X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=ssl%2Ftls13_enc.c;h=55e68c60db1178d517e2023ddeafc5a156bbd846;hp=7f786e150e61ffc645752a1719a85aa5e709d16c;hb=a599574be17579496877bcdcc5e1eeaf5b014cf3;hpb=49e7fe12eac1e84af726e0110ee29073699ed46b diff --git a/ssl/tls13_enc.c b/ssl/tls13_enc.c index 7f786e150e..55e68c60db 100644 --- a/ssl/tls13_enc.c +++ b/ssl/tls13_enc.c @@ -28,7 +28,7 @@ int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, const unsigned char *hash, unsigned char *out, size_t outlen) { - const unsigned char label_prefix[] = "TLS 1.3, "; + const unsigned char label_prefix[] = "tls13 "; EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); int ret; size_t hkdflabellen; @@ -56,6 +56,7 @@ int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, || !WPACKET_sub_memcpy_u8(&pkt, hash, (hash == NULL) ? 0 : hashlen) || !WPACKET_get_total_written(&pkt, &hkdflabellen) || !WPACKET_finish(&pkt)) { + EVP_PKEY_CTX_free(pctx); WPACKET_cleanup(&pkt); return 0; } @@ -77,26 +78,26 @@ int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on * success 0 on failure. */ -int tls13_derive_key(SSL *s, const unsigned char *secret, unsigned char *key, - size_t keylen) +int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret, + unsigned char *key, size_t keylen) { static const unsigned char keylabel[] = "key"; - return tls13_hkdf_expand(s, ssl_handshake_md(s), secret, keylabel, - sizeof(keylabel) - 1, NULL, key, keylen); + return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1, + NULL, key, keylen); } /* * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on * success 0 on failure. */ -int tls13_derive_iv(SSL *s, const unsigned char *secret, unsigned char *iv, - size_t ivlen) +int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret, + unsigned char *iv, size_t ivlen) { static const unsigned char ivlabel[] = "iv"; - return tls13_hkdf_expand(s, ssl_handshake_md(s), secret, ivlabel, - sizeof(ivlabel) - 1, NULL, iv, ivlen); + return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1, + NULL, iv, ivlen); } int tls13_derive_finishedkey(SSL *s, const EVP_MD *md, @@ -123,6 +124,8 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md, size_t mdlen, prevsecretlen; int ret; EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); + static const char derived_secret_label[] = "derived"; + unsigned char preextractsec[EVP_MAX_MD_SIZE]; if (pctx == NULL) return 0; @@ -137,6 +140,29 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md, prevsecret = default_zeros; prevsecretlen = 0; } else { + EVP_MD_CTX *mctx = EVP_MD_CTX_new(); + unsigned char hash[EVP_MAX_MD_SIZE]; + + /* The pre-extract derive step uses a hash of no messages */ + if (mctx == NULL + || EVP_DigestInit_ex(mctx, md, NULL) <= 0 + || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { + EVP_MD_CTX_free(mctx); + EVP_PKEY_CTX_free(pctx); + return 0; + } + EVP_MD_CTX_free(mctx); + + /* Generate the pre-extract secret */ + if (!tls13_hkdf_expand(s, md, prevsecret, + (unsigned char *)derived_secret_label, + sizeof(derived_secret_label) - 1, hash, + preextractsec, mdlen)) { + EVP_PKEY_CTX_free(pctx); + return 0; + } + + prevsecret = preextractsec; prevsecretlen = mdlen; } @@ -151,6 +177,8 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md, <= 0; EVP_PKEY_CTX_free(pctx); + if (prevsecret == preextractsec) + OPENSSL_cleanse(preextractsec, mdlen); return ret == 0; } @@ -242,7 +270,8 @@ int tls13_setup_key_block(SSL *s) return 1; } -static int derive_secret_key_and_iv(SSL *s, int send, +static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md, + const EVP_CIPHER *ciph, const unsigned char *insecret, const unsigned char *hash, const unsigned char *label, @@ -251,9 +280,7 @@ static int derive_secret_key_and_iv(SSL *s, int send, { unsigned char key[EVP_MAX_KEY_LENGTH]; size_t ivlen, keylen, taglen; - const EVP_MD *md = ssl_handshake_md(s); size_t hashlen = EVP_MD_size(md); - const EVP_CIPHER *ciph = s->s3->tmp.new_sym_enc; if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, secret, hashlen)) { @@ -264,9 +291,16 @@ static int derive_secret_key_and_iv(SSL *s, int send, /* TODO(size_t): convert me */ keylen = EVP_CIPHER_key_length(ciph); if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) { + uint32_t algenc; + ivlen = EVP_CCM_TLS_IV_LEN; - if (s->s3->tmp.new_cipher->algorithm_enc - & (SSL_AES128CCM8 | SSL_AES256CCM8)) + if (s->s3->tmp.new_cipher == NULL) { + /* We've not selected a cipher yet - we must be doing early data */ + algenc = s->session->cipher->algorithm_enc; + } else { + algenc = s->s3->tmp.new_cipher->algorithm_enc; + } + if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8)) taglen = EVP_CCM8_TLS_TAG_LEN; else taglen = EVP_CCM_TLS_TAG_LEN; @@ -275,13 +309,13 @@ static int derive_secret_key_and_iv(SSL *s, int send, taglen = 0; } - if (!tls13_derive_key(s, secret, key, keylen) - || !tls13_derive_iv(s, secret, iv, ivlen)) { + if (!tls13_derive_key(s, md, secret, key, keylen) + || !tls13_derive_iv(s, md, secret, iv, ivlen)) { SSLerr(SSL_F_DERIVE_SECRET_KEY_AND_IV, ERR_R_INTERNAL_ERROR); goto err; } - if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, send) <= 0 + if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 0 || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL) || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG, taglen, NULL)) @@ -290,20 +324,6 @@ static int derive_secret_key_and_iv(SSL *s, int send, goto err; } -#ifdef OPENSSL_SSL_TRACE_CRYPTO - if (s->msg_callback) { - int wh = send ? 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 - return 1; err: OPENSSL_cleanse(key, sizeof(key)); @@ -312,16 +332,13 @@ static int derive_secret_key_and_iv(SSL *s, int send, 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"; + 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"; unsigned char *iv; unsigned char secret[EVP_MAX_MD_SIZE]; unsigned char hashval[EVP_MAX_MD_SIZE]; @@ -334,6 +351,8 @@ int tls13_change_cipher_state(SSL *s, int which) 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) { @@ -367,13 +386,67 @@ int tls13_change_cipher_state(SSL *s, int which) if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE)) || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) { - if (which & SSL3_CC_HANDSHAKE) { + 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) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, + SSL_R_BAD_HANDSHAKE_LENGTH); + goto err; + } + if (sslcipher == NULL) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); + 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) { + SSLerr(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)) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); + EVP_MD_CTX_free(mdctx); + goto err; + } + hashlen = hashlenui; + EVP_MD_CTX_free(mdctx); + } 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; @@ -388,6 +461,7 @@ int tls13_change_cipher_state(SSL *s, int which) 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; @@ -403,10 +477,14 @@ int tls13_change_cipher_state(SSL *s, int which) } } - 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; + 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)) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); + goto err; + } } /* @@ -416,6 +494,9 @@ int tls13_change_cipher_state(SSL *s, int which) 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 @@ -429,10 +510,20 @@ int tls13_change_cipher_state(SSL *s, int which) goto err; } s->session->master_key_length = 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, s->exporter_master_secret, hashlen)) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); + goto err; + } } - if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, insecret, hash, - label, labellen, secret, iv, ciph_ctx)) { + if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher, + insecret, hash, label, labellen, secret, iv, + ciph_ctx)) { goto err; } @@ -459,10 +550,9 @@ int tls13_change_cipher_state(SSL *s, int which) return ret; } -int tls13_update_key(SSL *s, int send) +int tls13_update_key(SSL *s, int sending) { - static const unsigned char application_traffic[] = - "application traffic secret"; + static const unsigned char application_traffic[] = "traffic upd"; const EVP_MD *md = ssl_handshake_md(s); size_t hashlen = EVP_MD_size(md); unsigned char *insecret, *iv; @@ -470,12 +560,12 @@ int tls13_update_key(SSL *s, int send) EVP_CIPHER_CTX *ciph_ctx; int ret = 0; - if (s->server == send) + if (s->server == sending) insecret = s->server_app_traffic_secret; else insecret = s->client_app_traffic_secret; - if (send) { + if (sending) { iv = s->write_iv; ciph_ctx = s->enc_write_ctx; RECORD_LAYER_reset_write_sequence(&s->rlayer); @@ -485,7 +575,9 @@ int tls13_update_key(SSL *s, int send) RECORD_LAYER_reset_read_sequence(&s->rlayer); } - if (!derive_secret_key_and_iv(s, send, insecret, NULL, application_traffic, + if (!derive_secret_key_and_iv(s, sending, ssl_handshake_md(s), + s->s3->tmp.new_sym_enc, insecret, NULL, + application_traffic, sizeof(application_traffic) - 1, secret, iv, ciph_ctx)) goto err; @@ -500,8 +592,43 @@ int tls13_update_key(SSL *s, int send) int tls13_alert_code(int code) { - if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_END_OF_EARLY_DATA) + if (code == SSL_AD_MISSING_EXTENSION) return code; return tls1_alert_code(code); } + +int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen, + const char *label, size_t llen, + const unsigned char *context, + size_t contextlen, int use_context) +{ + unsigned char exportsecret[EVP_MAX_MD_SIZE]; + static const unsigned char exporterlabel[] = "exporter"; + unsigned char hash[EVP_MAX_MD_SIZE]; + const EVP_MD *md = ssl_handshake_md(s); + EVP_MD_CTX *ctx = EVP_MD_CTX_new(); + unsigned int hashsize; + int ret = 0; + + if (ctx == NULL || !SSL_is_init_finished(s)) + goto err; + + if (!use_context) + contextlen = 0; + + if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 + || EVP_DigestUpdate(ctx, context, contextlen) <= 0 + || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 + || !tls13_hkdf_expand(s, md, s->exporter_master_secret, + (const unsigned char *)label, llen, NULL, + exportsecret, 0) + || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, + sizeof(exporterlabel) - 1, hash, out, olen)) + goto err; + + ret = 1; + err: + EVP_MD_CTX_free(ctx); + return ret; +}