Switch tls13_enc.cc to spans.
The callers become filled with MakeConstSpans, but the various TLS 1.3
secrets will get fixed in a subsequent CL. We do still need a better
pattern for the EVP_MAX_MD_SIZE buffers.
Change-Id: Ide9c173bf0760ecdb8cc45e63969457c20310de2
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/37125
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
diff --git a/ssl/handshake_client.cc b/ssl/handshake_client.cc
index e1a506a..e1b6afe 100644
--- a/ssl/handshake_client.cc
+++ b/ssl/handshake_client.cc
@@ -456,11 +456,13 @@
return ssl_hs_error;
}
- if (!tls13_init_early_key_schedule(hs, ssl->session->master_key,
- ssl->session->master_key_length) ||
+ if (!tls13_init_early_key_schedule(
+ hs, MakeConstSpan(ssl->session->master_key,
+ ssl->session->master_key_length)) ||
!tls13_derive_early_secrets(hs) ||
- !tls13_set_traffic_key(ssl, ssl_encryption_early_data, evp_aead_seal,
- hs->early_traffic_secret, hs->hash_len)) {
+ !tls13_set_traffic_key(
+ ssl, ssl_encryption_early_data, evp_aead_seal,
+ MakeConstSpan(hs->early_traffic_secret, hs->hash_len))) {
return ssl_hs_error;
}
diff --git a/ssl/internal.h b/ssl/internal.h
index 580cf6e..621052f 100644
--- a/ssl/internal.h
+++ b/ssl/internal.h
@@ -1248,26 +1248,22 @@
// tls13_init_key_schedule initializes the handshake hash and key derivation
// state, and incorporates the PSK. The cipher suite and PRF hash must have been
// selected at this point. It returns true on success and false on error.
-bool tls13_init_key_schedule(SSL_HANDSHAKE *hs, const uint8_t *psk,
- size_t psk_len);
+bool tls13_init_key_schedule(SSL_HANDSHAKE *hs, Span<const uint8_t> psk);
// tls13_init_early_key_schedule initializes the handshake hash and key
// derivation state from the resumption secret and incorporates the PSK to
// derive the early secrets. It returns one on success and zero on error.
-bool tls13_init_early_key_schedule(SSL_HANDSHAKE *hs, const uint8_t *psk,
- size_t psk_len);
+bool tls13_init_early_key_schedule(SSL_HANDSHAKE *hs, Span<const uint8_t> psk);
// tls13_advance_key_schedule incorporates |in| into the key schedule with
// HKDF-Extract. It returns true on success and false on error.
-bool tls13_advance_key_schedule(SSL_HANDSHAKE *hs, const uint8_t *in,
- size_t len);
+bool tls13_advance_key_schedule(SSL_HANDSHAKE *hs, Span<const uint8_t> in);
// tls13_set_traffic_key sets the read or write traffic keys to
// |traffic_secret|. It returns true on success and false on error.
bool tls13_set_traffic_key(SSL *ssl, enum ssl_encryption_level_t level,
enum evp_aead_direction_t direction,
- const uint8_t *traffic_secret,
- size_t traffic_secret_len);
+ Span<const uint8_t> traffic_secret);
// tls13_derive_early_secrets derives the early traffic secret. It returns true
// on success and false on error.
diff --git a/ssl/tls13_client.cc b/ssl/tls13_client.cc
index f411e19..ba7dc55 100644
--- a/ssl/tls13_client.cc
+++ b/ssl/tls13_client.cc
@@ -365,11 +365,12 @@
// Set up the key schedule and incorporate the PSK into the running secret.
if (ssl->s3->session_reused) {
- if (!tls13_init_key_schedule(hs, hs->new_session->master_key,
- hs->new_session->master_key_length)) {
+ if (!tls13_init_key_schedule(
+ hs, MakeConstSpan(hs->new_session->master_key,
+ hs->new_session->master_key_length))) {
return ssl_hs_error;
}
- } else if (!tls13_init_key_schedule(hs, kZeroes, hash_len)) {
+ } else if (!tls13_init_key_schedule(hs, MakeConstSpan(kZeroes, hash_len))) {
return ssl_hs_error;
}
@@ -389,18 +390,21 @@
return ssl_hs_error;
}
- if (!tls13_advance_key_schedule(hs, dhe_secret.data(), dhe_secret.size()) ||
- !ssl_hash_message(hs, msg) || !tls13_derive_handshake_secrets(hs) ||
- !tls13_set_traffic_key(ssl, ssl_encryption_handshake, evp_aead_open,
- hs->server_handshake_secret, hs->hash_len)) {
+ if (!tls13_advance_key_schedule(hs, dhe_secret) ||
+ !ssl_hash_message(hs, msg) ||
+ !tls13_derive_handshake_secrets(hs) ||
+ !tls13_set_traffic_key(
+ ssl, ssl_encryption_handshake, evp_aead_open,
+ MakeConstSpan(hs->server_handshake_secret, hs->hash_len))) {
return ssl_hs_error;
}
if (!hs->early_data_offered) {
// If not sending early data, set client traffic keys now so that alerts are
// encrypted.
- if (!tls13_set_traffic_key(ssl, ssl_encryption_handshake, evp_aead_seal,
- hs->client_handshake_secret, hs->hash_len)) {
+ if (!tls13_set_traffic_key(
+ ssl, ssl_encryption_handshake, evp_aead_seal,
+ MakeConstSpan(hs->client_handshake_secret, hs->hash_len))) {
return ssl_hs_error;
}
}
@@ -615,7 +619,7 @@
!tls13_process_finished(hs, msg, false /* don't use saved value */) ||
!ssl_hash_message(hs, msg) ||
// Update the secret to the master secret and derive traffic keys.
- !tls13_advance_key_schedule(hs, kZeroes, hs->hash_len) ||
+ !tls13_advance_key_schedule(hs, MakeConstSpan(kZeroes, hs->hash_len)) ||
!tls13_derive_application_secrets(hs)) {
return ssl_hs_error;
}
@@ -640,8 +644,9 @@
}
if (hs->early_data_offered) {
- if (!tls13_set_traffic_key(ssl, ssl_encryption_handshake, evp_aead_seal,
- hs->client_handshake_secret, hs->hash_len)) {
+ if (!tls13_set_traffic_key(
+ ssl, ssl_encryption_handshake, evp_aead_seal,
+ MakeConstSpan(hs->client_handshake_secret, hs->hash_len))) {
return ssl_hs_error;
}
}
@@ -735,10 +740,12 @@
}
// Derive the final keys and enable them.
- if (!tls13_set_traffic_key(ssl, ssl_encryption_application, evp_aead_open,
- hs->server_traffic_secret_0, hs->hash_len) ||
- !tls13_set_traffic_key(ssl, ssl_encryption_application, evp_aead_seal,
- hs->client_traffic_secret_0, hs->hash_len) ||
+ if (!tls13_set_traffic_key(
+ ssl, ssl_encryption_application, evp_aead_open,
+ MakeConstSpan(hs->server_traffic_secret_0, hs->hash_len)) ||
+ !tls13_set_traffic_key(
+ ssl, ssl_encryption_application, evp_aead_seal,
+ MakeConstSpan(hs->client_traffic_secret_0, hs->hash_len)) ||
!tls13_derive_resumption_secret(hs)) {
return ssl_hs_error;
}
diff --git a/ssl/tls13_enc.cc b/ssl/tls13_enc.cc
index 7a98128..19ae052 100644
--- a/ssl/tls13_enc.cc
+++ b/ssl/tls13_enc.cc
@@ -33,7 +33,7 @@
BSSL_NAMESPACE_BEGIN
static bool init_key_schedule(SSL_HANDSHAKE *hs, uint16_t version,
- const SSL_CIPHER *cipher) {
+ const SSL_CIPHER *cipher) {
if (!hs->transcript.InitHash(version, cipher)) {
return false;
}
@@ -47,57 +47,58 @@
return true;
}
-bool tls13_init_key_schedule(SSL_HANDSHAKE *hs, const uint8_t *psk,
- size_t psk_len) {
+bool tls13_init_key_schedule(SSL_HANDSHAKE *hs, Span<const uint8_t> psk) {
if (!init_key_schedule(hs, ssl_protocol_version(hs->ssl), hs->new_cipher)) {
return false;
}
hs->transcript.FreeBuffer();
- return HKDF_extract(hs->secret, &hs->hash_len, hs->transcript.Digest(), psk,
- psk_len, hs->secret, hs->hash_len);
+ return HKDF_extract(hs->secret, &hs->hash_len, hs->transcript.Digest(),
+ psk.data(), psk.size(), hs->secret, hs->hash_len);
}
-bool tls13_init_early_key_schedule(SSL_HANDSHAKE *hs, const uint8_t *psk,
- size_t psk_len) {
+bool tls13_init_early_key_schedule(SSL_HANDSHAKE *hs, Span<const uint8_t> psk) {
SSL *const ssl = hs->ssl;
return init_key_schedule(hs, ssl_session_protocol_version(ssl->session.get()),
ssl->session->cipher) &&
- HKDF_extract(hs->secret, &hs->hash_len, hs->transcript.Digest(), psk,
- psk_len, hs->secret, hs->hash_len);
+ HKDF_extract(hs->secret, &hs->hash_len, hs->transcript.Digest(),
+ psk.data(), psk.size(), hs->secret, hs->hash_len);
}
-static bool hkdf_expand_label(uint8_t *out, const EVP_MD *digest,
- const uint8_t *secret, size_t secret_len,
- const char *label, size_t label_len,
- const uint8_t *hash, size_t hash_len,
- size_t len) {
- static const char kTLS13ProtocolLabel[] = "tls13 ";
+static Span<const char> label_to_span(const char *label) {
+ return MakeConstSpan(label, strlen(label));
+}
+static bool hkdf_expand_label(Span<uint8_t> out, const EVP_MD *digest,
+ Span<const uint8_t> secret,
+ Span<const char> label,
+ Span<const uint8_t> hash) {
+ Span<const char> protocol_label = label_to_span("tls13 ");
ScopedCBB cbb;
CBB child;
Array<uint8_t> hkdf_label;
- if (!CBB_init(cbb.get(), 2 + 1 + strlen(kTLS13ProtocolLabel) + label_len + 1 +
- hash_len) ||
- !CBB_add_u16(cbb.get(), len) ||
+ if (!CBB_init(cbb.get(), 2 + 1 + protocol_label.size() + label.size() + 1 +
+ hash.size()) ||
+ !CBB_add_u16(cbb.get(), out.size()) ||
!CBB_add_u8_length_prefixed(cbb.get(), &child) ||
- !CBB_add_bytes(&child, (const uint8_t *)kTLS13ProtocolLabel,
- strlen(kTLS13ProtocolLabel)) ||
- !CBB_add_bytes(&child, (const uint8_t *)label, label_len) ||
+ !CBB_add_bytes(&child,
+ reinterpret_cast<const uint8_t *>(protocol_label.data()),
+ protocol_label.size()) ||
+ !CBB_add_bytes(&child, reinterpret_cast<const uint8_t *>(label.data()),
+ label.size()) ||
!CBB_add_u8_length_prefixed(cbb.get(), &child) ||
- !CBB_add_bytes(&child, hash, hash_len) ||
+ !CBB_add_bytes(&child, hash.data(), hash.size()) ||
!CBBFinishArray(cbb.get(), &hkdf_label)) {
return false;
}
- return HKDF_expand(out, len, digest, secret, secret_len, hkdf_label.data(),
- hkdf_label.size());
+ return HKDF_expand(out.data(), out.size(), digest, secret.data(),
+ secret.size(), hkdf_label.data(), hkdf_label.size());
}
static const char kTLS13LabelDerived[] = "derived";
-bool tls13_advance_key_schedule(SSL_HANDSHAKE *hs, const uint8_t *in,
- size_t len) {
+bool tls13_advance_key_schedule(SSL_HANDSHAKE *hs, Span<const uint8_t> in) {
uint8_t derive_context[EVP_MAX_MD_SIZE];
unsigned derive_context_len;
if (!EVP_Digest(nullptr, 0, derive_context, &derive_context_len,
@@ -105,45 +106,41 @@
return false;
}
- if (!hkdf_expand_label(hs->secret, hs->transcript.Digest(), hs->secret,
- hs->hash_len, kTLS13LabelDerived,
- strlen(kTLS13LabelDerived), derive_context,
- derive_context_len, hs->hash_len)) {
+ if (!hkdf_expand_label(MakeSpan(hs->secret, hs->hash_len),
+ hs->transcript.Digest(),
+ MakeConstSpan(hs->secret, hs->hash_len),
+ label_to_span(kTLS13LabelDerived),
+ MakeConstSpan(derive_context, derive_context_len))) {
return false;
}
- return HKDF_extract(hs->secret, &hs->hash_len, hs->transcript.Digest(), in,
- len, hs->secret, hs->hash_len);
+ return HKDF_extract(hs->secret, &hs->hash_len, hs->transcript.Digest(),
+ in.data(), in.size(), hs->secret, hs->hash_len);
}
-// derive_secret derives a secret of length |len| and writes the result in |out|
-// with the given label and the current base secret and most recently-saved
-// handshake context. It returns true on success and false on error.
-static bool derive_secret(SSL_HANDSHAKE *hs, uint8_t *out, size_t len,
- const char *label, size_t label_len) {
+// derive_secret derives a secret of length |out.size()| and writes the result
+// in |out| with the given label, the current base secret, and the most
+// recently-saved handshake context. It returns true on success and false on
+// error.
+static bool derive_secret(SSL_HANDSHAKE *hs, Span<uint8_t> out,
+ Span<const char> label) {
uint8_t context_hash[EVP_MAX_MD_SIZE];
size_t context_hash_len;
if (!hs->transcript.GetHash(context_hash, &context_hash_len)) {
return false;
}
- return hkdf_expand_label(out, hs->transcript.Digest(), hs->secret,
- hs->hash_len, label, label_len, context_hash,
- context_hash_len, len);
+ return hkdf_expand_label(out, hs->transcript.Digest(),
+ MakeConstSpan(hs->secret, hs->hash_len), label,
+ MakeConstSpan(context_hash, context_hash_len));
}
bool tls13_set_traffic_key(SSL *ssl, enum ssl_encryption_level_t level,
enum evp_aead_direction_t direction,
- const uint8_t *traffic_secret,
- size_t traffic_secret_len) {
+ Span<const uint8_t> traffic_secret) {
const SSL_SESSION *session = SSL_get_session(ssl);
uint16_t version = ssl_session_protocol_version(session);
- if (traffic_secret_len > 0xff) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
- return false;
- }
-
UniquePtr<SSLAEADContext> traffic_aead;
if (ssl->quic_method == nullptr) {
// Look up cipher suite properties.
@@ -158,25 +155,26 @@
// Derive the key.
size_t key_len = EVP_AEAD_key_length(aead);
- uint8_t key[EVP_AEAD_MAX_KEY_LENGTH];
- if (!hkdf_expand_label(key, digest, traffic_secret, traffic_secret_len,
- "key", 3, NULL, 0, key_len)) {
+ uint8_t key_buf[EVP_AEAD_MAX_KEY_LENGTH];
+ auto key = MakeSpan(key_buf, key_len);
+ if (!hkdf_expand_label(key, digest, traffic_secret, label_to_span("key"),
+ {})) {
return false;
}
// Derive the IV.
size_t iv_len = EVP_AEAD_nonce_length(aead);
- uint8_t iv[EVP_AEAD_MAX_NONCE_LENGTH];
- if (!hkdf_expand_label(iv, digest, traffic_secret, traffic_secret_len, "iv",
- 2, NULL, 0, iv_len)) {
+ uint8_t iv_buf[EVP_AEAD_MAX_NONCE_LENGTH];
+ auto iv = MakeSpan(iv_buf, iv_len);
+ if (!hkdf_expand_label(iv, digest, traffic_secret, label_to_span("iv"),
+ {})) {
return false;
}
- traffic_aead = SSLAEADContext::Create(
- direction, session->ssl_version, SSL_is_dtls(ssl), session->cipher,
- MakeConstSpan(key, key_len), Span<const uint8_t>(),
- MakeConstSpan(iv, iv_len));
+ traffic_aead = SSLAEADContext::Create(direction, session->ssl_version,
+ SSL_is_dtls(ssl), session->cipher,
+ key, Span<const uint8_t>(), iv);
} else {
// Install a placeholder SSLAEADContext so that SSL accessors work. The
// encryption itself will be handled by the SSL_QUIC_METHOD.
@@ -199,15 +197,22 @@
}
// Save the traffic secret.
+ if (traffic_secret.size() >
+ OPENSSL_ARRAY_SIZE(ssl->s3->read_traffic_secret) ||
+ traffic_secret.size() >
+ OPENSSL_ARRAY_SIZE(ssl->s3->write_traffic_secret)) {
+ OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
+ return false;
+ }
if (direction == evp_aead_open) {
- OPENSSL_memmove(ssl->s3->read_traffic_secret, traffic_secret,
- traffic_secret_len);
- ssl->s3->read_traffic_secret_len = traffic_secret_len;
+ OPENSSL_memmove(ssl->s3->read_traffic_secret, traffic_secret.data(),
+ traffic_secret.size());
+ ssl->s3->read_traffic_secret_len = traffic_secret.size();
ssl->s3->read_level = level;
} else {
- OPENSSL_memmove(ssl->s3->write_traffic_secret, traffic_secret,
- traffic_secret_len);
- ssl->s3->write_traffic_secret_len = traffic_secret_len;
+ OPENSSL_memmove(ssl->s3->write_traffic_secret, traffic_secret.data(),
+ traffic_secret.size());
+ ssl->s3->write_traffic_secret_len = traffic_secret.size();
ssl->s3->write_level = level;
}
@@ -225,9 +230,8 @@
bool tls13_derive_early_secrets(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
- if (!derive_secret(hs, hs->early_traffic_secret, hs->hash_len,
- kTLS13LabelClientEarlyTraffic,
- strlen(kTLS13LabelClientEarlyTraffic)) ||
+ if (!derive_secret(hs, MakeSpan(hs->early_traffic_secret, hs->hash_len),
+ label_to_span(kTLS13LabelClientEarlyTraffic)) ||
!ssl_log_secret(ssl, "CLIENT_EARLY_TRAFFIC_SECRET",
hs->early_traffic_secret, hs->hash_len)) {
return false;
@@ -256,14 +260,12 @@
bool tls13_derive_handshake_secrets(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
- if (!derive_secret(hs, hs->client_handshake_secret, hs->hash_len,
- kTLS13LabelClientHandshakeTraffic,
- strlen(kTLS13LabelClientHandshakeTraffic)) ||
+ if (!derive_secret(hs, MakeSpan(hs->client_handshake_secret, hs->hash_len),
+ label_to_span(kTLS13LabelClientHandshakeTraffic)) ||
!ssl_log_secret(ssl, "CLIENT_HANDSHAKE_TRAFFIC_SECRET",
hs->client_handshake_secret, hs->hash_len) ||
- !derive_secret(hs, hs->server_handshake_secret, hs->hash_len,
- kTLS13LabelServerHandshakeTraffic,
- strlen(kTLS13LabelServerHandshakeTraffic)) ||
+ !derive_secret(hs, MakeSpan(hs->server_handshake_secret, hs->hash_len),
+ label_to_span(kTLS13LabelServerHandshakeTraffic)) ||
!ssl_log_secret(ssl, "SERVER_HANDSHAKE_TRAFFIC_SECRET",
hs->server_handshake_secret, hs->hash_len)) {
return false;
@@ -293,18 +295,16 @@
bool tls13_derive_application_secrets(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
ssl->s3->exporter_secret_len = hs->hash_len;
- if (!derive_secret(hs, hs->client_traffic_secret_0, hs->hash_len,
- kTLS13LabelClientApplicationTraffic,
- strlen(kTLS13LabelClientApplicationTraffic)) ||
+ if (!derive_secret(hs, MakeSpan(hs->client_traffic_secret_0, hs->hash_len),
+ label_to_span(kTLS13LabelClientApplicationTraffic)) ||
!ssl_log_secret(ssl, "CLIENT_TRAFFIC_SECRET_0",
hs->client_traffic_secret_0, hs->hash_len) ||
- !derive_secret(hs, hs->server_traffic_secret_0, hs->hash_len,
- kTLS13LabelServerApplicationTraffic,
- strlen(kTLS13LabelServerApplicationTraffic)) ||
+ !derive_secret(hs, MakeSpan(hs->server_traffic_secret_0, hs->hash_len),
+ label_to_span(kTLS13LabelServerApplicationTraffic)) ||
!ssl_log_secret(ssl, "SERVER_TRAFFIC_SECRET_0",
hs->server_traffic_secret_0, hs->hash_len) ||
- !derive_secret(hs, ssl->s3->exporter_secret, hs->hash_len,
- kTLS13LabelExporter, strlen(kTLS13LabelExporter)) ||
+ !derive_secret(hs, MakeSpan(ssl->s3->exporter_secret, hs->hash_len),
+ label_to_span(kTLS13LabelExporter)) ||
!ssl_log_secret(ssl, "EXPORTER_SECRET", ssl->s3->exporter_secret,
hs->hash_len)) {
return false;
@@ -334,26 +334,20 @@
static const char kTLS13LabelApplicationTraffic[] = "traffic upd";
bool tls13_rotate_traffic_key(SSL *ssl, enum evp_aead_direction_t direction) {
- uint8_t *secret;
- size_t secret_len;
+ Span<uint8_t> secret;
if (direction == evp_aead_open) {
- secret = ssl->s3->read_traffic_secret;
- secret_len = ssl->s3->read_traffic_secret_len;
+ secret = MakeSpan(ssl->s3->read_traffic_secret,
+ ssl->s3->read_traffic_secret_len);
} else {
- secret = ssl->s3->write_traffic_secret;
- secret_len = ssl->s3->write_traffic_secret_len;
+ secret = MakeSpan(ssl->s3->write_traffic_secret,
+ ssl->s3->write_traffic_secret_len);
}
const EVP_MD *digest = ssl_session_get_digest(SSL_get_session(ssl));
- if (!hkdf_expand_label(secret, digest, secret, secret_len,
- kTLS13LabelApplicationTraffic,
- strlen(kTLS13LabelApplicationTraffic), NULL, 0,
- secret_len)) {
- return false;
- }
-
- return tls13_set_traffic_key(ssl, ssl_encryption_application, direction,
- secret, secret_len);
+ return hkdf_expand_label(secret, digest, secret,
+ label_to_span(kTLS13LabelApplicationTraffic), {}) &&
+ tls13_set_traffic_key(ssl, ssl_encryption_application, direction,
+ secret);
}
static const char kTLS13LabelResumption[] = "res master";
@@ -364,24 +358,28 @@
return false;
}
hs->new_session->master_key_length = hs->hash_len;
- return derive_secret(hs, hs->new_session->master_key,
- hs->new_session->master_key_length,
- kTLS13LabelResumption, strlen(kTLS13LabelResumption));
+ return derive_secret(
+ hs,
+ MakeSpan(hs->new_session->master_key, hs->new_session->master_key_length),
+ label_to_span(kTLS13LabelResumption));
}
static const char kTLS13LabelFinished[] = "finished";
// tls13_verify_data sets |out| to be the HMAC of |context| using a derived
-// Finished key for both Finished messages and the PSK binder.
-static bool tls13_verify_data(const EVP_MD *digest, uint16_t version,
- uint8_t *out, size_t *out_len,
- const uint8_t *secret, size_t hash_len,
- const uint8_t *context, size_t context_len) {
- uint8_t key[EVP_MAX_MD_SIZE];
+// Finished key for both Finished messages and the PSK binder. |out| must have
+// space available for |EVP_MAX_MD_SIZE| bytes.
+static bool tls13_verify_data(uint8_t *out, size_t *out_len,
+ const EVP_MD *digest, uint16_t version,
+ Span<const uint8_t> secret,
+ Span<const uint8_t> context) {
+ uint8_t key_buf[EVP_MAX_MD_SIZE];
+ auto key = MakeSpan(key_buf, EVP_MD_size(digest));
unsigned len;
- if (!hkdf_expand_label(key, digest, secret, hash_len, kTLS13LabelFinished,
- strlen(kTLS13LabelFinished), NULL, 0, hash_len) ||
- HMAC(digest, key, hash_len, context, context_len, out, &len) == NULL) {
+ if (!hkdf_expand_label(key, digest, secret,
+ label_to_span(kTLS13LabelFinished), {}) ||
+ HMAC(digest, key.data(), key.size(), context.data(), context.size(), out,
+ &len) == nullptr) {
return false;
}
*out_len = len;
@@ -390,19 +388,19 @@
bool tls13_finished_mac(SSL_HANDSHAKE *hs, uint8_t *out, size_t *out_len,
bool is_server) {
- const uint8_t *traffic_secret;
+ Span<const uint8_t> traffic_secret;
if (is_server) {
- traffic_secret = hs->server_handshake_secret;
+ traffic_secret = MakeConstSpan(hs->server_handshake_secret, hs->hash_len);
} else {
- traffic_secret = hs->client_handshake_secret;
+ traffic_secret = MakeConstSpan(hs->client_handshake_secret, hs->hash_len);
}
uint8_t context_hash[EVP_MAX_MD_SIZE];
size_t context_hash_len;
if (!hs->transcript.GetHash(context_hash, &context_hash_len) ||
- !tls13_verify_data(hs->transcript.Digest(), hs->ssl->version, out,
- out_len, traffic_secret, hs->hash_len, context_hash,
- context_hash_len)) {
+ !tls13_verify_data(out, out_len, hs->transcript.Digest(),
+ hs->ssl->version, traffic_secret,
+ MakeConstSpan(context_hash, context_hash_len))) {
return 0;
}
return 1;
@@ -412,10 +410,11 @@
bool tls13_derive_session_psk(SSL_SESSION *session, Span<const uint8_t> nonce) {
const EVP_MD *digest = ssl_session_get_digest(session);
- return hkdf_expand_label(session->master_key, digest, session->master_key,
- session->master_key_length, kTLS13LabelResumptionPSK,
- strlen(kTLS13LabelResumptionPSK), nonce.data(),
- nonce.size(), session->master_key_length);
+ // The session initially stores the resumption_master_secret, which we
+ // override with the PSK.
+ auto session_key = MakeSpan(session->master_key, session->master_key_length);
+ return hkdf_expand_label(session_key, digest, session_key,
+ label_to_span(kTLS13LabelResumptionPSK), nonce);
}
static const char kTLS13LabelExportKeying[] = "exporter";
@@ -432,31 +431,32 @@
const EVP_MD *digest = ssl_session_get_digest(SSL_get_session(ssl));
- uint8_t hash[EVP_MAX_MD_SIZE];
- uint8_t export_context[EVP_MAX_MD_SIZE];
- uint8_t derived_secret[EVP_MAX_MD_SIZE];
+ uint8_t hash_buf[EVP_MAX_MD_SIZE];
+ uint8_t export_context_buf[EVP_MAX_MD_SIZE];
unsigned hash_len;
unsigned export_context_len;
- unsigned derived_secret_len = EVP_MD_size(digest);
- return EVP_Digest(context.data(), context.size(), hash, &hash_len, digest,
- nullptr) &&
- EVP_Digest(nullptr, 0, export_context, &export_context_len, digest,
- nullptr) &&
- hkdf_expand_label(derived_secret, digest, secret.data(), secret.size(),
- label.data(), label.size(), export_context,
- export_context_len, derived_secret_len) &&
- hkdf_expand_label(out.data(), digest, derived_secret,
- derived_secret_len, kTLS13LabelExportKeying,
- strlen(kTLS13LabelExportKeying), hash, hash_len,
- out.size());
+ if (!EVP_Digest(context.data(), context.size(), hash_buf, &hash_len, digest,
+ nullptr) ||
+ !EVP_Digest(nullptr, 0, export_context_buf, &export_context_len, digest,
+ nullptr)) {
+ return false;
+ }
+
+ auto hash = MakeConstSpan(hash_buf, hash_len);
+ auto export_context = MakeConstSpan(export_context_buf, export_context_len);
+ uint8_t derived_secret_buf[EVP_MAX_MD_SIZE];
+ auto derived_secret = MakeSpan(derived_secret_buf, EVP_MD_size(digest));
+ return hkdf_expand_label(derived_secret, digest, secret, label,
+ export_context) &&
+ hkdf_expand_label(out, digest, derived_secret,
+ label_to_span(kTLS13LabelExportKeying), hash);
}
static const char kTLS13LabelPSKBinder[] = "res binder";
-static bool tls13_psk_binder(uint8_t *out, uint16_t version,
- const EVP_MD *digest, const uint8_t *psk,
- size_t psk_len, const uint8_t *context,
- size_t context_len, size_t hash_len) {
+static bool tls13_psk_binder(uint8_t *out, size_t *out_len, uint16_t version,
+ const EVP_MD *digest, Span<const uint8_t> psk,
+ Span<const uint8_t> context) {
uint8_t binder_context[EVP_MAX_MD_SIZE];
unsigned binder_context_len;
if (!EVP_Digest(NULL, 0, binder_context, &binder_context_len, digest, NULL)) {
@@ -465,22 +465,22 @@
uint8_t early_secret[EVP_MAX_MD_SIZE] = {0};
size_t early_secret_len;
- if (!HKDF_extract(early_secret, &early_secret_len, digest, psk, psk_len, NULL,
- 0)) {
+ if (!HKDF_extract(early_secret, &early_secret_len, digest, psk.data(),
+ psk.size(), NULL, 0)) {
return false;
}
- uint8_t binder_key[EVP_MAX_MD_SIZE] = {0};
- size_t len;
- if (!hkdf_expand_label(binder_key, digest, early_secret, early_secret_len,
- kTLS13LabelPSKBinder, strlen(kTLS13LabelPSKBinder),
- binder_context, binder_context_len, hash_len) ||
- !tls13_verify_data(digest, version, out, &len, binder_key, hash_len,
- context, context_len)) {
+ uint8_t binder_key_buf[EVP_MAX_MD_SIZE] = {0};
+ auto binder_key = MakeSpan(binder_key_buf, EVP_MD_size(digest));
+ if (!hkdf_expand_label(binder_key, digest,
+ MakeConstSpan(early_secret, early_secret_len),
+ label_to_span(kTLS13LabelPSKBinder),
+ MakeConstSpan(binder_context, binder_context_len)) ||
+ !tls13_verify_data(out, out_len, digest, version, binder_key, context)) {
return false;
}
- assert(len == hash_len);
+ assert(*out_len == EVP_MD_size(digest));
return true;
}
@@ -513,42 +513,50 @@
ScopedEVP_MD_CTX ctx;
uint8_t context[EVP_MAX_MD_SIZE];
size_t context_len;
- uint8_t verify_data[EVP_MAX_MD_SIZE] = {0};
+ uint8_t verify_data[EVP_MAX_MD_SIZE];
+ size_t verify_data_len;
if (!hash_transcript_and_truncated_client_hello(
hs, context, &context_len, digest, msg,
1 /* length prefix */ + hash_len) ||
- !tls13_psk_binder(verify_data, ssl->session->ssl_version, digest,
- ssl->session->master_key,
- ssl->session->master_key_length, context, context_len,
- hash_len)) {
+ !tls13_psk_binder(verify_data, &verify_data_len,
+ ssl->session->ssl_version, digest,
+ MakeConstSpan(ssl->session->master_key,
+ ssl->session->master_key_length),
+ MakeConstSpan(context, context_len)) ||
+ verify_data_len != hash_len) {
+ OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return false;
}
- OPENSSL_memcpy(msg.data() + msg.size() - hash_len, verify_data, hash_len);
+ OPENSSL_memcpy(msg.data() + msg.size() - verify_data_len, verify_data,
+ verify_data_len);
return true;
}
bool tls13_verify_psk_binder(SSL_HANDSHAKE *hs, SSL_SESSION *session,
const SSLMessage &msg, CBS *binders) {
- size_t hash_len = hs->transcript.DigestLen();
uint8_t context[EVP_MAX_MD_SIZE];
size_t context_len;
- uint8_t verify_data[EVP_MAX_MD_SIZE] = {0};
+ uint8_t verify_data[EVP_MAX_MD_SIZE];
+ size_t verify_data_len;
CBS binder;
if (!hash_transcript_and_truncated_client_hello(hs, context, &context_len,
hs->transcript.Digest(),
msg.raw, CBS_len(binders)) ||
- !tls13_psk_binder(verify_data, hs->ssl->version, hs->transcript.Digest(),
- session->master_key, session->master_key_length,
- context, context_len, hash_len) ||
+ !tls13_psk_binder(
+ verify_data, &verify_data_len, hs->ssl->version,
+ hs->transcript.Digest(),
+ MakeConstSpan(session->master_key, session->master_key_length),
+ MakeConstSpan(context, context_len)) ||
// We only consider the first PSK, so compare against the first binder.
!CBS_get_u8_length_prefixed(binders, &binder)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return false;
}
- bool binder_ok = CBS_len(&binder) == hash_len &&
- CRYPTO_memcmp(CBS_data(&binder), verify_data, hash_len) == 0;
+ bool binder_ok =
+ CBS_len(&binder) == verify_data_len &&
+ CRYPTO_memcmp(CBS_data(&binder), verify_data, verify_data_len) == 0;
#if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
binder_ok = true;
#endif
diff --git a/ssl/tls13_server.cc b/ssl/tls13_server.cc
index 1e87bb9..7b6f5df 100644
--- a/ssl/tls13_server.cc
+++ b/ssl/tls13_server.cc
@@ -87,7 +87,7 @@
return 0;
}
- return tls13_advance_key_schedule(hs, dhe_secret.data(), dhe_secret.size());
+ return tls13_advance_key_schedule(hs, dhe_secret);
}
static int ssl_ext_supported_versions_add_serverhello(SSL_HANDSHAKE *hs,
@@ -428,11 +428,12 @@
// Set up the key schedule and incorporate the PSK into the running secret.
if (ssl->s3->session_reused) {
- if (!tls13_init_key_schedule(hs, hs->new_session->master_key,
- hs->new_session->master_key_length)) {
+ if (!tls13_init_key_schedule(
+ hs, MakeConstSpan(hs->new_session->master_key,
+ hs->new_session->master_key_length))) {
return ssl_hs_error;
}
- } else if (!tls13_init_key_schedule(hs, kZeroes, hash_len)) {
+ } else if (!tls13_init_key_schedule(hs, MakeConstSpan(kZeroes, hash_len))) {
return ssl_hs_error;
}
@@ -606,8 +607,9 @@
// Derive and enable the handshake traffic secrets.
if (!tls13_derive_handshake_secrets(hs) ||
- !tls13_set_traffic_key(ssl, ssl_encryption_handshake, evp_aead_seal,
- hs->server_handshake_secret, hs->hash_len)) {
+ !tls13_set_traffic_key(
+ ssl, ssl_encryption_handshake, evp_aead_seal,
+ MakeConstSpan(hs->server_handshake_secret, hs->hash_len))) {
return ssl_hs_error;
}
@@ -715,10 +717,11 @@
SSL *const ssl = hs->ssl;
if (!tls13_add_finished(hs) ||
// Update the secret to the master secret and derive traffic keys.
- !tls13_advance_key_schedule(hs, kZeroes, hs->hash_len) ||
+ !tls13_advance_key_schedule(hs, MakeConstSpan(kZeroes, hs->hash_len)) ||
!tls13_derive_application_secrets(hs) ||
- !tls13_set_traffic_key(ssl, ssl_encryption_application, evp_aead_seal,
- hs->server_traffic_secret_0, hs->hash_len)) {
+ !tls13_set_traffic_key(
+ ssl, ssl_encryption_application, evp_aead_seal,
+ MakeConstSpan(hs->server_traffic_secret_0, hs->hash_len))) {
return ssl_hs_error;
}
@@ -770,8 +773,9 @@
static enum ssl_hs_wait_t do_read_second_client_flight(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (ssl->s3->early_data_accepted) {
- if (!tls13_set_traffic_key(ssl, ssl_encryption_early_data, evp_aead_open,
- hs->early_traffic_secret, hs->hash_len)) {
+ if (!tls13_set_traffic_key(
+ ssl, ssl_encryption_early_data, evp_aead_open,
+ MakeConstSpan(hs->early_traffic_secret, hs->hash_len))) {
return ssl_hs_error;
}
hs->can_early_write = true;
@@ -805,8 +809,9 @@
ssl->method->next_message(ssl);
}
}
- if (!tls13_set_traffic_key(ssl, ssl_encryption_handshake, evp_aead_open,
- hs->client_handshake_secret, hs->hash_len)) {
+ if (!tls13_set_traffic_key(
+ ssl, ssl_encryption_handshake, evp_aead_open,
+ MakeConstSpan(hs->client_handshake_secret, hs->hash_len))) {
return ssl_hs_error;
}
hs->tls13_state = ssl->s3->early_data_accepted
@@ -912,8 +917,9 @@
// and derived the resumption secret.
!tls13_process_finished(hs, msg, ssl->s3->early_data_accepted) ||
// evp_aead_seal keys have already been switched.
- !tls13_set_traffic_key(ssl, ssl_encryption_application, evp_aead_open,
- hs->client_traffic_secret_0, hs->hash_len)) {
+ !tls13_set_traffic_key(
+ ssl, ssl_encryption_application, evp_aead_open,
+ MakeConstSpan(hs->client_traffic_secret_0, hs->hash_len))) {
return ssl_hs_error;
}
