NIST SP800-38A recommends two methods to generate unpredictable IVs
(Initilisation Vector) for CBC mode:
1) Apply the forward function to a nonce (ie. counter)
2) Use a FIPS-approved random number generator
This patch implements the first recommended method by using the forward
function to generate the IV.
Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy at intel.com>
---
examples/ipsec-secgw/esp.c | 99 +++++++++++++++++++++++++-------------------
examples/ipsec-secgw/ipsec.h | 33 ++++++++++++++-
2 files changed, 88 insertions(+), 44 deletions(-)
diff --git a/examples/ipsec-secgw/esp.c b/examples/ipsec-secgw/esp.c
index 05caa77..d640ab2 100644
--- a/examples/ipsec-secgw/esp.c
+++ b/examples/ipsec-secgw/esp.c
@@ -50,21 +50,6 @@
#include "esp.h"
#include "ipip.h"
-static inline void
-random_iv_u64(uint64_t *buf, uint16_t n)
-{
- uint32_t left = n & 0x7;
- uint32_t i;
-
- RTE_ASSERT((n & 0x3) == 0);
-
- for (i = 0; i < (n >> 3); i++)
- buf[i] = rte_rand();
-
- if (left)
- *((uint32_t *)&buf[i]) = (uint32_t)lrand48();
-}
-
int
esp_inbound(struct rte_mbuf *m, struct ipsec_sa *sa,
struct rte_crypto_op *cop)
@@ -98,22 +83,32 @@ esp_inbound(struct rte_mbuf *m, struct ipsec_sa *sa,
return -EINVAL;
}
- sym_cop = (struct rte_crypto_sym_op *)(cop + 1);
+ sym_cop = get_sym_cop(cop);
sym_cop->m_src = m;
sym_cop->cipher.data.offset = ip_hdr_len + sizeof(struct esp_hdr) +
sa->iv_len;
sym_cop->cipher.data.length = payload_len;
- sym_cop->cipher.iv.data = rte_pktmbuf_mtod_offset(m, void*,
- ip_hdr_len + sizeof(struct esp_hdr));
- sym_cop->cipher.iv.phys_addr = rte_pktmbuf_mtophys_offset(m,
- ip_hdr_len + sizeof(struct esp_hdr));
- sym_cop->cipher.iv.length = sa->iv_len;
+ uint8_t *iv = RTE_PTR_ADD(ip4, ip_hdr_len + sizeof(struct esp_hdr));
+
+ switch (sa->cipher_algo) {
+ case RTE_CRYPTO_CIPHER_NULL:
+ case RTE_CRYPTO_CIPHER_AES_CBC:
+ sym_cop->cipher.iv.data = iv;
+ sym_cop->cipher.iv.phys_addr = rte_pktmbuf_mtophys_offset(m,
+ ip_hdr_len + sizeof(struct esp_hdr));
+ sym_cop->cipher.iv.length = sa->iv_len;
- sym_cop->auth.data.offset = ip_hdr_len;
- sym_cop->auth.data.length = sizeof(struct esp_hdr) +
- sa->iv_len + payload_len;
+ sym_cop->auth.data.offset = ip_hdr_len;
+ sym_cop->auth.data.length = sizeof(struct esp_hdr) +
+ sa->iv_len + payload_len;
+ break;
+ default:
+ RTE_LOG(ERR, IPSEC_ESP, "unsupported cipher algorithm %u\n",
+ sa->cipher_algo);
+ return -EINVAL;
+ }
sym_cop->auth.digest.data = rte_pktmbuf_mtod_offset(m, void*,
rte_pktmbuf_pkt_len(m) - sa->digest_len);
@@ -282,10 +277,25 @@ esp_outbound(struct rte_mbuf *m, struct ipsec_sa *sa,
sa->seq++;
esp->spi = rte_cpu_to_be_32(sa->spi);
- esp->seq = rte_cpu_to_be_32(sa->seq);
+ esp->seq = rte_cpu_to_be_32((uint32_t)sa->seq);
- if (sa->cipher_algo == RTE_CRYPTO_CIPHER_AES_CBC)
- random_iv_u64((uint64_t *)(esp + 1), sa->iv_len);
+ uint64_t *iv = (uint64_t *)(esp + 1);
+
+ sym_cop = get_sym_cop(cop);
+ sym_cop->m_src = m;
+ switch (sa->cipher_algo) {
+ case RTE_CRYPTO_CIPHER_NULL:
+ case RTE_CRYPTO_CIPHER_AES_CBC:
+ memset(iv, 0, sa->iv_len);
+ sym_cop->cipher.data.offset = ip_hdr_len +
+ sizeof(struct esp_hdr);
+ sym_cop->cipher.data.length = pad_payload_len + sa->iv_len;
+ break;
+ default:
+ RTE_LOG(ERR, IPSEC_ESP, "unsupported cipher algorithm %u\n",
+ sa->cipher_algo);
+ return -EINVAL;
+ }
/* Fill pad_len using default sequential scheme */
for (i = 0; i < pad_len - 2; i++)
@@ -293,22 +303,27 @@ esp_outbound(struct rte_mbuf *m, struct ipsec_sa *sa,
padding[pad_len - 2] = pad_len - 2;
padding[pad_len - 1] = nlp;
- sym_cop = (struct rte_crypto_sym_op *)(cop + 1);
-
- sym_cop->m_src = m;
- sym_cop->cipher.data.offset = ip_hdr_len + sizeof(struct esp_hdr) +
- sa->iv_len;
- sym_cop->cipher.data.length = pad_payload_len;
-
- sym_cop->cipher.iv.data = rte_pktmbuf_mtod_offset(m, uint8_t *,
- ip_hdr_len + sizeof(struct esp_hdr));
+ struct cnt_blk *nonce = get_cnt_blk(m);
+ nonce->salt = sa->salt;
+ nonce->iv = sa->seq;
+ sym_cop->cipher.iv.data = (uint8_t *)nonce;
sym_cop->cipher.iv.phys_addr = rte_pktmbuf_mtophys_offset(m,
- ip_hdr_len + sizeof(struct esp_hdr));
- sym_cop->cipher.iv.length = sa->iv_len;
-
- sym_cop->auth.data.offset = ip_hdr_len;
- sym_cop->auth.data.length = sizeof(struct esp_hdr) + sa->iv_len +
- pad_payload_len;
+ (uint8_t *)nonce - rte_pktmbuf_mtod(m, uint8_t *));
+ /* FIXME should be 12 for GCM, but API needs 16 */
+ sym_cop->cipher.iv.length = 16;
+
+ switch (sa->cipher_algo) {
+ case RTE_CRYPTO_CIPHER_NULL:
+ case RTE_CRYPTO_CIPHER_AES_CBC:
+ sym_cop->auth.data.offset = ip_hdr_len;
+ sym_cop->auth.data.length = sizeof(struct esp_hdr) +
+ sa->iv_len + pad_payload_len;
+ break;
+ default:
+ RTE_LOG(ERR, IPSEC_ESP, "unsupported cipher algorithm %u\n",
+ sa->cipher_algo);
+ return -EINVAL;
+ }
sym_cop->auth.digest.data = rte_pktmbuf_mtod_offset(m, uint8_t *,
rte_pktmbuf_pkt_len(m) - sa->digest_len);
diff --git a/examples/ipsec-secgw/ipsec.h b/examples/ipsec-secgw/ipsec.h
index 4cc316c..d950df3 100644
--- a/examples/ipsec-secgw/ipsec.h
+++ b/examples/ipsec-secgw/ipsec.h
@@ -95,8 +95,9 @@ struct ip_addr {
struct ipsec_sa {
uint32_t spi;
uint32_t cdev_id_qp;
+ uint64_t seq;
+ uint32_t salt;
struct rte_cryptodev_sym_session *crypto_session;
- uint32_t seq;
enum rte_crypto_cipher_algorithm cipher_algo;
enum rte_crypto_auth_algorithm auth_algo;
uint16_t digest_len;
@@ -116,10 +117,11 @@ struct ipsec_sa {
} __rte_cache_aligned;
struct ipsec_mbuf_metadata {
+ uint8_t buf[32];
struct ipsec_sa *sa;
struct rte_crypto_op cop;
struct rte_crypto_sym_op sym_cop;
-};
+} __rte_cache_aligned;
struct cdev_qp {
uint16_t id;
@@ -157,6 +159,11 @@ struct socket_ctx {
struct rte_mempool *mbuf_pool;
};
+struct cnt_blk {
+ uint32_t salt;
+ uint64_t iv;
+};
+
uint16_t
ipsec_inbound(struct ipsec_ctx *ctx, struct rte_mbuf *pkts[],
uint16_t nb_pkts, uint16_t len);
@@ -177,6 +184,28 @@ get_priv(struct rte_mbuf *m)
return RTE_PTR_ADD(m, sizeof(struct rte_mbuf));
}
+static inline void *
+get_cnt_blk(struct rte_mbuf *m)
+{
+ struct ipsec_mbuf_metadata *priv = get_priv(m);
+
+ return &priv->buf[0];
+}
+
+static inline void *
+get_cop(struct rte_mbuf *m)
+{
+ struct ipsec_mbuf_metadata *priv = get_priv(m);
+
+ return &priv->cop;
+}
+
+static inline void *
+get_sym_cop(struct rte_crypto_op *cop)
+{
+ return (cop + 1);
+}
+
int
inbound_sa_check(struct sa_ctx *sa_ctx, struct rte_mbuf *m, uint32_t sa_idx);
--
2.5.5
