Multiple JWT Tokens and Multiple Auth Handlers - asp.net-core

Question

I currently have Auth in place for my API application using a JWT token with Identity User, Which works great, I am now trying to chain on another JWT Token which users keycloak and I want to setup A custom auth Handler just for that token type, is that possible? My Code looks as follows:
services.AddAuthentication()
.AddJwtBearer("KeyCloak", opt =>
{
opt.Authority = "site.co.za/auth/realms/Development";
opt.Audience = "dev";
opt.TokenValidationParameters = new Microsoft.IdentityModel.Tokens.TokenValidationParameters
{
ValidAudiences = new string[] { "dev" },
NameClaimType = "preferred_username",
RoleClaimType = "role"
};
opt.Events = new JwtBearerEvents()
{
OnAuthenticationFailed = c =>
{
c.NoResult();
c.Response.StatusCode = 500;
c.Response.ContentType = "text/plain";
return c.Response.WriteAsync(c.Exception.ToString());
}
};
opt.RequireHttpsMetadata = false;
opt.SaveToken = true;
opt.Validate();
})
.AddJwtBearer("Internal", opt =>
{
opt.TokenValidationParameters = new TokenValidationParameters
{
ValidateIssuer = false,
ValidateAudience = false,
ValidateLifetime = true,
ValidateIssuerSigningKey = true,
IssuerSigningKey = new SymmetricSecurityKey(System.Text.Encoding.UTF8.GetBytes(Constants.AuthTokenKey))
};
});
services.AddAuthorization(options =>
{
options.DefaultPolicy = new AuthorizationPolicyBuilder()
.RequireAuthenticatedUser()
.AddAuthenticationSchemes("KeyCloak", "Internal").Build();
});
I need to add a custom Auth HandleAuthenticateAsync just for keycloak and use the normal out of the box HandleAuthenticateAsync for internal. Is this possible to do?

Answer 1

You can do this:
this will select the jwt token validation based on API path.
builder.Services.AddAuthentication(options =>
{
options.DefaultScheme = "Custom";
})
.AddPolicyScheme("Custom", "Custom", options =>
{
options.ForwardDefaultSelector = context =>
{
bool isKeyCloakAuthRequired = context.Request.Path.StartsWithSegments("/apithatneedskeycloakauth");
if (isKeyCloakAuthRequired)
{
return "Keycloak";
}
else
{
return "Internal";
}
};
})
.AddJwtBearer("Keycloak", options =>
{
// your code for keycloak validation parameters.
})
.AddJwtBearer("Internal", options =>
{
// your code for token validation parameters.
})
Hope it helps.