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more organization and add some documentation to the awshttp module

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This commit is contained in:
Emil Lerch 2021-05-14 15:12:47 -07:00
parent 05fcc5755e
commit a732bc14db
Signed by: lobo
GPG Key ID: A7B62D657EF764F8
1 changed files with 180 additions and 150 deletions
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330
src/awshttp.zig
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@ -1,3 +1,12 @@
//! This module provides a low level http interface for working with AWS
//! It also provides an option to operate outside the AWS ecosystem through
//! the makeRequest call with a null signingOptions.
//!
//! Typical usage:
//! const client = awshttp.AwsHttp.init(allocator);
//! defer client.deinit()
//! const result = client.callApi (or client.makeRequest)
//! defer result.deinit();
const std = @import("std");
const c = @cImport({
@cInclude("bitfield-workaround.h");
@ -66,6 +75,7 @@ pub const SigningOptions = struct {
};
const HttpResult = struct {
response_code: u16, // actually 3 digits can fit in u10
body: []const u8,
pub fn deinit(self: HttpResult) void {
httplog.debug("http result deinit complete", .{});
@ -218,6 +228,10 @@ pub const AwsHttp = struct {
}
}
/// callApi allows the calling of AWS APIs through a higher-level interface.
/// It will calculate the appropriate endpoint and action parameters for the
/// service called, and will set up the signing options. The return
/// value is simply a raw HttpResult
pub fn callApi(self: Self, service: []const u8, version: []const u8, action: []const u8, options: Options) !HttpResult {
const endpoint = try regionSubDomain(self.allocator, service, options.region, options.dualstack);
defer endpoint.deinit();
@ -231,89 +245,24 @@ pub const AwsHttp = struct {
return try self.makeRequest(endpoint, "POST", "/", body, signing_options);
}
fn signRequest(self: Self, http_request: *c.aws_http_message, options: SigningOptions) !void {
const creds = try self.getCredentials();
defer c.aws_credentials_release(creds);
// print the access key. Creds are an opaque C type, so we
// use aws_credentials_get_access_key_id. That gets us an aws_byte_cursor,
// from which we create a new aws_string with the contents. We need
// to convert to c_str with aws_string_c_str
const access_key = c.aws_string_new_from_cursor(c_allocator, &c.aws_credentials_get_access_key_id(creds));
defer c.aws_mem_release(c_allocator, access_key);
// defer c_allocator.*.mem_release.?(c_allocator, access_key);
httplog.debug("Signing with access key: {s}", .{c.aws_string_c_str(access_key)});
const signable = c.aws_signable_new_http_request(c_allocator, http_request);
if (signable == null) {
httplog.warn("Could not create signable request", .{});
return AwsError.SignableError;
}
defer c.aws_signable_destroy(signable);
const signing_region = try std.fmt.allocPrint(self.allocator, "{s}", .{options.region});
defer self.allocator.free(signing_region);
const signing_service = try std.fmt.allocPrint(self.allocator, "{s}", .{options.service});
defer self.allocator.free(signing_service);
const temp_signing_config = c.bitfield_workaround_aws_signing_config_aws{
.algorithm = .AWS_SIGNING_ALGORITHM_V4,
.config_type = .AWS_SIGNING_CONFIG_AWS,
.signature_type = .AWS_ST_HTTP_REQUEST_HEADERS,
.region = c.aws_byte_cursor_from_c_str(@ptrCast([*c]const u8, signing_region)),
.service = c.aws_byte_cursor_from_c_str(@ptrCast([*c]const u8, signing_service)),
.should_sign_header = null,
.should_sign_header_ud = null,
.flags = c.bitfield_workaround_aws_signing_config_aws_flags{
.use_double_uri_encode = 0,
.should_normalize_uri_path = 0,
.omit_session_token = 1,
},
.signed_body_value = c.aws_byte_cursor_from_c_str(""),
.signed_body_header = .AWS_SBHT_X_AMZ_CONTENT_SHA256, //or AWS_SBHT_NONE
.credentials = creds,
.credentials_provider = self.credentialsProvider,
.expiration_in_seconds = 0,
};
var signing_config = c.new_aws_signing_config(c_allocator, &temp_signing_config);
defer c.aws_mem_release(c_allocator, signing_config);
var signing_result = AwsAsyncCallbackResult(c.aws_http_message){ .result = http_request };
var sign_result_request = AsyncResult(AwsAsyncCallbackResult(c.aws_http_message)){ .result = &signing_result };
if (c.aws_sign_request_aws(c_allocator, signable, fullCast([*c]const c.aws_signing_config_base, signing_config), signComplete, &sign_result_request) != c.AWS_OP_SUCCESS) {
const error_code = c.aws_last_error();
httplog.alert("Could not initiate signing request: {s}:{s}", .{ c.aws_error_name(error_code), c.aws_error_str(error_code) });
return AwsError.SigningInitiationError;
}
// Wait for callback. Note that execution, including real work of signing
// the http request, will continue in signComplete (below),
// then continue beyond this line
waitOnCallback(c.aws_http_message, &sign_result_request);
if (sign_result_request.result.error_code != c.AWS_ERROR_SUCCESS) {
return AwsError.SignableError;
}
}
/// It's my theory that the aws event loop has a trigger to corrupt the
/// signing result after this call completes. So the technique of assigning
/// now, using later will not work
fn signComplete(result: ?*c.aws_signing_result, error_code: c_int, user_data: ?*c_void) callconv(.C) void {
var async_result = userDataTo(AsyncResult(AwsAsyncCallbackResult(c.aws_http_message)), user_data);
var http_request = async_result.result.result;
async_result.sync.store(true, .SeqCst);
async_result.count += 1;
async_result.result.error_code = error_code;
if (result) |res| {
if (c.aws_apply_signing_result_to_http_request(http_request, c_allocator, result) != c.AWS_OP_SUCCESS) {
httplog.alert("Could not apply signing request to http request: {s}", .{c.aws_error_debug_str(c.aws_last_error())});
}
httplog.debug("signing result applied", .{});
} else {
httplog.alert("Did not receive signing result: {s}", .{c.aws_error_debug_str(c.aws_last_error())});
}
async_result.sync.store(false, .SeqCst);
}
/// makeRequest is a low level http/https function that can be used inside
/// or outside the context of AWS services. To use it outside AWS, simply
/// pass a null value in for signing_options.
///
/// Otherwise, it will simply take a URL endpoint (without path information),
/// HTTP method (e.g. GET, POST, etc.), and request body.
///
/// At the moment this does not allow the controlling of headers
/// This is likely to change. Current headers are:
///
/// Accept: application/json
/// User-Agent: zig-aws 1.0, Powered by the AWS Common Runtime.
/// Content-Type: application/x-www-form-urlencoded
/// Content-Length: (length of body)
///
/// Return value is an HttpResult, which will need the caller to deinit().
/// HttpResult currently contains the body only. The addition of Headers
/// and return code would be a relatively minor change
pub fn makeRequest(self: Self, endpoint: EndPoint, method: []const u8, path: []const u8, body: []const u8, signing_options: ?SigningOptions) !HttpResult {
// TODO: Try to re-encapsulate this
// var http_request = try createRequest(method, path, body);
@ -321,9 +270,6 @@ pub const AwsHttp = struct {
// TODO: Likely this should be encapsulated more
var http_request = c.aws_http_message_new_request(c_allocator);
defer c.aws_http_message_release(http_request);
// TODO: Verify if AWS cares about these headers (probably should be passing them...)
// Accept-Encoding: identity
// Content-Type: application/x-www-form-urlencoded
if (c.aws_http_message_set_request_method(http_request, c.aws_byte_cursor_from_c_str(@ptrCast([*c]const u8, method))) != c.AWS_OP_SUCCESS)
return AwsError.SetRequestMethodError;
@ -453,8 +399,6 @@ pub const AwsHttp = struct {
.request = http_request,
};
// C code
// app_ctx->response_code_written = false;
const stream = c.aws_http_connection_make_request(context.connection, &request_options);
if (stream == null) {
httplog.alert("failed to create request.", .{});
@ -484,7 +428,12 @@ pub const AwsHttp = struct {
if (context.body) |b| {
final_body = b;
}
// Headers would need to be allocated/copied into HttpResult similar
// to RequestContext, so we'll leave this as a later excercise
// if it becomes necessary
const rc = HttpResult{
.response_code = context.response_code.?,
.body = final_body,
};
return rc;
@ -495,9 +444,6 @@ pub const AwsHttp = struct {
fn createRequest(method: []const u8, path: []const u8, body: []const u8) !*c.aws_http_message {
// TODO: Likely this should be encapsulated more
var http_request = c.aws_http_message_new_request(c_allocator);
// TODO: Verify if AWS cares about these headers (probably should be passing them...)
// Accept-Encoding: identity
// Content-Type: application/x-www-form-urlencoded
if (c.aws_http_message_set_request_method(http_request, c.aws_byte_cursor_from_c_str(@ptrCast([*c]const u8, method))) != c.AWS_OP_SUCCESS)
return AwsError.SetRequestMethodError;
@ -511,6 +457,149 @@ pub const AwsHttp = struct {
c.aws_http_message_set_body_stream(http_request, request_body);
return http_request.?;
}
// TODO: Re-encapsulate or delete this function. It is not currently
// used and will not be touched by the compiler
fn setupTls(self: Self, host: []const u8) !*c.aws_tls_connection_options {
if (tls_ctx_options == null) {
httplog.debug("Setting up tls options", .{});
var opts: c.aws_tls_ctx_options = .{
.allocator = c_allocator,
.minimum_tls_version = @intToEnum(c.aws_tls_versions, c.AWS_IO_TLS_VER_SYS_DEFAULTS),
.cipher_pref = @intToEnum(c.aws_tls_cipher_pref, c.AWS_IO_TLS_CIPHER_PREF_SYSTEM_DEFAULT),
.ca_file = c.aws_byte_buf_from_c_str(""),
.ca_path = c.aws_string_new_from_c_str(c_allocator, ""),
.alpn_list = null,
.certificate = c.aws_byte_buf_from_c_str(""),
.private_key = c.aws_byte_buf_from_c_str(""),
.max_fragment_size = 0,
.verify_peer = true,
};
tls_ctx_options = &opts;
c.aws_tls_ctx_options_init_default_client(tls_ctx_options.?, c_allocator);
// h2;http/1.1
if (c.aws_tls_ctx_options_set_alpn_list(tls_ctx_options, "http/1.1") != c.AWS_OP_SUCCESS) {
httplog.alert("Failed to load alpn list with error {s}.", .{c.aws_error_debug_str(c.aws_last_error())});
return AwsError.AlpnError;
}
tls_ctx = c.aws_tls_client_ctx_new(c_allocator, tls_ctx_options.?);
if (tls_ctx == null) {
std.debug.panic("Failed to initialize TLS context with error {s}.", .{c.aws_error_debug_str(c.aws_last_error())});
}
httplog.debug("tls options setup applied", .{});
}
var tls_connection_options = c.aws_tls_connection_options{
.alpn_list = null,
.server_name = null,
.on_negotiation_result = null,
.on_data_read = null,
.on_error = null,
.user_data = null,
.ctx = null,
.advertise_alpn_message = false,
.timeout_ms = 0,
};
c.aws_tls_connection_options_init_from_ctx(&tls_connection_options, tls_ctx);
var host_var = host;
var host_cur = c.aws_byte_cursor_from_c_str(@ptrCast([*c]const u8, host_var));
if (c.aws_tls_connection_options_set_server_name(&tls_connection_options, c_allocator, &host_cur) != c.AWS_OP_SUCCESS) {
httplog.alert("Failed to set servername with error {s}.", .{c.aws_error_debug_str(c.aws_last_error())});
return AwsError.TlsError;
}
return &tls_connection_options;
// if (app_ctx.uri.port) {
// port = app_ctx.uri.port;
// }
}
fn signRequest(self: Self, http_request: *c.aws_http_message, options: SigningOptions) !void {
const creds = try self.getCredentials();
defer c.aws_credentials_release(creds);
// print the access key. Creds are an opaque C type, so we
// use aws_credentials_get_access_key_id. That gets us an aws_byte_cursor,
// from which we create a new aws_string with the contents. We need
// to convert to c_str with aws_string_c_str
const access_key = c.aws_string_new_from_cursor(c_allocator, &c.aws_credentials_get_access_key_id(creds));
defer c.aws_mem_release(c_allocator, access_key);
// defer c_allocator.*.mem_release.?(c_allocator, access_key);
httplog.debug("Signing with access key: {s}", .{c.aws_string_c_str(access_key)});
const signable = c.aws_signable_new_http_request(c_allocator, http_request);
if (signable == null) {
httplog.warn("Could not create signable request", .{});
return AwsError.SignableError;
}
defer c.aws_signable_destroy(signable);
const signing_region = try std.fmt.allocPrint(self.allocator, "{s}", .{options.region});
defer self.allocator.free(signing_region);
const signing_service = try std.fmt.allocPrint(self.allocator, "{s}", .{options.service});
defer self.allocator.free(signing_service);
const temp_signing_config = c.bitfield_workaround_aws_signing_config_aws{
.algorithm = .AWS_SIGNING_ALGORITHM_V4,
.config_type = .AWS_SIGNING_CONFIG_AWS,
.signature_type = .AWS_ST_HTTP_REQUEST_HEADERS,
.region = c.aws_byte_cursor_from_c_str(@ptrCast([*c]const u8, signing_region)),
.service = c.aws_byte_cursor_from_c_str(@ptrCast([*c]const u8, signing_service)),
.should_sign_header = null,
.should_sign_header_ud = null,
.flags = c.bitfield_workaround_aws_signing_config_aws_flags{
.use_double_uri_encode = 0,
.should_normalize_uri_path = 0,
.omit_session_token = 1,
},
.signed_body_value = c.aws_byte_cursor_from_c_str(""),
.signed_body_header = .AWS_SBHT_X_AMZ_CONTENT_SHA256, //or AWS_SBHT_NONE
.credentials = creds,
.credentials_provider = self.credentialsProvider,
.expiration_in_seconds = 0,
};
var signing_config = c.new_aws_signing_config(c_allocator, &temp_signing_config);
defer c.aws_mem_release(c_allocator, signing_config);
var signing_result = AwsAsyncCallbackResult(c.aws_http_message){ .result = http_request };
var sign_result_request = AsyncResult(AwsAsyncCallbackResult(c.aws_http_message)){ .result = &signing_result };
if (c.aws_sign_request_aws(c_allocator, signable, fullCast([*c]const c.aws_signing_config_base, signing_config), signComplete, &sign_result_request) != c.AWS_OP_SUCCESS) {
const error_code = c.aws_last_error();
httplog.alert("Could not initiate signing request: {s}:{s}", .{ c.aws_error_name(error_code), c.aws_error_str(error_code) });
return AwsError.SigningInitiationError;
}
// Wait for callback. Note that execution, including real work of signing
// the http request, will continue in signComplete (below),
// then continue beyond this line
waitOnCallback(c.aws_http_message, &sign_result_request);
if (sign_result_request.result.error_code != c.AWS_ERROR_SUCCESS) {
return AwsError.SignableError;
}
}
/// It's my theory that the aws event loop has a trigger to corrupt the
/// signing result after this call completes. So the technique of assigning
/// now, using later will not work
fn signComplete(result: ?*c.aws_signing_result, error_code: c_int, user_data: ?*c_void) callconv(.C) void {
var async_result = userDataTo(AsyncResult(AwsAsyncCallbackResult(c.aws_http_message)), user_data);
var http_request = async_result.result.result;
async_result.sync.store(true, .SeqCst);
async_result.count += 1;
async_result.result.error_code = error_code;
if (result) |res| {
if (c.aws_apply_signing_result_to_http_request(http_request, c_allocator, result) != c.AWS_OP_SUCCESS) {
httplog.alert("Could not apply signing request to http request: {s}", .{c.aws_error_debug_str(c.aws_last_error())});
}
httplog.debug("signing result applied", .{});
} else {
httplog.alert("Did not receive signing result: {s}", .{c.aws_error_debug_str(c.aws_last_error())});
}
async_result.sync.store(false, .SeqCst);
}
fn addHeaders(self: Self, request: *c.aws_http_message, host: []const u8, body: []const u8) !void {
const accept_header = c.aws_http_header{
.name = c.aws_byte_cursor_from_c_str("Accept"),
@ -629,65 +718,6 @@ pub const AwsHttp = struct {
httplog.debug("request complete", .{});
}
// TODO: Re-encapsulate or delete this function. It is not currently
// used and will not be touched by the compiler
fn setupTls(self: Self, host: []const u8) !*c.aws_tls_connection_options {
if (tls_ctx_options == null) {
httplog.debug("Setting up tls options", .{});
var opts: c.aws_tls_ctx_options = .{
.allocator = c_allocator,
.minimum_tls_version = @intToEnum(c.aws_tls_versions, c.AWS_IO_TLS_VER_SYS_DEFAULTS),
.cipher_pref = @intToEnum(c.aws_tls_cipher_pref, c.AWS_IO_TLS_CIPHER_PREF_SYSTEM_DEFAULT),
.ca_file = c.aws_byte_buf_from_c_str(""),
.ca_path = c.aws_string_new_from_c_str(c_allocator, ""),
.alpn_list = null,
.certificate = c.aws_byte_buf_from_c_str(""),
.private_key = c.aws_byte_buf_from_c_str(""),
.max_fragment_size = 0,
.verify_peer = true,
};
tls_ctx_options = &opts;
c.aws_tls_ctx_options_init_default_client(tls_ctx_options.?, c_allocator);
// h2;http/1.1
if (c.aws_tls_ctx_options_set_alpn_list(tls_ctx_options, "http/1.1") != c.AWS_OP_SUCCESS) {
httplog.alert("Failed to load alpn list with error {s}.", .{c.aws_error_debug_str(c.aws_last_error())});
return AwsError.AlpnError;
}
tls_ctx = c.aws_tls_client_ctx_new(c_allocator, tls_ctx_options.?);
if (tls_ctx == null) {
std.debug.panic("Failed to initialize TLS context with error {s}.", .{c.aws_error_debug_str(c.aws_last_error())});
}
httplog.debug("tls options setup applied", .{});
}
var tls_connection_options = c.aws_tls_connection_options{
.alpn_list = null,
.server_name = null,
.on_negotiation_result = null,
.on_data_read = null,
.on_error = null,
.user_data = null,
.ctx = null,
.advertise_alpn_message = false,
.timeout_ms = 0,
};
c.aws_tls_connection_options_init_from_ctx(&tls_connection_options, tls_ctx);
var host_var = host;
var host_cur = c.aws_byte_cursor_from_c_str(@ptrCast([*c]const u8, host_var));
if (c.aws_tls_connection_options_set_server_name(&tls_connection_options, c_allocator, &host_cur) != c.AWS_OP_SUCCESS) {
httplog.alert("Failed to set servername with error {s}.", .{c.aws_error_debug_str(c.aws_last_error())});
return AwsError.TlsError;
}
return &tls_connection_options;
// if (app_ctx.uri.port) {
// port = app_ctx.uri.port;
// }
}
fn getCredentials(self: Self) !*c.aws_credentials {
var credential_result = AwsAsyncCallbackResult(c.aws_credentials){};
var callback_results = AsyncResult(AwsAsyncCallbackResult(c.aws_credentials)){ .result = &credential_result };