/// <summary>
/// Validate the incoming Auth Header as a token sent from the Bot Framework Service.
/// </summary>
/// <remarks>
/// A token issued by the Bot Framework emulator will FAIL this check.
/// </remarks>
/// <param name="authHeader">The raw HTTP header in the format: "Bearer [longString]".</param>
/// <param name="credentials">The user defined set of valid credentials, such as the AppId.</param>
/// <param name="httpClient">Authentication of tokens requires calling out to validate Endorsements and related documents. The
/// HttpClient is used for making those calls. Those calls generally require TLS connections, which are expensive to
/// setup and teardown, so a shared HttpClient is recommended.</param>
/// <param name="channelId">The ID of the channel to validate.</param>
/// <param name="authConfig">The authentication configuration.</param>
/// <returns>
/// A valid ClaimsIdentity.
/// </returns>
public static async Task <ClaimsIdentity> AuthenticateChannelToken(string authHeader, ICredentialProvider credentials, HttpClient httpClient, string channelId, AuthenticationConfiguration authConfig)
{
if (authConfig == null)
{
throw new ArgumentNullException(nameof(authConfig));
}
var tokenExtractor = new JwtTokenExtractor(
httpClient,
ToBotFromChannelTokenValidationParameters,
OpenIdMetadataUrl,
AuthenticationConstants.AllowedSigningAlgorithms);
var identity = await tokenExtractor.GetIdentityAsync(authHeader, channelId, authConfig.RequiredEndorsements);
if (identity == null)
{
// No valid identity. Not Authorized.
throw new UnauthorizedAccessException();
}
if (!identity.IsAuthenticated)
{
// The token is in some way invalid. Not Authorized.
throw new UnauthorizedAccessException();
}
// Now check that the AppID in the claimset matches
// what we're looking for. Note that in a multi-tenant bot, this value
// comes from developer code that may be reaching out to a service, hence the
// Async validation.
// Look for the "aud" claim, but only if issued from the Bot Framework
Claim audienceClaim = identity.Claims.FirstOrDefault(
c => c.Issuer == AuthenticationConstants.ToBotFromChannelTokenIssuer && c.Type == AuthenticationConstants.AudienceClaim);
if (audienceClaim == null)
{
// The relevant audience Claim MUST be present. Not Authorized.
throw new UnauthorizedAccessException();
}
// The AppId from the claim in the token must match the AppId specified by the developer.
// In this case, the token is destined for the app, so we find the app ID in the audience claim.
string appIdFromClaim = audienceClaim.Value;
if (string.IsNullOrWhiteSpace(appIdFromClaim))
{
// Claim is present, but doesn't have a value. Not Authorized.
throw new UnauthorizedAccessException();
}
if (!await credentials.IsValidAppIdAsync(appIdFromClaim))
{
// The AppId is not valid. Not Authorized.
throw new UnauthorizedAccessException($"Invalid AppId passed on token: {appIdFromClaim}");
}
return(identity);
}
/// <summary>
/// Validates that the incoming Auth Header is a token sent from a bot to a skill or from a skill to a bot.
/// </summary>
/// <param name="authHeader">The raw HTTP header in the format: "Bearer [longString]".</param>
/// <param name="credentials">The user defined set of valid credentials, such as the AppId.</param>
/// <param name="httpClient">
/// Authentication of tokens requires calling out to validate Endorsements and related documents. The
/// HttpClient is used for making those calls. Those calls generally require TLS connections, which are expensive to
/// setup and teardown, so a shared HttpClient is recommended.
/// </param>
/// <param name="channelId">The ID of the channel to validate.</param>
/// <param name="authConfig">The authentication configuration.</param>
/// <returns>A <see cref="ClaimsIdentity"/> instance if the validation is successful.</returns>
public static async Task <ClaimsIdentity> AuthenticateChannelToken(string authHeader, ICredentialProvider credentials, HttpClient httpClient, string channelId, AuthenticationConfiguration authConfig)
{
if (authConfig == null)
{
throw new ArgumentNullException(nameof(authConfig));
}
var openIdMetadataUrl = AuthenticationConstants.ToBotFromEmulatorOpenIdMetadataUrl;
var tokenExtractor = new JwtTokenExtractor(
httpClient,
_tokenValidationParameters,
openIdMetadataUrl,
AuthenticationConstants.AllowedSigningAlgorithms);
var identity = await tokenExtractor.GetIdentityAsync(authHeader, channelId, authConfig.RequiredEndorsements).ConfigureAwait(false);
await ValidateIdentityAsync(identity, credentials).ConfigureAwait(false);
return(identity);
}
/// <summary>
/// Validate the incoming Auth Header as a token sent from the Bot Framework Emulator.
/// </summary>
/// <param name="authHeader">The raw HTTP header in the format: "Bearer [longString]".</param>
/// <param name="credentials">The user defined set of valid credentials, such as the AppId.</param>
/// <param name="httpClient">Authentication of tokens requires calling out to validate Endorsements and related documents. The
/// HttpClient is used for making those calls. Those calls generally require TLS connections, which are expensive to
/// setup and teardown, so a shared HttpClient is recommended.</param>
/// <param name="channelId">The ID of the channel to validate.</param>
/// <param name="authConfig">The authentication configuration.</param>
/// <returns>
/// A valid ClaimsIdentity.
/// </returns>
/// <remarks>
/// A token issued by the Bot Framework will FAIL this check. Only Emulator tokens will pass.
/// </remarks>
public static async Task <ClaimsIdentity> AuthenticateEmulatorToken(string authHeader, ICredentialProvider credentials, HttpClient httpClient, string channelId, AuthenticationConfiguration authConfig)
{
if (authConfig == null)
{
throw new ArgumentNullException(nameof(authConfig));
}
var openIdMetadataUrl = AuthenticationConstants.ToBotFromEmulatorOpenIdMetadataUrl;
var tokenExtractor = new JwtTokenExtractor(
httpClient,
ToBotFromEmulatorTokenValidationParameters,
openIdMetadataUrl,
AuthenticationConstants.AllowedSigningAlgorithms);
var identity = await tokenExtractor.GetIdentityAsync(authHeader, channelId, authConfig.RequiredEndorsements).ConfigureAwait(false);
if (identity == null)
{
// No valid identity. Not Authorized.
throw new UnauthorizedAccessException("Invalid Identity");
}
if (!identity.IsAuthenticated)
{
// The token is in some way invalid. Not Authorized.
throw new UnauthorizedAccessException("Token Not Authenticated");
}
// Now check that the AppID in the claimset matches
// what we're looking for. Note that in a multi-tenant bot, this value
// comes from developer code that may be reaching out to a service, hence the
// Async validation.
Claim versionClaim = identity.Claims.FirstOrDefault(c => c.Type == AuthenticationConstants.VersionClaim);
if (versionClaim == null)
{
throw new UnauthorizedAccessException("'ver' claim is required on Emulator Tokens.");
}
string tokenVersion = versionClaim.Value;
string appID = string.Empty;
// The Emulator, depending on Version, sends the AppId via either the
// appid claim (Version 1) or the Authorized Party claim (Version 2).
if (string.IsNullOrWhiteSpace(tokenVersion) || tokenVersion == "1.0")
{
// either no Version or a version of "1.0" means we should look for
// the claim in the "appid" claim.
Claim appIdClaim = identity.Claims.FirstOrDefault(c => c.Type == AuthenticationConstants.AppIdClaim);
if (appIdClaim == null)
{
// No claim around AppID. Not Authorized.
throw new UnauthorizedAccessException("'appid' claim is required on Emulator Token version '1.0'.");
}
appID = appIdClaim.Value;
}
else if (tokenVersion == "2.0")
{
// Emulator, "2.0" puts the AppId in the "azp" claim.
Claim appZClaim = identity.Claims.FirstOrDefault(c => c.Type == AuthenticationConstants.AuthorizedParty);
if (appZClaim == null)
{
// No claim around AppID. Not Authorized.
throw new UnauthorizedAccessException("'azp' claim is required on Emulator Token version '2.0'.");
}
appID = appZClaim.Value;
}
else
{
// Unknown Version. Not Authorized.
throw new UnauthorizedAccessException($"Unknown Emulator Token version '{tokenVersion}'.");
}
if (!await credentials.IsValidAppIdAsync(appID).ConfigureAwait(false))
{
throw new UnauthorizedAccessException($"Invalid AppId passed on token: {appID}");
}
return(identity);
}
