Author: jhb
Date: Wed Jan 24 20:15:49 2018
New Revision: 328360
URL: https://svnweb.freebsd.org/changeset/base/328360
Log:
Don't read or generate an IV until all error checking is complete.
In particular, this avoids edge cases where a generated IV might be
written into the output buffer even though the request is failed with
an error.
Sponsored by: Chelsio Communications
Modified:
head/sys/dev/cxgbe/crypto/t4_crypto.c
Modified: head/sys/dev/cxgbe/crypto/t4_crypto.c
==============================================================================
--- head/sys/dev/cxgbe/crypto/t4_crypto.c Wed Jan 24 20:14:57 2018
(r328359)
+++ head/sys/dev/cxgbe/crypto/t4_crypto.c Wed Jan 24 20:15:49 2018
(r328360)
@@ -581,24 +581,11 @@ ccr_blkcipher(struct ccr_softc *sc, uint32_t sid, stru
if (crd->crd_len > MAX_REQUEST_SIZE)
return (EFBIG);
- if (crd->crd_flags & CRD_F_ENCRYPT) {
+ if (crd->crd_flags & CRD_F_ENCRYPT)
op_type = CHCR_ENCRYPT_OP;
- if (crd->crd_flags & CRD_F_IV_EXPLICIT)
- memcpy(iv, crd->crd_iv, s->blkcipher.iv_len);
- else
- arc4rand(iv, s->blkcipher.iv_len, 0);
- if ((crd->crd_flags & CRD_F_IV_PRESENT) == 0)
- crypto_copyback(crp->crp_flags, crp->crp_buf,
- crd->crd_inject, s->blkcipher.iv_len, iv);
- } else {
+ else
op_type = CHCR_DECRYPT_OP;
- if (crd->crd_flags & CRD_F_IV_EXPLICIT)
- memcpy(iv, crd->crd_iv, s->blkcipher.iv_len);
- else
- crypto_copydata(crp->crp_flags, crp->crp_buf,
- crd->crd_inject, s->blkcipher.iv_len, iv);
- }
-
+
sglist_reset(sc->sg_dsgl);
error = sglist_append_sglist(sc->sg_dsgl, sc->sg_crp, crd->crd_skip,
crd->crd_len);
@@ -641,6 +628,27 @@ ccr_blkcipher(struct ccr_softc *sc, uint32_t sid, stru
crwr = wrtod(wr);
memset(crwr, 0, wr_len);
+ /*
+ * Read the existing IV from the request or generate a random
+ * one if none is provided. Optionally copy the generated IV
+ * into the output buffer if requested.
+ */
+ if (op_type == CHCR_ENCRYPT_OP) {
+ if (crd->crd_flags & CRD_F_IV_EXPLICIT)
+ memcpy(iv, crd->crd_iv, s->blkcipher.iv_len);
+ else
+ arc4rand(iv, s->blkcipher.iv_len, 0);
+ if ((crd->crd_flags & CRD_F_IV_PRESENT) == 0)
+ crypto_copyback(crp->crp_flags, crp->crp_buf,
+ crd->crd_inject, s->blkcipher.iv_len, iv);
+ } else {
+ if (crd->crd_flags & CRD_F_IV_EXPLICIT)
+ memcpy(iv, crd->crd_iv, s->blkcipher.iv_len);
+ else
+ crypto_copydata(crp->crp_flags, crp->crp_buf,
+ crd->crd_inject, s->blkcipher.iv_len, iv);
+ }
+
ccr_populate_wreq(sc, crwr, kctx_len, wr_len, sid, imm_len, sgl_len, 0,
crp);
@@ -799,30 +807,10 @@ ccr_authenc(struct ccr_softc *sc, uint32_t sid, struct
axf = s->hmac.auth_hash;
hash_size_in_response = s->hmac.hash_len;
-
- /*
- * The IV is always stored at the start of the buffer even
- * though it may be duplicated in the payload. The crypto
- * engine doesn't work properly if the IV offset points inside
- * of the AAD region, so a second copy is always required.
- */
- if (crde->crd_flags & CRD_F_ENCRYPT) {
+ if (crde->crd_flags & CRD_F_ENCRYPT)
op_type = CHCR_ENCRYPT_OP;
- if (crde->crd_flags & CRD_F_IV_EXPLICIT)
- memcpy(iv, crde->crd_iv, s->blkcipher.iv_len);
- else
- arc4rand(iv, s->blkcipher.iv_len, 0);
- if ((crde->crd_flags & CRD_F_IV_PRESENT) == 0)
- crypto_copyback(crp->crp_flags, crp->crp_buf,
- crde->crd_inject, s->blkcipher.iv_len, iv);
- } else {
+ else
op_type = CHCR_DECRYPT_OP;
- if (crde->crd_flags & CRD_F_IV_EXPLICIT)
- memcpy(iv, crde->crd_iv, s->blkcipher.iv_len);
- else
- crypto_copydata(crp->crp_flags, crp->crp_buf,
- crde->crd_inject, s->blkcipher.iv_len, iv);
- }
/*
* The output buffer consists of the cipher text followed by
@@ -876,6 +864,12 @@ ccr_authenc(struct ccr_softc *sc, uint32_t sid, struct
* The input buffer consists of the IV, any AAD, and then the
* cipher/plain text. For decryption requests the hash is
* appended after the cipher text.
+ *
+ * The IV is always stored at the start of the input buffer
+ * even though it may be duplicated in the payload. The
+ * crypto engine doesn't work properly if the IV offset points
+ * inside of the AAD region, so a second copy is always
+ * required.
*/
input_len = aad_len + crde->crd_len;
@@ -964,6 +958,27 @@ ccr_authenc(struct ccr_softc *sc, uint32_t sid, struct
crwr = wrtod(wr);
memset(crwr, 0, wr_len);
+ /*
+ * Read the existing IV from the request or generate a random
+ * one if none is provided. Optionally copy the generated IV
+ * into the output buffer if requested.
+ */
+ if (op_type == CHCR_ENCRYPT_OP) {
+ if (crde->crd_flags & CRD_F_IV_EXPLICIT)
+ memcpy(iv, crde->crd_iv, s->blkcipher.iv_len);
+ else
+ arc4rand(iv, s->blkcipher.iv_len, 0);
+ if ((crde->crd_flags & CRD_F_IV_PRESENT) == 0)
+ crypto_copyback(crp->crp_flags, crp->crp_buf,
+ crde->crd_inject, s->blkcipher.iv_len, iv);
+ } else {
+ if (crde->crd_flags & CRD_F_IV_EXPLICIT)
+ memcpy(iv, crde->crd_iv, s->blkcipher.iv_len);
+ else
+ crypto_copydata(crp->crp_flags, crp->crp_buf,
+ crde->crd_inject, s->blkcipher.iv_len, iv);
+ }
+
ccr_populate_wreq(sc, crwr, kctx_len, wr_len, sid, imm_len, sgl_len,
op_type == CHCR_DECRYPT_OP ? hash_size_in_response : 0, crp);
@@ -1129,47 +1144,30 @@ ccr_gcm(struct ccr_softc *sc, uint32_t sid, struct ccr
return (EMSGSIZE);
hash_size_in_response = s->gmac.hash_len;
-
- /*
- * The IV is always stored at the start of the buffer even
- * though it may be duplicated in the payload. The crypto
- * engine doesn't work properly if the IV offset points inside
- * of the AAD region, so a second copy is always required.
- *
- * The IV for GCM is further complicated in that IPSec
- * provides a full 16-byte IV (including the counter), whereas
- * the /dev/crypto interface sometimes provides a full 16-byte
- * IV (if no IV is provided in the ioctl) and sometimes a
- * 12-byte IV (if the IV was explicit). For now the driver
- * always assumes a 12-byte IV and initializes the low 4 byte
- * counter to 1.
- */
- if (crde->crd_flags & CRD_F_ENCRYPT) {
+ if (crde->crd_flags & CRD_F_ENCRYPT)
op_type = CHCR_ENCRYPT_OP;
- if (crde->crd_flags & CRD_F_IV_EXPLICIT)
- memcpy(iv, crde->crd_iv, s->blkcipher.iv_len);
- else
- arc4rand(iv, s->blkcipher.iv_len, 0);
- if ((crde->crd_flags & CRD_F_IV_PRESENT) == 0)
- crypto_copyback(crp->crp_flags, crp->crp_buf,
- crde->crd_inject, s->blkcipher.iv_len, iv);
- } else {
+ else
op_type = CHCR_DECRYPT_OP;
- if (crde->crd_flags & CRD_F_IV_EXPLICIT)
- memcpy(iv, crde->crd_iv, s->blkcipher.iv_len);
- else
- crypto_copydata(crp->crp_flags, crp->crp_buf,
- crde->crd_inject, s->blkcipher.iv_len, iv);
- }
/*
- * If the input IV is 12 bytes, append an explicit counter of
- * 1.
+ * The IV handling for GCM in OCF is a bit more complicated in
+ * that IPSec provides a full 16-byte IV (including the
+ * counter), whereas the /dev/crypto interface sometimes
+ * provides a full 16-byte IV (if no IV is provided in the
+ * ioctl) and sometimes a 12-byte IV (if the IV was explicit).
+ *
+ * When provided a 12-byte IV, assume the IV is really 16 bytes
+ * with a counter in the last 4 bytes initialized to 1.
+ *
+ * While iv_len is checked below, the value is currently
+ * always set to 12 when creating a GCM session in this driver
+ * due to limitations in OCF (there is no way to know what the
+ * IV length of a given request will be). This means that the
+ * driver always assumes as 12-byte IV for now.
*/
- if (s->blkcipher.iv_len == 12) {
- *(uint32_t *)&iv[12] = htobe32(1);
+ if (s->blkcipher.iv_len == 12)
iv_len = AES_BLOCK_LEN;
- } else
+ else
iv_len = s->blkcipher.iv_len;
/*
@@ -1220,6 +1218,12 @@ ccr_gcm(struct ccr_softc *sc, uint32_t sid, struct ccr
* The input buffer consists of the IV, any AAD, and then the
* cipher/plain text. For decryption requests the hash is
* appended after the cipher text.
+ *
+ * The IV is always stored at the start of the input buffer
+ * even though it may be duplicated in the payload. The
+ * crypto engine doesn't work properly if the IV offset points
+ * inside of the AAD region, so a second copy is always
+ * required.
*/
input_len = crda->crd_len + crde->crd_len;
if (op_type == CHCR_DECRYPT_OP)
@@ -1281,6 +1285,32 @@ ccr_gcm(struct ccr_softc *sc, uint32_t sid, struct ccr
}
crwr = wrtod(wr);
memset(crwr, 0, wr_len);
+
+ /*
+ * Read the existing IV from the request or generate a random
+ * one if none is provided. Optionally copy the generated IV
+ * into the output buffer if requested.
+ *
+ * If the input IV is 12 bytes, append an explicit 4-byte
+ * counter of 1.
+ */
+ if (op_type == CHCR_ENCRYPT_OP) {
+ if (crde->crd_flags & CRD_F_IV_EXPLICIT)
+ memcpy(iv, crde->crd_iv, s->blkcipher.iv_len);
+ else
+ arc4rand(iv, s->blkcipher.iv_len, 0);
+ if ((crde->crd_flags & CRD_F_IV_PRESENT) == 0)
+ crypto_copyback(crp->crp_flags, crp->crp_buf,
+ crde->crd_inject, s->blkcipher.iv_len, iv);
+ } else {
+ if (crde->crd_flags & CRD_F_IV_EXPLICIT)
+ memcpy(iv, crde->crd_iv, s->blkcipher.iv_len);
+ else
+ crypto_copydata(crp->crp_flags, crp->crp_buf,
+ crde->crd_inject, s->blkcipher.iv_len, iv);
+ }
+ if (s->blkcipher.iv_len == 12)
+ *(uint32_t *)&iv[12] = htobe32(1);
ccr_populate_wreq(sc, crwr, kctx_len, wr_len, sid, imm_len, sgl_len,
0, crp);
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