diff --git a/Userland/Libraries/LibTLS/CMakeLists.txt b/Userland/Libraries/LibTLS/CMakeLists.txt
index 21dcdce4d2..a9fbae4089 100644
--- a/Userland/Libraries/LibTLS/CMakeLists.txt
+++ b/Userland/Libraries/LibTLS/CMakeLists.txt
@@ -1,6 +1,7 @@
 add_compile_options(-Wvla)
 
 set(SOURCES
+    Certificate.cpp
     ClientHandshake.cpp
     Exchange.cpp
     Handshake.cpp
diff --git a/Userland/Libraries/LibTLS/Certificate.cpp b/Userland/Libraries/LibTLS/Certificate.cpp
new file mode 100644
index 0000000000..457e7dd20c
--- /dev/null
+++ b/Userland/Libraries/LibTLS/Certificate.cpp
@@ -0,0 +1,479 @@
+/*
+ * Copyright (c) 2020, Ali Mohammad Pur <mpfard@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "Certificate.h"
+#include <AK/Debug.h>
+#include <LibCrypto/ASN1/ASN1.h>
+#include <LibCrypto/ASN1/DER.h>
+#include <LibCrypto/ASN1/PEM.h>
+
+namespace TLS {
+
+constexpr static Array<int, 4>
+    common_name_oid { 2, 5, 4, 3 },
+    country_name_oid { 2, 5, 4, 6 },
+    locality_name_oid { 2, 5, 4, 7 },
+    organization_name_oid { 2, 5, 4, 10 },
+    organizational_unit_name_oid { 2, 5, 4, 11 };
+
+constexpr static Array<int, 7>
+    rsa_encryption_oid { 1, 2, 840, 113549, 1, 1, 1 },
+    rsa_md5_encryption_oid { 1, 2, 840, 113549, 1, 1, 4 },
+    rsa_sha1_encryption_oid { 1, 2, 840, 113549, 1, 1, 5 },
+    rsa_sha256_encryption_oid { 1, 2, 840, 113549, 1, 1, 11 },
+    rsa_sha512_encryption_oid { 1, 2, 840, 113549, 1, 1, 13 };
+
+constexpr static Array<int, 4>
+    subject_alternative_name_oid { 2, 5, 29, 17 };
+
+Optional<Certificate> Certificate::parse_asn1(ReadonlyBytes buffer, bool)
+{
+#define ENTER_SCOPE_WITHOUT_TYPECHECK(scope)                                               \
+    do {                                                                                   \
+        if (auto result = decoder.enter(); result.has_value()) {                           \
+            dbgln_if(TLS_DEBUG, "Failed to enter object (" scope "): {}", result.value()); \
+            return {};                                                                     \
+        }                                                                                  \
+    } while (0)
+
+#define ENTER_SCOPE_OR_FAIL(kind_name, scope)                                                                 \
+    do {                                                                                                      \
+        if (auto tag = decoder.peek(); tag.is_error() || tag.value().kind != Crypto::ASN1::Kind::kind_name) { \
+            if constexpr (TLS_DEBUG) {                                                                        \
+                if (tag.is_error())                                                                           \
+                    dbgln(scope " data was invalid: {}", tag.error());                                        \
+                else                                                                                          \
+                    dbgln(scope " data was not of kind " #kind_name);                                         \
+            }                                                                                                 \
+            return {};                                                                                        \
+        }                                                                                                     \
+        ENTER_SCOPE_WITHOUT_TYPECHECK(scope);                                                                 \
+    } while (0)
+
+#define EXIT_SCOPE(scope)                                                                  \
+    do {                                                                                   \
+        if (auto error = decoder.leave(); error.has_value()) {                             \
+            dbgln_if(TLS_DEBUG, "Error while exiting scope " scope ": {}", error.value()); \
+            return {};                                                                     \
+        }                                                                                  \
+    } while (0)
+
+#define ENSURE_OBJECT_KIND(_kind_name, scope)                                                                                   \
+    do {                                                                                                                        \
+        if (auto tag = decoder.peek(); tag.is_error() || tag.value().kind != Crypto::ASN1::Kind::_kind_name) {                  \
+            if constexpr (TLS_DEBUG) {                                                                                          \
+                if (tag.is_error())                                                                                             \
+                    dbgln(scope " data was invalid: {}", tag.error());                                                          \
+                else                                                                                                            \
+                    dbgln(scope " data was not of kind " #_kind_name ", it was {}", Crypto::ASN1::kind_name(tag.value().kind)); \
+            }                                                                                                                   \
+            return {};                                                                                                          \
+        }                                                                                                                       \
+    } while (0)
+
+#define READ_OBJECT_OR_FAIL(kind_name, type_name, value_name, scope)                                                   \
+    auto value_name##_result = decoder.read<type_name>(Crypto::ASN1::Class::Universal, Crypto::ASN1::Kind::kind_name); \
+    if (value_name##_result.is_error()) {                                                                              \
+        dbgln_if(TLS_DEBUG, scope " read of kind " #kind_name " failed: {}", value_name##_result.error());             \
+        return {};                                                                                                     \
+    }                                                                                                                  \
+    auto value_name = value_name##_result.release_value();
+
+#define DROP_OBJECT_OR_FAIL(scope)                                        \
+    do {                                                                  \
+        if (auto error = decoder.drop(); error.has_value()) {             \
+            dbgln_if(TLS_DEBUG, scope " read failed: {}", error.value()); \
+        }                                                                 \
+    } while (0)
+
+    Certificate certificate;
+    Crypto::ASN1::Decoder decoder { buffer };
+    // Certificate ::= Sequence {
+    //     certificate          TBSCertificate,
+    //     signature_algorithm  AlgorithmIdentifier,
+    //     signature_value      BitString
+    // }
+    ENTER_SCOPE_OR_FAIL(Sequence, "Certificate");
+
+    // TBSCertificate ::= Sequence {
+    //     version                  (0) EXPLICIT Version DEFAULT v1,
+    //     serial_number                CertificateSerialNumber,
+    //     signature                    AlgorithmIdentifier,
+    //     issuer                       Name,
+    //     validity                     Validity,
+    //     subject                      Name,
+    //     subject_public_key_info      SubjectPublicKeyInfo,
+    //     issuer_unique_id         (1) IMPLICIT UniqueIdentifer OPTIONAL (if present, version > v1),
+    //     subject_unique_id        (2) IMPLICIT UniqueIdentiier OPTIONAL (if present, version > v1),
+    //     extensions               (3) EXPLICIT Extensions OPTIONAL      (if present, version > v2)
+    // }
+    ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate");
+
+    // version
+    {
+        // Version :: Integer { v1(0), v2(1), v3(2) } (Optional)
+        if (auto tag = decoder.peek(); !tag.is_error() && tag.value().type == Crypto::ASN1::Type::Constructed) {
+            ENTER_SCOPE_WITHOUT_TYPECHECK("Certificate::version");
+            READ_OBJECT_OR_FAIL(Integer, Crypto::UnsignedBigInteger, value, "Certificate::version");
+            if (!(value < 3)) {
+                dbgln_if(TLS_DEBUG, "Certificate::version Invalid value for version: {}", value.to_base10());
+                return {};
+            }
+            certificate.version = value.words()[0];
+            EXIT_SCOPE("Certificate::version");
+        } else {
+            certificate.version = 0;
+        }
+    }
+
+    // serial_number
+    {
+        // CertificateSerialNumber :: Integer
+        READ_OBJECT_OR_FAIL(Integer, Crypto::UnsignedBigInteger, value, "Certificate::serial_number");
+        certificate.serial_number = move(value);
+    }
+
+    auto parse_algorithm_identifier = [&](CertificateKeyAlgorithm& field) -> Optional<bool> {
+        // AlgorithmIdentifier ::= Sequence {
+        //     algorithm   ObjectIdentifier,
+        //     parameters  ANY OPTIONAL
+        // }
+        ENTER_SCOPE_OR_FAIL(Sequence, "AlgorithmIdentifier");
+        READ_OBJECT_OR_FAIL(ObjectIdentifier, Vector<int>, identifier, "AlgorithmIdentifier::algorithm");
+        if (identifier == rsa_encryption_oid)
+            field = CertificateKeyAlgorithm ::RSA_RSA;
+        else if (identifier == rsa_md5_encryption_oid)
+            field = CertificateKeyAlgorithm ::RSA_MD5;
+        else if (identifier == rsa_sha1_encryption_oid)
+            field = CertificateKeyAlgorithm ::RSA_SHA1;
+        else if (identifier == rsa_sha256_encryption_oid)
+            field = CertificateKeyAlgorithm ::RSA_SHA256;
+        else if (identifier == rsa_sha512_encryption_oid)
+            field = CertificateKeyAlgorithm ::RSA_SHA512;
+        else
+            return {};
+
+        EXIT_SCOPE("AlgorithmIdentifier");
+        return true;
+    };
+
+    // signature
+    {
+        if (!parse_algorithm_identifier(certificate.algorithm).has_value())
+            return {};
+    }
+
+    auto parse_name = [&](auto& name_struct) -> Optional<bool> {
+        // Name ::= Choice {
+        //     rdn_sequence RDNSequence
+        // } // NOTE: since this is the only alternative, there's no index
+        // RDNSequence ::= Sequence OF RelativeDistinguishedName
+        ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::issuer/subject");
+
+        // RelativeDistinguishedName ::= Set OF AttributeTypeAndValue
+        // AttributeTypeAndValue ::= Sequence {
+        //     type   AttributeType,
+        //     value  AttributeValue
+        // }
+        // AttributeType ::= ObjectIdentifier
+        // AttributeValue ::= Any
+        while (!decoder.eof()) {
+            // Parse only the the required fields, and ignore the rest.
+            ENTER_SCOPE_OR_FAIL(Set, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName");
+            while (!decoder.eof()) {
+                ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue");
+                ENSURE_OBJECT_KIND(ObjectIdentifier, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::type");
+
+                if (auto type_identifier_or_error = decoder.read<Vector<int>>(); !type_identifier_or_error.is_error()) {
+                    // Figure out what type of identifier this is
+                    auto& identifier = type_identifier_or_error.value();
+                    if (identifier == common_name_oid) {
+                        READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
+                            "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
+                        name_struct.subject = name;
+                    } else if (identifier == country_name_oid) {
+                        READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
+                            "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
+                        name_struct.country = name;
+                    } else if (identifier == locality_name_oid) {
+                        READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
+                            "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
+                        name_struct.location = name;
+                    } else if (identifier == organization_name_oid) {
+                        READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
+                            "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
+                        name_struct.entity = name;
+                    } else if (identifier == organizational_unit_name_oid) {
+                        READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
+                            "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
+                        name_struct.unit = name;
+                    }
+                } else {
+                    dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::type data was invalid: {}", type_identifier_or_error.error());
+                    return {};
+                }
+
+                EXIT_SCOPE("Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue");
+            }
+            EXIT_SCOPE("Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName");
+        }
+
+        EXIT_SCOPE("Certificate::TBSCertificate::issuer/subject");
+        return true;
+    };
+
+    // issuer
+    {
+        if (!parse_name(certificate.issuer).has_value())
+            return {};
+    }
+
+    // validity
+    {
+        ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Validity");
+
+        auto parse_time = [&](Core::DateTime& datetime) -> Optional<bool> {
+            // Time ::= Choice {
+            //     utc_time     UTCTime,
+            //     general_time GeneralizedTime
+            // }
+            auto tag = decoder.peek();
+            if (tag.is_error()) {
+                dbgln_if(1, "Certificate::TBSCertificate::Validity::$::Time failed to read tag: {}", tag.error());
+                return {};
+            };
+
+            if (tag.value().kind == Crypto::ASN1::Kind::UTCTime) {
+                READ_OBJECT_OR_FAIL(UTCTime, StringView, time, "Certificate::TBSCertificate::Validity::$");
+                auto result = Crypto::ASN1::parse_utc_time(time);
+                if (!result.has_value()) {
+                    dbgln_if(1, "Certificate::TBSCertificate::Validity::$::Time Invalid UTC Time: {}", time);
+                    return {};
+                }
+                datetime = result.release_value();
+                return true;
+            }
+
+            if (tag.value().kind == Crypto::ASN1::Kind::GeneralizedTime) {
+                READ_OBJECT_OR_FAIL(UTCTime, StringView, time, "Certificate::TBSCertificate::Validity::$");
+                auto result = Crypto::ASN1::parse_generalized_time(time);
+                if (!result.has_value()) {
+                    dbgln_if(1, "Certificate::TBSCertificate::Validity::$::Time Invalid Generalized Time: {}", time);
+                    return {};
+                }
+                datetime = result.release_value();
+                return true;
+            }
+
+            dbgln_if(1, "Unrecognised Time format {}", Crypto::ASN1::kind_name(tag.value().kind));
+            return {};
+        };
+
+        if (!parse_time(certificate.not_before).has_value())
+            return {};
+
+        if (!parse_time(certificate.not_after).has_value())
+            return {};
+
+        EXIT_SCOPE("Certificate::TBSCertificate::Validity");
+    }
+
+    // subject
+    {
+        if (!parse_name(certificate.subject).has_value())
+            return {};
+    }
+
+    // subject_public_key_info
+    {
+        // SubjectPublicKeyInfo ::= Sequence {
+        //     algorithm           AlgorithmIdentifier,
+        //     subject_public_key  BitString
+        // }
+        ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::subject_public_key_info");
+
+        if (!parse_algorithm_identifier(certificate.key_algorithm).has_value())
+            return {};
+
+        READ_OBJECT_OR_FAIL(BitString, const BitmapView, value, "Certificate::TBSCertificate::subject_public_key_info::subject_public_key_info");
+        // Note: Once we support other kinds of keys, make sure to check the kind here!
+        auto key = Crypto::PK::RSA::parse_rsa_key({ value.data(), value.size_in_bytes() });
+        if (!key.public_key.length()) {
+            dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::subject_public_key_info::subject_public_key_info: Invalid key");
+            return {};
+        }
+        certificate.public_key = move(key.public_key);
+        EXIT_SCOPE("Certificate::TBSCertificate::subject_public_key_info");
+    }
+
+    auto parse_unique_identifier = [&]() -> Optional<bool> {
+        if (certificate.version == 0)
+            return true;
+
+        auto tag = decoder.peek();
+        if (tag.is_error()) {
+            dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::*::UniqueIdentifier could not read tag: {}", tag.error());
+            return {};
+        }
+
+        // The spec says to just ignore these.
+        if (static_cast<u8>(tag.value().kind) == 1 || static_cast<u8>(tag.value().kind) == 2)
+            DROP_OBJECT_OR_FAIL("UniqueIdentifier");
+
+        return true;
+    };
+
+    // issuer_unique_identifier
+    {
+        if (!parse_unique_identifier().has_value())
+            return {};
+    }
+
+    // subject_unique_identifier
+    {
+        if (!parse_unique_identifier().has_value())
+            return {};
+    }
+
+    // extensions
+    {
+        if (certificate.version == 2) {
+            auto tag = decoder.peek();
+            if (tag.is_error()) {
+                dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::*::UniqueIdentifier could not read tag: {}", tag.error());
+                return {};
+            }
+            if (static_cast<u8>(tag.value().kind) == 3) {
+                // Extensions ::= Sequence OF Extension
+                // Extension ::= Sequence {
+                //     extension_id     ObjectIdentifier,
+                //     critical         Boolean DEFAULT false,
+                //     extension_value  OctetString (DER-encoded)
+                // }
+                ENTER_SCOPE_WITHOUT_TYPECHECK("Certificate::TBSCertificate::Extensions(IMPLICIT)");
+                ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Extensions");
+
+                while (!decoder.eof()) {
+                    ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Extensions::$::Extension");
+                    READ_OBJECT_OR_FAIL(ObjectIdentifier, Vector<int>, extension_id, "Certificate::TBSCertificate::Extensions::$::Extension::extension_id");
+                    bool is_critical = false;
+                    if (auto tag = decoder.peek(); !tag.is_error() && tag.value().kind == Crypto::ASN1::Kind::Boolean) {
+                        // Read the 'critical' property
+                        READ_OBJECT_OR_FAIL(Boolean, bool, critical, "Certificate::TBSCertificate::Extensions::$::Extension::critical");
+                        is_critical = critical;
+                    }
+                    READ_OBJECT_OR_FAIL(OctetString, StringView, extension_value, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value");
+
+                    // Figure out what this extension is.
+                    if (extension_id == subject_alternative_name_oid) {
+                        Crypto::ASN1::Decoder decoder { extension_value.bytes() };
+                        // SubjectAlternativeName ::= GeneralNames
+                        // GeneralNames ::= Sequence OF GeneralName
+                        // GeneralName ::= CHOICE {
+                        //     other_name     (0) OtherName,
+                        //     rfc_822_name   (1) IA5String,
+                        //     dns_name       (2) IA5String,
+                        //     x400Address    (3) ORAddress,
+                        //     directory_name (4) Name,
+                        //     edi_party_name (5) EDIPartyName,
+                        //     uri            (6) IA5String,
+                        //     ip_address     (7) OctetString,
+                        //     registered_id  (8) ObjectIdentifier,
+                        // }
+                        ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName");
+
+                        while (!decoder.eof()) {
+                            auto tag = decoder.peek();
+                            if (tag.is_error()) {
+                                dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$ could not read tag: {}", tag.error());
+                                return {};
+                            }
+
+                            auto tag_value = static_cast<u8>(tag.value().kind);
+                            switch (tag_value) {
+                            case 0:
+                                // OtherName
+                                // We don't know how to use this.
+                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::OtherName");
+                                break;
+                            case 1:
+                                // RFC 822 name
+                                // We don't know how to use this.
+                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::RFC822Name");
+                                break;
+                            case 2: {
+                                // DNS Name
+                                READ_OBJECT_OR_FAIL(IA5String, StringView, name, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::DNSName");
+                                certificate.SAN.append(name);
+                                break;
+                            }
+                            case 3:
+                                // x400Address
+                                // We don't know how to use this.
+                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::X400Adress");
+                                break;
+                            case 4:
+                                // Directory name
+                                // We don't know how to use this.
+                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::DirectoryName");
+                                break;
+                            case 5:
+                                // edi party name
+                                // We don't know how to use this.
+                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::EDIPartyName");
+                                break;
+                            case 6: {
+                                // URI
+                                READ_OBJECT_OR_FAIL(IA5String, StringView, name, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::URI");
+                                certificate.SAN.append(name);
+                                break;
+                            }
+                            case 7:
+                                // IP Address
+                                // We can't handle these.
+                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::IPAddress");
+                                break;
+                            case 8:
+                                // Registered ID
+                                // We can't handle these.
+                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::RegisteredID");
+                                break;
+                            default:
+                                dbgln_if(TLS_DEBUG, "Unknown tag in SAN choice {}", tag_value);
+                                if (is_critical)
+                                    return {};
+                                else
+                                    DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::???");
+                            }
+                        }
+                    }
+
+                    EXIT_SCOPE("Certificate::TBSCertificate::Extensions::$::Extension");
+                }
+
+                EXIT_SCOPE("Certificate::TBSCertificate::Extensions");
+                EXIT_SCOPE("Certificate::TBSCertificate::Extensions(IMPLICIT)");
+            }
+        }
+    }
+
+    // Just ignore the rest of the data for now.
+    EXIT_SCOPE("Certificate::TBSCertificate");
+    EXIT_SCOPE("Certificate");
+
+    dbgln_if(TLS_DEBUG, "Certificate issued for {} by {}", certificate.subject.subject, certificate.issuer.subject);
+
+    return certificate;
+
+#undef DROP_OBJECT_OR_FAIL
+#undef ENSURE_OBJECT_KIND
+#undef ENTER_SCOPE_OR_FAIL
+#undef ENTER_SCOPE_WITHOUT_TYPECHECK
+#undef EXIT_SCOPE
+#undef READ_OBJECT_OR_FAIL
+}
+
+}
diff --git a/Userland/Libraries/LibTLS/Certificate.h b/Userland/Libraries/LibTLS/Certificate.h
index f5e31ed820..2810b3ac4f 100644
--- a/Userland/Libraries/LibTLS/Certificate.h
+++ b/Userland/Libraries/LibTLS/Certificate.h
@@ -8,6 +8,7 @@
 
 #include <AK/ByteBuffer.h>
 #include <AK/Forward.h>
+#include <AK/Optional.h>
 #include <AK/Singleton.h>
 #include <AK/Types.h>
 #include <LibCore/DateTime.h>
@@ -25,7 +26,8 @@ enum class CertificateKeyAlgorithm {
     RSA_SHA512 = 0x0d,
 };
 
-struct Certificate {
+class Certificate {
+public:
     u16 version { 0 };
     CertificateKeyAlgorithm algorithm { CertificateKeyAlgorithm::Unsupported };
     CertificateKeyAlgorithm key_algorithm { CertificateKeyAlgorithm::Unsupported };
@@ -51,6 +53,8 @@ struct Certificate {
     ByteBuffer der {};
     ByteBuffer data {};
 
+    static Optional<Certificate> parse_asn1(ReadonlyBytes, bool client_cert = false);
+
     bool is_valid() const;
 };
 
diff --git a/Userland/Libraries/LibTLS/TLSv12.cpp b/Userland/Libraries/LibTLS/TLSv12.cpp
index 9cb927bf30..796232273c 100644
--- a/Userland/Libraries/LibTLS/TLSv12.cpp
+++ b/Userland/Libraries/LibTLS/TLSv12.cpp
@@ -12,7 +12,6 @@
 #include <LibCore/FileStream.h>
 #include <LibCore/Timer.h>
 #include <LibCrypto/ASN1/ASN1.h>
-#include <LibCrypto/ASN1/DER.h>
 #include <LibCrypto/ASN1/PEM.h>
 #include <LibCrypto/PK/Code/EMSA_PSS.h>
 #include <LibTLS/TLSv12.h>
@@ -24,470 +23,6 @@
 
 namespace TLS {
 
-constexpr static Array<int, 4>
-    common_name_oid { 2, 5, 4, 3 },
-    country_name_oid { 2, 5, 4, 6 },
-    locality_name_oid { 2, 5, 4, 7 },
-    organization_name_oid { 2, 5, 4, 10 },
-    organizational_unit_name_oid { 2, 5, 4, 11 };
-
-constexpr static Array<int, 7>
-    rsa_encryption_oid { 1, 2, 840, 113549, 1, 1, 1 },
-    rsa_md5_encryption_oid { 1, 2, 840, 113549, 1, 1, 4 },
-    rsa_sha1_encryption_oid { 1, 2, 840, 113549, 1, 1, 5 },
-    rsa_sha256_encryption_oid { 1, 2, 840, 113549, 1, 1, 11 },
-    rsa_sha512_encryption_oid { 1, 2, 840, 113549, 1, 1, 13 };
-
-constexpr static Array<int, 4>
-    subject_alternative_name_oid { 2, 5, 29, 17 };
-
-Optional<Certificate> TLSv12::parse_asn1(ReadonlyBytes buffer, bool) const
-{
-#define ENTER_SCOPE_WITHOUT_TYPECHECK(scope)                                               \
-    do {                                                                                   \
-        if (auto result = decoder.enter(); result.has_value()) {                           \
-            dbgln_if(TLS_DEBUG, "Failed to enter object (" scope "): {}", result.value()); \
-            return {};                                                                     \
-        }                                                                                  \
-    } while (0)
-
-#define ENTER_SCOPE_OR_FAIL(kind_name, scope)                                                                 \
-    do {                                                                                                      \
-        if (auto tag = decoder.peek(); tag.is_error() || tag.value().kind != Crypto::ASN1::Kind::kind_name) { \
-            if constexpr (TLS_DEBUG) {                                                                        \
-                if (tag.is_error())                                                                           \
-                    dbgln(scope " data was invalid: {}", tag.error());                                        \
-                else                                                                                          \
-                    dbgln(scope " data was not of kind " #kind_name);                                         \
-            }                                                                                                 \
-            return {};                                                                                        \
-        }                                                                                                     \
-        ENTER_SCOPE_WITHOUT_TYPECHECK(scope);                                                                 \
-    } while (0)
-
-#define EXIT_SCOPE(scope)                                                                  \
-    do {                                                                                   \
-        if (auto error = decoder.leave(); error.has_value()) {                             \
-            dbgln_if(TLS_DEBUG, "Error while exiting scope " scope ": {}", error.value()); \
-            return {};                                                                     \
-        }                                                                                  \
-    } while (0)
-
-#define ENSURE_OBJECT_KIND(_kind_name, scope)                                                                                   \
-    do {                                                                                                                        \
-        if (auto tag = decoder.peek(); tag.is_error() || tag.value().kind != Crypto::ASN1::Kind::_kind_name) {                  \
-            if constexpr (TLS_DEBUG) {                                                                                          \
-                if (tag.is_error())                                                                                             \
-                    dbgln(scope " data was invalid: {}", tag.error());                                                          \
-                else                                                                                                            \
-                    dbgln(scope " data was not of kind " #_kind_name ", it was {}", Crypto::ASN1::kind_name(tag.value().kind)); \
-            }                                                                                                                   \
-            return {};                                                                                                          \
-        }                                                                                                                       \
-    } while (0)
-
-#define READ_OBJECT_OR_FAIL(kind_name, type_name, value_name, scope)                                                   \
-    auto value_name##_result = decoder.read<type_name>(Crypto::ASN1::Class::Universal, Crypto::ASN1::Kind::kind_name); \
-    if (value_name##_result.is_error()) {                                                                              \
-        dbgln_if(TLS_DEBUG, scope " read of kind " #kind_name " failed: {}", value_name##_result.error());             \
-        return {};                                                                                                     \
-    }                                                                                                                  \
-    auto value_name = value_name##_result.release_value();
-
-#define DROP_OBJECT_OR_FAIL(scope)                                        \
-    do {                                                                  \
-        if (auto error = decoder.drop(); error.has_value()) {             \
-            dbgln_if(TLS_DEBUG, scope " read failed: {}", error.value()); \
-        }                                                                 \
-    } while (0)
-
-    Certificate certificate;
-    Crypto::ASN1::Decoder decoder { buffer };
-    // Certificate ::= Sequence {
-    //     certificate          TBSCertificate,
-    //     signature_algorithm  AlgorithmIdentifier,
-    //     signature_value      BitString
-    // }
-    ENTER_SCOPE_OR_FAIL(Sequence, "Certificate");
-
-    // TBSCertificate ::= Sequence {
-    //     version                  (0) EXPLICIT Version DEFAULT v1,
-    //     serial_number                CertificateSerialNumber,
-    //     signature                    AlgorithmIdentifier,
-    //     issuer                       Name,
-    //     validity                     Validity,
-    //     subject                      Name,
-    //     subject_public_key_info      SubjectPublicKeyInfo,
-    //     issuer_unique_id         (1) IMPLICIT UniqueIdentifer OPTIONAL (if present, version > v1),
-    //     subject_unique_id        (2) IMPLICIT UniqueIdentiier OPTIONAL (if present, version > v1),
-    //     extensions               (3) EXPLICIT Extensions OPTIONAL      (if present, version > v2)
-    // }
-    ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate");
-
-    // version
-    {
-        // Version :: Integer { v1(0), v2(1), v3(2) } (Optional)
-        if (auto tag = decoder.peek(); !tag.is_error() && tag.value().type == Crypto::ASN1::Type::Constructed) {
-            ENTER_SCOPE_WITHOUT_TYPECHECK("Certificate::version");
-            READ_OBJECT_OR_FAIL(Integer, Crypto::UnsignedBigInteger, value, "Certificate::version");
-            if (!(value < 3)) {
-                dbgln_if(TLS_DEBUG, "Certificate::version Invalid value for version: {}", value.to_base10());
-                return {};
-            }
-            certificate.version = value.words()[0];
-            EXIT_SCOPE("Certificate::version");
-        } else {
-            certificate.version = 0;
-        }
-    }
-
-    // serial_number
-    {
-        // CertificateSerialNumber :: Integer
-        READ_OBJECT_OR_FAIL(Integer, Crypto::UnsignedBigInteger, value, "Certificate::serial_number");
-        certificate.serial_number = move(value);
-    }
-
-    auto parse_algorithm_identifier = [&](CertificateKeyAlgorithm& field) -> Optional<bool> {
-        // AlgorithmIdentifier ::= Sequence {
-        //     algorithm   ObjectIdentifier,
-        //     parameters  ANY OPTIONAL
-        // }
-        ENTER_SCOPE_OR_FAIL(Sequence, "AlgorithmIdentifier");
-        READ_OBJECT_OR_FAIL(ObjectIdentifier, Vector<int>, identifier, "AlgorithmIdentifier::algorithm");
-        if (identifier == rsa_encryption_oid)
-            field = CertificateKeyAlgorithm ::RSA_RSA;
-        else if (identifier == rsa_md5_encryption_oid)
-            field = CertificateKeyAlgorithm ::RSA_MD5;
-        else if (identifier == rsa_sha1_encryption_oid)
-            field = CertificateKeyAlgorithm ::RSA_SHA1;
-        else if (identifier == rsa_sha256_encryption_oid)
-            field = CertificateKeyAlgorithm ::RSA_SHA256;
-        else if (identifier == rsa_sha512_encryption_oid)
-            field = CertificateKeyAlgorithm ::RSA_SHA512;
-        else
-            return {};
-
-        EXIT_SCOPE("AlgorithmIdentifier");
-        return true;
-    };
-
-    // signature
-    {
-        if (!parse_algorithm_identifier(certificate.algorithm).has_value())
-            return {};
-    }
-
-    auto parse_name = [&](auto& name_struct) -> Optional<bool> {
-        // Name ::= Choice {
-        //     rdn_sequence RDNSequence
-        // } // NOTE: since this is the only alternative, there's no index
-        // RDNSequence ::= Sequence OF RelativeDistinguishedName
-        ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::issuer/subject");
-
-        // RelativeDistinguishedName ::= Set OF AttributeTypeAndValue
-        // AttributeTypeAndValue ::= Sequence {
-        //     type   AttributeType,
-        //     value  AttributeValue
-        // }
-        // AttributeType ::= ObjectIdentifier
-        // AttributeValue ::= Any
-        while (!decoder.eof()) {
-            // Parse only the the required fields, and ignore the rest.
-            ENTER_SCOPE_OR_FAIL(Set, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName");
-            while (!decoder.eof()) {
-                ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue");
-                ENSURE_OBJECT_KIND(ObjectIdentifier, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::type");
-
-                if (auto type_identifier_or_error = decoder.read<Vector<int>>(); !type_identifier_or_error.is_error()) {
-                    // Figure out what type of identifier this is
-                    auto& identifier = type_identifier_or_error.value();
-                    if (identifier == common_name_oid) {
-                        READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
-                            "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
-                        name_struct.subject = name;
-                    } else if (identifier == country_name_oid) {
-                        READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
-                            "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
-                        name_struct.country = name;
-                    } else if (identifier == locality_name_oid) {
-                        READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
-                            "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
-                        name_struct.location = name;
-                    } else if (identifier == organization_name_oid) {
-                        READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
-                            "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
-                        name_struct.entity = name;
-                    } else if (identifier == organizational_unit_name_oid) {
-                        READ_OBJECT_OR_FAIL(PrintableString, StringView, name,
-                            "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::Value");
-                        name_struct.unit = name;
-                    }
-                } else {
-                    dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue::type data was invalid: {}", type_identifier_or_error.error());
-                    return {};
-                }
-
-                EXIT_SCOPE("Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName::$::AttributeTypeAndValue");
-            }
-            EXIT_SCOPE("Certificate::TBSCertificate::issuer/subject::$::RelativeDistinguishedName");
-        }
-
-        EXIT_SCOPE("Certificate::TBSCertificate::issuer/subject");
-        return true;
-    };
-
-    // issuer
-    {
-        if (!parse_name(certificate.issuer).has_value())
-            return {};
-    }
-
-    // validity
-    {
-        ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Validity");
-
-        auto parse_time = [&](Core::DateTime& datetime) -> Optional<bool> {
-            // Time ::= Choice {
-            //     utc_time     UTCTime,
-            //     general_time GeneralizedTime
-            // }
-            auto tag = decoder.peek();
-            if (tag.is_error()) {
-                dbgln_if(1, "Certificate::TBSCertificate::Validity::$::Time failed to read tag: {}", tag.error());
-                return {};
-            };
-
-            if (tag.value().kind == Crypto::ASN1::Kind::UTCTime) {
-                READ_OBJECT_OR_FAIL(UTCTime, StringView, time, "Certificate::TBSCertificate::Validity::$");
-                auto result = Crypto::ASN1::parse_utc_time(time);
-                if (!result.has_value()) {
-                    dbgln_if(1, "Certificate::TBSCertificate::Validity::$::Time Invalid UTC Time: {}", time);
-                    return {};
-                }
-                datetime = result.release_value();
-                return true;
-            }
-
-            if (tag.value().kind == Crypto::ASN1::Kind::GeneralizedTime) {
-                READ_OBJECT_OR_FAIL(UTCTime, StringView, time, "Certificate::TBSCertificate::Validity::$");
-                auto result = Crypto::ASN1::parse_generalized_time(time);
-                if (!result.has_value()) {
-                    dbgln_if(1, "Certificate::TBSCertificate::Validity::$::Time Invalid Generalized Time: {}", time);
-                    return {};
-                }
-                datetime = result.release_value();
-                return true;
-            }
-
-            dbgln_if(1, "Unrecognised Time format {}", Crypto::ASN1::kind_name(tag.value().kind));
-            return {};
-        };
-
-        if (!parse_time(certificate.not_before).has_value())
-            return {};
-
-        if (!parse_time(certificate.not_after).has_value())
-            return {};
-
-        EXIT_SCOPE("Certificate::TBSCertificate::Validity");
-    }
-
-    // subject
-    {
-        if (!parse_name(certificate.subject).has_value())
-            return {};
-    }
-
-    // subject_public_key_info
-    {
-        // SubjectPublicKeyInfo ::= Sequence {
-        //     algorithm           AlgorithmIdentifier,
-        //     subject_public_key  BitString
-        // }
-        ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::subject_public_key_info");
-
-        if (!parse_algorithm_identifier(certificate.key_algorithm).has_value())
-            return {};
-
-        READ_OBJECT_OR_FAIL(BitString, const BitmapView, value, "Certificate::TBSCertificate::subject_public_key_info::subject_public_key_info");
-        // Note: Once we support other kinds of keys, make sure to check the kind here!
-        auto key = Crypto::PK::RSA::parse_rsa_key({ value.data(), value.size_in_bytes() });
-        if (!key.public_key.length()) {
-            dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::subject_public_key_info::subject_public_key_info: Invalid key");
-            return {};
-        }
-        certificate.public_key = move(key.public_key);
-        EXIT_SCOPE("Certificate::TBSCertificate::subject_public_key_info");
-    }
-
-    auto parse_unique_identifier = [&]() -> Optional<bool> {
-        if (certificate.version == 0)
-            return true;
-
-        auto tag = decoder.peek();
-        if (tag.is_error()) {
-            dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::*::UniqueIdentifier could not read tag: {}", tag.error());
-            return {};
-        }
-
-        // The spec says to just ignore these.
-        if (static_cast<u8>(tag.value().kind) == 1 || static_cast<u8>(tag.value().kind) == 2)
-            DROP_OBJECT_OR_FAIL("UniqueIdentifier");
-
-        return true;
-    };
-
-    // issuer_unique_identifier
-    {
-        if (!parse_unique_identifier().has_value())
-            return {};
-    }
-
-    // subject_unique_identifier
-    {
-        if (!parse_unique_identifier().has_value())
-            return {};
-    }
-
-    // extensions
-    {
-        if (certificate.version == 2) {
-            auto tag = decoder.peek();
-            if (tag.is_error()) {
-                dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::*::UniqueIdentifier could not read tag: {}", tag.error());
-                return {};
-            }
-            if (static_cast<u8>(tag.value().kind) == 3) {
-                // Extensions ::= Sequence OF Extension
-                // Extension ::= Sequence {
-                //     extension_id     ObjectIdentifier,
-                //     critical         Boolean DEFAULT false,
-                //     extension_value  OctetString (DER-encoded)
-                // }
-                ENTER_SCOPE_WITHOUT_TYPECHECK("Certificate::TBSCertificate::Extensions(IMPLICIT)");
-                ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Extensions");
-
-                while (!decoder.eof()) {
-                    ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Extensions::$::Extension");
-                    READ_OBJECT_OR_FAIL(ObjectIdentifier, Vector<int>, extension_id, "Certificate::TBSCertificate::Extensions::$::Extension::extension_id");
-                    bool is_critical = false;
-                    if (auto tag = decoder.peek(); !tag.is_error() && tag.value().kind == Crypto::ASN1::Kind::Boolean) {
-                        // Read the 'critical' property
-                        READ_OBJECT_OR_FAIL(Boolean, bool, critical, "Certificate::TBSCertificate::Extensions::$::Extension::critical");
-                        is_critical = critical;
-                    }
-                    READ_OBJECT_OR_FAIL(OctetString, StringView, extension_value, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value");
-
-                    // Figure out what this extension is.
-                    if (extension_id == subject_alternative_name_oid) {
-                        Crypto::ASN1::Decoder decoder { extension_value.bytes() };
-                        // SubjectAlternativeName ::= GeneralNames
-                        // GeneralNames ::= Sequence OF GeneralName
-                        // GeneralName ::= CHOICE {
-                        //     other_name     (0) OtherName,
-                        //     rfc_822_name   (1) IA5String,
-                        //     dns_name       (2) IA5String,
-                        //     x400Address    (3) ORAddress,
-                        //     directory_name (4) Name,
-                        //     edi_party_name (5) EDIPartyName,
-                        //     uri            (6) IA5String,
-                        //     ip_address     (7) OctetString,
-                        //     registered_id  (8) ObjectIdentifier,
-                        // }
-                        ENTER_SCOPE_OR_FAIL(Sequence, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName");
-
-                        while (!decoder.eof()) {
-                            auto tag = decoder.peek();
-                            if (tag.is_error()) {
-                                dbgln_if(TLS_DEBUG, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$ could not read tag: {}", tag.error());
-                                return {};
-                            }
-
-                            auto tag_value = static_cast<u8>(tag.value().kind);
-                            switch (tag_value) {
-                            case 0:
-                                // OtherName
-                                // We don't know how to use this.
-                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::OtherName");
-                                break;
-                            case 1:
-                                // RFC 822 name
-                                // We don't know how to use this.
-                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::RFC822Name");
-                                break;
-                            case 2: {
-                                // DNS Name
-                                READ_OBJECT_OR_FAIL(IA5String, StringView, name, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::DNSName");
-                                certificate.SAN.append(name);
-                                break;
-                            }
-                            case 3:
-                                // x400Address
-                                // We don't know how to use this.
-                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::X400Adress");
-                                break;
-                            case 4:
-                                // Directory name
-                                // We don't know how to use this.
-                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::DirectoryName");
-                                break;
-                            case 5:
-                                // edi party name
-                                // We don't know how to use this.
-                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::EDIPartyName");
-                                break;
-                            case 6: {
-                                // URI
-                                READ_OBJECT_OR_FAIL(IA5String, StringView, name, "Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::URI");
-                                certificate.SAN.append(name);
-                                break;
-                            }
-                            case 7:
-                                // IP Address
-                                // We can't handle these.
-                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::IPAddress");
-                                break;
-                            case 8:
-                                // Registered ID
-                                // We can't handle these.
-                                DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::RegisteredID");
-                                break;
-                            default:
-                                dbgln_if(TLS_DEBUG, "Unknown tag in SAN choice {}", tag_value);
-                                if (is_critical)
-                                    return {};
-                                else
-                                    DROP_OBJECT_OR_FAIL("Certificate::TBSCertificate::Extensions::$::Extension::extension_value::SubjectAlternativeName::$::???");
-                            }
-                        }
-                    }
-
-                    EXIT_SCOPE("Certificate::TBSCertificate::Extensions::$::Extension");
-                }
-
-                EXIT_SCOPE("Certificate::TBSCertificate::Extensions");
-                EXIT_SCOPE("Certificate::TBSCertificate::Extensions(IMPLICIT)");
-            }
-        }
-    }
-
-    // Just ignore the rest of the data for now.
-    EXIT_SCOPE("Certificate::TBSCertificate");
-    EXIT_SCOPE("Certificate");
-
-    dbgln_if(TLS_DEBUG, "Certificate issued for {} by {}", certificate.subject.subject, certificate.issuer.subject);
-
-    return certificate;
-
-#undef DROP_OBJECT_OR_FAIL
-#undef ENSURE_OBJECT_KIND
-#undef ENTER_SCOPE_OR_FAIL
-#undef ENTER_SCOPE_WITHOUT_TYPECHECK
-#undef EXIT_SCOPE
-#undef READ_OBJECT_OR_FAIL
-}
-
 ssize_t TLSv12::handle_certificate(ReadonlyBytes buffer)
 {
     ssize_t res = 0;
@@ -553,7 +88,7 @@ ssize_t TLSv12::handle_certificate(ReadonlyBytes buffer)
             }
             remaining -= certificate_size_specific;
 
-            auto certificate = parse_asn1(buffer.slice(res_cert, certificate_size_specific), false);
+            auto certificate = Certificate::parse_asn1(buffer.slice(res_cert, certificate_size_specific), false);
             if (certificate.has_value()) {
                 if (certificate.value().is_valid()) {
                     m_context.certificates.append(certificate.value());
@@ -883,7 +418,7 @@ bool TLSv12::add_client_key(ReadonlyBytes certificate_pem_buffer, ReadonlyBytes
         return false;
     }
 
-    auto maybe_certificate = parse_asn1(decoded_certificate);
+    auto maybe_certificate = Certificate::parse_asn1(decoded_certificate);
     if (!maybe_certificate.has_value()) {
         dbgln("Invalid certificate");
         return false;
diff --git a/Userland/Libraries/LibTLS/TLSv12.h b/Userland/Libraries/LibTLS/TLSv12.h
index 0d2f6276e1..46a6383074 100644
--- a/Userland/Libraries/LibTLS/TLSv12.h
+++ b/Userland/Libraries/LibTLS/TLSv12.h
@@ -277,7 +277,6 @@ public:
         m_context.extensions.SNI = sni;
     }
 
-    Optional<Certificate> parse_asn1(ReadonlyBytes, bool client_cert = false) const;
     bool load_certificates(ReadonlyBytes pem_buffer);
     bool load_private_key(ReadonlyBytes pem_buffer);