X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=ssl%2Ftls13_enc.c;h=5982c8e93d14e125e6de399be9b1480ffc54014f;hp=05355fb71438dece88d46baf4287ee54ce7c70b2;hb=aa2ed504ea9d55be6e75a9647d874709dc71823b;hpb=1f5878b8e25a785dde330bf485e6ed5a6ae09a1a diff --git a/ssl/tls13_enc.c b/ssl/tls13_enc.c index 05355fb714..5982c8e93d 100644 --- a/ssl/tls13_enc.c +++ b/ssl/tls13_enc.c @@ -1,5 +1,5 @@ /* - * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved. + * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the OpenSSL license (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy @@ -365,6 +365,7 @@ int tls13_change_cipher_state(SSL *s, int which) 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]; @@ -405,6 +406,7 @@ int tls13_change_cipher_state(SSL *s, int which) SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); goto err; } + EVP_CIPHER_CTX_ctrl(s->enc_write_ctx, EVP_CTRL_SET_DRBG, 0, s->drbg); } ciph_ctx = s->enc_write_ctx; iv = s->write_iv; @@ -481,6 +483,16 @@ int tls13_change_cipher_state(SSL *s, int which) } 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)) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, + SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); + goto err; + } } else if (which & SSL3_CC_HANDSHAKE) { insecret = s->handshake_secret; finsecret = s->client_finished_secret; @@ -690,3 +702,62 @@ int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen, EVP_MD_CTX_free(ctx); return ret; } + +int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen, + const char *label, size_t llen, + const unsigned char *context, + size_t contextlen) +{ + static const unsigned char exporterlabel[] = "exporter"; + unsigned char exportsecret[EVP_MAX_MD_SIZE]; + unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; + const EVP_MD *md; + EVP_MD_CTX *ctx = EVP_MD_CTX_new(); + unsigned int hashsize, datalen; + int ret = 0; + const SSL_CIPHER *sslcipher; + + if (ctx == NULL || !ossl_statem_export_early_allowed(s)) + goto err; + + if (!s->server && s->max_early_data > 0 + && s->session->ext.max_early_data == 0) + sslcipher = SSL_SESSION_get0_cipher(s->psksession); + else + sslcipher = SSL_SESSION_get0_cipher(s->session); + + md = ssl_md(sslcipher->algorithm2); + + /* + * Calculate the hash value and store it in |data|. The reason why + * the empty string is used is that the definition of TLS-Exporter + * is like so: + * + * TLS-Exporter(label, context_value, key_length) = + * HKDF-Expand-Label(Derive-Secret(Secret, label, ""), + * "exporter", Hash(context_value), key_length) + * + * Derive-Secret(Secret, Label, Messages) = + * HKDF-Expand-Label(Secret, Label, + * Transcript-Hash(Messages), Hash.length) + * + * Here Transcript-Hash is the cipher suite hash algorithm. + */ + if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 + || EVP_DigestUpdate(ctx, context, contextlen) <= 0 + || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 + || EVP_DigestInit_ex(ctx, md, NULL) <= 0 + || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 + || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret, + (const unsigned char *)label, llen, + data, datalen, exportsecret, hashsize) + || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, + sizeof(exporterlabel) - 1, hash, hashsize, + out, olen)) + goto err; + + ret = 1; + err: + EVP_MD_CTX_free(ctx); + return ret; +}