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Add CCM mode support for TLS 1.3

Browse source 
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2550)
This commit is contained in:
Dr. Stephen Henson 2017-02-03 02:44:15 +00:00
parent aa24c47c83
commit ec07b1d872
3 changed files with 41 additions and 22 deletions
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37
ssl/record/ssl3_record_tls13.c
View file

@ -24,7 +24,7 @@ int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int send)
{
EVP_CIPHER_CTX *ctx;
unsigned char iv[EVP_MAX_IV_LENGTH];
size_t ivlen, offset, loop;
size_t ivlen, taglen, offset, loop;
unsigned char *staticiv;
unsigned char *seq;
int lenu, lenf;
@ -53,21 +53,27 @@ int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int send)
}
ivlen = EVP_CIPHER_CTX_iv_length(ctx);
if (EVP_CIPHER_CTX_mode(ctx) == EVP_CIPH_CCM_MODE) {
if (s->s3->tmp.new_cipher->algorithm_enc
& (SSL_AES128CCM8 | SSL_AES256CCM8))
taglen = EVP_CCM8_TLS_TAG_LEN;
else
taglen = EVP_CCM_TLS_TAG_LEN;
if (send && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, taglen,
NULL) <= 0)
return -1;
} else {
taglen = EVP_GCM_TLS_TAG_LEN;
}
if (!send) {
/*
* Take off tag. There must be at least one byte of content type as
* well as the tag
*/
/*
* TODO(TLS1.3): We're going to need to figure out the tag len based on
* the cipher. For now we just support GCM tags.
* TODO(TLS1.3): When we've swapped over the record layer to TLSv1.3
* then the length must be 1 + the tag len to account for the content
* byte that we know must have been encrypted.
*/
if (rec->length < EVP_GCM_TLS_TAG_LEN)
if (rec->length < taglen + 1)
return 0;
rec->length -= EVP_GCM_TLS_TAG_LEN;
rec->length -= taglen;
}
/* Set up IV */
@ -93,22 +99,21 @@ int tls13_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int send)
/* TODO(size_t): lenu/lenf should be a size_t but EVP doesn't support it */
if (EVP_CipherInit_ex(ctx, NULL, NULL, NULL, iv, send) <= 0
|| (!send && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG,
taglen,
rec->data + rec->length) <= 0)
|| EVP_CipherUpdate(ctx, rec->data, &lenu, rec->input,
(unsigned int)rec->length) <= 0
|| (!send && EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG,
EVP_GCM_TLS_TAG_LEN,
rec->data + rec->length) <= 0)
|| EVP_CipherFinal_ex(ctx, rec->data + lenu, &lenf) <= 0
|| (size_t)(lenu + lenf) != rec->length) {
return -1;
}
if (send) {
/* Add the tag */
if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, EVP_GCM_TLS_TAG_LEN,
if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, taglen,
rec->data + rec->length) <= 0)
return -1;
rec->length += EVP_GCM_TLS_TAG_LEN;
rec->length += taglen;
}
return 1;

4
ssl/t1_enc.c
View file

@ -281,9 +281,9 @@ int tls1_change_cipher_state(SSL *s, int which)
int taglen;
if (s->s3->tmp.
new_cipher->algorithm_enc & (SSL_AES128CCM8 | SSL_AES256CCM8))
taglen = 8;
taglen = EVP_CCM8_TLS_TAG_LEN;
else
taglen = 16;
taglen = EVP_CCM_TLS_TAG_LEN;
if (!EVP_CipherInit_ex(dd, c, NULL, NULL, NULL, (which & SSL3_CC_WRITE))
|| !EVP_CIPHER_CTX_ctrl(dd, EVP_CTRL_AEAD_SET_IVLEN, 12, NULL)
|| !EVP_CIPHER_CTX_ctrl(dd, EVP_CTRL_AEAD_SET_TAG, taglen, NULL)

20
ssl/tls13_enc.c
View file

@ -264,7 +264,7 @@ int tls13_change_cipher_state(SSL *s, int which)
const char *log_label = NULL;
EVP_CIPHER_CTX *ciph_ctx;
const EVP_CIPHER *ciph = s->s3->tmp.new_sym_enc;
size_t ivlen, keylen, finsecretlen = 0;
size_t ivlen, keylen, taglen, finsecretlen = 0;
const unsigned char *label;
size_t labellen, hashlen = 0;
int ret = 0;
@ -373,7 +373,17 @@ int tls13_change_cipher_state(SSL *s, int which)
/* TODO(size_t): convert me */
keylen = EVP_CIPHER_key_length(ciph);
if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) {
ivlen = EVP_CCM_TLS_IV_LEN;
if (s->s3->tmp.new_cipher->algorithm_enc
& (SSL_AES128CCM8 | SSL_AES256CCM8))
taglen = EVP_CCM8_TLS_TAG_LEN;
else
taglen = EVP_CCM_TLS_TAG_LEN;
} else {
ivlen = EVP_CIPHER_iv_length(ciph);
taglen = 0;
}
if (!ssl_log_secret(s, log_label, secret, hashlen)) {
SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
@ -391,8 +401,12 @@ int tls13_change_cipher_state(SSL *s, int which)
goto err;
}
if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, key, NULL,
(which & SSL3_CC_WRITE)) <= 0) {
if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL,
(which & SSL3_CC_WRITE)) <= 0
|| !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL)
|| (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG,
taglen, NULL))
|| EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) {
SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_EVP_LIB);
goto err;
}