#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "cbor.h"

#include "ctap.h"
#include "ctap_parse.h"
#include "ctap_errors.h"
#include "cose_key.h"
#include "crypto.h"
#include "util.h"
#include "log.h"


#define PIN_TOKEN_SIZE      16
static uint8_t PIN_TOKEN[PIN_TOKEN_SIZE];
static uint8_t KEY_AGREEMENT_PUB[64];
static uint8_t KEY_AGREEMENT_PRIV[32];
static uint8_t PIN_CODE_SET = 0;
static uint8_t PIN_CODE[NEW_PIN_ENC_MAX_SIZE];
static uint8_t PIN_CODE_HASH[32];
static uint8_t DEVICE_LOCKOUT = 0;

static struct {
    CTAP_authDataHeader authData;
    uint8_t clientDataHash[CLIENT_DATA_HASH_SIZE];
    CTAP_credentialDescriptor creds[ALLOW_LIST_MAX_SIZE-1];
    uint8_t lastcmd;
    uint32_t count;
    uint32_t index;
    uint32_t time;
} getAssertionState;

uint8_t verify_pin_auth(uint8_t * pinAuth, uint8_t * clientDataHash)
{
    uint8_t hmac[32];

    crypto_sha256_hmac_init(PIN_TOKEN, PIN_TOKEN_SIZE, hmac);
    crypto_sha256_update(clientDataHash, CLIENT_DATA_HASH_SIZE);
    crypto_sha256_hmac_final(PIN_TOKEN, PIN_TOKEN_SIZE, hmac);

    if (memcmp(pinAuth, hmac, 16) == 0)
    {
        return 0;
    }
    else
    {
        printf2(TAG_ERR,"Pin auth failed\n");
        dump_hex1(TAG_ERR,pinAuth,16);
        dump_hex1(TAG_ERR,hmac,16);
        return CTAP2_ERR_PIN_AUTH_INVALID;
    }

}

uint8_t ctap_get_info(CborEncoder * encoder)
{
    int ret;
    CborEncoder array;
    CborEncoder map;
    CborEncoder options;
    CborEncoder pins;

    const int number_of_versions = 2;

    ret = cbor_encoder_create_map(encoder, &map, 5);
    check_ret(ret);
    {

        ret = cbor_encode_uint(&map, RESP_versions);     //  versions key
        check_ret(ret);
        {
            ret = cbor_encoder_create_array(&map, &array, number_of_versions);
            check_ret(ret);
            {
                ret = cbor_encode_text_stringz(&array, "U2F_V2");
                check_ret(ret);
                ret = cbor_encode_text_stringz(&array, "FIDO_2_0");
                check_ret(ret);
            }
            ret = cbor_encoder_close_container(&map, &array);
            check_ret(ret);
        }

        ret = cbor_encode_uint(&map, RESP_aaguid);
        check_ret(ret);
        {
            ret = cbor_encode_byte_string(&map, CTAP_AAGUID, 16);
            check_ret(ret);
        }

        ret = cbor_encode_uint(&map, RESP_maxMsgSize);
        check_ret(ret);
        {
            ret = cbor_encode_int(&map, CTAP_MAX_MESSAGE_SIZE);
            check_ret(ret);
        }

        ret = cbor_encode_uint(&map, RESP_pinProtocols);
        check_ret(ret);
        {
            ret = cbor_encoder_create_array(&map, &pins, 1);
            check_ret(ret);
            {
                ret = cbor_encode_int(&pins, 1);
                check_ret(ret);
            }
            ret = cbor_encoder_close_container(&map, &pins);
            check_ret(ret);
        }



        ret = cbor_encode_uint(&map, RESP_options);
        check_ret(ret);
        {
            ret = cbor_encoder_create_map(&map, &options,5);
            check_ret(ret);
            {
                ret = cbor_encode_text_string(&options, "plat", 4);
                check_ret(ret);
                {
                    ret = cbor_encode_boolean(&options, 0);     // Not attached to platform
                    check_ret(ret);
                }

                ret = cbor_encode_text_string(&options, "rk", 2);
                check_ret(ret);
                {
                    ret = cbor_encode_boolean(&options, 0);     // State-less device, requires allowList parameter.
                    check_ret(ret);
                }

                ret = cbor_encode_text_string(&options, "up", 2);
                check_ret(ret);
                {
                    ret = cbor_encode_boolean(&options, 1);     // Capable of testing user presence
                    check_ret(ret);
                }

                ret = cbor_encode_text_string(&options, "uv", 2);
                check_ret(ret);
                {
                    ret = cbor_encode_boolean(&options, 0);     // NOT [yet] capable of verifying user
                    check_ret(ret);
                }
                ret = cbor_encode_text_string(&options, "clientPin", 9);
                check_ret(ret);
                {
                    ret = cbor_encode_boolean(&options, ctap_is_pin_set());     // NOT [yet] capable of verifying user
                    check_ret(ret);
                }


            }
            ret = cbor_encoder_close_container(&map, &options);
            check_ret(ret);
        }


    }
    ret = cbor_encoder_close_container(encoder, &map);
    check_ret(ret);

    return CTAP1_ERR_SUCCESS;
}



static int ctap_add_cose_key(CborEncoder * cose_key, uint8_t * x, uint8_t * y, uint8_t credtype, int32_t algtype)
{
    int ret;
    CborEncoder map;

    ret = cbor_encoder_create_map(cose_key, &map, 5);
    check_ret(ret);


    {
        ret = cbor_encode_int(&map, COSE_KEY_LABEL_KTY);
        check_ret(ret);
        ret = cbor_encode_int(&map, COSE_KEY_KTY_EC2);
        check_ret(ret);
    }

    {
        ret = cbor_encode_int(&map, COSE_KEY_LABEL_ALG);
        check_ret(ret);
        ret = cbor_encode_int(&map, algtype);
        check_ret(ret);
    }

    {
        ret = cbor_encode_int(&map, COSE_KEY_LABEL_CRV);
        check_ret(ret);
        ret = cbor_encode_int(&map, COSE_KEY_CRV_P256);
        check_ret(ret);
    }


    {
        ret = cbor_encode_int(&map, COSE_KEY_LABEL_X);
        check_ret(ret);
        ret = cbor_encode_byte_string(&map, x, 32);
        check_ret(ret);
    }

    {
        ret = cbor_encode_int(&map, COSE_KEY_LABEL_Y);
        check_ret(ret);
        ret = cbor_encode_byte_string(&map, y, 32);
        check_ret(ret);
    }

    ret = cbor_encoder_close_container(cose_key, &map);
    check_ret(ret);

}
static int ctap_generate_cose_key(CborEncoder * cose_key, uint8_t * hmac_input, int len, uint8_t credtype, int32_t algtype)
{
    uint8_t x[32], y[32];

    if (credtype != PUB_KEY_CRED_PUB_KEY)
    {
        printf2(TAG_ERR,"Error, pubkey credential type not supported\n");
        return -1;
    }
    switch(algtype)
    {
        case COSE_ALG_ES256:
            crypto_ecc256_derive_public_key(hmac_input, len, x, y);
            break;
        default:
            printf2(TAG_ERR,"Error, COSE alg %d not supported\n", algtype);
            return -1;
    }
    ctap_add_cose_key(cose_key, x, y, credtype, algtype);
}

void make_auth_tag(struct rpId * rp, CTAP_userEntity * user, uint32_t count, uint8_t * tag)
{
    uint8_t hashbuf[32];
    crypto_sha256_init();
    crypto_sha256_update(rp->id, rp->size);
    crypto_sha256_update(user->id, user->id_size);
    crypto_sha256_update(user->name, strnlen(user->name, USER_NAME_LIMIT));
    crypto_sha256_update((uint8_t*)&count, 4);
    crypto_sha256_update_secret();
    crypto_sha256_final(hashbuf);

    memmove(tag, hashbuf, CREDENTIAL_TAG_SIZE);
}

static uint32_t auth_data_update_count(CTAP_authDataHeader * authData)
{
    uint32_t count = ctap_atomic_count( 0 );
    if (count == 0)     // count 0 will indicate invalid token
    {
        count = ctap_atomic_count( 0 );
    }
    authData->signCount = ntohl(count);
    return count;
}

static int ctap_make_auth_data(struct rpId * rp, CborEncoder * map, uint8_t * auth_data_buf, int len, CTAP_userEntity * user, uint8_t credtype, int32_t algtype)
{
    CborEncoder cose_key;
    int auth_data_sz, ret;
    uint32_t count;
    CTAP_authData * authData = (CTAP_authData *)auth_data_buf;

    uint8_t * cose_key_buf = auth_data_buf + sizeof(CTAP_authData);

    if((sizeof(CTAP_authDataHeader)) > len)
    {
        printf1(TAG_ERR,"assertion fail, auth_data_buf must be at least %d bytes\n", sizeof(CTAP_authData) - sizeof(CTAP_attestHeader));
        exit(1);
    }

    crypto_sha256_init();
    crypto_sha256_update(rp->id, rp->size);
    crypto_sha256_final(authData->head.rpIdHash);

    count = auth_data_update_count(&authData->head);

    authData->head.flags = (ctap_user_presence_test() << 0);
    authData->head.flags |= (ctap_user_verification(0) << 2);


    if (credtype != 0)
    {
        // add attestedCredentialData
        authData->head.flags |= (1 << 6);//include attestation data

        cbor_encoder_init(&cose_key, cose_key_buf, len - sizeof(CTAP_authData), 0);

        memmove(authData->attest.aaguid, CTAP_AAGUID, 16);
        authData->attest.credLenL = CREDENTIAL_ID_SIZE & 0x00FF;
        authData->attest.credLenH = (CREDENTIAL_ID_SIZE & 0xFF00) >> 8;

#if CREDENTIAL_ID_SIZE != 150
#error "need to double check credential ID layout"
#else
        memset(authData->attest.credential.id, 0, CREDENTIAL_ID_SIZE);

        // Make a tag we can later check to make sure this is a token we made
        make_auth_tag(rp, user, count, authData->attest.credential.fields.tag);

        memmove(&authData->attest.credential.fields.user, user, sizeof(CTAP_userEntity)); //TODO encrypt this

        authData->attest.credential.fields.count = count;

        ctap_generate_cose_key(&cose_key, authData->attest.credential.id, CREDENTIAL_ID_SIZE, credtype, algtype);

        printf1(TAG_MC,"COSE_KEY: "); dump_hex1(TAG_MC, cose_key_buf, cbor_encoder_get_buffer_size(&cose_key, cose_key_buf));

        auth_data_sz = sizeof(CTAP_authData) + cbor_encoder_get_buffer_size(&cose_key, cose_key_buf);
#endif

    }
    else
    {
        auth_data_sz = sizeof(CTAP_authDataHeader);
    }

    {
        ret = cbor_encode_int(map,RESP_authData);
        check_ret(ret);
        ret = cbor_encode_byte_string(map, auth_data_buf, auth_data_sz);
        check_ret(ret);
    }

    return auth_data_sz;
}

// require load_key prior to this
// @data data to hash before signature
// @clientDataHash for signature
// @tmp buffer for hash.  (can be same as data if data >= 32 bytes)
// @sigbuf location to deposit signature (must be 64 bytes)
// @sigder location to deposit der signature (must be 72 bytes)
// @return length of der signature
int ctap_calculate_signature(uint8_t * data, int datalen, uint8_t * clientDataHash, uint8_t * hashbuf, uint8_t * sigbuf, uint8_t * sigder)
{
    int i;
    // calculate attestation sig
    crypto_sha256_init();
    crypto_sha256_update(data, datalen);
    crypto_sha256_update(clientDataHash, CLIENT_DATA_HASH_SIZE);
    crypto_sha256_final(hashbuf);

    printf1(TAG_GREEN, "sha256: ");  dump_hex1(TAG_DUMP,hashbuf,32);
    crypto_ecc256_sign(hashbuf, 32, sigbuf);

    // Need to caress into dumb der format ..
    int8_t lead_s = 0;  // leading zeros
    int8_t lead_r = 0;
    for (i=0; i < 32; i++)
        if (sigbuf[i] == 0) lead_r++;
        else break;

    for (i=0; i < 32; i++)
        if (sigbuf[i+32] == 0) lead_s++;
        else break;

    int8_t pad_s = ((sigbuf[32 + lead_s] & 0x80) == 0x80);
    int8_t pad_r = ((sigbuf[0 + lead_r] & 0x80) == 0x80);

    sigder[0] = 0x30;
    sigder[1] = 0x44 + pad_s + pad_r - lead_s - lead_r;

    sigder[2] = 0x02;
    sigder[3 + pad_r] = 0;
    sigder[3] = 0x20 + pad_r - lead_r;
    memmove(sigder + 4 + pad_r, sigbuf + lead_r, 32);

    sigder[4 + 32 + pad_r - lead_r] = 0x02;
    sigder[5 + 32 + pad_r + pad_s - lead_r] = 0;
    sigder[5 + 32 + pad_r - lead_r] = 0x20 + pad_s - lead_s;
    memmove(sigder + 6 + 32 + pad_r + pad_s - lead_r, sigbuf + 32 + lead_s, 32);
    //

    return 0x46 + pad_s + pad_r - lead_r - lead_s;
}

uint8_t ctap_add_attest_statement(CborEncoder * map, uint8_t * sigder, int len)
{
    int ret;

    CborEncoder stmtmap;
    CborEncoder x5carr;


    ret = cbor_encode_int(map,RESP_attStmt);
    check_ret(ret);
    ret = cbor_encoder_create_map(map, &stmtmap, 3);
    check_ret(ret);
    {
        ret = cbor_encode_text_stringz(&stmtmap,"alg");
        check_ret(ret);
        ret = cbor_encode_int(&stmtmap,COSE_ALG_ES256);
        check_ret(ret);
    }
    {
        ret = cbor_encode_text_stringz(&stmtmap,"sig");
        check_ret(ret);
        ret = cbor_encode_byte_string(&stmtmap, sigder, len);
        check_ret(ret);
    }
    {
        ret = cbor_encode_text_stringz(&stmtmap,"x5c");
        check_ret(ret);
        ret = cbor_encoder_create_array(&stmtmap, &x5carr, 1);
        check_ret(ret);
        {
            ret = cbor_encode_byte_string(&x5carr, attestation_cert_der, attestation_cert_der_size);
            check_ret(ret);
            ret = cbor_encoder_close_container(&stmtmap, &x5carr);
            check_ret(ret);
        }
    }

    ret = cbor_encoder_close_container(map, &stmtmap);
    check_ret(ret);
}

// Return 1 if credential belongs to this token
int ctap_authenticate_credential(struct rpId * rp, CTAP_credentialDescriptor * desc)
{
    uint8_t tag[16];
    if (desc->type != PUB_KEY_CRED_PUB_KEY)
    {
        printf1(TAG_GA,"unsupported credential type: %d\n", desc->type);
        return 0;
    }

    make_auth_tag(rp, &desc->credential.fields.user, desc->credential.fields.count, tag);

    return (memcmp(desc->credential.fields.tag, tag, CREDENTIAL_TAG_SIZE) == 0);
}



uint8_t ctap_make_credential(CborEncoder * encoder, uint8_t * request, int length)
{
    CTAP_makeCredential MC;
    int ret, i;
    uint8_t auth_data_buf[300];
    CTAP_credentialDescriptor * excl_cred = (CTAP_credentialDescriptor *) auth_data_buf;
    uint8_t * hashbuf = auth_data_buf + 0;
    uint8_t * sigbuf = auth_data_buf + 32;
    uint8_t * sigder = auth_data_buf + 32 + 64;

    ret = ctap_parse_make_credential(&MC,encoder,request,length);
    if (ret != 0)
    {
        printf2(TAG_ERR,"error, parse_make_credential failed\n");
        return ret;
    }
    if ((MC.paramsParsed & MC_requiredMask) != MC_requiredMask)
    {
        printf2(TAG_ERR,"error, required parameter(s) for makeCredential are missing\n");
        return CTAP2_ERR_MISSING_PARAMETER;
    }

    if (ctap_is_pin_set() == 1 && MC.pinAuthPresent == 0)
    {
        printf2(TAG_ERR,"pinAuth is required\n");
        return CTAP2_ERR_PIN_REQUIRED;
    }
    else
    {
        if (ctap_is_pin_set())
        {
            ret = verify_pin_auth(MC.pinAuth, MC.clientDataHash);
            check_retr(ret);
        }
    }

    for (i = 0; i < MC.excludeListSize; i++)
    {
        ret = parse_credential_descriptor(&MC.excludeList, excl_cred);
        if (ret == CTAP2_ERR_CBOR_UNEXPECTED_TYPE)
        {
            continue;
        }
        check_retr(ret);

        if (ctap_authenticate_credential(&MC.rp, excl_cred))
        {
            return CTAP2_ERR_CREDENTIAL_EXCLUDED;
        }

        ret = cbor_value_advance(&MC.excludeList);
        check_ret(ret);
    }

    CborEncoder map;
    ret = cbor_encoder_create_map(encoder, &map, 3);
    check_ret(ret);

    int auth_data_sz = ctap_make_auth_data(&MC.rp, &map, auth_data_buf, sizeof(auth_data_buf),
            &MC.user, MC.publicKeyCredentialType, MC.COSEAlgorithmIdentifier);

    crypto_ecc256_load_attestation_key();
    int sigder_sz = ctap_calculate_signature(auth_data_buf, auth_data_sz, MC.clientDataHash, auth_data_buf, sigbuf, sigder);

    printf1(TAG_MC,"der sig [%d]: ", sigder_sz); dump_hex1(TAG_MC, sigder, sigder_sz);

    ret = ctap_add_attest_statement(&map, sigder, sigder_sz);
    check_retr(ret);

    {
        ret = cbor_encode_int(&map,RESP_fmt);
        check_ret(ret);
        ret = cbor_encode_text_stringz(&map, "packed");
        check_ret(ret);
    }

    ret = cbor_encoder_close_container(encoder, &map);
    check_ret(ret);
    return CTAP1_ERR_SUCCESS;
}

static int pick_first_authentic_credential(CTAP_getAssertion * GA)
{
    int i;
    for (i = 0; i < GA->credLen; i++)
    {
        if (GA->creds[i].credential.fields.count != 0)
        {
            return i;
        }
    }
    return -1;
}

static uint8_t ctap_add_credential_descriptor(CborEncoder * map, CTAP_credentialDescriptor * cred)
{
    CborEncoder desc;
    int ret = cbor_encode_int(map, RESP_credential);
    check_ret(ret);

    ret = cbor_encoder_create_map(map, &desc, 2);
    check_ret(ret);

    {
        ret = cbor_encode_text_string(&desc, "type", 4);
        check_ret(ret);

        ret = cbor_encode_int(&desc, cred->type);
        check_ret(ret);
    }
    {
        ret = cbor_encode_text_string(&desc, "id", 2);
        check_ret(ret);

        ret = cbor_encode_byte_string(&desc, cred->credential.id, CREDENTIAL_ID_SIZE);
        check_ret(ret);
    }

    ret = cbor_encoder_close_container(map, &desc);
    check_ret(ret);

    return 0;
}

uint8_t ctap_add_user_entity(CborEncoder * map, CTAP_userEntity * user)
{
    CborEncoder entity;
    int ret = cbor_encode_int(map, RESP_publicKeyCredentialUserEntity);
    check_ret(ret);

    ret = cbor_encoder_create_map(map, &entity, 2);
    check_ret(ret);

    {
        ret = cbor_encode_text_string(&entity, "id", 2);
        check_ret(ret);

        ret = cbor_encode_byte_string(&entity, user->id, user->id_size);
        check_ret(ret);
    }


    {
        ret = cbor_encode_text_string(&entity, "displayName", 11);
        check_ret(ret);

        ret = cbor_encode_text_stringz(&entity, user->name);
        check_ret(ret);
    }

    ret = cbor_encoder_close_container(map, &entity);
    check_ret(ret);

    return 0;
}

static int cred_cmp_func(const void * _a, const void * _b)
{
    CTAP_credentialDescriptor * a = (CTAP_credentialDescriptor * )_a;
    CTAP_credentialDescriptor * b = (CTAP_credentialDescriptor * )_b;
    return b->credential.fields.count - a->credential.fields.count;
}

// @return the number of valid credentials
// sorts the credentials.  Most recent creds will be first, invalid ones last.
int ctap_filter_invalid_credentials(CTAP_getAssertion * GA)
{
    int i;
    int count = 0;
    for (i = 0; i < GA->credLen; i++)
    {
        if (! ctap_authenticate_credential(&GA->rp, &GA->creds[i]))
        {
            printf1(TAG_GA, "CRED #%d is invalid\n", GA->creds[i].credential.fields.count);
            GA->creds[i].credential.fields.count = 0;      // invalidate
        }
        else
        {
            count++;
        }
    }
    printf("qsort length: %d\n", GA->credLen);
    qsort(GA->creds, GA->credLen, sizeof(CTAP_credentialDescriptor), cred_cmp_func);
    return count;
}


static void save_credential_list(CTAP_authDataHeader * head, uint8_t * clientDataHash, CTAP_credentialDescriptor * creds, uint32_t count)
{
    if(count)
    {
        memmove(getAssertionState.clientDataHash, clientDataHash, CLIENT_DATA_HASH_SIZE);
        memmove(&getAssertionState.authData, head, sizeof(CTAP_authDataHeader));
        memmove(getAssertionState.creds, creds, sizeof(CTAP_credentialDescriptor) * (count));
    }
    getAssertionState.count = count;
    printf1(TAG_GA,"saved %d credentials\n",count);
}

static CTAP_credentialDescriptor * pop_credential()
{
    if (getAssertionState.count > 0)
    {
        getAssertionState.count--;
        return &getAssertionState.creds[getAssertionState.count];
    }
    else
    {
        return NULL;
    }
}

uint8_t ctap_end_get_assertion(CborEncoder * map, CTAP_credentialDescriptor * cred, uint8_t * auth_data_buf, uint8_t * clientDataHash)
{
    int ret;
    uint8_t sigbuf[64];
    uint8_t sigder[72];


    ret = ctap_add_credential_descriptor(map, cred);
    check_retr(ret);

    ret = ctap_add_user_entity(map, &cred->credential.fields.user);
    check_retr(ret);

    crypto_ecc256_load_key(cred->credential.id, CREDENTIAL_ID_SIZE);

    printf1(TAG_GREEN,"auth_data_buf: "); dump_hex1(TAG_DUMP, auth_data_buf, sizeof(CTAP_authDataHeader));
    printf1(TAG_GREEN,"clientdatahash: "); dump_hex1(TAG_DUMP, clientDataHash, 32);
    printf1(TAG_GREEN,"credential: # %d\n", cred->credential.fields.count); 
    /*dump_hex1(TAG_DUMP, clientDataHash, 32);*/

    int sigder_sz = ctap_calculate_signature(auth_data_buf, sizeof(CTAP_authDataHeader), clientDataHash, auth_data_buf, sigbuf, sigder);

    {
        ret = cbor_encode_int(map, RESP_signature);
        check_ret(ret);
        ret = cbor_encode_byte_string(map, sigder, sigder_sz);
        check_ret(ret);
    }
    return 0;
}

uint8_t ctap_get_next_assertion(CborEncoder * encoder)
{
    int ret;
    CborEncoder map;
    CTAP_authDataHeader * authData = &getAssertionState.authData;

    CTAP_credentialDescriptor * cred = pop_credential();

    if (cred == NULL)
    {
        return CTAP2_ERR_NOT_ALLOWED;
    }

    auth_data_update_count(authData);


    ret = cbor_encoder_create_map(encoder, &map, 4);
    check_ret(ret);

    {
        ret = cbor_encode_int(&map,RESP_authData);
        check_ret(ret);
        ret = cbor_encode_byte_string(&map, (uint8_t *)authData, sizeof(CTAP_authDataHeader));
        check_ret(ret);
    }

    ret = ctap_end_get_assertion(&map, cred, (uint8_t *)authData, getAssertionState.clientDataHash);
    check_retr(ret);

    ret = cbor_encoder_close_container(encoder, &map);
    check_ret(ret);

    return 0;
}

uint8_t ctap_get_assertion(CborEncoder * encoder, uint8_t * request, int length)
{
    CTAP_getAssertion GA;
    uint8_t auth_data_buf[sizeof(CTAP_authDataHeader)];
    int ret = ctap_parse_get_assertion(&GA,request,length);

    if (ret != 0)
    {
        printf2(TAG_ERR,"error, parse_get_assertion failed\n");
        return ret;
    }

    if (PIN_CODE_SET == 1 && GA.pinAuthPresent == 0)
    {
        printf2(TAG_ERR,"pinAuth is required\n");
        return CTAP2_ERR_PIN_REQUIRED;
    }
    else
    {
        if (ctap_is_pin_set())
        {
            ret = verify_pin_auth(GA.pinAuth, GA.clientDataHash);
            check_retr(ret);
        }
    }


    CborEncoder map;
    ret = cbor_encoder_create_map(encoder, &map, 5);
    check_ret(ret);

    ctap_make_auth_data(&GA.rp, &map, auth_data_buf, sizeof(auth_data_buf), NULL, 0,0);

    printf1(TAG_GA, "ALLOW_LIST has %d creds\n", GA.credLen);
    for (int j = 0; j < GA.credLen; j++)
    {
        printf1(TAG_GA,"CRED ID (# %d): ", GA.creds[j].credential.fields.count);
        dump_hex1(TAG_GA, GA.creds[j].credential.id, CREDENTIAL_ID_SIZE);
        if (ctap_authenticate_credential(&GA.rp, &GA.creds[j]))   // warning encryption will break this
        {
            printf1(TAG_GA,"  Authenticated.\n");
        }
        else
        {
            printf1(TAG_GA,"  NOT authentic.\n");
        }
    }

    // Decrypt here

    //
    int validCredCount = ctap_filter_invalid_credentials(&GA);
    if (validCredCount > 0)
    {
        save_credential_list((CTAP_authDataHeader*)auth_data_buf, GA.clientDataHash, GA.creds, validCredCount-1);   // skip last one
    }
    else
    {
        printf2(TAG_ERR,"Error, no authentic credential\n");
        return CTAP2_ERR_CREDENTIAL_NOT_VALID;
    }

    printf1(TAG_RED,"resulting order of creds:\n");
    for (int j = 0; j < GA.credLen; j++)
    {
        printf1(TAG_RED,"CRED ID (# %d)\n", GA.creds[j].credential.fields.count);
    }

    {
        ret = cbor_encode_int(&map, RESP_numberOfCredentials);
        check_ret(ret);
        ret = cbor_encode_int(&map, validCredCount);
        check_ret(ret);
    }

    CTAP_credentialDescriptor * cred = &GA.creds[validCredCount - 1];

    ret = ctap_end_get_assertion(&map, cred, auth_data_buf, GA.clientDataHash);
    check_retr(ret);

    ret = cbor_encoder_close_container(encoder, &map);
    check_ret(ret);

}

uint8_t ctap_update_pin_if_verified(uint8_t * pinEnc, int len, uint8_t * platform_pubkey, uint8_t * pinAuth, uint8_t * pinHashEnc)
{
    uint8_t shared_secret[32];
    uint8_t hmac[32];
    int ret;

    if (len < 64)
    {
        return CTAP1_ERR_OTHER;
    }

    crypto_ecc256_shared_secret(platform_pubkey, KEY_AGREEMENT_PRIV, shared_secret);

    crypto_sha256_init();
    crypto_sha256_update(shared_secret, 32);
    crypto_sha256_final(shared_secret);

    crypto_sha256_hmac_init(shared_secret, 32, hmac);
    crypto_sha256_update(pinEnc, len);
    if (pinHashEnc != NULL)
    {
        crypto_sha256_update(pinHashEnc, 16);
    }
    crypto_sha256_hmac_final(shared_secret, 32, hmac);

    if (memcmp(hmac, pinAuth, 16) != 0)
    {
        printf2(TAG_ERR,"pinAuth failed for update pin\n");
        dump_hex1(TAG_ERR, hmac,16);
        dump_hex1(TAG_ERR, pinAuth,16);
        return CTAP2_ERR_PIN_AUTH_INVALID;
    }

    crypto_aes256_init(shared_secret);

    while((len & 0xf) != 0) // round up to nearest  AES block size multiple
    {
        len++;
    }

    crypto_aes256_decrypt(pinEnc, len);

    printf("new pin: %s\n", pinEnc);

    ret = strnlen(pinEnc, NEW_PIN_ENC_MAX_SIZE);
    if (ret == NEW_PIN_ENC_MAX_SIZE)
    {
        printf2(TAG_ERR,"No NULL terminator in new pin string\n");
        return CTAP1_ERR_OTHER;
    }
    else if (ret < 4)
    {
        printf2(TAG_ERR,"new PIN is too short\n");
        return CTAP2_ERR_PIN_POLICY_VIOLATION;
    }

    if (ctap_is_pin_set())
    {
        crypto_aes256_reset_iv();
        crypto_aes256_decrypt(pinHashEnc, 16);
        if (memcmp(pinHashEnc, PIN_CODE_HASH, 16) != 0)
        {
            crypto_ecc256_make_key_pair(KEY_AGREEMENT_PUB, KEY_AGREEMENT_PRIV);
            ctap_decrement_pin_attempts();
            return CTAP2_ERR_PIN_INVALID;
        }
        else
        {
            ctap_reset_pin_attempts();
        }
    }

    ctap_update_pin(pinEnc, ret);

    return 0;
}

uint8_t ctap_add_pin_if_verified(CborEncoder * map, uint8_t * platform_pubkey, uint8_t * pinHashEnc)
{
    uint8_t shared_secret[32];
    int ret;

    crypto_ecc256_shared_secret(platform_pubkey, KEY_AGREEMENT_PRIV, shared_secret);

    crypto_sha256_init();
    crypto_sha256_update(shared_secret, 32);
    crypto_sha256_final(shared_secret);

    crypto_aes256_init(shared_secret);

    crypto_aes256_decrypt(pinHashEnc, 16);


    if (memcmp(pinHashEnc, PIN_CODE_HASH, 16) != 0)
    {
        printf2(TAG_ERR,"Pin does not match!\n");
        printf2(TAG_ERR,"platform-pin-hash: "); dump_hex1(TAG_ERR, pinHashEnc, 16);
        printf2(TAG_ERR,"authentic-pin-hash: "); dump_hex1(TAG_ERR, PIN_CODE_HASH, 16);
        // Generate new keyAgreement pair
        crypto_ecc256_make_key_pair(KEY_AGREEMENT_PUB, KEY_AGREEMENT_PRIV);
        ctap_decrement_pin_attempts();
        return CTAP2_ERR_PIN_INVALID;
    }

    ctap_reset_pin_attempts();
    crypto_aes256_reset_iv();

    // reuse share_secret memory for encrypted pinToken
    memmove(shared_secret, PIN_TOKEN, PIN_TOKEN_SIZE);
    crypto_aes256_encrypt(shared_secret, PIN_TOKEN_SIZE);

    ret = cbor_encode_byte_string(map, shared_secret, PIN_TOKEN_SIZE);
    check_ret(ret);

    return 0;
}

uint8_t ctap_client_pin(CborEncoder * encoder, uint8_t * request, int length)
{
    CTAP_clientPin CP;
    CborEncoder map;
    int ret = ctap_parse_client_pin(&CP,request,length);


    if (ret != 0)
    {
        printf2(TAG_ERR,"error, parse_client_pin failed\n");
        return ret;
    }

    if (CP.pinProtocol != 1 || CP.subCommand == 0)
    {
        return CTAP1_ERR_OTHER;
    }

    int num_map = (CP.getRetries ? 1 : 0);

    switch(CP.subCommand)
    {
        case CP_cmdGetRetries:
            printf1(TAG_CP,"CP_cmdGetRetries\n");
            ret = cbor_encoder_create_map(encoder, &map, 1);
            check_ret(ret);

            CP.getRetries = 1;

            break;
        case CP_cmdGetKeyAgreement:
            printf1(TAG_CP,"CP_cmdGetKeyAgreement\n");
            num_map++;
            ret = cbor_encoder_create_map(encoder, &map, num_map);
            check_ret(ret);

            ret = cbor_encode_int(&map, RESP_keyAgreement);
            check_ret(ret);
            ret = ctap_add_cose_key(&map, KEY_AGREEMENT_PUB, KEY_AGREEMENT_PUB+32, PUB_KEY_CRED_PUB_KEY, COSE_ALG_ES256);
            check_retr(ret);

            break;
        case CP_cmdSetPin:
            printf1(TAG_CP,"CP_cmdSetPin\n");

            if (ctap_is_pin_set())
            {
                return CTAP2_ERR_NOT_ALLOWED;
            }
            if (!CP.newPinEncSize || !CP.pinAuthPresent || !CP.keyAgreementPresent)
            {
                return CTAP2_ERR_MISSING_PARAMETER;
            }

            ret = ctap_update_pin_if_verified(CP.newPinEnc, CP.newPinEncSize, (uint8_t*)&CP.keyAgreement.pubkey, CP.pinAuth, NULL);
            check_retr(ret);
            break;
        case CP_cmdChangePin:
            printf1(TAG_CP,"CP_cmdChangePin\n");

            if (! ctap_is_pin_set())
            {
                return CTAP2_ERR_PIN_NOT_SET;
            }

            if (!CP.newPinEncSize || !CP.pinAuthPresent || !CP.keyAgreementPresent || !CP.pinHashEncPresent)
            {
                return CTAP2_ERR_MISSING_PARAMETER;
            }

            ret = ctap_update_pin_if_verified(CP.newPinEnc, CP.newPinEncSize, (uint8_t*)&CP.keyAgreement.pubkey, CP.pinAuth, CP.pinHashEnc);
            check_retr(ret);
            break;
        case CP_cmdGetPinToken:
            if (!ctap_is_pin_set())
            {
                return CTAP2_ERR_PIN_NOT_SET;
            }
            num_map++;
            ret = cbor_encoder_create_map(encoder, &map, num_map);
            check_ret(ret);

            printf1(TAG_CP,"CP_cmdGetPinToken\n");
            if (CP.keyAgreementPresent == 0 || CP.pinHashEncPresent == 0)
            {
                printf2(TAG_ERR,"Error, missing keyAgreement or pinHashEnc for cmdGetPin\n");
                return CTAP2_ERR_MISSING_PARAMETER;
            }
            ret = cbor_encode_int(&map, RESP_pinToken);
            check_ret(ret);

            ret = ctap_add_pin_if_verified(&map, (uint8_t*)&CP.keyAgreement.pubkey, CP.pinHashEnc);
            check_retr(ret);

            break;

        default:
            printf2(TAG_ERR,"Error, invalid client pin subcommand\n");
            return CTAP1_ERR_OTHER;
    }

    if (CP.getRetries)
    {
        ret = cbor_encode_int(&map, RESP_retries);
        check_ret(ret);
        ret = cbor_encode_int(&map, ctap_leftover_pin_attempts());
        check_ret(ret);
    }

    if (num_map)
    {
        ret = cbor_encoder_close_container(encoder, &map);
        check_ret(ret);
    }

    return 0;
}



uint8_t ctap_handle_packet(uint8_t * pkt_raw, int length, CTAP_RESPONSE * resp)
{
    uint8_t status = 0;
    uint8_t cmd = *pkt_raw;
    pkt_raw++;
    length--;


    static uint8_t buf[1024];
    memset(buf,0,sizeof(buf));

    resp->data = buf;
    resp->length = 0;

    CborEncoder encoder;
    cbor_encoder_init(&encoder, buf, sizeof(buf), 0);

    printf1(TAG_CTAP,"cbor input structure: %d bytes\n", length);
    printf1(TAG_DUMP,"cbor req: "); dump_hex1(TAG_DUMP, pkt_raw, length);

    switch(cmd)
    {
        case CTAP_MAKE_CREDENTIAL:
        case CTAP_GET_ASSERTION:
        case CTAP_CLIENT_PIN:
            if (ctap_device_locked())
            {
                status = CTAP2_ERR_NOT_ALLOWED;
                goto done;
            }
            break;
    }

    switch(cmd)
    {
        case CTAP_MAKE_CREDENTIAL:
            printf1(TAG_CTAP,"CTAP_MAKE_CREDENTIAL\n");
            status = ctap_make_credential(&encoder, pkt_raw, length);

            dump_hex1(TAG_DUMP, buf, cbor_encoder_get_buffer_size(&encoder, buf));

            resp->length = cbor_encoder_get_buffer_size(&encoder, buf);
            break;
        case CTAP_GET_ASSERTION:
            printf1(TAG_CTAP,"CTAP_GET_ASSERTION\n");
            status = ctap_get_assertion(&encoder, pkt_raw, length);

            resp->length = cbor_encoder_get_buffer_size(&encoder, buf);

            printf1(TAG_DUMP,"cbor [%d]: \n",  cbor_encoder_get_buffer_size(&encoder, buf));
                dump_hex1(TAG_DUMP,buf, cbor_encoder_get_buffer_size(&encoder, buf));
            break;
        case CTAP_CANCEL:
            printf1(TAG_CTAP,"CTAP_CANCEL\n");
            break;
        case CTAP_GET_INFO:
            printf1(TAG_CTAP,"CTAP_GET_INFO\n");
            status = ctap_get_info(&encoder);

            resp->length = cbor_encoder_get_buffer_size(&encoder, buf);

            dump_hex1(TAG_DUMP, buf, cbor_encoder_get_buffer_size(&encoder, buf));

            break;
        case CTAP_CLIENT_PIN:
            printf1(TAG_CTAP,"CTAP_CLIENT_PIN\n");
            status = ctap_client_pin(&encoder, pkt_raw, length);
            resp->length = cbor_encoder_get_buffer_size(&encoder, buf);
            dump_hex1(TAG_DUMP, buf, cbor_encoder_get_buffer_size(&encoder, buf));
            break;
        case CTAP_RESET:
            printf1(TAG_CTAP,"CTAP_RESET\n");
            if (ctap_user_presence_test())
            {
                ctap_reset();
            }
            else
            {
                status = CTAP2_ERR_NOT_ALLOWED;
            }
            break;
        case GET_NEXT_ASSERTION:
            printf1(TAG_CTAP,"CTAP_NEXT_ASSERTION\n");
            if (getAssertionState.lastcmd == CTAP_GET_ASSERTION)
            {
                status = ctap_get_next_assertion(&encoder);
                resp->length = cbor_encoder_get_buffer_size(&encoder, buf);
                dump_hex1(TAG_DUMP, buf, cbor_encoder_get_buffer_size(&encoder, buf));
                if (status == 0)
                {
                    cmd = CTAP_GET_ASSERTION;       // allow for next assertion
                }
            }
            else
            {
                printf2(TAG_ERR, "unwanted GET_NEXT_ASSERTION\n");
                status = CTAP2_ERR_NOT_ALLOWED;
            }
            break;
        default:
            status = CTAP1_ERR_INVALID_COMMAND;
            printf2(TAG_ERR,"error, invalid cmd\n");
    }

done:
    getAssertionState.lastcmd = cmd;

    if (status != CTAP1_ERR_SUCCESS)
    {
        resp->length = 0;
    }

    printf1(TAG_CTAP,"cbor output structure: %d bytes\n", resp->length);
    return status;
}

void ctap_init()
{
    crypto_ecc256_init();
    ctap_reset_pin_attempts();

    DEVICE_LOCKOUT = 0;

    if (ctap_generate_rng(PIN_TOKEN, PIN_TOKEN_SIZE) != 1)
    {
        printf2(TAG_ERR,"Error, rng failed\n");
        exit(1);
    }

    crypto_ecc256_make_key_pair(KEY_AGREEMENT_PUB, KEY_AGREEMENT_PRIV);
}

uint8_t ctap_is_pin_set()
{
    return PIN_CODE_SET == 1;
}

uint8_t ctap_pin_matches(uint8_t * pin, int len)
{
    return memcmp(pin, PIN_CODE, len) == 0;
}


void ctap_update_pin(uint8_t * pin, int len)
{
    // TODO this should go in flash
    if (len > NEW_PIN_ENC_MAX_SIZE-1 || len < 4)
    {
        printf2(TAG_ERR, "Update pin fail length\n");
        exit(1);
    }
    memset(PIN_CODE,0,sizeof(PIN_CODE));
    memmove(PIN_CODE, pin, len);

    crypto_sha256_init();
    crypto_sha256_update(PIN_CODE, len);
    crypto_sha256_final(PIN_CODE_HASH);

    PIN_CODE_SET = 1;

    printf1(TAG_CTAP, "New pin set: %s\n", PIN_CODE);
}

// TODO flash
static int8_t _flash_tries;
uint8_t ctap_decrement_pin_attempts()
{
    if (_flash_tries > 0)
    {
        _flash_tries--;
        printf1(TAG_CP, "ATTEMPTS left: %d\n", _flash_tries);
    }
    else
    {
        DEVICE_LOCKOUT = 1;
        printf1(TAG_CP, "Device locked!\n");
        return -1;
    }
    return 0;
}

int8_t ctap_device_locked()
{
    return DEVICE_LOCKOUT == 1;
}

int8_t ctap_leftover_pin_attempts()
{
    return _flash_tries;
}

void ctap_reset_pin_attempts()
{
    _flash_tries = 8;
}

void ctap_reset()
{
    _flash_tries = 8;
    PIN_CODE_SET = 0;
    DEVICE_LOCKOUT = 0;
    memset(PIN_CODE,0,sizeof(PIN_CODE));
    memset(PIN_CODE_HASH,0,sizeof(PIN_CODE_HASH));
    crypto_ecc256_make_key_pair(KEY_AGREEMENT_PUB, KEY_AGREEMENT_PRIV);
    crypto_reset_master_secret();
}