[network/libktorrent] src/mse: ABI/API break: port RC4 encryptor to use QByteArrayView

Git commit 7c7158a054049e8487a76ec60832a96ea29d9db4 by Jack Hill.
Committed on 29/07/2026 at 21:32.
Pushed by jackh into branch 'master'.

ABI/API break: port RC4 encryptor to use QByteArrayView

No downstream changes required.

M  +2    -2    src/mse/encryptedauthenticate.cpp
M  +2    -2    src/mse/encryptedpacketsocket.cpp
M  +6    -6    src/mse/encryptedserverauthenticate.cpp
M  +10   -10   src/mse/rc4encryptor.cpp
M  +5    -3    src/mse/rc4encryptor.h

https://invent.kde.org/network/libktorrent/-/commit/7c7158a054049e8487a76ec60832a96ea29d9db4

diff --git a/src/mse/encryptedauthenticate.cpp b/src/mse/encryptedauthenticate.cpp
index 77b7583e..fbc507e9 100644
--- a/src/mse/encryptedauthenticate.cpp
+++ b/src/mse/encryptedauthenticate.cpp
@@ -117,7 +117,7 @@ void EncryptedAuthenticate::handleYB()
     WriteUint16(tmp_buf, 14, 68); // length of IA, which will be the bittorrent handshake
     // send IA which is the handshake
     makeHandshake(tmp_buf + 16, info_hash, our_peer_id);
-    sock->sendData(QByteArrayView{our_rc4->encrypt(tmp_buf, 84), 84});
+    sock->sendData(our_rc4->encrypt(QByteArrayView{tmp_buf, 84}));
 
     // search for the encrypted VC in the data
     findVC();
@@ -128,7 +128,7 @@ void EncryptedAuthenticate::findVC()
     Uint8 vc[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
 
     RC4Encryptor rc4(enc, dec);
-    memcpy(vc, rc4.encrypt(vc, 8), 8);
+    rc4.encryptReplace(vc, 8);
 
     const Uint32 max_i = buf_size - 8;
     for (Uint32 i = 96; i < max_i; i++) {
diff --git a/src/mse/encryptedpacketsocket.cpp b/src/mse/encryptedpacketsocket.cpp
index 69164fe2..e22945f9 100644
--- a/src/mse/encryptedpacketsocket.cpp
+++ b/src/mse/encryptedpacketsocket.cpp
@@ -99,9 +99,9 @@ Uint32 EncryptedPacketSocket::sendData(QByteArrayView data)
     if (enc) {
         // we need to make sure all data is sent because of the encryption
         Uint32 ds = 0;
-        const Uint8 *ed = enc->encrypt(reinterpret_cast<const Uint8 *>(data.data()), data.size());
+        const auto ed = enc->encrypt(data);
         while (sock->ok() && ds < data.size()) {
-            const Uint32 ret = sock->send(QByteArrayView{ed, data.size()}.sliced(ds));
+            const Uint32 ret = sock->send(ed.sliced(ds));
             ds += ret;
             if (ret == 0) {
                 Out(SYS_CON | LOG_DEBUG) << "ret = 0" << endl;
diff --git a/src/mse/encryptedserverauthenticate.cpp b/src/mse/encryptedserverauthenticate.cpp
index 814f8f82..713faac0 100644
--- a/src/mse/encryptedserverauthenticate.cpp
+++ b/src/mse/encryptedserverauthenticate.cpp
@@ -6,6 +6,7 @@
 #include "encryptedserverauthenticate.h"
 
 #include <array>
+#include <cstddef>
 
 #include <QRandomGenerator>
 
@@ -152,18 +153,17 @@ void EncryptedServerAuthenticate::processVC()
 
     // now we have crypto_provide we can send
     // ENCRYPT(VC, crypto_select, len(padD), padD)
-    Uint8 tmp[14];
-    memset(tmp, 0, 14); // VC
+    std::array<std::byte, 14> tmp{};
+    memset(tmp.data(), 0, 8); // VC
     if (crypto_provide & 0x0000002) { // RC4
-        WriteUint32(tmp, 8, 0x0000002);
         crypto_select = 0x0000002;
     } else {
-        WriteUint32(tmp, 8, 0x0000001);
         crypto_select = 0x0000001;
     }
-    bt::WriteUint16(tmp, 12, 0); // no pad D
+    WriteUint32(tmp.data(), 8, crypto_select);
+    WriteUint16(tmp.data(), 12, 0); // no pad D
 
-    sock->sendData(QByteArrayView{our_rc4->encrypt(tmp, 14), 14});
+    sock->sendData(our_rc4->encrypt(tmp));
 
     // handle pad C
     if (buf_size < req1_off + 14 + pad_C_len) {
diff --git a/src/mse/rc4encryptor.cpp b/src/mse/rc4encryptor.cpp
index 1bdded34..7fafae9e 100644
--- a/src/mse/rc4encryptor.cpp
+++ b/src/mse/rc4encryptor.cpp
@@ -82,16 +82,16 @@ void RC4Encryptor::decrypt(Uint8 *data, Uint32 len)
     EVP_DecryptUpdate(dec.get(), data, &out_len, data, static_cast<int>(len));
 }
 
-const Uint8 *RC4Encryptor::encrypt(const Uint8 *data, Uint32 len)
+QByteArrayView RC4Encryptor::encrypt(QByteArrayView data)
 {
     static_assert(sizeof(rc4_enc_buffer) <= static_cast<unsigned int>(INT_MAX), "rc4_enc_buffer size is too large");
-    if (len > sizeof(rc4_enc_buffer)) {
-        throw bt::Error(QStringLiteral("RC4Encryptor::encrypt is called with a too large input: ") + QString::number(len) + QStringLiteral(" bytes"));
+    if (static_cast<size_t>(data.size()) > sizeof(rc4_enc_buffer)) {
+        throw bt::Error(QStringLiteral("RC4Encryptor::encrypt is called with a too large input: %1 bytes").arg(data.size()));
     }
 
     int out_len = 0;
-    EVP_EncryptUpdate(enc.get(), rc4_enc_buffer, &out_len, data, static_cast<int>(len));
-    return rc4_enc_buffer;
+    EVP_EncryptUpdate(enc.get(), rc4_enc_buffer, &out_len, reinterpret_cast<const Uint8 *>(data.data()), static_cast<int>(data.size()));
+    return QByteArrayView{rc4_enc_buffer, data.size()};
 }
 
 void RC4Encryptor::encryptReplace(Uint8 *data, Uint32 len)
@@ -130,13 +130,13 @@ void RC4Encryptor::decrypt(Uint8 *data, Uint32 len)
     gcry_cipher_decrypt(dec, data, len, data, len);
 }
 
-const Uint8 *RC4Encryptor::encrypt(const Uint8 *data, Uint32 len)
+QByteArrayView RC4Encryptor::encrypt(QByteArrayView data)
 {
-    if (len > sizeof(rc4_enc_buffer)) {
-        throw bt::Error(QStringLiteral("RC4Encryptor::encrypt is called with a too large input: ") + QString::number(len) + QStringLiteral(" bytes"));
+    if (static_cast<size_t>(data.size()) > sizeof(rc4_enc_buffer)) {
+        throw bt::Error(QStringLiteral("RC4Encryptor::encrypt is called with a too large input: %1 bytes").arg(data.size()));
     }
-    gcry_cipher_encrypt(enc, rc4_enc_buffer, len, data, len);
-    return rc4_enc_buffer;
+    gcry_cipher_encrypt(enc, rc4_enc_buffer, data.size(), data.data(), data.size());
+    return QByteArrayView{rc4_enc_buffer, data.size()};
 }
 
 void RC4Encryptor::encryptReplace(Uint8 *data, Uint32 len)
diff --git a/src/mse/rc4encryptor.h b/src/mse/rc4encryptor.h
index a7f1fab5..e8e1f779 100644
--- a/src/mse/rc4encryptor.h
+++ b/src/mse/rc4encryptor.h
@@ -12,6 +12,9 @@
 #elif defined(LIBKTORRENT_USE_LIBGCRYPT)
 #include <gcrypt.h>
 #endif
+
+#include <QByteArrayView>
+
 #include <ktorrent_export.h>
 #include <util/constants.h>
 #include <util/sha1hash.h>
@@ -46,10 +49,9 @@ public:
      * If we send pieces we point directly to the mmap region of data,
      * this cannot be overwritten, hence the static buffer.
      * \param data The data
-     * \param len The length of the data
-     * \return Pointer to the static buffer
+     * \return View over the static buffer
      */
-    const bt::Uint8 *encrypt(const bt::Uint8 *data, bt::Uint32 len);
+    QByteArrayView encrypt(QByteArrayView data);
 
     /*!
      * Encrypt data, encryption will happen in the same buffer. So data will