extmod/moducryptolib: Add an mbedTLS implementation for this module.
@@ -54,6 +54,24 @@ enum {
#define AES_CTX_IMPL AES_CTX
#endif
+#if MICROPY_SSL_MBEDTLS
+#include <mbedtls/aes.h>
+
+// we can't run mbedtls AES key schedule until we know whether we're used for encrypt or decrypt.
+// therefore, we store the key & keysize and on the first call to encrypt/decrypt we override them
+// with the mbedtls_aes_context, as they are not longer required. (this is done to save space)
+struct mbedtls_aes_ctx_with_key {
+ union {
+ mbedtls_aes_context mbedtls_ctx;
+ struct {
+ uint8_t key[32];
+ uint8_t keysize;
+ } init_data;
+ } u;
+ unsigned char iv[16];
+};
+#define AES_CTX_IMPL struct mbedtls_aes_ctx_with_key
+#endif
typedef struct _mp_obj_aes_t {
mp_obj_base_t base;
@@ -104,6 +122,42 @@ STATIC void aes_process_cbc_impl(AES_CTX_IMPL *ctx, const uint8_t *in, uint8_t *
}
#endif
+#if MICROPY_SSL_MBEDTLS
+STATIC void aes_initial_set_key_impl(AES_CTX_IMPL *ctx, const uint8_t *key, size_t keysize, const uint8_t iv[16]) {
+ ctx->u.init_data.keysize = keysize;
+ memcpy(ctx->u.init_data.key, key, keysize);
+
+ if (NULL != iv) {
+ memcpy(ctx->iv, iv, sizeof(ctx->iv));
+ }
+}
+
+STATIC void aes_final_set_key_impl(AES_CTX_IMPL *ctx, bool encrypt) {
+ // first, copy key aside
+ uint8_t key[32];
+ uint8_t keysize = ctx->u.init_data.keysize;
+ memcpy(key, ctx->u.init_data.key, keysize);
+ // now, override key with the mbedtls context object
+ mbedtls_aes_init(&ctx->u.mbedtls_ctx);
+
+ // setkey call will succeed, we've already checked the keysize earlier.
+ assert(16 == keysize || 32 == keysize);
+ if (encrypt) {
+ mbedtls_aes_setkey_enc(&ctx->u.mbedtls_ctx, key, keysize * 8);
+ } else {
+ mbedtls_aes_setkey_dec(&ctx->u.mbedtls_ctx, key, keysize * 8);
+ }
+}
+
+STATIC void aes_process_ecb_impl(AES_CTX_IMPL *ctx, const uint8_t in[16], uint8_t out[16], bool encrypt) {
+ mbedtls_aes_crypt_ecb(&ctx->u.mbedtls_ctx, encrypt ? MBEDTLS_AES_ENCRYPT : MBEDTLS_AES_DECRYPT, in, out);
+}
+
+STATIC void aes_process_cbc_impl(AES_CTX_IMPL *ctx, const uint8_t *in, uint8_t *out, size_t in_len, bool encrypt) {
+ mbedtls_aes_crypt_cbc(&ctx->u.mbedtls_ctx, encrypt ? MBEDTLS_AES_ENCRYPT : MBEDTLS_AES_DECRYPT, in_len, ctx->iv, in, out);
+}
+#endif
+
STATIC mp_obj_t aes_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
mp_arg_check_num(n_args, n_kw, 2, 3, false);
mp_obj_aes_t *o = m_new_obj(mp_obj_aes_t);
