Implement tls13_change_cipher_state()

Reviewed-by: Rich Salz <rsalz@openssl.org>

7 files changed, 170 insertions, 2 deletions

diff --git a/include/openssl/ssl.h b/include/openssl/ssl.h
index 1f9aaf855e..5064e65cf5 100644
--- a/include/openssl/ssl.h
+++ b/include/openssl/ssl.h
@@ -2242,6 +2242,7 @@ int ERR_load_SSL_strings(void);
 # define SSL_F_SSL_WRITE_EX                               433
 # define SSL_F_STATE_MACHINE                              353
 # define SSL_F_TLS12_CHECK_PEER_SIGALG                    333
+# define SSL_F_TLS13_CHANGE_CIPHER_STATE                  435
 # define SSL_F_TLS1_CHANGE_CIPHER_STATE                   209
 # define SSL_F_TLS1_CHECK_DUPLICATE_EXTENSIONS            341
 # define SSL_F_TLS1_ENC                                   401
diff --git a/include/openssl/ssl3.h b/include/openssl/ssl3.h
index aca1922306..321a8dde31 100644
--- a/include/openssl/ssl3.h
+++ b/include/openssl/ssl3.h
@@ -296,6 +296,8 @@ extern "C" {
 # define SSL3_CC_WRITE           0x02
 # define SSL3_CC_CLIENT          0x10
 # define SSL3_CC_SERVER          0x20
+# define SSL3_CC_HANDSHAKE       0x40
+# define SSL3_CC_APPLICATION     0x80
 # define SSL3_CHANGE_CIPHER_CLIENT_WRITE (SSL3_CC_CLIENT|SSL3_CC_WRITE)
 # define SSL3_CHANGE_CIPHER_SERVER_READ  (SSL3_CC_SERVER|SSL3_CC_READ)
 # define SSL3_CHANGE_CIPHER_CLIENT_READ  (SSL3_CC_CLIENT|SSL3_CC_READ)
diff --git a/ssl/ssl_err.c b/ssl/ssl_err.c
index 235a53ccc8..b7ba8a5202 100644
--- a/ssl/ssl_err.c
+++ b/ssl/ssl_err.c
@@ -238,6 +238,7 @@ static ERR_STRING_DATA SSL_str_functs[] = {
     {ERR_FUNC(SSL_F_SSL_WRITE_EX), "SSL_write_ex"},
     {ERR_FUNC(SSL_F_STATE_MACHINE), "state_machine"},
     {ERR_FUNC(SSL_F_TLS12_CHECK_PEER_SIGALG), "tls12_check_peer_sigalg"},
+    {ERR_FUNC(SSL_F_TLS13_CHANGE_CIPHER_STATE), "tls13_change_cipher_state"},
     {ERR_FUNC(SSL_F_TLS1_CHANGE_CIPHER_STATE), "tls1_change_cipher_state"},
     {ERR_FUNC(SSL_F_TLS1_CHECK_DUPLICATE_EXTENSIONS),
      "tls1_check_duplicate_extensions"},
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index 5f2c941b79..4d41b17fa0 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -3828,8 +3828,7 @@ EVP_MD_CTX *ssl_replace_hash(EVP_MD_CTX **hash, const EVP_MD *md)
 void ssl_clear_hash_ctx(EVP_MD_CTX **hash)
 {
 
-    if (*hash)
-        EVP_MD_CTX_free(*hash);
+    EVP_MD_CTX_free(*hash);
     *hash = NULL;
 }
 
diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h
index 41382bafc0..527b2b40e2 100644
--- a/ssl/ssl_locl.h
+++ b/ssl/ssl_locl.h
@@ -2003,6 +2003,7 @@ __owur size_t tls1_final_finish_mac(SSL *s, const char *str, size_t slen,
 __owur int tls1_generate_master_secret(SSL *s, unsigned char *out,
                                        unsigned char *p, size_t len,
                                        size_t *secret_size);
+__owur int tls13_change_cipher_state(SSL *s, int which);
 __owur int tls13_derive_secret(SSL *s, const unsigned char *insecret,
                                const unsigned char *label, size_t labellen,
                                unsigned char *secret);
diff --git a/ssl/tls13_enc.c b/ssl/tls13_enc.c
index 39a61f4461..04dba3b23e 100644
--- a/ssl/tls13_enc.c
+++ b/ssl/tls13_enc.c
@@ -214,4 +214,160 @@ int tls13_generate_master_secret(SSL *s, unsigned char *out,
     return tls13_generate_secret(s, prev, NULL, 0, out);
 }
 
+const unsigned char client_handshake_traffic[] =
+    "client handshake traffic secret";
+const unsigned char client_application_traffic[] =
+    "client application traffic secret";
+const unsigned char server_handshake_traffic[] =
+    "server handshake traffic secret";
+const unsigned char server_application_traffic[] =
+    "server application traffic secret";
 
+int tls13_change_cipher_state(SSL *s, int which)
+{
+    unsigned char key[EVP_MAX_KEY_LENGTH];
+    unsigned char iv[EVP_MAX_IV_LENGTH];
+    unsigned char secret[EVP_MAX_MD_SIZE];
+    unsigned char *insecret;
+    EVP_CIPHER_CTX *ciph_ctx;
+    const EVP_CIPHER *ciph = s->s3->tmp.new_sym_enc;;
+    size_t ivlen, keylen;
+    const unsigned char *label;
+    size_t labellen;
+
+    if (which & SSL3_CC_READ) {
+        if (s->enc_read_ctx != NULL) {
+            EVP_CIPHER_CTX_reset(s->enc_read_ctx);
+        } else {
+            s->enc_read_ctx = EVP_CIPHER_CTX_new();
+            if (s->enc_read_ctx == NULL) {
+                SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
+                goto err;
+            }
+        }
+        ciph_ctx = s->enc_read_ctx;
+
+        RECORD_LAYER_reset_read_sequence(&s->rlayer);
+    } else {
+        if (s->enc_write_ctx != NULL) {
+            EVP_CIPHER_CTX_reset(s->enc_write_ctx);
+        } else {
+            s->enc_write_ctx = EVP_CIPHER_CTX_new();
+            if (s->enc_write_ctx == NULL) {
+                SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE);
+                goto err;
+            }
+        }
+        ciph_ctx = s->enc_write_ctx;
+
+        RECORD_LAYER_reset_write_sequence(&s->rlayer);
+    }
+
+    if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE))
+            || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) {
+        if (which & SSL3_CC_HANDSHAKE) {
+            insecret = s->handshake_secret;
+            label = client_handshake_traffic;
+            labellen = sizeof(client_handshake_traffic) - 1;
+        } else {
+            insecret = s->session->master_key;
+            label = client_application_traffic;
+            labellen = sizeof(client_application_traffic) - 1;
+        }
+    } else {
+        if (which & SSL3_CC_HANDSHAKE) {
+            insecret = s->handshake_secret;
+            label = server_handshake_traffic;
+            labellen = sizeof(server_handshake_traffic) - 1;
+        } else {
+            insecret = s->session->master_key;
+            label = server_application_traffic;
+            labellen = sizeof(server_application_traffic) - 1;
+        }
+    }
+
+    if (!tls13_derive_secret(s, insecret, label, labellen, secret)) {
+        SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    /* TODO(size_t): convert me */
+    keylen = EVP_CIPHER_key_length(ciph);
+
+    if (EVP_CIPHER_mode(ciph) == EVP_CIPH_GCM_MODE)
+        ivlen = EVP_GCM_TLS_FIXED_IV_LEN;
+    else if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE)
+        ivlen = EVP_CCM_TLS_FIXED_IV_LEN;
+    else
+        ivlen = EVP_CIPHER_iv_length(ciph);
+
+    if (!tls13_derive_key(s, secret, key, keylen)
+            || !tls13_derive_iv(s, secret, iv, ivlen)) {
+        SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
+        goto err;
+    }
+
+    if (EVP_CIPHER_mode(ciph) == EVP_CIPH_GCM_MODE) {
+        if (!EVP_CipherInit_ex(ciph_ctx, ciph, NULL, key, NULL,
+                               (which & SSL3_CC_WRITE))
+                || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_GCM_SET_IV_FIXED,
+                                        (int)ivlen, iv)) {
+            SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_EVP_LIB);
+            goto err;
+        }
+    } else if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) {
+        int taglen;
+        if (s->s3->tmp.new_cipher->algorithm_enc
+                & (SSL_AES128CCM8 | SSL_AES256CCM8))
+            taglen = 8;
+        else
+            taglen = 16;
+        if (!EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL,
+                               (which & SSL3_CC_WRITE))
+                || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, 12,
+                                        NULL)
+                || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG, taglen,
+                                        NULL)
+                || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_CCM_SET_IV_FIXED,
+                                        (int)ivlen, iv)
+                || !EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1)) {
+            SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_EVP_LIB);
+            goto err;
+        }
+    } else {
+        if (!EVP_CipherInit_ex(ciph_ctx, ciph, NULL, key, iv,
+                               (which & SSL3_CC_WRITE))) {
+            SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_EVP_LIB);
+            goto err;
+        }
+    }
+
+#ifdef OPENSSL_SSL_TRACE_CRYPTO
+    if (s->msg_callback) {
+        int wh = which & SSL3_CC_WRITE ? TLS1_RT_CRYPTO_WRITE : 0;
+
+        if (ciph->key_len)
+            s->msg_callback(2, s->version, wh | TLS1_RT_CRYPTO_KEY,
+                            key, ciph->key_len, s, s->msg_callback_arg);
+        if (ivlen) {
+            if (EVP_CIPHER_mode(ciph) == EVP_CIPH_GCM_MODE)
+                wh |= TLS1_RT_CRYPTO_FIXED_IV;
+            else
+                wh |= TLS1_RT_CRYPTO_IV;
+            s->msg_callback(2, s->version, wh, iv, ivlen, s,
+                            s->msg_callback_arg);
+        }
+    }
+#endif
+
+    OPENSSL_cleanse(secret, sizeof(secret));
+    OPENSSL_cleanse(key, sizeof(key));
+    OPENSSL_cleanse(iv, sizeof(iv));
+    return 1;
+
+ err:
+    OPENSSL_cleanse(secret, sizeof(secret));
+    OPENSSL_cleanse(key, sizeof(key));
+    OPENSSL_cleanse(iv, sizeof(iv));
+    return 0;
+}
diff --git a/test/tls13secretstest.c b/test/tls13secretstest.c
index 6b6c9bc946..ceafd3d824 100644
--- a/test/tls13secretstest.c
+++ b/test/tls13secretstest.c
@@ -162,6 +162,14 @@ const EVP_MD *ssl_handshake_md(SSL *s)
     return EVP_sha256();
 }
 
+void RECORD_LAYER_reset_read_sequence(RECORD_LAYER *rl)
+{
+}
+
+void RECORD_LAYER_reset_write_sequence(RECORD_LAYER *rl)
+{
+}
+
 /* End of mocked out code */
 
 static int test_secret(SSL *s, unsigned char *prk,