wbrawner/openssl
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Update tls13_hkdf_expand() to take the length of the data

Browse source 
In most scenarios the length of the input data is the hashsize, or 0 if
the data is NULL. However with the new ticket_nonce changes the length can
be different.

Reviewed-by: Ben Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/3852)
This commit is contained in:
Matt Caswell 2017-07-05 11:23:16 +01:00
parent de2f409ef9
commit a19ae67d8d
4 changed files with 23 additions and 20 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
ssl/ssl_locl.h
View file

@ -2265,7 +2265,7 @@ __owur int tls13_update_key(SSL *s, int send);
__owur int tls13_hkdf_expand(SSL *s, const EVP_MD *md,
const unsigned char *secret,
const unsigned char *label, size_t labellen,
const unsigned char *hash,
const unsigned char *data, size_t datalen,
unsigned char *out, size_t outlen);
__owur int tls13_derive_key(SSL *s, const EVP_MD *md,
const unsigned char *secret, unsigned char *key,

2
ssl/statem/extensions.c
View file

@ -1280,7 +1280,7 @@ int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart,
/* Generate the binder key */
if (!tls13_hkdf_expand(s, md, early_secret, (unsigned char *)label,
labelsize, hash, binderkey, hashsize)) {
labelsize, hash, hashsize, binderkey, hashsize)) {
SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR);
goto err;
}

35
ssl/tls13_enc.c
View file

@ -18,14 +18,14 @@
static const unsigned char default_zeros[EVP_MAX_MD_SIZE];
/*
* Given a |secret|; a |label| of length |labellen|; and a |hash| of the
* handshake messages, derive a new secret |outlen| bytes long and store it in
* the location pointed to be |out|. The |hash| value may be NULL. Returns 1 on
* success 0 on failure.
* 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.
*/
int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
const unsigned char *label, size_t labellen,
const unsigned char *hash,
const unsigned char *data, size_t datalen,
unsigned char *out, size_t outlen)
{
const unsigned char label_prefix[] = "tls13 ";
@ -53,7 +53,7 @@ int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret,
|| !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1)
|| !WPACKET_memcpy(&pkt, label, labellen)
|| !WPACKET_close(&pkt)
|| !WPACKET_sub_memcpy_u8(&pkt, hash, (hash == NULL) ? 0 : hashlen)
|| !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen)
|| !WPACKET_get_total_written(&pkt, &hkdflabellen)
|| !WPACKET_finish(&pkt)) {
EVP_PKEY_CTX_free(pctx);
@ -84,7 +84,7 @@ 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, key, keylen);
NULL, 0, key, keylen);
}
/*
@ -97,7 +97,7 @@ 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, iv, ivlen);
NULL, 0, iv, ivlen);
}
int tls13_derive_finishedkey(SSL *s, const EVP_MD *md,
@ -107,7 +107,7 @@ 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, fin, finlen);
sizeof(finishedlabel) - 1, NULL, 0, fin, finlen);
}
/*
@ -156,7 +156,7 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md,
/* Generate the pre-extract secret */
if (!tls13_hkdf_expand(s, md, prevsecret,
(unsigned char *)derived_secret_label,
sizeof(derived_secret_label) - 1, hash,
sizeof(derived_secret_label) - 1, hash, mdlen,
preextractsec, mdlen)) {
EVP_PKEY_CTX_free(pctx);
return 0;
@ -282,8 +282,8 @@ static int derive_secret_key_and_iv(SSL *s, int sending, const EVP_MD *md,
size_t ivlen, keylen, taglen;
size_t hashlen = EVP_MD_size(md);
if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, secret,
hashlen)) {
if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
secret, hashlen)) {
SSLerr(SSL_F_DERIVE_SECRET_KEY_AND_IV, ERR_R_INTERNAL_ERROR);
goto err;
}
@ -505,7 +505,8 @@ int tls13_change_cipher_state(SSL *s, int which)
if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
resumption_master_secret,
sizeof(resumption_master_secret) - 1,
hashval, s->session->master_key, hashlen)) {
hashval, hashlen, s->session->master_key,
hashlen)) {
SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
goto err;
}
@ -515,7 +516,8 @@ int tls13_change_cipher_state(SSL *s, int which)
if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret,
exporter_master_secret,
sizeof(exporter_master_secret) - 1,
hash, s->exporter_master_secret, hashlen)) {
hash, hashlen, s->exporter_master_secret,
hashlen)) {
SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
goto err;
}
@ -621,10 +623,11 @@ int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen,
|| 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,
(const unsigned char *)label, llen, NULL, 0,
exportsecret, hashsize)
|| !tls13_hkdf_expand(s, md, exportsecret, exporterlabel,
sizeof(exporterlabel) - 1, hash, out, olen))
sizeof(exporterlabel) - 1, hash, hashsize,
out, olen))
goto err;
ret = 1;

4
test/tls13secretstest.c
View file

@ -226,8 +226,8 @@ static int test_secret(SSL *s, unsigned char *prk,
return 0;
}
if (!tls13_hkdf_expand(s, md, prk, label, labellen, hash, gensecret,
hashsize)) {
if (!tls13_hkdf_expand(s, md, prk, label, labellen, hash, hashsize,
gensecret, hashsize)) {
TEST_error("Secret generation failed");
return 0;
}