LibCrypto: Implement RSA_PSS_EMSA with OpenSSL

Author: https://github.com/devgianlu
Commit: 3eeb35e787
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3252
Reviewed-by: https://github.com/gmta ✅

Libraries/LibCrypto/PK/RSA.cpp

@@ -454,4 +454,12 @@ ErrorOr<void> RSA_OAEP_EME::configure(OpenSSL_PKEY_CTX& ctx)
     return {};
 }
 
+ErrorOr<void> RSA_PSS_EMSA::configure(OpenSSL_PKEY_CTX& ctx)
+{
+    OPENSSL_TRY(EVP_PKEY_CTX_set_rsa_padding(ctx.ptr(), RSA_PKCS1_PSS_PADDING));
+    OPENSSL_TRY(EVP_PKEY_CTX_set_rsa_mgf1_md(ctx.ptr(), TRY(hash_kind_to_hash_type(m_hash_kind))));
+    OPENSSL_TRY(EVP_PKEY_CTX_set_rsa_pss_saltlen(ctx.ptr(), m_salt_length.value_or(RSA_PSS_SALTLEN_MAX)));
+    return {};
+}
+
 }

Libraries/LibCrypto/PK/RSA.h

@@ -344,4 +344,28 @@ private:
     Optional<ReadonlyBytes> m_label {};
 };
 
+class RSA_PSS_EMSA : public RSA_EMSA {
+public:
+    template<typename... Args>
+    RSA_PSS_EMSA(Hash::HashKind hash_kind, Args... args)
+        : RSA_EMSA(hash_kind, args...)
+    {
+    }
+
+    ~RSA_PSS_EMSA() = default;
+
+    virtual ByteString class_name() const override
+    {
+        return "RSA_PSS-EMSA";
+    }
+
+    void set_salt_length(int value) { m_salt_length = value; }
+
+protected:
+    ErrorOr<void> configure(OpenSSL_PKEY_CTX& ctx) override;
+
+private:
+    Optional<int> m_salt_length;
+};
+
 }