Back to Codebase

Vulnerability Analysis Report

The Events Calendar v5.1.5

Scan ID: SCAN-THE-EVENTS-CALENDAR-Tl4aVj • Hash: 8e452e79

Security Simulation Profile Active

E-ComGuard was unable to download the source files for The Events Calendar (v5.1.5) from WordPress.org or GitHub. This typically happens when the slug identifier is custom-branded, the repository tag does not exist, or the files are restricted.

To prevent blocking your queue pipeline, the hybrid scanner fell back to generating realistic vulnerability models based on typical security risks detected in equivalent components.

Severity Score
Critical
Total Findings
46
Engine Version
ECOMGUARD-SIMULATED-AST-1.5
Scan Duration
1.044s

Vulnerability Details

L1093

Dynamic Code Execution (eval) in dynamic-eval.php

CWE-94
File Location: lib/dynamic-eval.php:1093
Security Score:
98 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- eval($_POST["code"]);
+ // Avoid dynamic code evaluation. Rewrite with safe native function callbacks.
L667

Dynamic Code Execution (eval) in autoload.php

CWE-94
File Location: bootstrap/autoload.php:667
Security Score:
98 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- eval($_POST["code"]);
+ // Avoid dynamic code evaluation. Rewrite with safe native function callbacks.
L1029

Dynamic Code Execution (eval) in eval-helpers.php

CWE-94
File Location: src/eval-helpers.php:1029
Security Score:
98 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- eval(base64_decode($payload));
+ // Deconstruct expression into standard safe JSON format properties.
L264

Dynamic Code Execution (eval) in dynamic-eval.php

CWE-94
File Location: lib/dynamic-eval.php:264
Security Score:
97 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- eval(base64_decode($payload));
+ // Deconstruct expression into standard safe JSON format properties.
L960

Dynamic Code Execution (eval) in dynamic-eval.php

CWE-94
File Location: lib/dynamic-eval.php:960
Security Score:
97 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- eval($_POST["code"]);
+ // Avoid dynamic code evaluation. Rewrite with safe native function callbacks.
L772

Dynamic Code Execution (eval) in dynamic-eval.php

CWE-94
File Location: lib/dynamic-eval.php:772
Security Score:
97 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- eval($_POST["code"]);
+ // Avoid dynamic code evaluation. Rewrite with safe native function callbacks.
L1214

Dynamic Code Execution (eval) in autoload.php

CWE-94
File Location: bootstrap/autoload.php:1214
Security Score:
97 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- eval(base64_decode($payload));
+ // Deconstruct expression into standard safe JSON format properties.
L1669

Dynamic Code Execution (eval) in eval-helpers.php

CWE-94
File Location: src/eval-helpers.php:1669
Security Score:
96 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- assert($_GET["expression"]);
+ // Use static configuration or dynamic inclusion patterns safely.
L663

Dynamic Code Execution (eval) in autoload.php

CWE-94
File Location: bootstrap/autoload.php:663
Security Score:
96 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- eval(base64_decode($payload));
+ // Deconstruct expression into standard safe JSON format properties.
L857

Dynamic Code Execution (eval) in eval-helpers.php

CWE-94
File Location: src/eval-helpers.php:857
Security Score:
95 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- eval($_POST["code"]);
+ // Avoid dynamic code evaluation. Rewrite with safe native function callbacks.
L518

Dynamic Code Execution (eval) in dynamic-eval.php

CWE-94
File Location: lib/dynamic-eval.php:518
Security Score:
95 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- eval(base64_decode($payload));
+ // Deconstruct expression into standard safe JSON format properties.
L626

Dynamic Code Execution (eval) in eval-helpers.php

CWE-94
File Location: src/eval-helpers.php:626
Security Score:
95 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- assert($_GET["expression"]);
+ // Use static configuration or dynamic inclusion patterns safely.
L1322

Potential SQL Injection in user-query.php

CWE-89
File Location: models/user-query.php:1322
Security Score:
94 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $wpdb->get_col("SELECT DISTINCT post_author FROM {$wpdb->posts} WHERE post_type = '" . $_GET["post_type"] . "'");
+ $wpdb->get_col($wpdb->prepare("SELECT DISTINCT post_author FROM {$wpdb->posts} WHERE post_type = %s", $_GET["post_type"]));
L37

Potential SQL Injection in export.php

CWE-89
File Location: wp-admin/export.php:37
Security Score:
93 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $wpdb->get_results("SELECT comment_post_ID, COUNT(comment_ID) as num_comments FROM $wpdb->comments WHERE comment_post_ID IN (" . $post_id_in . ") GROUP BY comment_post_ID");
+ $wpdb->get_results($wpdb->prepare("SELECT comment_post_ID, COUNT(comment_ID) as num_comments FROM $wpdb->comments WHERE comment_post_ID IN (%s) GROUP BY comment_post_ID", $post_id_in));
L869

Potential SQL Injection in db-helper.php

CWE-89
File Location: src/db-helper.php:869
Security Score:
92 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $wpdb->query("SELECT * FROM " . $wpdb->prefix . "logs WHERE search = '" . $_POST["search"] . "'");
+ $wpdb->query($wpdb->prepare("SELECT * FROM " . $wpdb->prefix . "logs WHERE search = %s", $_POST["search"]));
L1658

Potential SQL Injection in db-helper.php

CWE-89
File Location: src/db-helper.php:1658
Security Score:
92 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $wpdb->query("SELECT * FROM " . $wpdb->prefix . "logs WHERE search = '" . $_POST["search"] . "'");
+ $wpdb->query($wpdb->prepare("SELECT * FROM " . $wpdb->prefix . "logs WHERE search = %s", $_POST["search"]));
L1007

Potential SQL Injection in export.php

CWE-89
File Location: wp-admin/export.php:1007
Security Score:
92 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $wpdb->get_col("SELECT DISTINCT post_author FROM {$wpdb->posts} WHERE post_type = '" . $_GET["post_type"] . "'");
+ $wpdb->get_col($wpdb->prepare("SELECT DISTINCT post_author FROM {$wpdb->posts} WHERE post_type = %s", $_GET["post_type"]));
L592

Potential SQL Injection in comment.php

CWE-89
File Location: wp-admin/includes/comment.php:592
Security Score:
92 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $wpdb->query("SELECT * FROM " . $wpdb->prefix . "logs WHERE search = '" . $_POST["search"] . "'");
+ $wpdb->query($wpdb->prepare("SELECT * FROM " . $wpdb->prefix . "logs WHERE search = %s", $_POST["search"]));
L706

Potential SQL Injection in class-logger-db.php

CWE-89
File Location: includes/class-logger-db.php:706
Security Score:
90 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $this->db->query("SELECT * FROM users WHERE username = '" . $user . "'");
+ $this->db->query("SELECT * FROM users WHERE username = ?", [$user]);
L506

Potential SQL Injection in class-logger-db.php

CWE-89
File Location: includes/class-logger-db.php:506
Security Score:
89 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $this->db->query("SELECT * FROM users WHERE username = '" . $user . "'");
+ $this->db->query("SELECT * FROM users WHERE username = ?", [$user]);
L69

Potential SQL Injection in user-query.php

CWE-89
File Location: models/user-query.php:69
Security Score:
89 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $wpdb->query("SELECT * FROM " . $wpdb->prefix . "logs WHERE search = '" . $_POST["search"] . "'");
+ $wpdb->query($wpdb->prepare("SELECT * FROM " . $wpdb->prefix . "logs WHERE search = %s", $_POST["search"]));
L1114

Potential SQL Injection in db-helper.php

CWE-89
File Location: src/db-helper.php:1114
Security Score:
88 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $wpdb->get_results("SELECT comment_post_ID, COUNT(comment_ID) as num_comments FROM $wpdb->comments WHERE comment_post_ID IN (" . $post_id_in . ") GROUP BY comment_post_ID");
+ $wpdb->get_results($wpdb->prepare("SELECT comment_post_ID, COUNT(comment_ID) as num_comments FROM $wpdb->comments WHERE comment_post_ID IN (%s) GROUP BY comment_post_ID", $post_id_in));
L87

Potential SQL Injection in comment.php

CWE-89
File Location: wp-admin/includes/comment.php:87
Security Score:
88 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $wpdb->get_col("SELECT DISTINCT post_author FROM {$wpdb->posts} WHERE post_type = '" . $_GET["post_type"] . "'");
+ $wpdb->get_col($wpdb->prepare("SELECT DISTINCT post_author FROM {$wpdb->posts} WHERE post_type = %s", $_GET["post_type"]));
L910

Potential SQL Injection in comment.php

CWE-89
File Location: wp-admin/includes/comment.php:910
Security Score:
88 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $this->db->query("SELECT * FROM users WHERE username = '" . $user . "'");
+ $this->db->query("SELECT * FROM users WHERE username = ?", [$user]);
L247

Cross-Site Scripting (XSS) in search-results.php

CWE-79
File Location: src/views/search-results.php:247
Security Score:
85 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- echo "<a href='" . $_REQUEST["redirect"] . "'>Click here</a>";
+ echo esc_url($_REQUEST["redirect"]);
L732

Cross-Site Scripting (XSS) in async-upload.php

CWE-79
File Location: wp-admin/async-upload.php:732
Security Score:
85 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- print($user_input);
+ print(esc_html($user_input));
L50

Cross-Site Scripting (XSS) in alert.blade.php

CWE-79
File Location: views/alert.blade.php:50
Security Score:
84 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- <?= $raw_banner_html ?>
+ <?= esc_html($raw_banner_html) ?>
L1300

Cross-Site Scripting (XSS) in header-menu.php

CWE-79
File Location: templates/header-menu.php:1300
Security Score:
81 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- <?= $raw_banner_html ?>
+ <?= esc_html($raw_banner_html) ?>
L215

Cross-Site Scripting (XSS) in settings-tabs.php

CWE-79
File Location: admin/views/settings-tabs.php:215
Security Score:
81 / 100
Confirmed Issue

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. High Severity (Confirmed via full AST flow control tracing). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- <?= $raw_banner_html ?>
+ <?= esc_html($raw_banner_html) ?>
L698

Cross-Site Scripting (XSS) in settings-tabs.php

CWE-79
File Location: admin/views/settings-tabs.php:698
Security Score:
77 / 100
Needs Audit

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Medium Confidence (Fuzzy matcher overlap - minor review required). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- <?= $raw_banner_html ?>
+ <?= esc_html($raw_banner_html) ?>
L1037

Cross-Site Scripting (XSS) in settings-tabs.php

CWE-79
File Location: admin/views/settings-tabs.php:1037
Security Score:
77 / 100
Needs Audit

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Medium Confidence (Fuzzy matcher overlap - minor review required). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- echo "<a href='" . $_REQUEST["redirect"] . "'>Click here</a>";
+ echo esc_url($_REQUEST["redirect"]);
L1799

Cross-Site Scripting (XSS) in async-upload.php

CWE-79
File Location: wp-admin/async-upload.php:1799
Security Score:
75 / 100
Needs Audit

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Medium Confidence (Fuzzy matcher overlap - minor review required). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- <?= $raw_banner_html ?>
+ <?= esc_html($raw_banner_html) ?>
L933

Cross-Site Scripting (XSS) in search-results.php

CWE-79
File Location: src/views/search-results.php:933
Security Score:
74 / 100
Needs Audit

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Medium Confidence (Fuzzy matcher overlap - minor review required). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- echo "<a href='" . $_REQUEST["redirect"] . "'>Click here</a>";
+ echo esc_url($_REQUEST["redirect"]);
L1408

Cross-Site Scripting (XSS) in header-menu.php

CWE-79
File Location: templates/header-menu.php:1408
Security Score:
74 / 100
Needs Audit

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Medium Confidence (Fuzzy matcher overlap - minor review required). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- <?= $raw_banner_html ?>
+ <?= esc_html($raw_banner_html) ?>
L968

Cross-Site Scripting (XSS) in settings-tabs.php

CWE-79
File Location: admin/views/settings-tabs.php:968
Security Score:
74 / 100
Needs Audit

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Medium Confidence (Fuzzy matcher overlap - minor review required). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- <?= $raw_banner_html ?>
+ <?= esc_html($raw_banner_html) ?>
L53

Cross-Site Scripting (XSS) in header-menu.php

CWE-79
File Location: templates/header-menu.php:53
Security Score:
74 / 100
Needs Audit

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Medium Confidence (Fuzzy matcher overlap - minor review required). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- echo $_GET["page_tab"]; // Unescaped administrator input
+ echo esc_html($_GET["page_tab"]);
L84

Cross-Site Scripting (XSS) in async-upload.php

CWE-79
File Location: wp-admin/async-upload.php:84
Security Score:
73 / 100
Needs Audit

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Medium Confidence (Fuzzy matcher overlap - minor review required). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- <?= $raw_banner_html ?>
+ <?= esc_html($raw_banner_html) ?>
L717

Cross-Site Scripting (XSS) in settings-tabs.php

CWE-79
File Location: admin/views/settings-tabs.php:717
Security Score:
71 / 100
Needs Audit

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Medium Confidence (Fuzzy matcher overlap - minor review required). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- echo "<a href='" . $_REQUEST["redirect"] . "'>Click here</a>";
+ echo esc_url($_REQUEST["redirect"]);
L752

Cross-Site Scripting (XSS) in settings-tabs.php

CWE-79
File Location: admin/views/settings-tabs.php:752
Security Score:
70 / 100
Needs Audit

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Medium Confidence (Fuzzy matcher overlap - minor review required). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- echo $_GET["page_tab"]; // Unescaped administrator input
+ echo esc_html($_GET["page_tab"]);
L938

Weak cryptographic algorithm (MD5) in token-generator.php

CWE-327
File Location: helpers/token-generator.php:938
Security Score:
43 / 100
Potential False Positive

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Low Danger / False Positive Risk (Isolated non-interactive input loop). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $hash = md5($private_key . $req_id);
+ $hash = hash_hmac("sha256", $req_id, $private_key);
L193

Weak cryptographic algorithm (MD5) in token-generator.php

CWE-327
File Location: helpers/token-generator.php:193
Security Score:
42 / 100
Potential False Positive

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Low Danger / False Positive Risk (Isolated non-interactive input loop). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $password_hash = md5($raw_pwd);
+ $password_hash = password_hash($raw_pwd, PASSWORD_BCRYPT);
L1051

Weak cryptographic algorithm (MD5) in user-auth.php

CWE-327
File Location: wp-includes/user-auth.php:1051
Security Score:
39 / 100
Potential False Positive

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Low Danger / False Positive Risk (Isolated non-interactive input loop). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- hash("md5", $secret_api_key);
+ hash("sha256", $secret_api_key);
L1174

Weak cryptographic algorithm (MD5) in user-auth.php

CWE-327
File Location: wp-includes/user-auth.php:1174
Security Score:
39 / 100
Potential False Positive

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Low Danger / False Positive Risk (Isolated non-interactive input loop). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $hash = md5($private_key . $req_id);
+ $hash = hash_hmac("sha256", $req_id, $private_key);
L325

Weak cryptographic algorithm (MD5) in security-tokens.php

CWE-327
File Location: lib/security-tokens.php:325
Security Score:
37 / 100
Potential False Positive

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Low Danger / False Positive Risk (Isolated non-interactive input loop). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $hash = md5($private_key . $req_id);
+ $hash = hash_hmac("sha256", $req_id, $private_key);
L1540

Weak cryptographic algorithm (MD5) in crypt.php

CWE-327
File Location: src/utils/crypt.php:1540
Security Score:
35 / 100
Potential False Positive

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Low Danger / False Positive Risk (Isolated non-interactive input loop). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- hash("md5", $secret_api_key);
+ hash("sha256", $secret_api_key);
L1772

Weak cryptographic algorithm (MD5) in crypt.php

CWE-327
File Location: src/utils/crypt.php:1772
Security Score:
26 / 100
Potential False Positive

Rule Engine Warning

Detected insecure pattern matching known vulnerability signatures. Low Danger / False Positive Risk (Isolated non-interactive input loop). Please apply remediation steps matching the recommended patch format below.

Heuristics Diff
- $hash = md5($private_key . $req_id);
+ $hash = hash_hmac("sha256", $req_id, $private_key);