feat: add openssl aes-ecb wrapper.

src/pch.h

@@ -19,6 +19,7 @@ using namespace llvm;
 #include <bit>
 
 #include <cstring>
+#include <span>
 #include <string>
 #include <string_view>
 

src/util/aes.cpp

@@ -0,0 +1,84 @@
+#include "aes.h"
+
+#include <openssl/err.h>
+#include <openssl/evp.h>
+
+namespace di {
+
+void handle_openssl_errors() {
+    std::string   str;
+    unsigned long code;
+    while ((code = ERR_get_error()) != 0) {
+        char buffer[256];
+        ERR_error_string_n(code, buffer, sizeof(buffer));
+        str += std::string(buffer) + "\n";
+    }
+    if (str.empty()) str = "Unknown error.";
+    throw OpenSSLException("{}", str);
+}
+
+AES::AES(const std::span<uint8_t>& key) : m_ctx(nullptr) {
+    m_ctx = EVP_CIPHER_CTX_new();
+    if (!m_ctx) {
+        handle_openssl_errors();
+    }
+
+    const EVP_CIPHER* cipher_type = nullptr;
+    switch (key.size()) {
+    case 16: // AES-128
+        cipher_type = EVP_aes_128_ecb();
+        break;
+    case 24: // AES-192
+        cipher_type = EVP_aes_192_ecb();
+        break;
+    case 32: // AES-256
+        cipher_type = EVP_aes_256_ecb();
+        break;
+    default:
+        EVP_CIPHER_CTX_free(m_ctx);
+        throw OpenSSLException("Invalid key size. Must be 16/24/32 bytes.");
+    }
+
+    if (EVP_DecryptInit_ex(m_ctx, cipher_type, nullptr, key.data(), nullptr)
+        != 1) {
+        EVP_CIPHER_CTX_free(m_ctx);
+        handle_openssl_errors();
+    }
+}
+
+AES::~AES() {
+    if (m_ctx) {
+        EVP_CIPHER_CTX_free(m_ctx);
+    }
+}
+
+std::vector<uint8_t> AES::decrypt(const std::span<uint8_t>& ciphertext) {
+    if (ciphertext.empty()) {
+        return {};
+    }
+
+    std::vector<uint8_t> plaintext(ciphertext.size());
+    int                  len = 0;
+
+    if (EVP_DecryptUpdate(
+            m_ctx,
+            plaintext.data(),
+            &len,
+            ciphertext.data(),
+            ciphertext.size()
+        )
+        != 1) {
+        handle_openssl_errors();
+    }
+    int plaintext_len = len;
+
+    if (EVP_DecryptFinal_ex(m_ctx, plaintext.data() + len, &len) != 1) {
+        handle_openssl_errors();
+    }
+    plaintext_len += len;
+
+    plaintext.resize(plaintext_len);
+    return plaintext;
+}
+
+} // namespace di

src/util/aes.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <openssl/types.h>
+
+namespace di {
+
+class AES {
+public:
+    explicit AES(const std::span<uint8_t>& key);
+
+    ~AES();
+
+    AES(const AES&)            = delete;
+    AES(AES&&)                 = delete;
+    AES& operator=(const AES&) = delete;
+    AES& operator=(AES&&)      = delete;
+
+    std::vector<uint8_t> decrypt(const std::span<uint8_t>& ciphertext);
+
+private:
+    EVP_CIPHER_CTX* m_ctx;
+};
+
+class OpenSSLException : public RuntimeException<OpenSSLException> {
+public:
+    using RuntimeException::RuntimeException;
+
+    constexpr std::string category() const { return "exception.ossl"; }
+};
+
+} // namespace di

xmake.lua

@@ -5,6 +5,7 @@ add_requires('nlohmann_json 3.12.0')
 add_requires('xxhash        0.8.3')
 add_requires('libllvm       19.1.7')
 add_requires('magic_enum    0.9.7')
+add_requires('openssl3      3.5.1')
 add_requires('boost         1.88.0', {
     system = false, 
     configs = {
@@ -62,6 +63,7 @@ target('libdi')
         'libllvm',
         'boost',
         'nlohmann_json',
+        'openssl3',
         {public = true}
     )