Snapshot along the way to ECDSA. Code mostly written, except for

ecdsa_verify().  Untested.  Point addition and doubling algorithms are
the ones from libtomcrypt, main point of this commit is to save those
before replacing them with faster algorithms from hyperelliptic.org.

1 files changed, 62 insertions, 0 deletions

diff --git a/hal.h b/hal.h
index 8b731d4..9e7bd67 100644
--- a/hal.h
+++ b/hal.h
@@ -446,6 +446,7 @@
   DEFINE_HAL_ERROR(HAL_ERROR_ALLOCATION_FAILURE,        "Memory allocation failed")                     \
   DEFINE_HAL_ERROR(HAL_ERROR_RESULT_TOO_LONG,           "Result too long for buffer")                   \
   DEFINE_HAL_ERROR(HAL_ERROR_ASN1_PARSE_FAILED,         "ASN.1 parse failed")                           \
+  DEFINE_HAL_ERROR(HAL_ERROR_KEY_NOT_ON_CURVE,          "EC key is not on its purported curve")         \
   END_OF_HAL_ERROR_LIST
 
 /* Marker to forestall silly line continuation errors */
@@ -671,6 +672,67 @@ extern hal_error_t hal_rsa_key_from_der(hal_rsa_key_t *key,
                                         void *keybuf, const size_t keybuf_len,
                                         const uint8_t * const der, const size_t der_len);
 
+/*
+ * ECDSA.
+ */
+
+typedef enum { HAL_ECDSA_PRIVATE, HAL_ECDSA_PUBLIC } hal_ecdsa_key_type_t;
+
+typedef enum { HAL_ECDSA_CURVE_P256, HAL_ECDSA_CURVE_P384, HAL_ECDSA_CURVE_P521 } hal_ecdsa_curve_t;
+
+typedef struct hal_ecdsa_key hal_ecdsa_key_t;
+
+extern const size_t hal_ecdsa_key_t_size;
+
+extern void hal_ecdsa_set_debug(const int onoff);
+
+extern hal_error_t hal_ecdsa_key_load_private(hal_ecdsa_key_t **key,
+                                              void *keybuf, const size_t keybuf_len,
+                                              const hal_ecdsa_curve_t curve,
+                                              const uint8_t * const x, const size_t x_len,
+                                              const uint8_t * const y, const size_t y_len,
+                                              const uint8_t * const d, const size_t d_len);
+
+extern hal_error_t hal_ecdsa_key_load_public(hal_ecdsa_key_t **key,
+                                             void *keybuf, const size_t keybuf_len,
+                                             const hal_ecdsa_curve_t curve,
+                                             const uint8_t * const x, const size_t x_len,
+                                             const uint8_t * const y, const size_t y_len);
+
+extern hal_error_t hal_ecdsa_key_get_type(const hal_ecdsa_key_t * const key,
+                                          hal_ecdsa_key_type_t *key_type);
+
+extern hal_error_t hal_ecdsa_key_get_curve(const hal_ecdsa_key_t * const key,
+                                           hal_ecdsa_curve_t *curve);
+
+extern hal_error_t hal_ecdsa_key_get_public(const hal_ecdsa_key_t * const key,
+                                            uint8_t *x, size_t *x_len, const size_t x_max,
+                                            uint8_t *y, size_t *y_len, const size_t y_max);
+
+extern void hal_ecdsa_key_clear(hal_ecdsa_key_t *key);
+
+extern hal_error_t hal_ecdsa_sign(const hal_ecdsa_key_t * const key,
+                                  const hal_hash_descriptor_t * const hash_descriptor,
+                                  const uint8_t * const input, const size_t input_len,
+                                  uint8_t *output, size_t *output_len, const size_t output_max);
+
+extern hal_error_t hal_ecdsa_verify(const hal_ecdsa_key_t * const key,
+                                    const hal_hash_descriptor_t * const hash_descriptor,
+                                    const uint8_t * const input, const size_t input_len);
+
+extern hal_error_t hal_ecdsa_key_gen(hal_ecdsa_key_t **key,
+                                     void *keybuf, const size_t keybuf_len,
+                                     const hal_ecdsa_curve_t curve);
+
+extern hal_error_t hal_ecdsa_key_to_der(const hal_ecdsa_key_t * const key,
+                                        uint8_t *der, size_t *der_len, const size_t der_max);
+
+extern size_t hal_ecdsa_key_to_der_len(const hal_ecdsa_key_t * const key);
+
+extern hal_error_t hal_ecdsa_key_from_der(hal_ecdsa_key_t **key,
+                                          void *keybuf, const size_t keybuf_len,
+                                          const uint8_t * const der, const size_t der_len);
+
 #endif /* _HAL_H_ */
 
 /*