diff options
| -rw-r--r-- | sys/opencrypto/xform_aes_cbc.c | 44 |
1 files changed, 37 insertions, 7 deletions
diff --git a/sys/opencrypto/xform_aes_cbc.c b/sys/opencrypto/xform_aes_cbc.c index 38b7aeb33ec2..b2a45e595fda 100644 --- a/sys/opencrypto/xform_aes_cbc.c +++ b/sys/opencrypto/xform_aes_cbc.c @@ -53,15 +53,21 @@ __FBSDID("$FreeBSD$"); #include <crypto/rijndael/rijndael.h> #include <opencrypto/xform_enc.h> +struct aes_cbc_ctx { + rijndael_ctx key; + char iv[AES_BLOCK_LEN]; +}; + static int aes_cbc_setkey(void *, const uint8_t *, int); static void aes_cbc_encrypt(void *, const uint8_t *, uint8_t *); static void aes_cbc_decrypt(void *, const uint8_t *, uint8_t *); +static void aes_cbc_reinit(void *, const uint8_t *, size_t); /* Encryption instances */ const struct enc_xform enc_xform_aes_cbc = { .type = CRYPTO_AES_CBC, .name = "AES-CBC", - .ctxsize = sizeof(rijndael_ctx), + .ctxsize = sizeof(struct aes_cbc_ctx), .blocksize = AES_BLOCK_LEN, .ivsize = AES_BLOCK_LEN, .minkey = AES_MIN_KEY, @@ -69,30 +75,54 @@ const struct enc_xform enc_xform_aes_cbc = { .encrypt = aes_cbc_encrypt, .decrypt = aes_cbc_decrypt, .setkey = aes_cbc_setkey, + .reinit = aes_cbc_reinit, }; /* * Encryption wrapper routines. */ static void -aes_cbc_encrypt(void *key, const uint8_t *in, uint8_t *out) +aes_cbc_encrypt(void *vctx, const uint8_t *in, uint8_t *out) { - rijndael_encrypt(key, in, out); + struct aes_cbc_ctx *ctx = vctx; + + for (u_int i = 0; i < AES_BLOCK_LEN; i++) + out[i] = in[i] ^ ctx->iv[i]; + rijndael_encrypt(&ctx->key, out, out); + memcpy(ctx->iv, out, AES_BLOCK_LEN); } static void -aes_cbc_decrypt(void *key, const uint8_t *in, uint8_t *out) +aes_cbc_decrypt(void *vctx, const uint8_t *in, uint8_t *out) { - rijndael_decrypt(key, in, out); + struct aes_cbc_ctx *ctx = vctx; + char block[AES_BLOCK_LEN]; + + memcpy(block, in, AES_BLOCK_LEN); + rijndael_decrypt(&ctx->key, in, out); + for (u_int i = 0; i < AES_BLOCK_LEN; i++) + out[i] ^= ctx->iv[i]; + memcpy(ctx->iv, block, AES_BLOCK_LEN); + explicit_bzero(block, sizeof(block)); } static int -aes_cbc_setkey(void *sched, const uint8_t *key, int len) +aes_cbc_setkey(void *vctx, const uint8_t *key, int len) { + struct aes_cbc_ctx *ctx = vctx; if (len != 16 && len != 24 && len != 32) return (EINVAL); - rijndael_set_key(sched, key, len * 8); + rijndael_set_key(&ctx->key, key, len * 8); return (0); } + +static void +aes_cbc_reinit(void *vctx, const uint8_t *iv, size_t iv_len) +{ + struct aes_cbc_ctx *ctx = vctx; + + KASSERT(iv_len == sizeof(ctx->iv), ("%s: bad IV length", __func__)); + memcpy(ctx->iv, iv, sizeof(ctx->iv)); +} |