diff options
Diffstat (limited to 'ssl/tls13_enc.c')
-rw-r--r-- | ssl/tls13_enc.c | 81 |
1 files changed, 48 insertions, 33 deletions
diff --git a/ssl/tls13_enc.c b/ssl/tls13_enc.c index b6825d20c2dc0..1f956e61e9c1c 100644 --- a/ssl/tls13_enc.c +++ b/ssl/tls13_enc.c @@ -1,5 +1,5 @@ /* - * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved. + * Copyright 2016-2019 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 @@ -13,14 +13,7 @@ #include <openssl/evp.h> #include <openssl/kdf.h> -/* - * RFC 8446, 7.1 Key Schedule, says: - * Note: With common hash functions, any label longer than 12 characters - * requires an additional iteration of the hash function to compute. - * The labels in this specification have all been chosen to fit within - * this limit. - */ -#define TLS13_MAX_LABEL_LEN 12 +#define TLS13_MAX_LABEL_LEN 249 /* Always filled with zeros */ static const unsigned char default_zeros[EVP_MAX_MD_SIZE]; @@ -29,12 +22,13 @@ static const unsigned char default_zeros[EVP_MAX_MD_SIZE]; * Given a |secret|; a |label| of length |labellen|; and |data| of length * |datalen| (e.g. typically a hash of the handshake messages), derive a new * secret |outlen| bytes long and store it in the location pointed to be |out|. - * The |data| value may be zero length. Returns 1 on success 0 on failure. + * The |data| value may be zero length. Any errors will be treated as fatal if + * |fatal| is set. Returns 1 on success 0 on failure. */ int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, const unsigned char *label, size_t labellen, const unsigned char *data, size_t datalen, - unsigned char *out, size_t outlen) + unsigned char *out, size_t outlen, int fatal) { static const unsigned char label_prefix[] = "tls13 "; EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); @@ -47,13 +41,28 @@ int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, * + bytes for the hash itself */ unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) + - + sizeof(label_prefix) + TLS13_MAX_LABEL_LEN - + EVP_MAX_MD_SIZE]; + + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN + + 1 + EVP_MAX_MD_SIZE]; WPACKET pkt; if (pctx == NULL) return 0; + if (labellen > TLS13_MAX_LABEL_LEN) { + if (fatal) { + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, + ERR_R_INTERNAL_ERROR); + } else { + /* + * Probably we have been called from SSL_export_keying_material(), + * or SSL_export_keying_material_early(). + */ + SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL); + } + EVP_PKEY_CTX_free(pctx); + return 0; + } + hashlen = EVP_MD_size(md); if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0) @@ -67,8 +76,11 @@ int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, || !WPACKET_finish(&pkt)) { EVP_PKEY_CTX_free(pctx); WPACKET_cleanup(&pkt); - SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, - ERR_R_INTERNAL_ERROR); + if (fatal) + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, + ERR_R_INTERNAL_ERROR); + else + SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR); return 0; } @@ -82,9 +94,13 @@ int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, EVP_PKEY_CTX_free(pctx); - if (ret != 0) - SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, - ERR_R_INTERNAL_ERROR); + if (ret != 0) { + if (fatal) + SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, + ERR_R_INTERNAL_ERROR); + else + SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR); + } return ret == 0; } @@ -99,7 +115,7 @@ int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret, static const unsigned char keylabel[] = "key"; return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1, - NULL, 0, key, keylen); + NULL, 0, key, keylen, 1); } /* @@ -112,7 +128,7 @@ int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret, static const unsigned char ivlabel[] = "iv"; return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1, - NULL, 0, iv, ivlen); + NULL, 0, iv, ivlen, 1); } int tls13_derive_finishedkey(SSL *s, const EVP_MD *md, @@ -122,7 +138,7 @@ int tls13_derive_finishedkey(SSL *s, const EVP_MD *md, static const unsigned char finishedlabel[] = "finished"; return tls13_hkdf_expand(s, md, secret, finishedlabel, - sizeof(finishedlabel) - 1, NULL, 0, fin, finlen); + sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1); } /* @@ -185,7 +201,7 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md, if (!tls13_hkdf_expand(s, md, prevsecret, (unsigned char *)derived_secret_label, sizeof(derived_secret_label) - 1, hash, mdlen, - preextractsec, mdlen)) { + preextractsec, mdlen, 1)) { /* SSLfatal() already called */ EVP_PKEY_CTX_free(pctx); return 0; @@ -307,11 +323,9 @@ int tls13_setup_key_block(SSL *s) { const EVP_CIPHER *c; const EVP_MD *hash; - int mac_type = NID_undef; s->session->cipher = s->s3->tmp.new_cipher; - if (!ssl_cipher_get_evp - (s->session, &c, &hash, &mac_type, NULL, NULL, 0)) { + if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) { SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_SETUP_KEY_BLOCK, SSL_R_CIPHER_OR_HASH_UNAVAILABLE); return 0; @@ -345,7 +359,7 @@ static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md, hashlen = (size_t)hashleni; if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen, - secret, hashlen)) { + secret, hashlen, 1)) { /* SSLfatal() already called */ goto err; } @@ -525,7 +539,8 @@ int tls13_change_cipher_state(SSL *s, int which) early_exporter_master_secret, sizeof(early_exporter_master_secret) - 1, hashval, hashlen, - s->early_exporter_master_secret, 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; @@ -612,7 +627,7 @@ int tls13_change_cipher_state(SSL *s, int which) resumption_master_secret, sizeof(resumption_master_secret) - 1, hashval, hashlen, s->resumption_master_secret, - hashlen)) { + hashlen, 1)) { /* SSLfatal() already called */ goto err; } @@ -632,7 +647,7 @@ int tls13_change_cipher_state(SSL *s, int which) exporter_master_secret, sizeof(exporter_master_secret) - 1, hash, hashlen, s->exporter_master_secret, - hashlen)) { + hashlen, 1)) { /* SSLfatal() already called */ goto err; } @@ -746,10 +761,10 @@ int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen, || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 || !tls13_hkdf_expand(s, md, s->exporter_master_secret, (const unsigned char *)label, llen, - data, datalen, exportsecret, hashsize) + data, datalen, exportsecret, hashsize, 0) || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, sizeof(exporterlabel) - 1, hash, hashsize, - out, olen)) + out, olen, 0)) goto err; ret = 1; @@ -805,10 +820,10 @@ int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen, || 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) + data, datalen, exportsecret, hashsize, 0) || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, sizeof(exporterlabel) - 1, hash, hashsize, - out, olen)) + out, olen, 0)) goto err; ret = 1; |