[PATCH] lib/cryptodev: set minimal output buffer size for RSA op

[Gowrishankar Muthukrishnan]

Depending on RSA op, the output buffer size could be set
minimal expected memory, rather than 0 as today. This will allow
PMD to do any validation on the size, in case an application
did not create enough memory or even in case of any memory
fault.

Signed-off-by: Gowrishankar Muthukrishnan <gmuthukri...@marvell.com>
---
 app/test/test_cryptodev_asym.c  |  6 +++---
 lib/cryptodev/rte_crypto_asym.h | 15 ++++++++++-----
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/app/test/test_cryptodev_asym.c b/app/test/test_cryptodev_asym.c
index 9236817650..bb4c70deba 100644
--- a/app/test/test_cryptodev_asym.c
+++ b/app/test/test_cryptodev_asym.c
@@ -90,7 +90,7 @@ queue_ops_rsa_sign_verify(void *sess)
 
        asym_op->rsa.message.data = rsaplaintext.data;
        asym_op->rsa.message.length = rsaplaintext.len;
-       asym_op->rsa.sign.length = 0;
+       asym_op->rsa.sign.length = RTE_DIM(rsa_n);
        asym_op->rsa.sign.data = output_buf;
        asym_op->rsa.padding.type = RTE_CRYPTO_RSA_PADDING_PKCS1_5;
 
@@ -181,7 +181,7 @@ queue_ops_rsa_enc_dec(void *sess)
 
        asym_op->rsa.message.data = rsaplaintext.data;
        asym_op->rsa.cipher.data = cipher_buf;
-       asym_op->rsa.cipher.length = 0;
+       asym_op->rsa.cipher.length = RTE_DIM(rsa_n);
        asym_op->rsa.message.length = rsaplaintext.len;
        asym_op->rsa.padding.type = RTE_CRYPTO_RSA_PADDING_PKCS1_5;
 
@@ -213,7 +213,7 @@ queue_ops_rsa_enc_dec(void *sess)
 
        /* Use the resulted output as decryption Input vector*/
        asym_op = result_op->asym;
-       asym_op->rsa.message.length = 0;
+       asym_op->rsa.message.length = RTE_DIM(rsa_n);
        asym_op->rsa.op_type = RTE_CRYPTO_ASYM_OP_DECRYPT;
        asym_op->rsa.padding.type = RTE_CRYPTO_RSA_PADDING_PKCS1_5;
 
diff --git a/lib/cryptodev/rte_crypto_asym.h b/lib/cryptodev/rte_crypto_asym.h
index 989f38323f..bdf92d4358 100644
--- a/lib/cryptodev/rte_crypto_asym.h
+++ b/lib/cryptodev/rte_crypto_asym.h
@@ -414,7 +414,8 @@ struct rte_crypto_rsa_op_param {
         * In this case the underlying array should have been
         * allocated with enough memory to hold plaintext output
         * (i.e. must be at least RSA key size). The message.length
-        * field should be 0 and will be overwritten by the PMD
+        * field could be either 0 or minimal length expected from PMD.
+        * This could be validated and overwritten by the PMD
         * with the decrypted length.
         */
 
@@ -427,8 +428,10 @@ struct rte_crypto_rsa_op_param {
         * - for RSA public encrypt.
         * In this case the underlying array should have been allocated
         * with enough memory to hold ciphertext output (i.e. must be
-        * at least RSA key size). The cipher.length field should
-        * be 0 and will be overwritten by the PMD with the encrypted length.
+        * at least RSA key size). The cipher.length field could be
+        * either 0 or minimal length expected from PMD.
+        * This could be validated and overwritten by the PMD
+        * with the encrypted length.
         *
         * When RTE_CRYPTO_RSA_PADDING_NONE and RTE_CRYPTO_ASYM_OP_VERIFY
         * selected, this is an output of decrypted signature.
@@ -443,8 +446,10 @@ struct rte_crypto_rsa_op_param {
         * - for RSA private encrypt.
         * In this case the underlying array should have been allocated
         * with enough memory to hold signature output (i.e. must be
-        * at least RSA key size). The sign.length field should
-        * be 0 and will be overwritten by the PMD with the signature length.
+        * at least RSA key size). The sign.length field could be
+        * either 0 or minimal length expected from PMD.
+        * This could be validated and overwritten by the PMD
+        * with the signature length.
         */
 
        struct rte_crypto_rsa_padding padding;
-- 
2.25.1