Commit 0bce0b02 authored by Matt Caswell's avatar Matt Caswell
Browse files

Narrow the scope of local variables in tls_construct_client_key_exchange() 



This is in preparation for splitting up this over long function.

Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
parent d4450e4b

ssl/statem/statem_clnt.c

+58 −52
Original line number Diff line number Diff line
@@ -2020,20 +2020,7 @@ int tls_construct_client_key_exchange(SSL *s) 
    size_t pskhdrlen = 0;

#endif

    unsigned long alg_k;

#ifndef OPENSSL_NO_RSA

    unsigned char *q;

    EVP_PKEY *pkey = NULL;

    EVP_PKEY_CTX *pctx = NULL;

#endif

#if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)

    EVP_PKEY *ckey = NULL, *skey = NULL;

#endif

#ifndef OPENSSL_NO_EC

    unsigned char *encodedPoint = NULL;

    int encoded_pt_len = 0;

#endif

    unsigned char *pms = NULL;

    size_t pmslen = 0;



    alg_k = s->s3->tmp.new_cipher->algorithm_mkey;



    p = ssl_handshake_start(s);
@@ -2050,6 +2037,8 @@ int tls_construct_client_key_exchange(SSL *s) 
        char identity[PSK_MAX_IDENTITY_LEN + 1];

        size_t identitylen;

        unsigned char psk[PSK_MAX_PSK_LEN];

        unsigned char *tmppsk;

        char *tmpidentity;

        size_t psklen;



        if (s->psk_client_callback == NULL) {
@@ -2073,35 +2062,36 @@ int tls_construct_client_key_exchange(SSL *s) 
                   SSL_R_PSK_IDENTITY_NOT_FOUND);

            goto psk_err;

        }

        OPENSSL_free(s->s3->tmp.psk);

        s->s3->tmp.psk = OPENSSL_memdup(psk, psklen);

        OPENSSL_cleanse(psk, psklen);



        if (s->s3->tmp.psk == NULL) {

            OPENSSL_cleanse(identity, sizeof(identity));

            goto memerr;

        }



        s->s3->tmp.psklen = psklen;

        identitylen = strlen(identity);

        if (identitylen > PSK_MAX_IDENTITY_LEN) {

            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE,

                   ERR_R_INTERNAL_ERROR);

            goto psk_err;

        }

        OPENSSL_free(s->session->psk_identity);

        s->session->psk_identity = OPENSSL_strdup(identity);

        if (s->session->psk_identity == NULL) {



        tmppsk = OPENSSL_memdup(psk, psklen);

        tmpidentity = OPENSSL_strdup(identity);

        if (tmppsk == NULL || tmpidentity == NULL) {

            OPENSSL_cleanse(identity, sizeof(identity));

            OPENSSL_cleanse(psk, psklen);

            OPENSSL_clear_free(tmppsk, psklen);

            OPENSSL_clear_free(tmpidentity, identitylen);

            goto memerr;

        }



        OPENSSL_free(s->s3->tmp.psk);

        s->s3->tmp.psk = tmppsk;

        s->s3->tmp.psklen = psklen;

        OPENSSL_free(s->session->psk_identity);

        s->session->psk_identity = tmpidentity;

        s2n(identitylen, p);

        memcpy(p, identity, identitylen);

        pskhdrlen = 2 + identitylen;

        p += identitylen;

        psk_err = 0;

psk_err:

        OPENSSL_cleanse(psk, psklen);

        OPENSSL_cleanse(identity, sizeof(identity));

        if (psk_err != 0) {

            ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
@@ -2118,11 +2108,12 @@ psk_err: 
    }

#ifndef OPENSSL_NO_RSA

    else if (alg_k & (SSL_kRSA | SSL_kRSAPSK)) {

        unsigned char *q;

        EVP_PKEY *pkey = NULL;

        EVP_PKEY_CTX *pctx = NULL;

        size_t enclen;

        pmslen = SSL_MAX_MASTER_KEY_LENGTH;

        pms = OPENSSL_malloc(pmslen);

        if (pms == NULL)

            goto memerr;

        unsigned char *pms = NULL;

        size_t pmslen = 0;



        if (s->session->peer == NULL) {

            /*
@@ -2140,10 +2131,17 @@ psk_err: 
            goto err;

        }



        pmslen = SSL_MAX_MASTER_KEY_LENGTH;

        pms = OPENSSL_malloc(pmslen);

        if (pms == NULL)

            goto memerr;



        pms[0] = s->client_version >> 8;

        pms[1] = s->client_version & 0xff;

        if (RAND_bytes(pms + 2, pmslen - 2) <= 0)

        if (RAND_bytes(pms + 2, pmslen - 2) <= 0) {

            OPENSSL_clear_free(pms, pmslen);

            goto err;

        }



        q = p;

        /* Fix buf for TLS and beyond */
@@ -2152,11 +2150,15 @@ psk_err: 
        pctx = EVP_PKEY_CTX_new(pkey, NULL);

        if (pctx == NULL || EVP_PKEY_encrypt_init(pctx) <= 0

            || EVP_PKEY_encrypt(pctx, NULL, &enclen, pms, pmslen) <= 0) {

            OPENSSL_clear_free(pms, pmslen);

            EVP_PKEY_CTX_free(pctx);

            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE,

                   ERR_R_EVP_LIB);

            goto err;

        }

        if (EVP_PKEY_encrypt(pctx, p, &enclen, pms, pmslen) <= 0) {

            OPENSSL_clear_free(pms, pmslen);

            EVP_PKEY_CTX_free(pctx);

            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE,

                   SSL_R_BAD_RSA_ENCRYPT);

            goto err;
@@ -2176,12 +2178,17 @@ psk_err: 
            s2n(n, q);

            n += 2;

        }



        s->s3->tmp.pms = pms;

        s->s3->tmp.pmslen = pmslen;

    }

#endif

#ifndef OPENSSL_NO_DH

    else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {

        DH *dh_clnt = NULL;

        const BIGNUM *pub_key;

        EVP_PKEY *ckey = NULL, *skey = NULL;



        skey = s->s3->peer_tmp;

        if (skey == NULL) {

            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE,
@@ -2194,6 +2201,7 @@ psk_err: 
        if (dh_clnt == NULL || ssl_derive(s, ckey, skey) == 0) {

            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE,

                   ERR_R_INTERNAL_ERROR);

            EVP_PKEY_free(ckey);

            goto err;

        }
@@ -2211,6 +2219,9 @@ psk_err: 


#ifndef OPENSSL_NO_EC

    else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {

        unsigned char *encodedPoint = NULL;

        int encoded_pt_len = 0;

        EVP_PKEY *ckey = NULL, *skey = NULL;



        skey = s->s3->peer_tmp;

        if ((skey == NULL) || EVP_PKEY_get0_EC_KEY(skey) == NULL) {
@@ -2223,6 +2234,7 @@ psk_err: 


        if (ssl_derive(s, ckey, skey) == 0) {

            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE, ERR_R_EVP_LIB);

            EVP_PKEY_free(ckey);

            goto err;

        }
@@ -2233,6 +2245,7 @@ psk_err: 


        if (encoded_pt_len == 0) {

            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE, ERR_R_EC_LIB);

            EVP_PKEY_free(ckey);

            goto err;

        }
@@ -2263,15 +2276,13 @@ psk_err: 
        unsigned char shared_ukm[32], tmp[256];

        EVP_MD_CTX *ukm_hash;

        int dgst_nid = NID_id_GostR3411_94;

        unsigned char *pms = NULL;

        size_t pmslen = 0;



        if ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aGOST12) != 0)

            dgst_nid = NID_id_GostR3411_2012_256;





        pmslen = 32;

        pms = OPENSSL_malloc(pmslen);

        if (pms == NULL)

            goto memerr;



        /*

         * Get server sertificate PKEY and create ctx from it

         */
@@ -2295,12 +2306,17 @@ psk_err: 
         */



        /* Otherwise, generate ephemeral key pair */

        pmslen = 32;

        pms = OPENSSL_malloc(pmslen);

        if (pms == NULL)

            goto memerr;



        if (pkey_ctx == NULL

                || EVP_PKEY_encrypt_init(pkey_ctx) <= 0

                /* Generate session key */

                || RAND_bytes(pms, pmslen) <= 0) {

            EVP_PKEY_CTX_free(pkey_ctx);

            OPENSSL_clear_free(pms, pmslen);

            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE,

                   ERR_R_INTERNAL_ERROR);

            goto err;
@@ -2331,6 +2347,7 @@ psk_err: 
                                    SSL3_RANDOM_SIZE) <= 0

                || EVP_DigestFinal_ex(ukm_hash, shared_ukm, &md_len) <= 0) {

            EVP_MD_CTX_free(ukm_hash);

            OPENSSL_clear_free(pms, pmslen);

            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE,

                   ERR_R_INTERNAL_ERROR);

            goto err;
@@ -2339,6 +2356,7 @@ psk_err: 
        if (EVP_PKEY_CTX_ctrl

            (pkey_ctx, -1, EVP_PKEY_OP_ENCRYPT, EVP_PKEY_CTRL_SET_IV, 8,

             shared_ukm) < 0) {

            OPENSSL_clear_free(pms, pmslen);

            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE,

                   SSL_R_LIBRARY_BUG);

            goto err;
@@ -2350,6 +2368,7 @@ psk_err: 
        *(p++) = V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED;

        msglen = 255;

        if (EVP_PKEY_encrypt(pkey_ctx, tmp, &msglen, pms, pmslen) <= 0) {

            OPENSSL_clear_free(pms, pmslen);

            SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE,

                   SSL_R_LIBRARY_BUG);

            goto err;
@@ -2370,7 +2389,8 @@ psk_err: 
            s->s3->flags |= TLS1_FLAGS_SKIP_CERT_VERIFY;

        }

        EVP_PKEY_CTX_free(pkey_ctx);



        s->s3->tmp.pms = pms;

        s->s3->tmp.pmslen = pmslen;

    }

#endif

#ifndef OPENSSL_NO_SRP
@@ -2411,27 +2431,13 @@ psk_err: 
        goto err;

    }



    if (pms != NULL) {

        s->s3->tmp.pms = pms;

        s->s3->tmp.pmslen = pmslen;

    }



    return 1;

 memerr:

    ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);

    SSLerr(SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE, ERR_R_MALLOC_FAILURE);

 err:

    OPENSSL_clear_free(pms, pmslen);

    OPENSSL_clear_free(s->s3->tmp.pms, s->s3->tmp.pmslen);

    s->s3->tmp.pms = NULL;

#ifndef OPENSSL_NO_RSA

    EVP_PKEY_CTX_free(pctx);

#endif

#ifndef OPENSSL_NO_EC

    OPENSSL_free(encodedPoint);

#endif

#if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)

    EVP_PKEY_free(ckey);

#endif

#ifndef OPENSSL_NO_PSK

    OPENSSL_clear_free(s->s3->tmp.psk, s->s3->tmp.psklen);

    s->s3->tmp.psk = NULL;