[PATCH 5/8] crypto: stm32/cryp - check early input data

From: Nicolas Toromanoff
Date: Fri Oct 29 2021 - 10:01:46 EST


Return early for empty buffer
Accept all valid authsize for gcm(aes)
Check iv for ccm(aes)
Check buffer size is a multiple of algorithm block size.

Fixes: 9e054ec21ef8 ("crypto: stm32 - Support for STM32 CRYP crypto module")

Signed-off-by: Nicolas Toromanoff <nicolas.toromanoff@xxxxxxxxxxx>
---
drivers/crypto/stm32/stm32-cryp.c | 114 +++++++++++++++++++++++++++++-
1 file changed, 113 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/stm32/stm32-cryp.c b/drivers/crypto/stm32/stm32-cryp.c
index f97f9ee68d6f..874bec6d868e 100644
--- a/drivers/crypto/stm32/stm32-cryp.c
+++ b/drivers/crypto/stm32/stm32-cryp.c
@@ -801,7 +801,20 @@ static int stm32_cryp_aes_aead_setkey(struct crypto_aead *tfm, const u8 *key,
static int stm32_cryp_aes_gcm_setauthsize(struct crypto_aead *tfm,
unsigned int authsize)
{
- return authsize == AES_BLOCK_SIZE ? 0 : -EINVAL;
+ switch (authsize) {
+ case 4:
+ case 8:
+ case 12:
+ case 13:
+ case 14:
+ case 15:
+ case 16:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
}

static int stm32_cryp_aes_ccm_setauthsize(struct crypto_aead *tfm,
@@ -825,31 +838,61 @@ static int stm32_cryp_aes_ccm_setauthsize(struct crypto_aead *tfm,

static int stm32_cryp_aes_ecb_encrypt(struct skcipher_request *req)
{
+ if (req->cryptlen % AES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_AES | FLG_ECB | FLG_ENCRYPT);
}

static int stm32_cryp_aes_ecb_decrypt(struct skcipher_request *req)
{
+ if (req->cryptlen % AES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_AES | FLG_ECB);
}

static int stm32_cryp_aes_cbc_encrypt(struct skcipher_request *req)
{
+ if (req->cryptlen % AES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_AES | FLG_CBC | FLG_ENCRYPT);
}

static int stm32_cryp_aes_cbc_decrypt(struct skcipher_request *req)
{
+ if (req->cryptlen % AES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_AES | FLG_CBC);
}

static int stm32_cryp_aes_ctr_encrypt(struct skcipher_request *req)
{
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_AES | FLG_CTR | FLG_ENCRYPT);
}

static int stm32_cryp_aes_ctr_decrypt(struct skcipher_request *req)
{
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_AES | FLG_CTR);
}

@@ -863,53 +906,122 @@ static int stm32_cryp_aes_gcm_decrypt(struct aead_request *req)
return stm32_cryp_aead_crypt(req, FLG_AES | FLG_GCM);
}

+static inline int crypto_ccm_check_iv(const u8 *iv)
+{
+ /* 2 <= L <= 8, so 1 <= L' <= 7. */
+ if (iv[0] < 1 || iv[0] > 7)
+ return -EINVAL;
+
+ return 0;
+}
+
static int stm32_cryp_aes_ccm_encrypt(struct aead_request *req)
{
+ int err;
+
+ err = crypto_ccm_check_iv(req->iv);
+ if (err)
+ return err;
+
return stm32_cryp_aead_crypt(req, FLG_AES | FLG_CCM | FLG_ENCRYPT);
}

static int stm32_cryp_aes_ccm_decrypt(struct aead_request *req)
{
+ int err;
+
+ err = crypto_ccm_check_iv(req->iv);
+ if (err)
+ return err;
+
return stm32_cryp_aead_crypt(req, FLG_AES | FLG_CCM);
}

static int stm32_cryp_des_ecb_encrypt(struct skcipher_request *req)
{
+ if (req->cryptlen % DES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_DES | FLG_ECB | FLG_ENCRYPT);
}

static int stm32_cryp_des_ecb_decrypt(struct skcipher_request *req)
{
+ if (req->cryptlen % DES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_DES | FLG_ECB);
}

static int stm32_cryp_des_cbc_encrypt(struct skcipher_request *req)
{
+ if (req->cryptlen % DES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_DES | FLG_CBC | FLG_ENCRYPT);
}

static int stm32_cryp_des_cbc_decrypt(struct skcipher_request *req)
{
+ if (req->cryptlen % DES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_DES | FLG_CBC);
}

static int stm32_cryp_tdes_ecb_encrypt(struct skcipher_request *req)
{
+ if (req->cryptlen % DES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_TDES | FLG_ECB | FLG_ENCRYPT);
}

static int stm32_cryp_tdes_ecb_decrypt(struct skcipher_request *req)
{
+ if (req->cryptlen % DES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_TDES | FLG_ECB);
}

static int stm32_cryp_tdes_cbc_encrypt(struct skcipher_request *req)
{
+ if (req->cryptlen % DES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_TDES | FLG_CBC | FLG_ENCRYPT);
}

static int stm32_cryp_tdes_cbc_decrypt(struct skcipher_request *req)
{
+ if (req->cryptlen % DES_BLOCK_SIZE)
+ return -EINVAL;
+
+ if (req->cryptlen == 0)
+ return 0;
+
return stm32_cryp_crypt(req, FLG_TDES | FLG_CBC);
}

--
2.17.1