tls1_change_cipher_state rewrite
The previous version of the function made adding AEAD changes very
difficult. This change should be a semantic no-op - it should be purely
a cleanup.
diff --git a/ssl/ssl.h b/ssl/ssl.h
index bb6aa88..c030806 100644
--- a/ssl/ssl.h
+++ b/ssl/ssl.h
@@ -2657,6 +2657,7 @@
#define SSL_F_ssl3_get_channel_id 275
#define SSL_F_ssl3_send_channel_id 276
#define SSL_F_SSL_CTX_set_cipher_list_tls11 277
+#define SSL_F_tls1_change_cipher_state_cipher 278
#define SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS 100
#define SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC 101
#define SSL_R_INVALID_NULL_CMD_NAME 102
diff --git a/ssl/ssl_error.c b/ssl/ssl_error.c
index 9b00411..26fb4a2 100644
--- a/ssl/ssl_error.c
+++ b/ssl/ssl_error.c
@@ -190,6 +190,7 @@
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_PRF, 0), "tls1_PRF"},
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_cert_verify_mac, 0), "tls1_cert_verify_mac"},
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_change_cipher_state, 0), "tls1_change_cipher_state"},
+ {ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_change_cipher_state_cipher, 0), "tls1_change_cipher_state_cipher"},
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_export_keying_material, 0), "tls1_export_keying_material"},
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_get_server_supplemental_data, 0), "tls1_get_server_supplemental_data"},
{ERR_PACK(ERR_LIB_SSL, SSL_F_tls1_heartbeat, 0), "tls1_heartbeat"},
diff --git a/ssl/t1_enc.c b/ssl/t1_enc.c
index 7a38545..b351c51 100644
--- a/ssl/t1_enc.c
+++ b/ssl/t1_enc.c
@@ -311,249 +311,252 @@
return ret;
}
-int tls1_change_cipher_state(SSL *s, int which)
+/* tls1_change_cipher_state_cipher performs the work needed to switch cipher
+ * states when using EVP_CIPHER. The argument |is_read| is true iff this
+ * function is being called due to reading, as opposed to writing, a
+ * ChangeCipherSpec message. In order to support export ciphersuites,
+ * use_client_keys indicates whether the key material provided is in the
+ * "client write" direction. */
+static int tls1_change_cipher_state_cipher(
+ SSL *s, char is_read, char use_client_keys,
+ const unsigned char *mac_secret, unsigned mac_secret_len,
+ const unsigned char *key, unsigned key_len,
+ const unsigned char *iv, unsigned iv_len)
{
- static const unsigned char empty[]="";
- unsigned char *p,*mac_secret;
- unsigned char *exp_label;
- unsigned char tmp1[EVP_MAX_KEY_LENGTH];
- unsigned char tmp2[EVP_MAX_KEY_LENGTH];
- unsigned char iv1[EVP_MAX_IV_LENGTH*2];
- unsigned char iv2[EVP_MAX_IV_LENGTH*2];
- unsigned char *ms,*key,*iv;
- int client_write;
- EVP_CIPHER_CTX *dd;
- const EVP_CIPHER *c;
- const EVP_MD *m;
- int mac_type;
- int *mac_secret_size;
+ const EVP_CIPHER *cipher = s->s3->tmp.new_sym_enc;
+ const char is_export = SSL_C_IS_EXPORT(s->s3->tmp.new_cipher) != 0;
+ EVP_CIPHER_CTX *cipher_ctx;
EVP_MD_CTX *mac_ctx;
- EVP_PKEY *mac_key;
- int is_export,n,i,j,k,exp_label_len,cl;
- int reuse_dd = 0;
+ char is_aead_cipher;
- is_export=SSL_C_IS_EXPORT(s->s3->tmp.new_cipher);
- c=s->s3->tmp.new_sym_enc;
- m=s->s3->tmp.new_hash;
- mac_type = s->s3->tmp.new_mac_pkey_type;
+ unsigned char export_tmp1[EVP_MAX_KEY_LENGTH];
+ unsigned char export_tmp2[EVP_MAX_KEY_LENGTH];
+ unsigned char export_iv1[EVP_MAX_IV_LENGTH * 2];
+ unsigned char export_iv2[EVP_MAX_IV_LENGTH * 2];
-#ifdef KSSL_DEBUG
- printf("tls1_change_cipher_state(which= %d) w/\n", which);
- printf("\talg= %ld/%ld, comp= %p\n",
- s->s3->tmp.new_cipher->algorithm_mkey,
- s->s3->tmp.new_cipher->algorithm_auth,
- comp);
- printf("\tevp_cipher == %p ==? &d_cbc_ede_cipher3\n", c);
- printf("\tevp_cipher: nid, blksz= %d, %d, keylen=%d, ivlen=%d\n",
- c->nid,c->block_size,c->key_len,c->iv_len);
- printf("\tkey_block: len= %d, data= ", s->s3->tmp.key_block_length);
- {
- int i;
- for (i=0; i<s->s3->tmp.key_block_length; i++)
- printf("%02x", s->s3->tmp.key_block[i]); printf("\n");
- }
-#endif /* KSSL_DEBUG */
-
- if (which & SSL3_CC_READ)
+ if (is_read)
{
if (s->s3->tmp.new_cipher->algorithm2 & TLS1_STREAM_MAC)
s->mac_flags |= SSL_MAC_FLAG_READ_MAC_STREAM;
else
s->mac_flags &= ~SSL_MAC_FLAG_READ_MAC_STREAM;
- if (s->enc_read_ctx != NULL)
- reuse_dd = 1;
- else if ((s->enc_read_ctx=OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL)
+ if (s->enc_read_ctx != NULL && !SSL_IS_DTLS(s))
+ EVP_CIPHER_CTX_cleanup(s->enc_read_ctx);
+ else if ((s->enc_read_ctx=EVP_CIPHER_CTX_new()) == NULL)
goto err;
- else
- /* make sure it's intialized in case we exit later with an error */
- EVP_CIPHER_CTX_init(s->enc_read_ctx);
- dd= s->enc_read_ctx;
- mac_ctx=ssl_replace_hash(&s->read_hash,NULL);
- /* this is done by dtls1_reset_seq_numbers for DTLS1_VERSION */
- if (s->version != DTLS1_VERSION)
- memset(&(s->s3->read_sequence[0]),0,8);
- mac_secret= &(s->s3->read_mac_secret[0]);
- mac_secret_size=&(s->s3->read_mac_secret_size);
+
+ cipher_ctx = s->enc_read_ctx;
+ mac_ctx = ssl_replace_hash(&s->read_hash, NULL);
+
+ memcpy(s->s3->read_mac_secret, mac_secret, mac_secret_len);
+ s->s3->read_mac_secret_size = mac_secret_len;
}
else
{
if (s->s3->tmp.new_cipher->algorithm2 & TLS1_STREAM_MAC)
s->mac_flags |= SSL_MAC_FLAG_WRITE_MAC_STREAM;
- else
+ else
s->mac_flags &= ~SSL_MAC_FLAG_WRITE_MAC_STREAM;
+
+ /* When updating the write contexts for DTLS, we do not wish to
+ * free the old ones because DTLS stores pointers to them in
+ * order to implement retransmission. */
+
if (s->enc_write_ctx != NULL && !SSL_IS_DTLS(s))
- reuse_dd = 1;
- else if ((s->enc_write_ctx=EVP_CIPHER_CTX_new()) == NULL)
+ EVP_CIPHER_CTX_cleanup(s->enc_write_ctx);
+ else if ((s->enc_write_ctx=OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL)
goto err;
- dd= s->enc_write_ctx;
+ else
+ /* make sure it's intialized in case we exit later with an error */
+ EVP_CIPHER_CTX_init(s->enc_write_ctx);
+
+ cipher_ctx = s->enc_write_ctx;
if (SSL_IS_DTLS(s))
{
+ /* This is the same as ssl_replace_hash, but doesn't
+ * free the old |s->write_hash|. */
mac_ctx = EVP_MD_CTX_create();
if (!mac_ctx)
goto err;
s->write_hash = mac_ctx;
}
else
- mac_ctx = ssl_replace_hash(&s->write_hash,NULL);
- /* this is done by dtls1_reset_seq_numbers for DTLS1_VERSION */
- if (s->version != DTLS1_VERSION)
- memset(&(s->s3->write_sequence[0]),0,8);
- mac_secret= &(s->s3->write_mac_secret[0]);
- mac_secret_size = &(s->s3->write_mac_secret_size);
+ mac_ctx = ssl_replace_hash(&s->write_hash, NULL);
+
+ memcpy(s->s3->write_mac_secret, mac_secret, mac_secret_len);
+ s->s3->write_mac_secret_size = mac_secret_len;
}
- if (reuse_dd)
- EVP_CIPHER_CTX_cleanup(dd);
-
- p=s->s3->tmp.key_block;
- i=*mac_secret_size=s->s3->tmp.new_mac_secret_size;
-
- cl=EVP_CIPHER_key_length(c);
- j=is_export ? (cl < SSL_C_EXPORT_KEYLENGTH(s->s3->tmp.new_cipher) ?
- cl : SSL_C_EXPORT_KEYLENGTH(s->s3->tmp.new_cipher)) : cl;
- /* Was j=(exp)?5:EVP_CIPHER_key_length(c); */
- /* If GCM mode only part of IV comes from PRF */
- if (EVP_CIPHER_mode(c) == EVP_CIPH_GCM_MODE)
- k = EVP_GCM_TLS_FIXED_IV_LEN;
- else
- k=EVP_CIPHER_iv_length(c);
- if ( (which == SSL3_CHANGE_CIPHER_CLIENT_WRITE) ||
- (which == SSL3_CHANGE_CIPHER_SERVER_READ))
- {
- ms= &(p[ 0]); n=i+i;
- key= &(p[ n]); n+=j+j;
- iv= &(p[ n]); n+=k+k;
- exp_label=(unsigned char *)TLS_MD_CLIENT_WRITE_KEY_CONST;
- exp_label_len=TLS_MD_CLIENT_WRITE_KEY_CONST_SIZE;
- client_write=1;
- }
- else
- {
- n=i;
- ms= &(p[ n]); n+=i+j;
- key= &(p[ n]); n+=j+k;
- iv= &(p[ n]); n+=k;
- exp_label=(unsigned char *)TLS_MD_SERVER_WRITE_KEY_CONST;
- exp_label_len=TLS_MD_SERVER_WRITE_KEY_CONST_SIZE;
- client_write=0;
- }
-
- if (n > s->s3->tmp.key_block_length)
- {
- OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state, ERR_R_INTERNAL_ERROR);
- goto err2;
- }
-
- memcpy(mac_secret,ms,i);
-
- if (!(EVP_CIPHER_flags(c)&EVP_CIPH_FLAG_AEAD_CIPHER))
- {
- mac_key = EVP_PKEY_new_mac_key(mac_type, NULL,
- mac_secret,*mac_secret_size);
- EVP_DigestSignInit(mac_ctx,NULL,m,NULL,mac_key);
- EVP_PKEY_free(mac_key);
- }
-#ifdef TLS_DEBUG
-printf("which = %04X\nmac key=",which);
-{ int z; for (z=0; z<i; z++) printf("%02X%c",ms[z],((z+1)%16)?' ':'\n'); }
-#endif
if (is_export)
{
/* In here I set both the read and write key/iv to the
* same value since only the correct one will be used :-).
*/
- if (!tls1_PRF(ssl_get_algorithm2(s),
- exp_label,exp_label_len,
- s->s3->client_random,SSL3_RANDOM_SIZE,
- s->s3->server_random,SSL3_RANDOM_SIZE,
- NULL,0,NULL,0,
- key,j,tmp1,tmp2,EVP_CIPHER_key_length(c)))
- goto err2;
- key=tmp1;
+ const unsigned char *label;
+ unsigned label_len;
- if (k > 0)
+ if (use_client_keys)
{
+ label = (const unsigned char*) TLS_MD_CLIENT_WRITE_KEY_CONST;
+ label_len = TLS_MD_CLIENT_WRITE_KEY_CONST_SIZE;
+ }
+ else
+ {
+ label = (const unsigned char*) TLS_MD_SERVER_WRITE_KEY_CONST;
+ label_len = TLS_MD_SERVER_WRITE_KEY_CONST_SIZE;
+ }
+
+ if (!tls1_PRF(ssl_get_algorithm2(s),
+ label, label_len,
+ s->s3->client_random, SSL3_RANDOM_SIZE,
+ s->s3->server_random, SSL3_RANDOM_SIZE,
+ NULL, 0, NULL, 0,
+ key /* secret */, key_len /* secret length */,
+ export_tmp1 /* output */,
+ export_tmp2 /* scratch space */,
+ EVP_CIPHER_key_length(s->s3->tmp.new_sym_enc) /* output length */))
+ return 0;
+ key = export_tmp1;
+
+ if (iv_len > 0)
+ {
+ static const unsigned char empty[] = "";
+
if (!tls1_PRF(ssl_get_algorithm2(s),
- TLS_MD_IV_BLOCK_CONST,TLS_MD_IV_BLOCK_CONST_SIZE,
- s->s3->client_random,SSL3_RANDOM_SIZE,
- s->s3->server_random,SSL3_RANDOM_SIZE,
- NULL,0,NULL,0,
- empty,0,iv1,iv2,k*2))
- goto err2;
- if (client_write)
- iv=iv1;
+ TLS_MD_IV_BLOCK_CONST, TLS_MD_IV_BLOCK_CONST_SIZE,
+ s->s3->client_random, SSL3_RANDOM_SIZE,
+ s->s3->server_random, SSL3_RANDOM_SIZE,
+ NULL, 0, NULL, 0,
+ empty /* secret */ ,0 /* secret length */,
+ export_iv1 /* output */,
+ export_iv2 /* scratch space */,
+ iv_len * 2 /* output length */))
+ return 0;
+
+ if (use_client_keys)
+ iv = export_iv1;
else
- iv= &(iv1[k]);
+ iv = &export_iv1[iv_len];
}
}
- s->session->key_arg_length=0;
-#ifdef KSSL_DEBUG
- {
- int i;
- printf("EVP_CipherInit_ex(dd,c,key=,iv=,which)\n");
- printf("\tkey= "); for (i=0; i<c->key_len; i++) printf("%02x", key[i]);
- printf("\n");
- printf("\t iv= "); for (i=0; i<c->iv_len; i++) printf("%02x", iv[i]);
- printf("\n");
- }
-#endif /* KSSL_DEBUG */
+ /* is_aead_cipher indicates whether the EVP_CIPHER implements an AEAD
+ * interface. This is different from the newer EVP_AEAD interface. */
+ is_aead_cipher = (EVP_CIPHER_flags(cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) != 0;
- if (EVP_CIPHER_mode(c) == EVP_CIPH_GCM_MODE)
+ if (!is_aead_cipher)
{
- EVP_CipherInit_ex(dd,c,NULL,key,NULL,(which & SSL3_CC_WRITE));
- EVP_CIPHER_CTX_ctrl(dd, EVP_CTRL_GCM_SET_IV_FIXED, k, iv);
+ EVP_PKEY *mac_key =
+ EVP_PKEY_new_mac_key(s->s3->tmp.new_mac_pkey_type,
+ NULL, mac_secret, mac_secret_len);
+ if (!mac_key)
+ return 0;
+ EVP_DigestSignInit(mac_ctx, NULL, s->s3->tmp.new_hash, NULL, mac_key);
+ EVP_PKEY_free(mac_key);
}
- else
- EVP_CipherInit_ex(dd,c,NULL,key,iv,(which & SSL3_CC_WRITE));
+
+ if (EVP_CIPHER_mode(cipher) == EVP_CIPH_GCM_MODE)
+ {
+ EVP_CipherInit_ex(cipher_ctx, cipher, NULL /* engine */, key,
+ NULL /* iv */, !is_read);
+ EVP_CIPHER_CTX_ctrl(cipher_ctx, EVP_CTRL_GCM_SET_IV_FIXED, iv_len, (void*) iv);
+ }
+ else
+ EVP_CipherInit_ex(cipher_ctx, cipher, NULL /* engine */, key, iv, !is_read);
/* Needed for "composite" AEADs, such as RC4-HMAC-MD5 */
- if ((EVP_CIPHER_flags(c)&EVP_CIPH_FLAG_AEAD_CIPHER) && *mac_secret_size)
- EVP_CIPHER_CTX_ctrl(dd,EVP_CTRL_AEAD_SET_MAC_KEY,
- *mac_secret_size,mac_secret);
+ if (is_aead_cipher && mac_secret_len > 0)
+ EVP_CIPHER_CTX_ctrl(cipher_ctx, EVP_CTRL_AEAD_SET_MAC_KEY,
+ mac_secret_len, (void*) mac_secret);
-#ifdef OPENSSL_SSL_TRACE_CRYPTO
- if (s->msg_callback)
+ if (is_export)
{
- int wh = which & SSL3_CC_WRITE ? TLS1_RT_CRYPTO_WRITE : 0;
- if (*mac_secret_size)
- s->msg_callback(2, s->version, wh | TLS1_RT_CRYPTO_MAC,
- mac_secret, *mac_secret_size,
- s, s->msg_callback_arg);
- if (c->key_len)
- s->msg_callback(2, s->version, wh | TLS1_RT_CRYPTO_KEY,
- key, c->key_len,
- s, s->msg_callback_arg);
- if (k)
- {
- if (EVP_CIPHER_mode(c) == EVP_CIPH_GCM_MODE)
- wh |= TLS1_RT_CRYPTO_FIXED_IV;
- else
- wh |= TLS1_RT_CRYPTO_IV;
- s->msg_callback(2, s->version, wh, iv, k,
- s, s->msg_callback_arg);
- }
+ OPENSSL_cleanse(export_tmp1, sizeof(export_tmp1));
+ OPENSSL_cleanse(export_tmp2, sizeof(export_tmp1));
+ OPENSSL_cleanse(export_iv1, sizeof(export_iv1));
+ OPENSSL_cleanse(export_iv2, sizeof(export_iv2));
}
-#endif
-#ifdef TLS_DEBUG
-printf("which = %04X\nkey=",which);
-{ int z; for (z=0; z<EVP_CIPHER_key_length(c); z++) printf("%02X%c",key[z],((z+1)%16)?' ':'\n'); }
-printf("\niv=");
-{ int z; for (z=0; z<k; z++) printf("%02X%c",iv[z],((z+1)%16)?' ':'\n'); }
-printf("\n");
-#endif
+ return 1;
- OPENSSL_cleanse(tmp1,sizeof(tmp1));
- OPENSSL_cleanse(tmp2,sizeof(tmp1));
- OPENSSL_cleanse(iv1,sizeof(iv1));
- OPENSSL_cleanse(iv2,sizeof(iv2));
- return(1);
err:
- OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state, ERR_R_MALLOC_FAILURE);
-err2:
- return(0);
+ OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state_cipher, ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+
+int tls1_change_cipher_state(SSL *s, int which)
+ {
+ /* is_read is true if we have just read a ChangeCipherSpec message -
+ * i.e. we need to update the read cipherspec. Otherwise we have just
+ * written one. */
+ const char is_read = (which & SSL3_CC_READ) != 0;
+ /* use_client_keys is true if we wish to use the keys for the "client
+ * write" direction. This is the case if we're a client sending a
+ * ChangeCipherSpec, or a server reading a client's ChangeCipherSpec. */
+ const char use_client_keys = which == SSL3_CHANGE_CIPHER_CLIENT_WRITE ||
+ which == SSL3_CHANGE_CIPHER_SERVER_READ;
+ const unsigned char *client_write_mac_secret, *server_write_mac_secret, *mac_secret;
+ const unsigned char *client_write_key, *server_write_key, *key;
+ const unsigned char *client_write_iv, *server_write_iv, *iv;
+ const EVP_CIPHER *cipher = s->s3->tmp.new_sym_enc;
+ unsigned key_len, iv_len, mac_secret_len;
+ const unsigned char *key_data;
+ const char is_export = SSL_C_IS_EXPORT(s->s3->tmp.new_cipher) != 0;
+
+ /* Reset sequence number to zero. */
+ if (s->version != DTLS1_VERSION)
+ memset(is_read ? s->s3->read_sequence : s->s3->write_sequence, 0, 8);
+
+ /* key_arg is used for SSLv2. We don't need it for TLS. */
+ s->session->key_arg_length = 0;
+
+ mac_secret_len = s->s3->tmp.new_mac_secret_size;
+
+ key_len = EVP_CIPHER_key_length(cipher);
+ if (is_export && key_len > SSL_C_EXPORT_KEYLENGTH(s->s3->tmp.new_cipher))
+ key_len = SSL_C_EXPORT_KEYLENGTH(s->s3->tmp.new_cipher);
+
+ if (EVP_CIPHER_mode(cipher) == EVP_CIPH_GCM_MODE)
+ iv_len = EVP_GCM_TLS_FIXED_IV_LEN;
+ else
+ iv_len = EVP_CIPHER_iv_length(cipher);
+
+ key_data = s->s3->tmp.key_block;
+ client_write_mac_secret = key_data; key_data += mac_secret_len;
+ server_write_mac_secret = key_data; key_data += mac_secret_len;
+ client_write_key = key_data; key_data += key_len;
+ server_write_key = key_data; key_data += key_len;
+ client_write_iv = key_data; key_data += iv_len;
+ server_write_iv = key_data; key_data += iv_len;
+
+ if (use_client_keys)
+ {
+ mac_secret = client_write_mac_secret;
+ key = client_write_key;
+ iv = client_write_iv;
+ }
+ else
+ {
+ mac_secret = server_write_mac_secret;
+ key = server_write_key;
+ iv = server_write_iv;
+ }
+
+ if (key_data - s->s3->tmp.key_block != s->s3->tmp.key_block_length)
+ {
+ OPENSSL_PUT_ERROR(SSL, tls1_change_cipher_state, ERR_R_INTERNAL_ERROR);
+ return 0;
+ }
+
+ if (!tls1_change_cipher_state_cipher(s, is_read, use_client_keys,
+ mac_secret, mac_secret_len,
+ key, key_len,
+ iv, iv_len)) {
+ return 0;
+ }
+
+ return 1;
}
int tls1_setup_key_block(SSL *s)
@@ -565,6 +568,7 @@
SSL_COMP *comp;
int mac_type= NID_undef,mac_secret_size=0;
int ret=0;
+ int iv_len;
#ifdef KSSL_DEBUG
printf ("tls1_setup_key_block()\n");
@@ -579,11 +583,16 @@
return(0);
}
+ if (EVP_CIPHER_mode(c) == EVP_CIPH_GCM_MODE)
+ iv_len = EVP_GCM_TLS_FIXED_IV_LEN;
+ else
+ iv_len = EVP_CIPHER_iv_length(c);
+
s->s3->tmp.new_sym_enc=c;
s->s3->tmp.new_hash=hash;
s->s3->tmp.new_mac_pkey_type = mac_type;
s->s3->tmp.new_mac_secret_size = mac_secret_size;
- num=EVP_CIPHER_key_length(c)+mac_secret_size+EVP_CIPHER_iv_length(c);
+ num=EVP_CIPHER_key_length(c)+mac_secret_size+iv_len;
num*=2;
ssl3_cleanup_key_block(s);
