Example #1
0
int tls13_derive_traffic_secret_0(SSL *ssl) {
    SSL_HANDSHAKE *hs = ssl->s3->hs;

    return derive_secret(ssl, hs->traffic_secret_0, hs->hash_len,
                         (const uint8_t *)kTLS13LabelApplicationTraffic,
                         strlen(kTLS13LabelApplicationTraffic)) &&
           ssl_log_secret(ssl, "TRAFFIC_SECRET_0", hs->traffic_secret_0,
                          hs->hash_len);
}
Example #2
0
int tls13_set_handshake_traffic(SSL *ssl) {
    SSL_HANDSHAKE *hs = ssl->s3->hs;

    uint8_t traffic_secret[EVP_MAX_MD_SIZE];
    if (!derive_secret(ssl, traffic_secret, hs->hash_len,
                       (const uint8_t *)kTLS13LabelHandshakeTraffic,
                       strlen(kTLS13LabelHandshakeTraffic)) ||
            !ssl_log_secret(ssl, "HANDSHAKE_TRAFFIC_SECRET", traffic_secret,
                            hs->hash_len) ||
            !tls13_set_traffic_key(ssl, type_handshake, evp_aead_open, traffic_secret,
                                   hs->hash_len) ||
            !tls13_set_traffic_key(ssl, type_handshake, evp_aead_seal, traffic_secret,
                                   hs->hash_len)) {
        return 0;
    }
    return 1;
}
Example #3
0
int tls13_change_cipher_state(SSL *s, int which)
{
    static const unsigned char client_early_traffic[] = "c e traffic";
    static const unsigned char client_handshake_traffic[] = "c hs traffic";
    static const unsigned char client_application_traffic[] = "c ap traffic";
    static const unsigned char server_handshake_traffic[] = "s hs traffic";
    static const unsigned char server_application_traffic[] = "s ap traffic";
    static const unsigned char exporter_master_secret[] = "exp master";
    static const unsigned char resumption_master_secret[] = "res master";
    static const unsigned char early_exporter_master_secret[] = "e exp master";
    unsigned char *iv;
    unsigned char secret[EVP_MAX_MD_SIZE];
    unsigned char hashval[EVP_MAX_MD_SIZE];
    unsigned char *hash = hashval;
    unsigned char *insecret;
    unsigned char *finsecret = NULL;
    const char *log_label = NULL;
    EVP_CIPHER_CTX *ciph_ctx;
    size_t finsecretlen = 0;
    const unsigned char *label;
    size_t labellen, hashlen = 0;
    int ret = 0;
    const EVP_MD *md = NULL;
    const EVP_CIPHER *cipher = NULL;

    if (which & SSL3_CC_READ) {
        if (s->enc_read_ctx != NULL) {
            EVP_CIPHER_CTX_reset(s->enc_read_ctx);
        } else {
            s->enc_read_ctx = EVP_CIPHER_CTX_new();
            if (s->enc_read_ctx == NULL) {
                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                         SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
                goto err;
            }
        }
        ciph_ctx = s->enc_read_ctx;
        iv = s->read_iv;

        RECORD_LAYER_reset_read_sequence(&s->rlayer);
    } else {
        s->statem.enc_write_state = ENC_WRITE_STATE_INVALID;
        if (s->enc_write_ctx != NULL) {
            EVP_CIPHER_CTX_reset(s->enc_write_ctx);
        } else {
            s->enc_write_ctx = EVP_CIPHER_CTX_new();
            if (s->enc_write_ctx == NULL) {
                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                         SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
                goto err;
            }
        }
        ciph_ctx = s->enc_write_ctx;
        iv = s->write_iv;

        RECORD_LAYER_reset_write_sequence(&s->rlayer);
    }

    if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
            || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
        if (which & SSL3_CC_EARLY) {
            EVP_MD_CTX *mdctx = NULL;
            long handlen;
            void *hdata;
            unsigned int hashlenui;
            const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session);

            insecret = s->early_secret;
            label = client_early_traffic;
            labellen = sizeof(client_early_traffic) - 1;
            log_label = CLIENT_EARLY_LABEL;

            handlen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
            if (handlen <= 0) {
                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                         SSL_F_TLS13_CHANGE_CIPHER_STATE,
                         SSL_R_BAD_HANDSHAKE_LENGTH);
                goto err;
            }

            if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
                    && s->max_early_data > 0
                    && s->session->ext.max_early_data == 0) {
                /*
                 * If we are attempting to send early data, and we've decided to
                 * actually do it but max_early_data in s->session is 0 then we
                 * must be using an external PSK.
                 */
                if (!ossl_assert(s->psksession != NULL
                        && s->max_early_data ==
                           s->psksession->ext.max_early_data)) {
                    SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                             SSL_F_TLS13_CHANGE_CIPHER_STATE,
                             ERR_R_INTERNAL_ERROR);
                    goto err;
                }
                sslcipher = SSL_SESSION_get0_cipher(s->psksession);
            }
            if (sslcipher == NULL) {
                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                         SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK);
                goto err;
            }

            /*
             * We need to calculate the handshake digest using the digest from
             * the session. We haven't yet selected our ciphersuite so we can't
             * use ssl_handshake_md().
             */
            mdctx = EVP_MD_CTX_new();
            if (mdctx == NULL) {
                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                         SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
                goto err;
            }
            cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher));
            md = ssl_md(sslcipher->algorithm2);
            if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL)
                    || !EVP_DigestUpdate(mdctx, hdata, handlen)
                    || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) {
                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                         SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
                EVP_MD_CTX_free(mdctx);
                goto err;
            }
            hashlen = hashlenui;
            EVP_MD_CTX_free(mdctx);

            if (!tls13_hkdf_expand(s, md, insecret,
                                   early_exporter_master_secret,
                                   sizeof(early_exporter_master_secret) - 1,
                                   hashval, hashlen,
                                   s->early_exporter_master_secret, hashlen,
                                   1)) {
                SSLfatal(s, SSL_AD_INTERNAL_ERROR,
                         SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
                goto err;
            }

            if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL,
                                s->early_exporter_master_secret, hashlen)) {
                /* SSLfatal() already called */
                goto err;
            }
        } else if (which & SSL3_CC_HANDSHAKE) {
            insecret = s->handshake_secret;
            finsecret = s->client_finished_secret;
            finsecretlen = EVP_MD_size(ssl_handshake_md(s));
            label = client_handshake_traffic;
            labellen = sizeof(client_handshake_traffic) - 1;
            log_label = CLIENT_HANDSHAKE_LABEL;
            /*
             * The handshake hash used for the server read/client write handshake
             * traffic secret is the same as the hash for the server
             * write/client read handshake traffic secret. However, if we
             * processed early data then we delay changing the server
             * read/client write cipher state until later, and the handshake
             * hashes have moved on. Therefore we use the value saved earlier
             * when we did the server write/client read change cipher state.
             */
            hash = s->handshake_traffic_hash;
        } else {
            insecret = s->master_secret;
            label = client_application_traffic;
            labellen = sizeof(client_application_traffic) - 1;
            log_label = CLIENT_APPLICATION_LABEL;
            /*
             * For this we only use the handshake hashes up until the server
             * Finished hash. We do not include the client's Finished, which is
             * what ssl_handshake_hash() would give us. Instead we use the
             * previously saved value.
             */
            hash = s->server_finished_hash;
        }
    } else {
        /* Early data never applies to client-read/server-write */
        if (which & SSL3_CC_HANDSHAKE) {
            insecret = s->handshake_secret;
            finsecret = s->server_finished_secret;
            finsecretlen = EVP_MD_size(ssl_handshake_md(s));
            label = server_handshake_traffic;
            labellen = sizeof(server_handshake_traffic) - 1;
            log_label = SERVER_HANDSHAKE_LABEL;
        } else {
            insecret = s->master_secret;
            label = server_application_traffic;
            labellen = sizeof(server_application_traffic) - 1;
            log_label = SERVER_APPLICATION_LABEL;
        }
    }

    if (!(which & SSL3_CC_EARLY)) {
        md = ssl_handshake_md(s);
        cipher = s->s3->tmp.new_sym_enc;
        if (!ssl3_digest_cached_records(s, 1)
                || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
            /* SSLfatal() already called */;
            goto err;
        }
    }

    /*
     * Save the hash of handshakes up to now for use when we calculate the
     * client application traffic secret
     */
    if (label == server_application_traffic)
        memcpy(s->server_finished_hash, hashval, hashlen);

    if (label == server_handshake_traffic)
        memcpy(s->handshake_traffic_hash, hashval, hashlen);

    if (label == client_application_traffic) {
        /*
         * We also create the resumption master secret, but this time use the
         * hash for the whole handshake including the Client Finished
         */
        if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
                               resumption_master_secret,
                               sizeof(resumption_master_secret) - 1,
                               hashval, hashlen, s->resumption_master_secret,
                               hashlen, 1)) {
            /* SSLfatal() already called */
            goto err;
        }
    }

    if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher,
                                  insecret, hash, label, labellen, secret, iv,
                                  ciph_ctx)) {
        /* SSLfatal() already called */
        goto err;
    }

    if (label == server_application_traffic) {
        memcpy(s->server_app_traffic_secret, secret, hashlen);
        /* Now we create the exporter master secret */
        if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
                               exporter_master_secret,
                               sizeof(exporter_master_secret) - 1,
                               hash, hashlen, s->exporter_master_secret,
                               hashlen, 1)) {
            /* SSLfatal() already called */
            goto err;
        }

        if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret,
                            hashlen)) {
            /* SSLfatal() already called */
            goto err;
        }
    } else if (label == client_application_traffic)
        memcpy(s->client_app_traffic_secret, secret, hashlen);

    if (!ssl_log_secret(s, log_label, secret, hashlen)) {
        /* SSLfatal() already called */
        goto err;
    }

    if (finsecret != NULL
            && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret,
                                         finsecret, finsecretlen)) {
        /* SSLfatal() already called */
        goto err;
    }

    if (!s->server && label == client_early_traffic)
        s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS;
    else
        s->statem.enc_write_state = ENC_WRITE_STATE_VALID;
    ret = 1;
 err:
    OPENSSL_cleanse(secret, sizeof(secret));
    return ret;
}
Example #4
0
int tls13_change_cipher_state(SSL *s, int which)
{
    static const unsigned char client_handshake_traffic[] =
        "client handshake traffic secret";
    static const unsigned char client_application_traffic[] =
        "client application traffic secret";
    static const unsigned char server_handshake_traffic[] =
        "server handshake traffic secret";
    static const unsigned char server_application_traffic[] =
        "server application traffic secret";
    static const unsigned char resumption_master_secret[] =
        "resumption master secret";
    unsigned char key[EVP_MAX_KEY_LENGTH];
    unsigned char *iv;
    unsigned char secret[EVP_MAX_MD_SIZE];
    unsigned char hashval[EVP_MAX_MD_SIZE];
    unsigned char *hash = hashval;
    unsigned char *insecret;
    unsigned char *finsecret = NULL;
    const char *log_label = NULL;
    EVP_CIPHER_CTX *ciph_ctx;
    const EVP_CIPHER *ciph = s->s3->tmp.new_sym_enc;
    size_t ivlen, keylen, finsecretlen = 0;
    const unsigned char *label;
    size_t labellen, hashlen = 0;
    int ret = 0;

    if (which & SSL3_CC_READ) {
        if (s->enc_read_ctx != NULL) {
            EVP_CIPHER_CTX_reset(s->enc_read_ctx);
        } else {
            s->enc_read_ctx = EVP_CIPHER_CTX_new();
            if (s->enc_read_ctx == NULL) {
                SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
                goto err;
            }
        }
        ciph_ctx = s->enc_read_ctx;
        iv = s->read_iv;

        RECORD_LAYER_reset_read_sequence(&s->rlayer);
    } else {
        if (s->enc_write_ctx != NULL) {
            EVP_CIPHER_CTX_reset(s->enc_write_ctx);
        } else {
            s->enc_write_ctx = EVP_CIPHER_CTX_new();
            if (s->enc_write_ctx == NULL) {
                SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
                goto err;
            }
        }
        ciph_ctx = s->enc_write_ctx;
        iv = s->write_iv;

        RECORD_LAYER_reset_write_sequence(&s->rlayer);
    }

    if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
            || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
        if (which & SSL3_CC_HANDSHAKE) {
            insecret = s->handshake_secret;
            finsecret = s->client_finished_secret;
            finsecretlen = EVP_MD_size(ssl_handshake_md(s));
            label = client_handshake_traffic;
            labellen = sizeof(client_handshake_traffic) - 1;
            log_label = CLIENT_HANDSHAKE_LABEL;
        } else {
            insecret = s->master_secret;
            label = client_application_traffic;
            labellen = sizeof(client_application_traffic) - 1;
            log_label = CLIENT_APPLICATION_LABEL;
            /*
             * For this we only use the handshake hashes up until the server
             * Finished hash. We do not include the client's Finished, which is
             * what ssl_handshake_hash() would give us. Instead we use the
             * previously saved value.
             */
            hash = s->server_finished_hash;
        }
    } else {
        if (which & SSL3_CC_HANDSHAKE) {
            insecret = s->handshake_secret;
            finsecret = s->server_finished_secret;
            finsecretlen = EVP_MD_size(ssl_handshake_md(s));
            label = server_handshake_traffic;
            labellen = sizeof(server_handshake_traffic) - 1;
            log_label = SERVER_HANDSHAKE_LABEL;
        } else {
            insecret = s->master_secret;
            label = server_application_traffic;
            labellen = sizeof(server_application_traffic) - 1;
            log_label = SERVER_APPLICATION_LABEL;
        }
    }

    if (!ssl3_digest_cached_records(s, 1)
            || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) {
        SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
        goto err;
    }

    /*
     * Save the hash of handshakes up to now for use when we calculate the
     * client application traffic secret
     */
    if (label == server_application_traffic)
        memcpy(s->server_finished_hash, hashval, hashlen);

    if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, label, labellen,
                           hash, secret, hashlen)) {
        SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
        goto err;
    }

    if (label == client_application_traffic) {
        /*
         * We also create the resumption master secret, but this time use the
         * hash for the whole handshake including the Client Finished
         */
        if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
                               resumption_master_secret,
                               sizeof(resumption_master_secret) - 1,
                               hashval, s->session->master_key, hashlen)) {
            SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
            goto err;
        }
        s->session->master_key_length = hashlen;
    }

    /* TODO(size_t): convert me */
    keylen = EVP_CIPHER_key_length(ciph);
    ivlen = EVP_CIPHER_iv_length(ciph);

    if (!ssl_log_secret(s, log_label, secret, hashlen)) {
        SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
        goto err;
    }

    if (!tls13_derive_key(s, secret, key, keylen)
            || !tls13_derive_iv(s, secret, iv, ivlen)
            || (finsecret != NULL && !tls13_derive_finishedkey(s,
                                                           ssl_handshake_md(s),
                                                           secret,
                                                           finsecret,
                                                           finsecretlen))) {
        SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
        goto err;
    }

    if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, key, NULL,
                          (which & SSL3_CC_WRITE)) <= 0) {
        SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_EVP_LIB);
        goto err;
    }

#ifdef OPENSSL_SSL_TRACE_CRYPTO
    if (s->msg_callback) {
        int wh = which & SSL3_CC_WRITE ? TLS1_RT_CRYPTO_WRITE : 0;

        if (ciph->key_len)
            s->msg_callback(2, s->version, wh | TLS1_RT_CRYPTO_KEY,
                            key, ciph->key_len, s, s->msg_callback_arg);

        wh |= TLS1_RT_CRYPTO_IV;
        s->msg_callback(2, s->version, wh, iv, ivlen, s,
                        s->msg_callback_arg);
    }
#endif

    ret = 1;
 err:
    OPENSSL_cleanse(secret, sizeof(secret));
    OPENSSL_cleanse(key, sizeof(key));
    return ret;
}