diff --git a/Userland/Libraries/LibCrypto/PK/Code/EMSA_PKCS1_V1_5.h b/Userland/Libraries/LibCrypto/PK/Code/EMSA_PKCS1_V1_5.h
new file mode 100644
index 0000000000..987e5d56c3
--- /dev/null
+++ b/Userland/Libraries/LibCrypto/PK/Code/EMSA_PKCS1_V1_5.h
@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2022, Michiel Visser <opensource@webmichiel.nl>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Array.h>
+#include <AK/Format.h>
+#include <AK/Random.h>
+#include <AK/Vector.h>
+#include <LibCrypto/Hash/MD5.h>
+#include <LibCrypto/Hash/SHA1.h>
+#include <LibCrypto/Hash/SHA2.h>
+#include <LibCrypto/PK/Code/Code.h>
+
+namespace Crypto {
+namespace PK {
+
+template<typename HashFunction>
+class EMSA_PKCS1_V1_5 : public Code<HashFunction> {
+public:
+    template<typename... Args>
+    EMSA_PKCS1_V1_5(Args... args)
+        : Code<HashFunction>(args...)
+    {
+    }
+
+    virtual void encode(ReadonlyBytes in, ByteBuffer& out, size_t em_bits) override
+    {
+        auto& hash_fn = this->hasher();
+        hash_fn.update(in);
+        auto message_digest = hash_fn.digest();
+        auto message_digest_size = message_digest.bytes().size();
+
+        auto digest_info = hash_function_digest_info();
+        auto encoded_message_length = digest_info.size() + message_digest_size;
+
+        auto em_bytes = (em_bits + 7) / 8;
+        // RFC8017 section 9.2: 3. If emLen < tLen + 11, output "intended encoded message length too short" and stop.
+        if (em_bytes < encoded_message_length + 11) {
+            dbgln("EMSA-PKCS1-V1_5-ENCODE: intended encoded message length too short");
+            return;
+        }
+
+        auto offset = 0;
+        // Build the padding 0x0001ffff..ff00
+        out[offset++] = 0x00;
+        out[offset++] = 0x01;
+        for (size_t i = 0; i < em_bytes - encoded_message_length - 3; i++)
+            out[offset++] = 0xff;
+        out[offset++] = 0x00;
+        // Add the digest info and message digest
+        out.overwrite(offset, digest_info.data(), digest_info.size());
+        offset += digest_info.size();
+        out.overwrite(offset, message_digest.immutable_data(), message_digest.data_length());
+    }
+
+    virtual VerificationConsistency verify(ReadonlyBytes msg, ReadonlyBytes emsg, size_t em_bits) override
+    {
+        auto em_bytes = (em_bits + 7) / 8;
+        auto buffer_result = ByteBuffer::create_uninitialized(em_bytes);
+        if (buffer_result.is_error()) {
+            dbgln("EMSA-PKCS1-V1_5-VERIFY: out of memory");
+            return VerificationConsistency::Inconsistent;
+        }
+        auto buffer = buffer_result.release_value();
+
+        // Encode the supplied message into the buffer
+        encode(msg, buffer, em_bits);
+
+        // Check that the expected message matches the encoded original message
+        if (emsg != buffer) {
+            return VerificationConsistency::Inconsistent;
+        }
+        return VerificationConsistency::Consistent;
+    }
+
+private:
+    inline ReadonlyBytes hash_function_digest_info();
+};
+
+template<>
+inline ReadonlyBytes EMSA_PKCS1_V1_5<Crypto::Hash::MD5>::hash_function_digest_info()
+{
+    // RFC8017 section 9.2 notes 1
+    return { "\x30\x20\x30\x0c\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x05\x05\x00\x04\x10", 18 };
+}
+
+template<>
+inline ReadonlyBytes EMSA_PKCS1_V1_5<Crypto::Hash::SHA1>::hash_function_digest_info()
+{
+    // RFC8017 section 9.2 notes 1
+    return { "\x30\x21\x30\x09\x06\x05\x2b\x0e\x03\x02\x1a\x05\x00\x04\x14", 15 };
+}
+
+template<>
+inline ReadonlyBytes EMSA_PKCS1_V1_5<Crypto::Hash::SHA256>::hash_function_digest_info()
+{
+    // RFC8017 section 9.2 notes 1
+    return { "\x30\x31\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x01\x05\x00\x04\x20", 19 };
+}
+
+template<>
+inline ReadonlyBytes EMSA_PKCS1_V1_5<Crypto::Hash::SHA384>::hash_function_digest_info()
+{
+    // RFC8017 section 9.2 notes 1
+    return { "\x30\x41\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x02\x05\x00\x04\x30", 19 };
+}
+
+template<>
+inline ReadonlyBytes EMSA_PKCS1_V1_5<Crypto::Hash::SHA512>::hash_function_digest_info()
+{
+    // RFC8017 section 9.2 notes 1
+    return { "\x30\x51\x30\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x03\x05\x00\x04\x40", 19 };
+}
+
+}
+}