Assuming you've created your app, added correct redirect URL and enabled "Sign In with LinkedIn" product for your app, the issue you are having is probably that the first call returns a login page where your users are supposed to authenticate.
- submit the request to
https://www.linkedin.com/oauth/v2/authorization (you seem to have done that)
- parse response of step 1 and extract all form values, add username and password to simulate user login
- make POST request and use values from previous step as
x-www-form-urlencoded data
- manually follow the redirect header from step 3
- make note of second redirect header but do not follow it - instead extract the code
- POST code from previous step to
https://www.linkedin.com/oauth/v2/accessToken and get access_token in response
From here, I was able to successfully transition to the auth code by following the steps.
I am not sure if you use the online Postman, but here's my complete collection export file for reference:
{
"info": {
"_postman_id": "397761c9-4287-43f2-860a-3c34cb710d50",
"name": "Linkedin oAuth",
"schema": "https://schema.getpostman.com/json/collection/v2.1.0/collection.json"
},
"item": [
{
"name": "01 request Login form",
"event": [
{
"listen": "test",
"script": {
"exec": [
"const $ = cheerio.load(pm.response.text());\r",
"var inputs = $('form').serializeArray();\r",
"var payload = '';\r",
"inputs.forEach(i => {\r",
" payload += encodeURIComponent(i.name)+ '=' + encodeURIComponent(i.value) + '&';\r",
"})\r",
"payload += 'session_key='+ encodeURIComponent(pm.collectionVariables.get('username')) + '&'\r",
"payload += 'session_password='+ encodeURIComponent(pm.collectionVariables.get('password'))\r",
"\r",
"pm.collectionVariables.set(\"form_data\", payload);"
],
"type": "text/javascript"
}
}
],
"request": {
"method": "GET",
"header": [],
"url": {
"raw": "https://www.linkedin.com/oauth/v2/authorization?response_type=code&client_id={{client_id}}&redirect_uri={{redirect_uri}}&scope=r_liteprofile&state={{$guid}}",
"protocol": "https",
"host": [
"www",
"linkedin",
"com"
],
"path": [
"oauth",
"v2",
"authorization"
],
"query": [
{
"key": "response_type",
"value": "code"
},
{
"key": "client_id",
"value": "{{client_id}}"
},
{
"key": "redirect_uri",
"value": "{{redirect_uri}}"
},
{
"key": "scope",
"value": "r_liteprofile"
},
{
"key": "state",
"value": "{{$guid}}"
}
]
}
},
"response": []
},
{
"name": "02 Submit login form",
"event": [
{
"listen": "prerequest",
"script": {
"exec": [
""
],
"type": "text/javascript"
}
},
{
"listen": "test",
"script": {
"exec": [
"var url = 'https://www.linkedin.com'+ pm.response.headers.get(\"Location\");\r",
"pm.collectionVariables.set('first_redirect', url);\r",
"//console.log(pm.collectionVariables.get('first_redirect'));"
],
"type": "text/javascript"
}
}
],
"protocolProfileBehavior": {
"followRedirects": false
},
"request": {
"method": "POST",
"header": [
{
"key": "Content-Type",
"value": "application/x-www-form-urlencoded",
"type": "text"
}
],
"body": {
"mode": "raw",
"raw": "{{form_data}}",
"options": {
"raw": {
"language": "text"
}
}
},
"url": {
"raw": "https://www.linkedin.com/checkpoint/lg/login-submit",
"protocol": "https",
"host": [
"www",
"linkedin",
"com"
],
"path": [
"checkpoint",
"lg",
"login-submit"
]
}
},
"response": []
},
{
"name": "03 handle login-success redirect",
"event": [
{
"listen": "test",
"script": {
"exec": [
"var sdk = require('postman-collection');\r",
"var redirect = new sdk.Url(pm.response.headers.get(\"Location\"));\r",
"pm.collectionVariables.set('code', redirect.query.filter(q => q.key === 'code').map(k => k.value)[0]);\r",
"//console.log(pm.collectionVariables.get('code'));"
],
"type": "text/javascript"
}
},
{
"listen": "prerequest",
"script": {
"exec": [
"console.log(pm.variables.get('first_redirect'));\r",
"pm.request.url.update(pm.variables.get('first_redirect'));"
],
"type": "text/javascript"
}
}
],
"protocolProfileBehavior": {
"followRedirects": false
},
"request": {
"method": "GET",
"header": [],
"url": {
"raw": "{{first_redirect}}",
"host": [
"{{first_redirect}}"
]
}
},
"response": []
},
{
"name": "04 Get Auth Code",
"request": {
"method": "POST",
"header": [],
"url": {
"raw": "https://www.linkedin.com/oauth/v2/accessToken?grant_type=authorization_code&code={{code}}&redirect_uri={{redirect_uri}}&client_id={{client_id}}&client_secret={{client_secret}}",
"protocol": "https",
"host": [
"www",
"linkedin",
"com"
],
"path": [
"oauth",
"v2",
"accessToken"
],
"query": [
{
"key": "grant_type",
"value": "authorization_code"
},
{
"key": "code",
"value": "{{code}}"
},
{
"key": "redirect_uri",
"value": "{{redirect_uri}}"
},
{
"key": "client_id",
"value": "{{client_id}}"
},
{
"key": "client_secret",
"value": "{{client_secret}}"
}
]
}
},
"response": []
}
],
"event": [
{
"listen": "prerequest",
"script": {
"type": "text/javascript",
"exec": [
""
]
}
},
{
"listen": "test",
"script": {
"type": "text/javascript",
"exec": [
""
]
}
}
],
"variable": [
{
"key": "client_id",
"value": "your app id"
},
{
"key": "client_secret",
"value": "your app secret"
},
{
"key": "redirect_uri",
"value": "your urlencoded redirect uri such as https%3A%2F%2Flocalhost%3A8080"
},
{
"key": "username",
"value": "user login"
},
{
"key": "password",
"value": "user password"
}
]
}
