Commit 7dc1c647 authored by Matt Caswell's avatar Matt Caswell
Browse files

Split out the PSK preamble from tls_process_key_exchange() 



The tls_process_key_exchange() function is too long. This commit starts
the process of splitting it up by moving the PSK preamble code to a
separate function.

Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
parent 02a74590

ssl/statem/statem_clnt.c

+42 −41
Original line number Diff line number Diff line
@@ -1302,19 +1302,52 @@ MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt) 
    return ret;

}



static int tls_process_ske_psk_preamble(SSL *s, int *al)

static int tls_process_ske_psk_preamble(SSL *s, PACKET *pkt, int *al)

{

#ifndef OPENSSL_NO_PSK

    PACKET psk_identity_hint;



#else

    /* PSK ciphersuites are preceded by an identity hint */



    if (!PACKET_get_length_prefixed_2(pkt, &psk_identity_hint)) {

        *al = SSL_AD_DECODE_ERROR;

        SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);

        return 0;

    }



    /*

     * Store PSK identity hint for later use, hint is used in

     * tls_construct_client_key_exchange.  Assume that the maximum length of

     * a PSK identity hint can be as long as the maximum length of a PSK

     * identity.

     */

    if (PACKET_remaining(&psk_identity_hint) > PSK_MAX_IDENTITY_LEN) {

        *al = SSL_AD_HANDSHAKE_FAILURE;

        SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_DATA_LENGTH_TOO_LONG);

        return 0;

    }



    if (PACKET_remaining(&psk_identity_hint) == 0) {

        OPENSSL_free(s->session->psk_identity_hint);

        s->session->psk_identity_hint = NULL;

    } else if (!PACKET_strndup(&psk_identity_hint,

                        &s->session->psk_identity_hint)) {

        *al = SSL_AD_INTERNAL_ERROR;

        return 0;

    }



    return 1;

#else

    SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);

    *al = SSL_AD_INTERNAL_ERROR;

    return 0;

#endif

}



MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt)

{

    EVP_MD_CTX *md_ctx;

    int al;

    int al = -1;

    long alg_k, alg_a;

    EVP_PKEY *pkey = NULL;

    PACKET save_param_start, signature;
@@ -1337,48 +1370,13 @@ MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt) 


    alg_a = s->s3->tmp.new_cipher->algorithm_auth;



    al = SSL_AD_DECODE_ERROR;



#ifndef OPENSSL_NO_PSK

    /* PSK ciphersuites are preceded by an identity hint */

    if (alg_k & SSL_PSK) {

        PACKET psk_identity_hint;

        if (!PACKET_get_length_prefixed_2(pkt, &psk_identity_hint)) {

            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_LENGTH_MISMATCH);

            goto f_err;

        }



        /*

         * Store PSK identity hint for later use, hint is used in

         * ssl3_send_client_key_exchange.  Assume that the maximum length of

         * a PSK identity hint can be as long as the maximum length of a PSK

         * identity.

         */

        if (PACKET_remaining(&psk_identity_hint) > PSK_MAX_IDENTITY_LEN) {

            al = SSL_AD_HANDSHAKE_FAILURE;

            SSLerr(SSL_F_TLS_PROCESS_KEY_EXCHANGE, SSL_R_DATA_LENGTH_TOO_LONG);

            goto f_err;

        }



        if (PACKET_remaining(&psk_identity_hint) == 0) {

            OPENSSL_free(s->session->psk_identity_hint);

            s->session->psk_identity_hint = NULL;

        } else if (!PACKET_strndup(&psk_identity_hint,

                            &s->session->psk_identity_hint)) {

            al = SSL_AD_INTERNAL_ERROR;

            goto f_err;

        }

        if (!tls_process_ske_psk_preamble(s, pkt, &al))

            goto err;

    }



    /* Nothing else to do for plain PSK or RSAPSK */

    if (alg_k & (SSL_kPSK | SSL_kRSAPSK)) {

    } else

#endif                          /* !OPENSSL_NO_PSK */

    /*

     * Dummy "if" to ensure sane C code in the event of various OPENSSL_NO_*

     * options

     */

    if (0) {

    }

#ifndef OPENSSL_NO_SRP

    else if (alg_k & SSL_kSRP) {
@@ -1678,8 +1676,11 @@ MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt) 
    EVP_MD_CTX_free(md_ctx);

    return MSG_PROCESS_CONTINUE_READING;

 f_err:

    ssl3_send_alert(s, SSL3_AL_FATAL, al);

    if (al == -1)

        al = SSL_AD_DECODE_ERROR;

 err:

    if (al != -1)

        ssl3_send_alert(s, SSL3_AL_FATAL, al);

    EVP_MD_CTX_free(md_ctx);

    ossl_statem_set_error(s);

    return MSG_PROCESS_ERROR;