c2pa 0.82.1

Rust SDK for C2PA (Coalition for Content Provenance and Authenticity) implementors
Documentation 
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
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224

// Copyright 2022 Adobe. All rights reserved.
// This file is licensed to you under the Apache License,
// Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
// or the MIT license (http://opensource.org/licenses/MIT),
// at your option.

// Unless required by applicable law or agreed to in writing,
// this software is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR REPRESENTATIONS OF ANY KIND, either express or
// implied. See the LICENSE-MIT and LICENSE-APACHE files for the
// specific language governing permissions and limitations under
// each license.

use std::collections::HashMap;

use serde::{Deserialize, Serialize};
use serde_json::Value;

use crate::{
    assertion::AssertionData, claim::Claim, crypto::base64, store::Store,
    validation_results::ValidationResults, validation_status::ValidationStatus, Result,
    ValidationState,
};

/// Low level JSON based representation of Manifest Store - used for debugging
#[non_exhaustive]
#[derive(Serialize, Deserialize, Debug, Default)]
pub struct ManifestStoreReport {
    #[serde(skip_serializing_if = "Option::is_none")]
    active_manifest: Option<String>,
    manifests: HashMap<String, ManifestReport>,
    #[serde(skip_serializing_if = "Option::is_none")]
    validation_status: Option<Vec<ValidationStatus>>,
    pub(crate) validation_results: Option<ValidationResults>,
    pub(crate) validation_state: Option<ValidationState>,
}

impl ManifestStoreReport {
    /// Creates a ManifestStoreReport from an existing Store
    pub(crate) fn from_store(store: &Store) -> Result<Self> {
        let mut manifests = HashMap::<String, ManifestReport>::new();
        for claim in store.claims() {
            manifests.insert(claim.label().to_owned(), ManifestReport::from_claim(claim)?);
        }

        Ok(ManifestStoreReport {
            active_manifest: store.provenance_label(),
            manifests,
            validation_status: None,
            validation_results: None,
            validation_state: None,
        })
    }

    pub(crate) fn from_store_with_results(
        store: &Store,
        validation_results: &ValidationResults,
    ) -> Result<Self> {
        let mut report = Self::from_store(store)?;
        report.validation_results = Some(validation_results.clone());
        report.validation_state = Some(validation_results.validation_state());
        Ok(report)
    }

    /// create a json string representation of this structure, omitting binaries
    fn to_json(&self) -> String {
        let mut json = serde_json::to_string_pretty(self).unwrap_or_else(|e| e.to_string());

        json = b64_tag(json, "hash");
        json = omit_tag(json, "pad");

        json
    }
}

impl std::fmt::Display for ManifestStoreReport {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.write_str(&self.to_json())
    }
}

#[derive(Serialize, Deserialize, Debug, Default)]
struct ManifestReport {
    claim: Value,
    assertion_store: HashMap<String, Value>,
    #[serde(skip_serializing_if = "Option::is_none")]
    credential_store: Option<Vec<Value>>,
    signature: SignatureReport,
}

impl ManifestReport {
    fn from_claim(claim: &Claim) -> Result<Self> {
        let mut assertion_store = HashMap::<String, Value>::new();
        let claim_assertions = claim.claim_assertion_store();
        for claim_assertion in claim_assertions.iter() {
            let hashlink = claim_assertion.label();
            let (label, instance) = Claim::assertion_label_from_link(&hashlink);
            let label = Claim::label_with_instance(&label, instance);
            let value = match claim_assertion.assertion().decode_data() {
                AssertionData::Json(_) | AssertionData::Cbor(_) => {
                    claim_assertion.assertion().as_json_object()? // todo:  this may cause data loss
                }
                AssertionData::Binary(x) => {
                    serde_json::to_value(format!("<omitted> len = {}", x.len()))?
                }
                AssertionData::Uuid(s, x) => {
                    serde_json::to_value(format!("uuid: {}, data: {}", s, base64::encode(x)))?
                }
            };
            assertion_store.insert(label, value);
        }

        // convert credential store to json values
        let credential_store: Vec<Value> = claim
            .get_verifiable_credentials()
            .iter()
            .filter_map(|d| match d {
                AssertionData::Json(s) => serde_json::from_str(s).ok(),
                _ => None,
            })
            .collect();

        let signature = match claim.signature_info() {
            Some(info) => SignatureReport {
                alg: info.alg.map_or_else(String::new, |a| a.to_string()),
                issuer: info.issuer_org,
                common_name: info.common_name,
                time: info.date.map(|d| d.to_rfc3339()),
            },
            None => SignatureReport::default(),
        };
        let mut claim_value = serde_json::to_value(claim)?; // todo:  this will lose tagging info
        if let Value::Object(map) = &mut claim_value {
            map.insert(
                "claim_version".to_string(),
                serde_json::to_value(claim.version())?,
            );
        }
        Ok(Self {
            claim: claim_value,
            assertion_store,
            credential_store: if !credential_store.is_empty() {
                Some(credential_store)
            } else {
                None
            },
            signature,
        })
    }

    /// create a json string representation of this structure, omitting binaries
    fn to_json(&self) -> String {
        let mut json = serde_json::to_string_pretty(self).unwrap_or_else(|e| e.to_string());

        json = b64_tag(json, "hash");
        json = omit_tag(json, "pad");
        json = omit_tag(json, "pad1");

        json
    }
}

impl std::fmt::Display for ManifestReport {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.write_str(&self.to_json())
    }
}

// used to report information from signature data
#[derive(Default, Debug, Deserialize, Serialize)]
struct SignatureReport {
    alg: String,
    // human readable issuing authority for this signature
    #[serde(skip_serializing_if = "Option::is_none")]
    issuer: Option<String>,

    // human readable common name for this signature
    #[serde(skip_serializing_if = "Option::is_none")]
    common_name: Option<String>,

    // the time the signature was created
    #[serde(skip_serializing_if = "Option::is_none")]
    time: Option<String>,
}

// replace the value of any field in the json string with a given key with the string <omitted>
fn omit_tag(mut json: String, tag: &str) -> String {
    while let Some(index) = json.find(&format!("\"{tag}\": [")) {
        if let Some(idx2) = json[index..].find(']') {
            json = format!(
                "{}\"{}\": \"<omitted>\"{}",
                &json[..index],
                tag,
                &json[index + idx2 + 1..]
            );
        }
    }
    json
}

// make a base64 hash from the value of any field in the json string with key base64 hash
fn b64_tag(mut json: String, tag: &str) -> String {
    while let Some(index) = json.find(&format!("\"{tag}\": [")) {
        if let Some(idx2) = json[index..].find(']') {
            let idx3 = json[index..].find('[').unwrap_or_default(); // ok since we just found it
            let bytes: Vec<u8> =
                serde_json::from_slice(&json.as_bytes()[index + idx3..index + idx2 + 1])
                    .unwrap_or_default();
            json = format!(
                "{}\"{}\": \"{}\"{}",
                &json[..index],
                tag,
                base64::encode(&bytes),
                &json[index + idx2 + 1..]
            );
        }
    }
    json
}

#[cfg(test)]
mod tests {
    #![allow(clippy::expect_used)]
}