csaf-rs 0.5.0

A parser for the CSAF standard written in Rust
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

use std::sync::LazyLock;

use jsonschema::Validator;
use serde_json::{Map, Value};

use crate::csaf::types::csaf_vuln_metric::CsafVulnerabilityMetric;
use crate::{
    csaf_traits::{ContentTrait, CsafTrait, MetricTrait, VulnerabilityTrait},
    validation::ValidationError,
};

static CVSS20_VALIDATOR: LazyLock<Validator> =
    LazyLock::new(|| create_validator(include_str!("../../assets/cvss-v2.0.json")));
static CVSS30_VALIDATOR: LazyLock<Validator> =
    LazyLock::new(|| create_validator(include_str!("../../assets/cvss-v3.0.json")));
static CVSS31_VALIDATOR: LazyLock<Validator> =
    LazyLock::new(|| create_validator(include_str!("../../assets/cvss-v3.1.json")));
static CVSS40_VALIDATOR: LazyLock<Validator> =
    LazyLock::new(|| create_draft_validator(include_str!("../../assets/cvss-v4.0.2.json")));

/// 6.1.8 Invalid CVSS
/// Invalid CVSS object according to scheme
pub fn test_6_1_08_invalid_cvss(doc: &impl CsafTrait) -> Result<(), Vec<ValidationError>> {
    let mut errors: Vec<ValidationError> = Vec::new();

    for (i_v, vulnerability) in doc.get_vulnerabilities().iter().enumerate() {
        if let Some(metrics) = vulnerability.get_metrics() {
            for (metric_index, metric) in metrics.iter().enumerate() {
                let content = metric.get_content();
                let instance_prefix = content.get_content_json_path(i_v, metric_index);
                if let Some(cvss2) = content.get_cvss_v2() {
                    evaluate_cvss(
                        cvss2,
                        &CVSS20_VALIDATOR,
                        &instance_prefix,
                        CsafVulnerabilityMetric::CvssV2("2.0".to_string()),
                        &mut errors,
                    );
                }
                if let Some(cvss3) = content.get_cvss_v3() {
                    // Use as_str because otherwise additional quotation marks would be included
                    if let Some(version) = cvss3.get("version").and_then(|v| v.as_str()) {
                        let metric_type = CsafVulnerabilityMetric::CvssV3(version.to_string());
                        if version == "3.0" {
                            evaluate_cvss(cvss3, &CVSS30_VALIDATOR, &instance_prefix, metric_type, &mut errors);
                        } else if version == "3.1" {
                            evaluate_cvss(cvss3, &CVSS31_VALIDATOR, &instance_prefix, metric_type, &mut errors);
                        }
                    }
                }
                if let Some(cvss4) = content.get_cvss_v4() {
                    evaluate_cvss(
                        cvss4,
                        &CVSS40_VALIDATOR,
                        &instance_prefix,
                        CsafVulnerabilityMetric::CvssV4("4.0".to_string()),
                        &mut errors,
                    );
                }
            }
        }
    }

    if errors.is_empty() { Ok(()) } else { Err(errors) }
}

crate::test_validation::impl_validator!(ValidatorForTest6_1_8, test_6_1_08_invalid_cvss);

fn create_validator(schema_str: &str) -> Validator {
    jsonschema::validator_for(&serde_json::from_str(schema_str).unwrap()).unwrap()
}

fn create_draft_validator(schema_str: &str) -> Validator {
    jsonschema::draft202012::new(&serde_json::from_str(schema_str).unwrap()).unwrap()
}

/// Run the CVSS through json schema validation, add every error during validation to `errors`
/// TODO: The metric prop is kinda weird, but this will be removed after CVSS validation is implemented.
fn evaluate_cvss(
    cvss_value: &Map<String, Value>,
    validator: &Validator,
    base_path: &str,
    metric: CsafVulnerabilityMetric,
    errors: &mut Vec<ValidationError>,
) {
    let value = serde_json::to_value(cvss_value).unwrap();
    for error in validator.iter_errors(&value) {
        errors.push(create_validation_error(error.to_string(), base_path, metric.clone()));
    }
}

fn create_validation_error(message: String, base: &str, metric: CsafVulnerabilityMetric) -> ValidationError {
    ValidationError {
        message,
        instance_path: format!("{}/{}", base, metric.get_metric_prop_name()),
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::csaf2_0::testcases::TESTS_2_0;
    use crate::csaf2_1::testcases::TESTS_2_1;

    #[test]
    fn test_test_6_1_08() {
        // CSAF 2.0 has 7 test cases (01-03, 11-14)
        TESTS_2_0.test_6_1_8.expect(
            Err(vec![create_validation_error(
                "\"baseSeverity\" is a required property".to_string(),
                "/vulnerabilities/0/scores/0",
                CsafVulnerabilityMetric::CvssV3("3.1".to_string()),
            )]),
            Err(vec![create_validation_error(
                "\"baseSeverity\" is a required property".to_string(),
                "/vulnerabilities/0/scores/0",
                CsafVulnerabilityMetric::CvssV3("3.0".to_string()),
            )]),
            Err(vec![create_validation_error(
                "\"version\" is a required property".to_string(),
                "/vulnerabilities/0/scores/0",
                CsafVulnerabilityMetric::CvssV2("2.0".to_string()),
            )]),
            Ok(()), // case_11
            Ok(()), // case_12
            Ok(()), // case_13
            Ok(()), // case_14
        );

        // CSAF 2.1 has 13 test cases (01-06, 11-17)
        TESTS_2_1.test_6_1_8.expect(
            Err(vec![create_validation_error(
                "\"baseSeverity\" is a required property".to_string(),
                "/vulnerabilities/0/metrics/0/content",
                CsafVulnerabilityMetric::CvssV3("3.1".to_string()),
            )]),
            Err(vec![create_validation_error(
                "\"baseSeverity\" is a required property".to_string(),
                "/vulnerabilities/0/metrics/0/content",
                CsafVulnerabilityMetric::CvssV3("3.0".to_string()),
            )]),
            Err(vec![create_validation_error(
                "\"version\" is a required property".to_string(),
                "/vulnerabilities/0/metrics/0/content",
                CsafVulnerabilityMetric::CvssV2("2.0".to_string()),
            )]),
            Err(vec![create_validation_error(
                "\"baseSeverity\" is a required property".to_string(),
                "/vulnerabilities/0/metrics/0/content",
                CsafVulnerabilityMetric::CvssV4("4.0".to_string()),
            )]),
            Err(vec![
                create_validation_error(
                    "Unevaluated properties are not allowed ('threatScore', 'threatSeverity' were unexpected)".to_string(),
                    "/vulnerabilities/0/metrics/0/content",
                    CsafVulnerabilityMetric::CvssV4("4.0".to_string()),
                ),
            ]),
            Err(vec![
                create_validation_error(
                    "Unevaluated properties are not allowed ('threatScore', 'threatSeverity', 'environmentalScore', 'environmentalSeverity' were unexpected)".to_string(),
                    "/vulnerabilities/0/metrics/0/content",
                    CsafVulnerabilityMetric::CvssV4("4.0".to_string()),
                ),
            ]),
            Ok(()), // case_11
            Ok(()), // case_12
            Ok(()), // case_13
            Ok(()), // case_14
            Ok(()), // case_15
            Ok(()), // case_16
            Ok(()), // case_17
        );
    }
}