Signed-off-by: Nikhil Agarwal <[email protected]>
---
 doc/users-guide/users-guide.adoc | 83 +++++++++++++++++++++++++++++++---------
 1 file changed, 65 insertions(+), 18 deletions(-)

diff --git a/doc/users-guide/users-guide.adoc b/doc/users-guide/users-guide.adoc
index 0221634..e8d690e 100644
--- a/doc/users-guide/users-guide.adoc
+++ b/doc/users-guide/users-guide.adoc
@@ -909,24 +909,71 @@ include::users-guide-pktio.adoc[]
 
 == Cryptographic services
 
-ODP provides support for cryptographic operations required by various security
-protocols (e.g. IPSec). To apply a cryptographic operation to a packet a 
session
-must be created first. Packets processed by a session share the same 
cryptographic
-parameters like algorithms, keys, initialization vectors. A session is created 
with
-*odp_crypto_session_create()* call. After session creation a cryptographic 
operation
-can be applied to a packet using *odp_crypto_operation()* call.
-Depending on the session type - synchronous or asynchronous the operation 
returns
-when the operation completed or after the request has been submitted. In the
-asynchronous case an operation completion event will be enqueued on the session
-completion queue. The completion event conveys the status of the operation and
-the result. The application has the responsibility to free the completion 
event.
-The operation arguments specify for each packet the areas which are to be 
encrypted
-or decrypted and authenticated. Also, in asynchronous case a context can be
-associated with a given operation and when the operation completion event is
-retrieved the associated context can be retrieved. An operation can be executed
-in-place, when the output packet is the same as the input packet or the output
-packet can be a new packet provided by the application or allocated by the
-implementation from the session output pool.
+ODP provides APIs to perform cryptographic operations required by various
+communication protocols (e.g. IPSec). ODP cryptographic APIs are session based.
+
+ODP provides APIs for following cryptographic services:
+
+* Ciphering
+* Authentication/data integrity via Keyed-Hashing (HMAC)
+* Random number generation
+* Crypto capability inquiries
+
+=== Crypto Sessions
+
+To apply a cryptographic operation to a packet a session must be created. All
+packets processed by a session share the parameters that define the session.
+
+ODP supports synchronous and asynchronous crypto sessions. For asynchronous
+sessions, the output of crypto operation is posted in a queue defined as
+completion queue in session parameters.
+
+ODP crypto APIs support chained operation sessions in which hashing and 
ciphering
+both can be achieved using single session and operation call. The order of 
cipher
+and hashing can be controlled by `auth_cipher_text` session parameter.
+
+Other Session parameters include algorithms, keys, initialization vector
+(optional), encode or decode, output queue for async mode and output packet 
pool
+for allocation of an output packet if required.
+
+=== Crypto operations
+
+After session creation, a cryptographic operation can be applied to a packet
+using the `odp_crypto_operation()` API. Depending on the implementation
+(synchronous or asynchronous) the API returns when the operation is completed
+or after the request has been submitted.
+
+The operation arguments specify for each packet the areas that are to be
+encrypted or decrypted and authenticated. Also, there is an option of 
overriding
+the initialization vector specified in session parameters.
+
+An operation can be executed in in-place, out-of-place or new buffer mode.
+In in-place mode output packet is same as the input packet.
+In case of out-of-place mode output packet is different from input packet as
+specified by the application, while in new buffer mode implementation allocates
+a new output buffer from the session’s output pool.
+
+User can also specify a context associated with a given operation that will be
+retained during async operation and can be retrieved via the completion event.
+
+In the case of an async session, the `*posted` (output variable of
+odp_crypto_operation API) will be set to true. Results of an asynchronous
+session will be posted as completion events to the session’s completion queue,
+which can be accessed directly or via ODP scheduler. The completion event
+contains the status of the operation and the result. The application has the
+responsibility to free the completion event.
+
+=== Random number Generation
+
+ODP provides an API `odp_random_data` to generate random data bytes. It has
+an argument to specify whether to use system entropy source for random number
+generation or not.
+
+=== Capability inquiries
+
+ODP provides an API interface `odp_crypto_capability` to inquire 
implementation’s
+crypto capabilities. This interface returns a bitmask for supported algorithms
+and hardware backed algorithms.
 
 include::users-guide-tm.adoc[]
 
-- 
2.8.2

_______________________________________________
lng-odp mailing list
[email protected]
https://lists.linaro.org/mailman/listinfo/lng-odp

Reply via email to