1 files changed, 94 insertions, 30 deletions

diff --git a/sys/opencrypto/cryptosoft.c b/sys/opencrypto/cryptosoft.c
index ae71f0d6c096..e51bade8a3f8 100644
--- a/sys/opencrypto/cryptosoft.c
+++ b/sys/opencrypto/cryptosoft.c
@@ -636,16 +636,69 @@ out:
 	return (error);
 }
 
+static void
+build_ccm_b0(const char *nonce, u_int nonce_length, u_int aad_length,
+    u_int data_length, u_int tag_length, uint8_t *b0)
+{
+	uint8_t *bp;
+	uint8_t flags, L;
+
+	KASSERT(nonce_length >= 7 && nonce_length <= 13,
+	    ("nonce_length must be between 7 and 13 bytes"));
+
+	/*
+	 * Need to determine the L field value.  This is the number of
+	 * bytes needed to specify the length of the message; the length
+	 * is whatever is left in the 16 bytes after specifying flags and
+	 * the nonce.
+	 */
+	L = 15 - nonce_length;
+
+	flags = ((aad_length > 0) << 6) +
+	    (((tag_length - 2) / 2) << 3) +
+	    L - 1;
+
+	/*
+	 * Now we need to set up the first block, which has flags, nonce,
+	 * and the message length.
+	 */
+	b0[0] = flags;
+	memcpy(b0 + 1, nonce, nonce_length);
+	bp = b0 + 1 + nonce_length;
+
+	/* Need to copy L' [aka L-1] bytes of data_length */
+	for (uint8_t *dst = b0 + CCM_CBC_BLOCK_LEN - 1; dst >= bp; dst--) {
+		*dst = data_length;
+		data_length >>= 8;
+	}
+}
+
+/* NB: OCF only supports AAD lengths < 2^32. */
+static int
+build_ccm_aad_length(u_int aad_length, uint8_t *blk)
+{
+	if (aad_length < ((1 << 16) - (1 << 8))) {
+		be16enc(blk, aad_length);
+		return (sizeof(uint16_t));
+	} else {
+		blk[0] = 0xff;
+		blk[1] = 0xfe;
+		be32enc(blk + 2, aad_length);
+		return (2 + sizeof(uint32_t));
+	}
+}
+
 static int
 swcr_ccm_cbc_mac(struct swcr_session *ses, struct cryptop *crp)
 {
-	u_char tag[AES_CBC_MAC_HASH_LEN];
 	u_char iv[AES_BLOCK_LEN];
+	u_char blk[CCM_CBC_BLOCK_LEN];
+	u_char tag[AES_CBC_MAC_HASH_LEN];
 	union authctx ctx;
 	const struct crypto_session_params *csp;
 	struct swcr_auth *swa;
 	const struct auth_hash *axf;
-	int error, ivlen;
+	int error, ivlen, len;
 
 	csp = crypto_get_params(crp->crp_session);
 	swa = &ses->swcr_auth;
@@ -657,25 +710,24 @@ swcr_ccm_cbc_mac(struct swcr_session *ses, struct cryptop *crp)
 	ivlen = csp->csp_ivlen;
 	crypto_read_iv(crp, iv);
 
-	/*
-	 * AES CCM-CBC-MAC needs to know the length of both the auth
-	 * data and payload data before doing the auth computation.
-	 */
-	ctx.aes_cbc_mac_ctx.authDataLength = crp->crp_payload_length;
-	ctx.aes_cbc_mac_ctx.cryptDataLength = 0;
+	/* Supply MAC with IV */
+	axf->Reinit(&ctx, crp->crp_iv, ivlen);
 
-	axf->Reinit(&ctx, iv, ivlen);
-	if (crp->crp_aad != NULL)
-		error = axf->Update(&ctx, crp->crp_aad, crp->crp_aad_length);
-	else
-		error = crypto_apply(crp, crp->crp_payload_start,
-		    crp->crp_payload_length, axf->Update, &ctx);
-	if (error)
-		return (error);
+	/* Supply MAC with b0. */
+	build_ccm_b0(crp->crp_iv, ivlen, crp->crp_payload_length, 0,
+	    swa->sw_mlen, blk);
+	axf->Update(&ctx, blk, CCM_CBC_BLOCK_LEN);
+
+	len = build_ccm_aad_length(crp->crp_payload_length, blk);
+	axf->Update(&ctx, blk, len);
+
+	crypto_apply(crp, crp->crp_payload_start, crp->crp_payload_length,
+	    axf->Update, &ctx);
 
 	/* Finalize MAC */
 	axf->Final(tag, &ctx);
 
+	error = 0;
 	if (crp->crp_op & CRYPTO_OP_VERIFY_DIGEST) {
 		u_char tag2[AES_CBC_MAC_HASH_LEN];
 
@@ -689,6 +741,7 @@ swcr_ccm_cbc_mac(struct swcr_session *ses, struct cryptop *crp)
 		crypto_copyback(crp, crp->crp_digest_start, swa->sw_mlen, tag);
 	}
 	explicit_bzero(tag, sizeof(tag));
+	explicit_bzero(blk, sizeof(blk));
 	explicit_bzero(iv, sizeof(iv));
 	return (error);
 }
@@ -733,24 +786,35 @@ swcr_ccm(struct swcr_session *ses, struct cryptop *crp)
 
 	ivlen = csp->csp_ivlen;
 
-	/*
-	 * AES CCM-CBC-MAC needs to know the length of both the auth
-	 * data and payload data before doing the auth computation.
-	 */
-	ctx.aes_cbc_mac_ctx.authDataLength = crp->crp_aad_length;
-	ctx.aes_cbc_mac_ctx.cryptDataLength = crp->crp_payload_length;
-
 	/* Supply MAC with IV */
 	axf->Reinit(&ctx, crp->crp_iv, ivlen);
 
+	/* Supply MAC with b0. */
+	_Static_assert(sizeof(blkbuf) >= CCM_CBC_BLOCK_LEN,
+	    "blkbuf too small for b0");
+	build_ccm_b0(crp->crp_iv, ivlen, crp->crp_aad_length,
+	    crp->crp_payload_length, swa->sw_mlen, blk);
+	axf->Update(&ctx, blk, CCM_CBC_BLOCK_LEN);
+
 	/* Supply MAC with AAD */
-	if (crp->crp_aad != NULL)
-		error = axf->Update(&ctx, crp->crp_aad, crp->crp_aad_length);
-	else
-		error = crypto_apply(crp, crp->crp_aad_start,
-		    crp->crp_aad_length, axf->Update, &ctx);
-	if (error)
-		return (error);
+	if (crp->crp_aad_length != 0) {
+		len = build_ccm_aad_length(crp->crp_aad_length, blk);
+		axf->Update(&ctx, blk, len);
+		if (crp->crp_aad != NULL)
+			axf->Update(&ctx, crp->crp_aad,
+			    crp->crp_aad_length);
+		else
+			crypto_apply(crp, crp->crp_aad_start,
+			    crp->crp_aad_length, axf->Update, &ctx);
+
+		/* Pad the AAD (including length field) to a full block. */
+		len = (len + crp->crp_aad_length) % CCM_CBC_BLOCK_LEN;
+		if (len != 0) {
+			len = CCM_CBC_BLOCK_LEN - len;
+			memset(blk, 0, CCM_CBC_BLOCK_LEN);
+			axf->Update(&ctx, blk, len);
+		}
+	}
 
 	if (crp->crp_cipher_key != NULL)
 		exf->setkey(swe->sw_kschedule, crp->crp_cipher_key,