\n' as a linebreak, like so:

.env

{
  "PRIVATE_KEY": "-----BEGIN RSA PRIVATE KEY-----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\nsteX0GR4TKYNeXLC+zz7Qr0DzhpqRswSyHG5GckkIRdgHx4l/Uza\n-----END RSA PRIVATE KEY-----",
  "PUBLIC_KEY": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAz7pZEypvrFJCDshsbOam\nj9bmy/dXnUOyCo5b3xSvvTNIoFAC5ePXozCD/5Byih1JB6ZYE6OceEW6oArkPzZO\nl8bFBlqV9k30oerMtVei18+CfF/uFLWlJXs9FvXrRTKtsL43OmpLCH3LdzK9/+Zq\nhEx/TShp3JudUWuRW8ALqrBd8QW5CWJHYozYVaIpFzwJ9KW6fJ9GpZfcToCOquLW\no8iINnAovXmvcAtdmzgIqoucD988f9oerll/CubJLy2rOiyeRvsAYouoefoyQZWN\n8IYPlnb5IB6Z7qnVL6rZz44dAjVwS3uARW3lxpfeZn3TN7wpPkBssGBF0OSEHNrX\nVwIDAQAB\n-----END PUBLIC KEY-----"
}

Node-foreman will load the variables into the process, where they can be used seamlessly with the jsonwebtoken library as expected.

[yasithph]

I had the same issue and none of the answers given here or else where did not work. Finally I found out that one of the '-' in -----BEGIN RSA KEY----- was missing. There need to 5 dashes exactly.