psa: Add mbedtls_psa_cipher_xyz() APIs
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/library/psa_crypto_cipher.c b/library/psa_crypto_cipher.c
index 73a2dab..91d471b 100644
--- a/library/psa_crypto_cipher.c
+++ b/library/psa_crypto_cipher.c
@@ -24,7 +24,10 @@
#include <psa_crypto_cipher.h>
#include "psa_crypto_core.h"
+#include "psa_crypto_random_impl.h"
+
#include "mbedtls/cipher.h"
+#include "mbedtls/error.h"
#include <string.h>
@@ -143,4 +146,220 @@
key_buffer, key_buffer_size,
alg, MBEDTLS_DECRYPT ) );
}
+
+psa_status_t mbedtls_psa_cipher_generate_iv(
+ psa_cipher_operation_t *operation,
+ uint8_t *iv, size_t iv_size, size_t *iv_length )
+{
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+
+ if( iv_size < operation->iv_size )
+ return( PSA_ERROR_BUFFER_TOO_SMALL );
+
+ ret = mbedtls_psa_get_random( MBEDTLS_PSA_RANDOM_STATE,
+ iv, operation->iv_size );
+ if( ret != 0 )
+ return( mbedtls_to_psa_error( ret ) );
+
+ *iv_length = operation->iv_size;
+
+ return( mbedtls_psa_cipher_set_iv( operation, iv, *iv_length ) );
+}
+
+psa_status_t mbedtls_psa_cipher_set_iv( psa_cipher_operation_t *operation,
+ const uint8_t *iv,
+ size_t iv_length )
+{
+ if( iv_length != operation->iv_size )
+ return( PSA_ERROR_INVALID_ARGUMENT );
+
+ return( mbedtls_to_psa_error(
+ mbedtls_cipher_set_iv( &operation->ctx.cipher,
+ iv, iv_length ) ) );
+}
+
+/* Process input for which the algorithm is set to ECB mode. This requires
+ * manual processing, since the PSA API is defined as being able to process
+ * arbitrary-length calls to psa_cipher_update() with ECB mode, but the
+ * underlying mbedtls_cipher_update only takes full blocks. */
+static psa_status_t psa_cipher_update_ecb(
+ mbedtls_cipher_context_t *ctx,
+ const uint8_t *input,
+ size_t input_length,
+ uint8_t *output,
+ size_t output_size,
+ size_t *output_length )
+{
+ psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+ size_t block_size = ctx->cipher_info->block_size;
+ size_t internal_output_length = 0;
+ *output_length = 0;
+
+ if( input_length == 0 )
+ {
+ status = PSA_SUCCESS;
+ goto exit;
+ }
+
+ if( ctx->unprocessed_len > 0 )
+ {
+ /* Fill up to block size, and run the block if there's a full one. */
+ size_t bytes_to_copy = block_size - ctx->unprocessed_len;
+
+ if( input_length < bytes_to_copy )
+ bytes_to_copy = input_length;
+
+ memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ),
+ input, bytes_to_copy );
+ input_length -= bytes_to_copy;
+ input += bytes_to_copy;
+ ctx->unprocessed_len += bytes_to_copy;
+
+ if( ctx->unprocessed_len == block_size )
+ {
+ status = mbedtls_to_psa_error(
+ mbedtls_cipher_update( ctx,
+ ctx->unprocessed_data,
+ block_size,
+ output, &internal_output_length ) );
+
+ if( status != PSA_SUCCESS )
+ goto exit;
+
+ output += internal_output_length;
+ output_size -= internal_output_length;
+ *output_length += internal_output_length;
+ ctx->unprocessed_len = 0;
+ }
+ }
+
+ while( input_length >= block_size )
+ {
+ /* Run all full blocks we have, one by one */
+ status = mbedtls_to_psa_error(
+ mbedtls_cipher_update( ctx, input,
+ block_size,
+ output, &internal_output_length ) );
+
+ if( status != PSA_SUCCESS )
+ goto exit;
+
+ input_length -= block_size;
+ input += block_size;
+
+ output += internal_output_length;
+ output_size -= internal_output_length;
+ *output_length += internal_output_length;
+ }
+
+ if( input_length > 0 )
+ {
+ /* Save unprocessed bytes for later processing */
+ memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ),
+ input, input_length );
+ ctx->unprocessed_len += input_length;
+ }
+
+ status = PSA_SUCCESS;
+
+exit:
+ return( status );
+}
+
+psa_status_t mbedtls_psa_cipher_update( psa_cipher_operation_t *operation,
+ const uint8_t *input,
+ size_t input_length,
+ uint8_t *output,
+ size_t output_size,
+ size_t *output_length )
+{
+ psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+ size_t expected_output_size;
+
+ if( ! PSA_ALG_IS_STREAM_CIPHER( operation->alg ) )
+ {
+ /* Take the unprocessed partial block left over from previous
+ * update calls, if any, plus the input to this call. Remove
+ * the last partial block, if any. You get the data that will be
+ * output in this call. */
+ expected_output_size =
+ ( operation->ctx.cipher.unprocessed_len + input_length )
+ / operation->block_size * operation->block_size;
+ }
+ else
+ {
+ expected_output_size = input_length;
+ }
+
+ if( output_size < expected_output_size )
+ return( PSA_ERROR_BUFFER_TOO_SMALL );
+
+ if( operation->alg == PSA_ALG_ECB_NO_PADDING )
+ {
+ /* mbedtls_cipher_update has an API inconsistency: it will only
+ * process a single block at a time in ECB mode. Abstract away that
+ * inconsistency here to match the PSA API behaviour. */
+ status = psa_cipher_update_ecb( &operation->ctx.cipher,
+ input,
+ input_length,
+ output,
+ output_size,
+ output_length );
+ }
+ else
+ {
+ status = mbedtls_to_psa_error(
+ mbedtls_cipher_update( &operation->ctx.cipher, input,
+ input_length, output, output_length ) );
+ }
+
+ return( status );
+}
+
+psa_status_t mbedtls_psa_cipher_finish( psa_cipher_operation_t *operation,
+ uint8_t *output,
+ size_t output_size,
+ size_t *output_length )
+{
+ psa_status_t status = PSA_ERROR_GENERIC_ERROR;
+ uint8_t temp_output_buffer[MBEDTLS_MAX_BLOCK_LENGTH];
+
+ if( operation->ctx.cipher.unprocessed_len != 0 )
+ {
+ if( operation->alg == PSA_ALG_ECB_NO_PADDING ||
+ operation->alg == PSA_ALG_CBC_NO_PADDING )
+ {
+ status = PSA_ERROR_INVALID_ARGUMENT;
+ goto exit;
+ }
+ }
+
+ status = mbedtls_to_psa_error(
+ mbedtls_cipher_finish( &operation->ctx.cipher,
+ temp_output_buffer,
+ output_length ) );
+ if( status != PSA_SUCCESS )
+ goto exit;
+
+ if( *output_length == 0 )
+ ; /* Nothing to copy. Note that output may be NULL in this case. */
+ else if( output_size >= *output_length )
+ memcpy( output, temp_output_buffer, *output_length );
+ else
+ status = PSA_ERROR_BUFFER_TOO_SMALL;
+
+exit:
+ mbedtls_platform_zeroize( temp_output_buffer,
+ sizeof( temp_output_buffer ) );
+
+ return( status );
+}
+
+psa_status_t mbedtls_psa_cipher_abort( psa_cipher_operation_t *operation )
+{
+ mbedtls_cipher_free( &operation->ctx.cipher );
+
+ return( PSA_SUCCESS );
+}
+
#endif /* MBEDTLS_PSA_CRYPTO_C */