1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173

/*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0
 */

use crate::client::identity::{Identity, IdentityResolver, IdentityResolvers};
use crate::client::orchestrator::{BoxError, HttpRequest};
use crate::config_bag::ConfigBag;
use crate::type_erasure::{TypeErasedBox, TypedBox};
use aws_smithy_types::Document;
use std::borrow::Cow;
use std::fmt;
use std::sync::Arc;

#[cfg(feature = "http-auth")]
pub mod http;

pub mod option_resolver;

/// New type around an auth scheme ID.
#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
pub struct AuthSchemeId {
    scheme_id: &'static str,
}

impl AuthSchemeId {
    /// Creates a new auth scheme ID.
    pub const fn new(scheme_id: &'static str) -> Self {
        Self { scheme_id }
    }

    /// Returns the string equivalent of this auth scheme ID.
    pub const fn as_str(&self) -> &'static str {
        self.scheme_id
    }
}

impl From<&'static str> for AuthSchemeId {
    fn from(scheme_id: &'static str) -> Self {
        Self::new(scheme_id)
    }
}

#[derive(Debug)]
pub struct AuthOptionResolverParams(TypeErasedBox);

impl AuthOptionResolverParams {
    pub fn new<T: fmt::Debug + Send + Sync + 'static>(params: T) -> Self {
        Self(TypedBox::new(params).erase())
    }

    pub fn get<T: fmt::Debug + Send + Sync + 'static>(&self) -> Option<&T> {
        self.0.downcast_ref()
    }
}

pub trait AuthOptionResolver: Send + Sync + fmt::Debug {
    fn resolve_auth_options(
        &self,
        params: &AuthOptionResolverParams,
    ) -> Result<Cow<'_, [AuthSchemeId]>, BoxError>;
}

impl AuthOptionResolver for Box<dyn AuthOptionResolver> {
    fn resolve_auth_options(
        &self,
        params: &AuthOptionResolverParams,
    ) -> Result<Cow<'_, [AuthSchemeId]>, BoxError> {
        (**self).resolve_auth_options(params)
    }
}

#[derive(Debug)]
struct HttpAuthSchemesInner {
    schemes: Vec<(AuthSchemeId, Box<dyn HttpAuthScheme>)>,
}
#[derive(Clone, Debug)]
pub struct HttpAuthSchemes {
    inner: Arc<HttpAuthSchemesInner>,
}

impl HttpAuthSchemes {
    pub fn builder() -> builders::HttpAuthSchemesBuilder {
        Default::default()
    }

    pub fn scheme(&self, scheme_id: AuthSchemeId) -> Option<&dyn HttpAuthScheme> {
        self.inner
            .schemes
            .iter()
            .find(|scheme| scheme.0 == scheme_id)
            .map(|scheme| &*scheme.1)
    }
}

pub trait HttpAuthScheme: Send + Sync + fmt::Debug {
    fn scheme_id(&self) -> AuthSchemeId;

    fn identity_resolver<'a>(
        &self,
        identity_resolvers: &'a IdentityResolvers,
    ) -> Option<&'a dyn IdentityResolver>;

    fn request_signer(&self) -> &dyn HttpRequestSigner;
}

pub trait HttpRequestSigner: Send + Sync + fmt::Debug {
    /// Return a signed version of the given request using the given identity.
    ///
    /// If the provided identity is incompatible with this signer, an error must be returned.
    fn sign_request(
        &self,
        request: &mut HttpRequest,
        identity: &Identity,
        auth_scheme_endpoint_config: AuthSchemeEndpointConfig<'_>,
        config_bag: &ConfigBag,
    ) -> Result<(), BoxError>;
}

/// Endpoint configuration for the selected auth scheme.
///
/// This struct gets added to the request state by the auth orchestrator.
#[non_exhaustive]
#[derive(Clone, Debug)]
pub struct AuthSchemeEndpointConfig<'a>(Option<&'a Document>);

impl<'a> AuthSchemeEndpointConfig<'a> {
    /// Creates a new [`AuthSchemeEndpointConfig`].
    pub fn new(config: Option<&'a Document>) -> Self {
        Self(config)
    }

    /// Creates an empty AuthSchemeEndpointConfig.
    pub fn empty() -> Self {
        Self(None)
    }

    pub fn config(&self) -> Option<&'a Document> {
        self.0
    }
}

pub mod builders {
    use super::*;

    #[derive(Debug, Default)]
    pub struct HttpAuthSchemesBuilder {
        schemes: Vec<(AuthSchemeId, Box<dyn HttpAuthScheme>)>,
    }

    impl HttpAuthSchemesBuilder {
        pub fn new() -> Self {
            Default::default()
        }

        pub fn auth_scheme(
            mut self,
            scheme_id: AuthSchemeId,
            auth_scheme: impl HttpAuthScheme + 'static,
        ) -> Self {
            self.schemes.push((scheme_id, Box::new(auth_scheme) as _));
            self
        }

        pub fn build(self) -> HttpAuthSchemes {
            HttpAuthSchemes {
                inner: Arc::new(HttpAuthSchemesInner {
                    schemes: self.schemes,
                }),
            }
        }
    }
}