psa: programs: Add cipher AES CBC no padding
diff --git a/programs/psa/crypto_examples.c b/programs/psa/crypto_examples.c
index 3a549ff..18f93a2 100644
--- a/programs/psa/crypto_examples.c
+++ b/programs/psa/crypto_examples.c
@@ -1,4 +1,214 @@
+#include "psa/crypto.h"
+#include <string.h>
+
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdio.h>
+#define mbedtls_printf printf
+#endif
+
+#define ASSERT( predicate )                                                   \
+    do                                                                        \
+    {                                                                         \
+        if( ! ( predicate ) )                                                 \
+        {                                                                     \
+            mbedtls_printf( "\tassertion failed at %s:%d - '%s'\r\n",         \
+                            __FILE__, __LINE__, #predicate);                  \
+            goto exit;                                                        \
+        }                                                                     \
+    } while ( 0 )
+
+#define ASSERT_STATUS( actual, expected )                                     \
+    do                                                                        \
+    {                                                                         \
+        if( ( actual ) != ( expected ) )                                      \
+        {                                                                     \
+            mbedtls_printf( "\tassertion failed at %s:%d - "                  \
+                            "actual:%d expected:%d\r\n", __FILE__, __LINE__,  \
+                            (psa_status_t) actual, (psa_status_t) expected ); \
+            goto exit;                                                        \
+        }                                                                     \
+    } while ( 0 )
+
+/* Use key slot 1 for our cipher key. Key slot 0 is reserved as unused. */
+static const psa_key_slot_t key_slot_cipher = 1;
+
+static psa_status_t set_key_policy( psa_key_slot_t key_slot,
+                                    psa_key_usage_t key_usage,
+                                    psa_algorithm_t alg )
+{
+    psa_status_t status;
+    psa_key_policy_t policy;
+
+    psa_key_policy_init( &policy );
+    psa_key_policy_set_usage( &policy, key_usage, alg );
+    status = psa_set_key_policy( key_slot, &policy );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+exit:
+    return( status );
+}
+
+static psa_status_t cipher_operation( psa_cipher_operation_t *operation,
+                                      const uint8_t * input,
+                                      size_t input_size,
+                                      size_t part_size,
+                                      uint8_t * output,
+                                      size_t output_size,
+                                      size_t *output_len )
+{
+    psa_status_t status;
+    size_t bytes_to_write = 0, bytes_written = 0, len = 0;
+
+    *output_len = 0;
+    while( bytes_written != input_size )
+    {
+        bytes_to_write = ( input_size - bytes_written > part_size ?
+                           part_size :
+                           input_size - bytes_written );
+
+        status = psa_cipher_update( operation, input + bytes_written,
+                                    bytes_to_write, output + *output_len,
+                                    output_size - *output_len, &len );
+        ASSERT_STATUS( status, PSA_SUCCESS );
+
+        bytes_written += bytes_to_write;
+        *output_len += len;
+    }
+
+    status = psa_cipher_finish( operation, output + *output_len,
+                                output_size - *output_len, &len );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+    *output_len += len;
+
+exit:
+    return( status );
+}
+
+static psa_status_t cipher_encrypt( psa_key_slot_t key_slot,
+                                    psa_algorithm_t alg,
+                                    uint8_t * iv,
+                                    size_t iv_size,
+                                    const uint8_t * input,
+                                    size_t input_size,
+                                    size_t part_size,
+                                    uint8_t * output,
+                                    size_t output_size,
+                                    size_t *output_len )
+{
+    psa_status_t status;
+    psa_cipher_operation_t operation;
+    size_t iv_len = 0;
+
+    memset( &operation, 0, sizeof( operation ) );
+    status = psa_cipher_encrypt_setup( &operation, key_slot, alg );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+
+    status = psa_cipher_generate_iv( &operation, iv, iv_size, &iv_len );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+
+    status = cipher_operation( &operation, input, input_size, part_size,
+                               output, output_size, output_len );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+
+exit:
+    psa_cipher_abort( &operation );
+    return( status );
+}
+
+static psa_status_t cipher_decrypt( psa_key_slot_t key_slot,
+                                    psa_algorithm_t alg,
+                                    const uint8_t * iv,
+                                    size_t iv_size,
+                                    const uint8_t * input,
+                                    size_t input_size,
+                                    size_t part_size,
+                                    uint8_t * output,
+                                    size_t output_size,
+                                    size_t *output_len )
+{
+    psa_status_t status;
+    psa_cipher_operation_t operation;
+
+    memset( &operation, 0, sizeof( operation ) );
+    status = psa_cipher_decrypt_setup( &operation, key_slot, alg );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+
+    status = psa_cipher_set_iv( &operation, iv, iv_size );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+
+    status = cipher_operation( &operation, input, input_size, part_size,
+                               output, output_size, output_len );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+
+exit:
+    psa_cipher_abort( &operation );
+    return( status );
+}
+
+static psa_status_t
+cipher_example_encrypt_decrypt_aes_cbc_nopad_1_block( void )
+{
+    enum {
+        block_size = PSA_BLOCK_CIPHER_BLOCK_SIZE( PSA_KEY_TYPE_AES ),
+        key_bits = 256,
+        part_size = block_size,
+    };
+    const psa_algorithm_t alg = PSA_ALG_CBC_BASE |
+                                PSA_ALG_BLOCK_CIPHER_PAD_NONE;
+
+    psa_status_t status;
+    size_t output_len = 0;
+    uint8_t iv[block_size];
+    uint8_t input[block_size];
+    uint8_t encrypt[block_size];
+    uint8_t decrypt[block_size];
+
+    status = psa_generate_random( input, sizeof( input ) );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+
+    status = set_key_policy( key_slot_cipher,
+                             PSA_KEY_USAGE_ENCRYPT | PSA_KEY_USAGE_DECRYPT,
+                             alg );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+
+    status = psa_generate_key( key_slot_cipher, PSA_KEY_TYPE_AES, key_bits,
+                               NULL, 0 );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+
+    status = cipher_encrypt( key_slot_cipher, alg, iv, sizeof( iv ),
+                             input, sizeof( input ), part_size,
+                             encrypt, sizeof( encrypt ), &output_len );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+
+    status = cipher_decrypt( key_slot_cipher, alg, iv, sizeof( iv ),
+                             encrypt, output_len, part_size,
+                             decrypt, sizeof( decrypt ), &output_len );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+
+    status = memcmp( input, decrypt, sizeof( input ) );
+    ASSERT_STATUS( status, PSA_SUCCESS );
+
+exit:
+    psa_destroy_key( key_slot_cipher );
+    return( status );
+}
+
+static void cipher_examples( void )
+{
+    psa_status_t status;
+
+    mbedtls_printf( "cipher encrypt/decrypt AES CBC no padding:\r\n" );
+    status = cipher_example_encrypt_decrypt_aes_cbc_nopad_1_block( );
+    if( status == PSA_SUCCESS )
+        mbedtls_printf( "\tsuccess!\r\n" );
+}
+
 int main( void )
 {
+    ASSERT( psa_crypto_init( ) == PSA_SUCCESS );
+    cipher_examples( );
+exit:
+    mbedtls_psa_crypto_free( );
     return( 0 );
 }