// p≡p Basic API

// Copyleft (c) 2019, p≡p foundation
// this file is under GNU General Public License 3.0
// see LICENSE.txt

// written by Nana Karlstetter and Volker Birk


type ISO639_1 is string size=2 > a-z;

type hexcode is string > a-f0-9;

type hash doc="32bit Key ID to SHA512 in hexcode"
    is hexcode min=16, max=128;

type hash_list doc="sequence of fingerprints of keys"
    is list< hash >;

type TID doc="UUID version 4 variant 1"
    is binary size=16;

type binary_ref is weak< binary >;

enum content_disposition {
    item attachment 0;
    item inline 1;
    item other -1  doc="must be affirmatively set";
}

struct blob {
    field function=free binary_ref value;

    field size_t size;
    field string mime_type;
    field string filename;
    field content_disposition disposition;
}


type blob_list is list< blob >;

type identity_list is list< identity >;

type string_list is list< string >; 

type string_pair is pair< string, string >;

type string_pair_list is list< string_pair >;

type any_ref is weak< any >;


enum cipher_suite {
    item default 0;
    item cv25519 1;
    item p256 2;
    item p384 3;
    item p521 4;
    item rsa2k 5;
    item rsa3k 6;
    item rsa4k 7;
    item rsa8k 8;
}


enum comm_type {
    hex unknown 0;

    doc > range 0x01 to 0x09: no encryption, 0x0a to 0x0e: nothing reasonable

    hex no_encryption 0x01;
    hex no_encrypted_channel 0x02;
    hex key_not_found 0x03;
    hex key_expired 0x04;
    hex key_revoked 0x05;
    hex key_b0rken 0x06;

    hex key_expired_but_confirmed 0x07 
        doc="NOT with confirmed bit. Just retaining info here in case of renewal.";

    hex my_key_not_included 0x09;

    hex security_by_obscurity 0x0a;
    hex b0rken_crypto 0x0b;
    hex key_too_short 0x0c;

    hex compromised 0x0e                   doc="known compromised connection";
    hex mistrusted 0x0f                    doc="known mistrusted key";

    doc > range 0x10 to 0x3f: unconfirmed encryption

    hex unconfirmed_encryption 0x10        doc="generic";
    hex OpenPGP_weak_unconfirmed 0x11      doc="RSA 1024 is weak";

    hex to_be_checked 0x20                 doc="generic";
    hex SMIME_unconfirmed 0x21             doc="encrypted with S/MIME";
    hex CMS_unconfirmed 0x22;

    hex strong_but_unconfirmed 0x30        doc="generic";
    hex OpenPGP_unconfirmed 0x38           doc="key at least 2048 bit RSA, EC, or anything useful";
    hex OTR_unconfirmed 0x3a               doc="encrypted with OTR";

    doc > range 0x40 to 0x7f: unconfirmed encryption and anonymization

    hex unconfirmed_enc_anon 0x40          doc="generic";
    hex pEp_unconfirmed 0x7f               doc="encrypted with pEp";

    hex confirmed 0x80                     doc="this bit decides if trust is confirmed";

    doc > range 0x81 to 0x8f: reserved
    doc > range 0x90 to 0xbf: confirmed encryption

    hex confirmed_encryption 0x90          doc="generic";
    hex OpenPGP_weak 0x91                  doc="RSA 1024 is weak (unused)";

    hex to_be_checked_confirmed 0xa0       doc="generic";
    hex SMIME 0xa1;
    hex CMS 0xa2;

    hex strong_encryption 0xb0             doc="generic";
    hex OpenPGP 0xb8                       doc="key at least 2048 bit RSA or EC";
    hex OTR 0xba;

    doc > range 0xc0 to 0xff: confirmed encryption and anonymization

    hex confirmed_enc_anon 0xc0            doc="generic";
    hex pEp 0xff;

} // enum comm_type


struct identity {
    field string address doc="SMTP address or URI. String with address UTF-8 encoded";
    field hash fpr doc="fingerprint of key being used as ID. String with fingerprint UTF-8 encoded";
    field string user_id doc="ID for person or system in case of M2M";
    doc ||
        user_id MIGHT be set to "pEp_own_userId" (use PEP_OWN_USERID preprocessor define)
        if this is own user's identity. But it is not REQUIRED to be.
        ||
    field string username doc="descriptive string. String with user name UTF-8 encoded";
    field comm_type comm_type doc="type of communication with this ID";
    field ISO639_1 lang[3] doc="ISO 639-1 ALPHA-2, last byte is 0";
    field bool me doc="if this is the local user herself/himself";
    field unsigned major_ver doc="highest version of pEp message received, if any";
    field unsigned minor_ver doc="highest version of pEp message received, if any";

    flags {
        flag not_for_sync 0x0001
            doc="don't use this identity for Sync";

        flag list 0x0002
            doc="identity of list of persons";

        doc | the second octet flags are calculated

        flag devicegroup 0x0100
            doc="identity of a device group member";
    }
} // struct Identity


protocol session {
    callback messageToSend doc="a message needs to be delivered by application"
    {
        // parms

        provide struct_message msg doc="message struct with message to send";

        // exceptions

        throws any doc="any other value on error";
    }


    method config_passive_mode doc="enable passive mode"
    {
        // parms

       use bool enable doc="flag if enabled or disabled";
    }


    method config_unencrypted_subject doc="disable subject encryption"
    {
        // parms

        use bool enable doc="flag if enabled or disabled";
    }


    method config_use_only_own_private_keys doc="enable passive mode"
    {
        // parms

        use bool enable doc="flag if enabled or disabled";
    }


    method config_service_log doc="log more for service purposes"
    {
        // parms

        use bool enable doc="flag if enabled or disabled";
    }


    method config_cipher_suite doc="cipher suite being used when encrypting"
    {
        // parms

        use suite cipher_suite doc="cipher suite to use";

        // exceptions

        throws cannot_config 
        doc="""
            configuration failed; falling back to default. the default
            ciphersuite for a crypt tech implementation is implementation 
            defined.
            """;
            
       throws illegal_value doc="illegal parameter values";
    }


    method log_event
    doc="""
        log a user defined event defined by UTF-8 encoded strings into 
        management log.
        """
    {
        // parms

        use string title doc="string with event name";

        use string entity doc="string with name of entity which is logging";

        use string description doc="string with long description for event or NULL if omitted";

        use string comment doc="string with user defined comment or NULL if omitted";
        
        // exceptions

       throws illegal_value doc="illegal parameter values";
    }


    method get_default own_userid doc="get the user_id of the own user"
    {
        // parms

        create string userid 
        doc="""
            own user id (if it exists). userid will be NULL if not found; otherwise, 
            returned string belongs to the caller.
            """;

        // exceptions

        throws cannot_find_identity doc="no own_user found in the DB";

        throws unknown_error 
        doc="""
            results were returned, but no ID found (no reason this 
            should ever occur).
            """;
            
       throws illegal_value doc="illegal parameter value";
       
       throws out_of_memory doc="out of memory";
    }


    method mark_as_compromised doc="mark key in trust db as compromised"
    {
        // parms

        use hash fpr doc="fingerprint of key to mark";
        
        // exceptions
            
       throws illegal_value doc="illegal parameter value";
       
       throws cannot_set_trust:
    }


    method mark_as_compromized doc="deprecated to fix misspelling. Please move to mark_as_compromised"


    method import_key_with_fpr_return 
    doc="""
        import keys from data, return optional list of fprs imported
        """;
    {
        // parms

        use string key_data doc="key data, i.e. ASCII armored OpenPGP key";

        use size_t size doc="amount of data to handle";

        create identity_list private_keys 
        doc="""
            list of identities containing the private keys that have been imported. Private_keys
            and imported_keys can be left NULL, it is then ignored.
            *** THIS IS THE ACTUAL FUNCTION IMPLEMENTED BY CRYPTOTECH "import_key" ***
            """;
            
        create identity_list imported keys doc="if non-NULL, list of actual keys imported"
        
        create identity_list changed_public_keys
        doc="""
            if non-NULL AND imported_keys is non-NULL: bitvector - corresponds to the first 
            64 keys imported. If nth bit is set, import changed a key corresponding to the nth 
            element in imported keys (i.e. key was in DB and was changed by import).
            """;
            
        // exceptions

        throws out_of_memory doc="out of memory";
        
        throws illegal_value 
        doc="""
            there is no key data to import, or imported keys was NULL and changed_public_keys 
            was not.
            """;    
    }


    method export_key doc="export ascii armored key"
    {
        // parms

        use hash fpr doc="fingerprint of key";

        create string key_data 
        doc="""
            ASCII armored OpenPGP key. The key_data goes to the ownership of the 
            caller. The caller is responsible to free() it (on Windoze use pEp_free())
            """;

        return size_t size doc="amount of data to handle";

        // exceptions

        throws out_of_memory doc="out of memory";

        throws key_not_found doc="key not found";
        
        throws illegal_value doc="illegal parameter value";
    }


    method export_secret_key doc="export secret key ascii armored"
    {
        // parms

        use hash fpr doc="fingerprint of key, at least 16 hex digits";

        create string key_data 
        doc="""
            ASCII armored OpenPGP secret key. The key_data goes to the ownership of the 
            caller. The caller is responsible to free() it (on Windoze use pEp_free()).
            beware of leaking secret key data - overwrite it in memory after use!
            """;

        return size_t size doc="amount of data to handle";

        // exceptions

        throws out_of_memory doc="out of memory";

        throws key_not_found doc="key not found";

        throws cannot_export_key doc="cannot export secret key (i.e. it's on an HKS)";
        
        throws illegal_value doc="illegal parameter value";
    }


    method export_secrect_key doc="deprecated misspelled function. Please replace with export_secret_key"


    method get_crashdump_log doc="get the last log messages out"
    {
        // parms

        use int maxlines doc="maximum number of lines (0 for default)";

        create string logdata 
        doc="""
            logdata as string in double quoted CSV format
            column1 is title
            column2 is entity
            column3 is description
            column4 is comment
            """;
            
        // exceptions

        throws out_of_memory doc="out of memory";
        
        throws illegal_value doc="illegal parameter value";
        
        throws unknown_error;
    }


    method get_languagelist doc="get the list of languages"
    {
        //parms

        create string language 
        doc="""
            languages as string in double quoted CSV format
            column 1 is the ISO 639-1 language code
            column 2 is the name of the language
            """;
            
       // exceptions

        throws out_of_memory doc="out of memory";
        
        throws illegal_value doc="illegal parameter value";
        
        throws unknown_error;
    }


    method get_phrase doc="get phrase in a dedicated language through i18n"
    {
        // parms

        use string lang doc="string with ISO 639-1 language code";

        use int phrase_id doc="id of phrase in i18n";

        create string phrase doc="phrase as UTF-8 string";
        
        // exceptions

        throws out_of_memory doc="out of memory";
        
        throws illegal_value doc="illegal parameter value";
        
        throws unknown_db_error:
        
        throws phrase_not_found;
    }


    method get_engine_version
    doc="""
        returns the current version of pEpEngine (this is different
        from the pEp protocol version!).
        """
    {
        // parms doc="none"

        // exceptions

        throws engine_version; 
    }

    method is_pEp_user
    doc="""
        returns true if the USER corresponding to this identity has been listed 
        in the *person* table as a pEp user.
        """
    {
        // parms

        use identity ident
        doc="""
            identity containing the user_id to check (this is the only part of 
            the struct we require to be set).
            """;

        return bool is_pEp
        doc="""
            boolean pointer - will return true or false by reference with respect 
            to whether or not user is a known pEp user
            """;

        // exceptions

        throws illegal_value doc="if no user_id in input";

        throws cannot_find_person doc="if user_id doesn't exist";
    }


    method per_user_directory doc="returns the directory for pEp management db"
    {
        // exceptions

        throws char* doc="path to actual per user directory";
        
        throws NULL doc="on failure";
    }

    method per_machine_directory doc="returns the directory for pEp system db"
    {
        // exceptions

        throws char* doc="path to actual per machine directory";
        
        throws NULL doc="on failure";
    }
}