git: 64c043d2d2cf - stable/13 - crypto: Support Chacha20-Poly1305 with a nonce size of 8 bytes.
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Date: Thu, 21 Oct 2021 22:04:29 UTC
The branch stable/13 has been updated by jhb:
URL: https://cgit.FreeBSD.org/src/commit/?id=64c043d2d2cfa44128361c9354d1fad023087be8
commit 64c043d2d2cfa44128361c9354d1fad023087be8
Author: John Baldwin <jhb@FreeBSD.org>
AuthorDate: 2021-10-06 21:08:49 +0000
Commit: John Baldwin <jhb@FreeBSD.org>
CommitDate: 2021-10-21 21:19:30 +0000
crypto: Support Chacha20-Poly1305 with a nonce size of 8 bytes.
This is useful for WireGuard which uses a nonce of 8 bytes rather
than the 12 bytes used for IPsec and TLS.
Note that this also fixes a (should be) harmless bug in ossl(4) where
the counter was incorrectly treated as a 64-bit counter instead of a
32-bit counter in terms of wrapping when using a 12 byte nonce.
However, this required a single message (TLS record) longer than 64 *
(2^32 - 1) bytes (about 256 GB) to trigger.
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D32122
(cherry picked from commit 42dcd39528c6188a259951e28bbad309234324e4)
---
share/man/man7/crypto.7 | 2 +-
sys/crypto/openssl/ossl_chacha20.c | 14 ++++++++------
sys/opencrypto/crypto.c | 7 ++++++-
sys/opencrypto/cryptosoft.c | 3 ---
sys/opencrypto/xform_chacha20_poly1305.c | 31 +++++++++++++++++++++++++------
tools/tools/crypto/cryptocheck.c | 4 ++--
6 files changed, 42 insertions(+), 19 deletions(-)
diff --git a/share/man/man7/crypto.7 b/share/man/man7/crypto.7
index d75daa62adcb..c7af22af4deb 100644
--- a/share/man/man7/crypto.7
+++ b/share/man/man7/crypto.7
@@ -167,7 +167,7 @@ The following AEAD algorithms are supported:
AES Galois/Counter Mode
.It Dv CRYPTO_AES_CCM_16 Ta 12, 7-13 Ta 16, 24, 32 Ta 16 Ta
AES Counter with CBC-MAC
-.It Dv CRYPTO_CHACHA20_POLY1305 Ta 12 Ta 32 Ta 16 Ta
+.It Dv CRYPTO_CHACHA20_POLY1305 Ta 12, 8 Ta 32 Ta 16 Ta
ChaCha20-Poly1305
.El
.Sh SEE ALSO
diff --git a/sys/crypto/openssl/ossl_chacha20.c b/sys/crypto/openssl/ossl_chacha20.c
index a6f56aca1f8f..aa125121e8b4 100644
--- a/sys/crypto/openssl/ossl_chacha20.c
+++ b/sys/crypto/openssl/ossl_chacha20.c
@@ -161,7 +161,8 @@ ossl_chacha20_poly1305_encrypt(struct cryptop *crp,
for (i = 0; i < nitems(key); i++)
key[i] = CHACHA_U8TOU32(cipher_key + i * 4);
- crypto_read_iv(crp, counter + 1);
+ memset(counter, 0, sizeof(counter));
+ crypto_read_iv(crp, counter + (CHACHA_CTR_SIZE - csp->csp_ivlen) / 4);
for (i = 1; i < nitems(counter); i++)
counter[i] = le32toh(counter[i]);
@@ -223,7 +224,7 @@ ossl_chacha20_poly1305_encrypt(struct cryptop *crp,
/* Truncate if the 32-bit counter would roll over. */
next_counter = counter[0] + todo / CHACHA_BLK_SIZE;
- if (next_counter < counter[0]) {
+ if (csp->csp_ivlen == 8 && next_counter < counter[0]) {
todo -= next_counter * CHACHA_BLK_SIZE;
next_counter = 0;
}
@@ -232,7 +233,7 @@ ossl_chacha20_poly1305_encrypt(struct cryptop *crp,
Poly1305_Update(&auth_ctx, out, todo);
counter[0] = next_counter;
- if (counter[0] == 0)
+ if (csp->csp_ivlen == 8 && counter[0] == 0)
counter[1]++;
if (out == block) {
@@ -307,7 +308,8 @@ ossl_chacha20_poly1305_decrypt(struct cryptop *crp,
for (i = 0; i < nitems(key); i++)
key[i] = CHACHA_U8TOU32(cipher_key + i * 4);
- crypto_read_iv(crp, counter + 1);
+ memset(counter, 0, sizeof(counter));
+ crypto_read_iv(crp, counter + (CHACHA_CTR_SIZE - csp->csp_ivlen) / 4);
for (i = 1; i < nitems(counter); i++)
counter[i] = le32toh(counter[i]);
@@ -391,7 +393,7 @@ ossl_chacha20_poly1305_decrypt(struct cryptop *crp,
/* Truncate if the 32-bit counter would roll over. */
next_counter = counter[0] + todo / CHACHA_BLK_SIZE;
- if (next_counter < counter[0]) {
+ if (csp->csp_ivlen == 8 && next_counter < counter[0]) {
todo -= next_counter * CHACHA_BLK_SIZE;
next_counter = 0;
}
@@ -399,7 +401,7 @@ ossl_chacha20_poly1305_decrypt(struct cryptop *crp,
ChaCha20_ctr32(out, in, todo, key, counter);
counter[0] = next_counter;
- if (counter[0] == 0)
+ if (csp->csp_ivlen == 8 && counter[0] == 0)
counter[1]++;
if (out == block) {
diff --git a/sys/opencrypto/crypto.c b/sys/opencrypto/crypto.c
index a3a42827d51b..f0fd3fe662a9 100644
--- a/sys/opencrypto/crypto.c
+++ b/sys/opencrypto/crypto.c
@@ -882,10 +882,15 @@ check_csp(const struct crypto_session_params *csp)
return (false);
break;
case CRYPTO_AES_NIST_GCM_16:
- case CRYPTO_CHACHA20_POLY1305:
if (csp->csp_auth_mlen > 16)
return (false);
break;
+ case CRYPTO_CHACHA20_POLY1305:
+ if (csp->csp_ivlen != 8 && csp->csp_ivlen != 12)
+ return (false);
+ if (csp->csp_auth_mlen > POLY1305_HASH_LEN)
+ return (false);
+ break;
}
break;
case CSP_MODE_ETA:
diff --git a/sys/opencrypto/cryptosoft.c b/sys/opencrypto/cryptosoft.c
index fb43a08970c7..567a0f4748d5 100644
--- a/sys/opencrypto/cryptosoft.c
+++ b/sys/opencrypto/cryptosoft.c
@@ -1393,9 +1393,6 @@ swcr_setup_chacha20_poly1305(struct swcr_session *ses,
struct swcr_auth *swa;
struct auth_hash *axf;
- if (csp->csp_ivlen != CHACHA20_POLY1305_IV_LEN)
- return (EINVAL);
-
/* First, setup the auth side. */
swa = &ses->swcr_auth;
axf = &auth_hash_chacha20_poly1305;
diff --git a/sys/opencrypto/xform_chacha20_poly1305.c b/sys/opencrypto/xform_chacha20_poly1305.c
index e893287145f2..f593faa9b5ef 100644
--- a/sys/opencrypto/xform_chacha20_poly1305.c
+++ b/sys/opencrypto/xform_chacha20_poly1305.c
@@ -34,6 +34,7 @@
struct chacha20_poly1305_cipher_ctx {
const void *key;
uint32_t ic;
+ bool ietf;
char nonce[CHACHA20_POLY1305_IV_LEN];
};
@@ -58,7 +59,8 @@ chacha20_poly1305_reinit(void *vctx, const uint8_t *iv, size_t ivlen)
("%s: invalid nonce length", __func__));
/* Block 0 is used for the poly1305 key. */
- memcpy(ctx->nonce, iv, sizeof(ctx->nonce));
+ memcpy(ctx->nonce, iv, ivlen);
+ ctx->ietf = (ivlen == CHACHA20_POLY1305_IV_LEN);
ctx->ic = 1;
}
@@ -68,8 +70,12 @@ chacha20_poly1305_crypt(void *vctx, const uint8_t *in, uint8_t *out)
struct chacha20_poly1305_cipher_ctx *ctx = vctx;
int error;
- error = crypto_stream_chacha20_ietf_xor_ic(out, in,
- CHACHA20_NATIVE_BLOCK_LEN, ctx->nonce, ctx->ic, ctx->key);
+ if (ctx->ietf)
+ error = crypto_stream_chacha20_ietf_xor_ic(out, in,
+ CHACHA20_NATIVE_BLOCK_LEN, ctx->nonce, ctx->ic, ctx->key);
+ else
+ error = crypto_stream_chacha20_xor_ic(out, in,
+ CHACHA20_NATIVE_BLOCK_LEN, ctx->nonce, ctx->ic, ctx->key);
KASSERT(error == 0, ("%s failed: %d", __func__, error));
ctx->ic++;
}
@@ -82,8 +88,12 @@ chacha20_poly1305_crypt_last(void *vctx, const uint8_t *in, uint8_t *out,
int error;
- error = crypto_stream_chacha20_ietf_xor_ic(out, in, len, ctx->nonce,
- ctx->ic, ctx->key);
+ if (ctx->ietf)
+ error = crypto_stream_chacha20_ietf_xor_ic(out, in, len,
+ ctx->nonce, ctx->ic, ctx->key);
+ else
+ error = crypto_stream_chacha20_xor_ic(out, in, len, ctx->nonce,
+ ctx->ic, ctx->key);
KASSERT(error == 0, ("%s failed: %d", __func__, error));
}
@@ -129,7 +139,16 @@ chacha20_poly1305_Reinit(void *vctx, const uint8_t *nonce, u_int noncelen)
struct chacha20_poly1305_auth_ctx *ctx = vctx;
char block[CHACHA20_NATIVE_BLOCK_LEN];
- crypto_stream_chacha20_ietf(block, sizeof(block), nonce, ctx->key);
+ switch (noncelen) {
+ case 8:
+ crypto_stream_chacha20(block, sizeof(block), nonce, ctx->key);
+ break;
+ case CHACHA20_POLY1305_IV_LEN:
+ crypto_stream_chacha20_ietf(block, sizeof(block), nonce, ctx->key);
+ break;
+ default:
+ __assert_unreachable();
+ }
crypto_onetimeauth_poly1305_init(&ctx->state, block);
explicit_bzero(block, sizeof(block));
}
diff --git a/tools/tools/crypto/cryptocheck.c b/tools/tools/crypto/cryptocheck.c
index 63c6ce1f9d28..05b761a0c87a 100644
--- a/tools/tools/crypto/cryptocheck.c
+++ b/tools/tools/crypto/cryptocheck.c
@@ -126,7 +126,7 @@
* aes-ccm 128-bit AES-CCM
* aes-ccm192 192-bit AES-CCM
* aes-ccm256 256-bit AES-CCM
- * chacha20-poly1305 Chacha20 (96 bit nonce) with Poly1305 per RFC 8439
+ * chacha20-poly1305 Chacha20 with Poly1305 per RFC 8439
*/
#include <sys/param.h>
@@ -233,7 +233,7 @@ static const struct alg {
.evp_cipher = EVP_aes_256_ccm },
{ .name = "chacha20-poly1305", .cipher = CRYPTO_CHACHA20_POLY1305,
.type = T_AEAD, .tag_len = POLY1305_HASH_LEN,
- .iv_sizes = { CHACHA20_POLY1305_IV_LEN },
+ .iv_sizes = { CHACHA20_POLY1305_IV_LEN, 8 },
.evp_cipher = EVP_chacha20_poly1305 },
};