Detecting bit size is no longer required

Storage format has been changed to always store the key's bit size

Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 1901281..74b9871 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -982,174 +982,6 @@
     return( PSA_SUCCESS );
 }
 
-psa_status_t psa_detect_bit_size_in_slot( psa_key_slot_t *slot )
-{
-    if( slot->attr.bits != 0 )
-        return( PSA_SUCCESS );
-
-    if( key_type_is_raw_bytes( slot->attr.type ) )
-    {
-        slot->attr.bits =
-            (psa_key_bits_t) PSA_BYTES_TO_BITS( slot->data.key.bytes );
-        return( PSA_SUCCESS );
-    }
-    else if( PSA_KEY_TYPE_IS_ECC( slot->attr.type ) )
-    {
-        /* Keys are stored in export format, and we are currently
-         * restricted to known curves, so do the reverse lookup based
-         * on data length. */
-        size_t byte_length = slot->data.key.bytes;
-        if( PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->attr.type ) &&
-            PSA_KEY_TYPE_ECC_GET_FAMILY( slot->attr.type ) !=
-                PSA_ECC_FAMILY_MONTGOMERY )
-        {
-            /* A Weierstrass public key is represented as:
-             * - The byte 0x04;
-             * - `x_P` as a `ceiling(m/8)`-byte string, big-endian;
-             * - `y_P` as a `ceiling(m/8)`-byte string, big-endian.
-             * So its data length is 2m+1 where m is the curve size in bits.
-             */
-            if( ( byte_length & 1 ) == 0 )
-                return( PSA_ERROR_BAD_STATE );
-            byte_length = byte_length / 2;
-
-            /* Montgomery public keys are represented in compressed format,
-             * meaning their curve_size is equal to the amount of input. */
-
-            /* Private keys are represented in uncompressed private random
-             * integer format, meaning their curve_size is equal to the
-             * amount of input. */
-        }
-
-        switch( PSA_KEY_TYPE_ECC_GET_FAMILY( slot->attr.type ) )
-        {
-            case PSA_ECC_FAMILY_SECP_R1:
-                switch( byte_length )
-                {
-                    case PSA_BITS_TO_BYTES( 192 ):
-                        slot->attr.bits = 192;
-                        break;
-                    case PSA_BITS_TO_BYTES( 224 ):
-                        slot->attr.bits = 224;
-                        break;
-                    case PSA_BITS_TO_BYTES( 256 ):
-                        slot->attr.bits = 256;
-                        break;
-                    case PSA_BITS_TO_BYTES( 384 ):
-                        slot->attr.bits = 384;
-                        break;
-                    case PSA_BITS_TO_BYTES( 521 ):
-                        slot->attr.bits = 521;
-                        break;
-                    default:
-                        return( PSA_ERROR_BAD_STATE );
-                }
-                break;
-
-            case PSA_ECC_FAMILY_BRAINPOOL_P_R1:
-                switch( byte_length )
-                {
-                    case PSA_BITS_TO_BYTES( 256 ):
-                        slot->attr.bits = 256;
-                        break;
-                    case PSA_BITS_TO_BYTES( 384 ):
-                        slot->attr.bits = 384;
-                        break;
-                    case PSA_BITS_TO_BYTES( 512 ):
-                        slot->attr.bits = 512;
-                        break;
-                    default:
-                        return( PSA_ERROR_BAD_STATE );
-                }
-                break;
-
-            case PSA_ECC_FAMILY_MONTGOMERY:
-                switch( byte_length )
-                {
-                    case PSA_BITS_TO_BYTES( 255 ):
-                        slot->attr.bits = 255;
-                        break;
-                    case PSA_BITS_TO_BYTES( 448 ):
-                        slot->attr.bits = 448;
-                        break;
-                    default:
-                        return( PSA_ERROR_BAD_STATE );
-                }
-                break;
-
-            case PSA_ECC_FAMILY_SECP_K1:
-                switch( byte_length )
-                {
-                    case PSA_BITS_TO_BYTES( 192 ):
-                        slot->attr.bits = 192;
-                        break;
-                    case PSA_BITS_TO_BYTES( 224 ):
-                        slot->attr.bits = 224;
-                        break;
-                    case PSA_BITS_TO_BYTES( 256 ):
-                        slot->attr.bits = 256;
-                        break;
-                    default:
-                        return( PSA_ERROR_BAD_STATE );
-                }
-                break;
-
-            default:
-                return( PSA_ERROR_BAD_STATE );
-        }
-
-        return( PSA_SUCCESS );
-    }
-    else if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) )
-    {
-        /* There's no easy way of figuring out the RSA bit size from
-         * the data length of the export representation. For now, use
-         * the mbed TLS software implementation to figure it out. */
-        psa_key_attributes_t attributes = {
-            .core = slot->attr
-        };
-        size_t bits;
-        psa_status_t status = psa_driver_wrapper_validate_key(
-                                &attributes,
-                                slot->data.key.data,
-                                slot->data.key.bytes,
-                                &bits );
-        if( status == PSA_SUCCESS )
-            slot->attr.bits = (psa_key_bits_t) bits;
-        if( status != PSA_ERROR_NOT_SUPPORTED )
-            return( status );
-
-        /* If no accelerator was able to figure it out, try software. */
-#if defined(MBEDTLS_RSA_C)
-        mbedtls_rsa_context *rsa = NULL;
-
-        /* Parse input */
-        status = psa_load_rsa_representation( slot->attr.type,
-                                              slot->data.key.data,
-                                              slot->data.key.bytes,
-                                              &rsa );
-        if( status != PSA_SUCCESS )
-        {
-            mbedtls_rsa_free( rsa );
-            mbedtls_free( rsa );
-            return( status );
-        }
-
-        slot->attr.bits = (psa_key_bits_t) PSA_BYTES_TO_BITS(
-            mbedtls_rsa_get_len( rsa ) );
-
-        mbedtls_rsa_free( rsa );
-        mbedtls_free( rsa );
-
-        return( PSA_SUCCESS );
-#else
-        return( PSA_ERROR_NOT_SUPPORTED );
-#endif
-    }
-    else
-        return( PSA_ERROR_NOT_SUPPORTED );
-}
-
 /** Import key data into a slot.
  *
  * `slot->type` must have been set previously.
diff --git a/library/psa_crypto_core.h b/library/psa_crypto_core.h
index 2786b79..8d1f1bb 100644
--- a/library/psa_crypto_core.h
+++ b/library/psa_crypto_core.h
@@ -158,25 +158,6 @@
                                               const uint8_t *data,
                                               size_t data_length );
 
-/** Detect the key bit size for a key in a slot where bit size
- *  is unset.
- *
- * This function assumes that the slot contains key material in
- * export format.
- *
- * \param[in,out] slot  Key slot to detect and set the bit size in.
- *
- * \retval #PSA_SUCCESS
- *         The key bit size was already set, or has been detected
- *         and set accordingly.
- * \retval #PSA_ERROR_BAD_STATE
- *         The size of the key material in the slot doesn't match
- *         with the declared key type.
- * \retval #PSA_ERROR_NOT_SUPPORTED
- *         The key type is unknown to the implementation.
- */
-psa_status_t psa_detect_bit_size_in_slot( psa_key_slot_t *slot );
-
 /** Convert an mbed TLS error code to a PSA error code
  *
  * \note This function is provided solely for the convenience of
diff --git a/library/psa_crypto_slot_management.c b/library/psa_crypto_slot_management.c
index f33c4f2..5140772 100644
--- a/library/psa_crypto_slot_management.c
+++ b/library/psa_crypto_slot_management.c
@@ -144,8 +144,6 @@
         status = psa_copy_key_material_into_slot( slot, key_data, key_data_length );
         if( status != PSA_SUCCESS )
             goto exit;
-
-        status = psa_detect_bit_size_in_slot( slot );
     }
 
 exit: