#include <openssl/evp.h>
#include <openssl/kdf.h>
-#define TLS13_MAX_LABEL_LEN 246
+#define TLS13_MAX_LABEL_LEN 249
/* Always filled with zeros */
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)
{
- const unsigned char label_prefix[] = "tls13 ";
+ static const unsigned char label_prefix[] = "tls13 ";
EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
int ret;
size_t hkdflabellen;
size_t hashlen;
/*
- * 2 bytes for length of whole HkdfLabel + 1 byte for length of combined
- * prefix and label + bytes for the label itself + bytes for the hash
+ * 2 bytes for length of derived secret + 1 byte for length of combined
+ * prefix and label + bytes for the label itself + 1 byte length of hash
+ * + 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];
+ + 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)
|| !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;
}
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;
}
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);
}
/*
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,
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);
}
/*
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;
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;
}
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;
resumption_master_secret,
sizeof(resumption_master_secret) - 1,
hashval, hashlen, s->resumption_master_secret,
- hashlen)) {
+ hashlen, 1)) {
/* SSLfatal() already called */
goto err;
}
exporter_master_secret,
sizeof(exporter_master_secret) - 1,
hash, hashlen, s->exporter_master_secret,
- hashlen)) {
+ hashlen, 1)) {
/* SSLfatal() already called */
goto err;
}
|| 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;
|| 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;
* no test vectors so all we do is test that both sides of the communication
* produce the same results for different protocol versions.
*/
+#define SMALL_LABEL_LEN 10
+#define LONG_LABEL_LEN 249
static int test_export_key_mat(int tst)
{
int testresult = 0;
SSL_CTX *cctx = NULL, *sctx = NULL, *sctx2 = NULL;
SSL *clientssl = NULL, *serverssl = NULL;
- const char label[] = "test label";
+ const char label[LONG_LABEL_LEN + 1] = "test label";
const unsigned char context[] = "context";
const unsigned char *emptycontext = NULL;
unsigned char ckeymat1[80], ckeymat2[80], ckeymat3[80];
unsigned char skeymat1[80], skeymat2[80], skeymat3[80];
+ size_t labellen;
const int protocols[] = {
TLS1_VERSION,
TLS1_1_VERSION,
TLS1_2_VERSION,
+ TLS1_3_VERSION,
+ TLS1_3_VERSION,
TLS1_3_VERSION
};
return 1;
#endif
#ifdef OPENSSL_NO_TLS1_3
- if (tst == 3)
+ if (tst >= 3)
return 1;
#endif
if (!TEST_true(create_ssl_ctx_pair(TLS_server_method(), TLS_client_method(),
SSL_ERROR_NONE)))
goto end;
+ if (tst == 5) {
+ /*
+ * TLSv1.3 imposes a maximum label len of 249 bytes. Check we fail if we
+ * go over that.
+ */
+ if (!TEST_int_le(SSL_export_keying_material(clientssl, ckeymat1,
+ sizeof(ckeymat1), label,
+ LONG_LABEL_LEN + 1, context,
+ sizeof(context) - 1, 1), 0))
+ goto end;
+
+ testresult = 1;
+ goto end;
+ } else if (tst == 4) {
+ labellen = LONG_LABEL_LEN;
+ } else {
+ labellen = SMALL_LABEL_LEN;
+ }
+
if (!TEST_int_eq(SSL_export_keying_material(clientssl, ckeymat1,
sizeof(ckeymat1), label,
- sizeof(label) - 1, context,
+ labellen, context,
sizeof(context) - 1, 1), 1)
|| !TEST_int_eq(SSL_export_keying_material(clientssl, ckeymat2,
sizeof(ckeymat2), label,
- sizeof(label) - 1,
+ labellen,
emptycontext,
0, 1), 1)
|| !TEST_int_eq(SSL_export_keying_material(clientssl, ckeymat3,
sizeof(ckeymat3), label,
- sizeof(label) - 1,
+ labellen,
NULL, 0, 0), 1)
|| !TEST_int_eq(SSL_export_keying_material(serverssl, skeymat1,
sizeof(skeymat1), label,
- sizeof(label) - 1,
+ labellen,
context,
sizeof(context) -1, 1),
1)
|| !TEST_int_eq(SSL_export_keying_material(serverssl, skeymat2,
sizeof(skeymat2), label,
- sizeof(label) - 1,
+ labellen,
emptycontext,
0, 1), 1)
|| !TEST_int_eq(SSL_export_keying_material(serverssl, skeymat3,
sizeof(skeymat3), label,
- sizeof(label) - 1,
+ labellen,
NULL, 0, 0), 1)
/*
* Check that both sides created the same key material with the
* Check that an empty context and no context produce different results in
* protocols less than TLSv1.3. In TLSv1.3 they should be the same.
*/
- if ((tst != 3 && !TEST_mem_ne(ckeymat2, sizeof(ckeymat2), ckeymat3,
+ if ((tst < 3 && !TEST_mem_ne(ckeymat2, sizeof(ckeymat2), ckeymat3,
sizeof(ckeymat3)))
- || (tst ==3 && !TEST_mem_eq(ckeymat2, sizeof(ckeymat2), ckeymat3,
- sizeof(ckeymat3))))
+ || (tst >= 3 && !TEST_mem_eq(ckeymat2, sizeof(ckeymat2), ckeymat3,
+ sizeof(ckeymat3))))
goto end;
testresult = 1;
ADD_ALL_TESTS(test_custom_exts, 3);
#endif
ADD_ALL_TESTS(test_serverinfo, 8);
- ADD_ALL_TESTS(test_export_key_mat, 4);
+ ADD_ALL_TESTS(test_export_key_mat, 6);
#ifndef OPENSSL_NO_TLS1_3
ADD_ALL_TESTS(test_export_key_mat_early, 3);
#endif