Add ECPoint I/O functions. ASN.1 cleanup.

9 files changed, 254 insertions, 124 deletions

diff --git a/asn1.c b/asn1.c
index 98cb734..2ea44bd 100644
--- a/asn1.c
+++ b/asn1.c
@@ -58,8 +58,18 @@
 #include "asn1_internal.h"
 
 /*
- * Encode tag and length fields of an ASN.1 object.  If der is NULL,
- * just return the size that would be encoded.
+ * Encode tag and length fields of an ASN.1 object.
+ *
+ * Sets *der_len to the size of of the ASN.1 header (tag and length
+ * fields); caller supplied length of value field, so presumably
+ * already knows it.
+ *
+ * If der is NULL, just return the size of the header that would be
+ * encoded and returns HAL_OK.
+ *
+ * If der isn't NULL, returns HAL_ERROR_RESULT_TOO_LONG unless full
+ * header plus value will fit; this is a bit weird, but is useful when
+ * using this to construct encoders for complte ASN.1 objects.
  */
 
 hal_error_t hal_asn1_encode_header(const uint8_t tag,
@@ -126,17 +136,15 @@ hal_error_t hal_asn1_encode_integer(const fp_int * const bn,
   hal_error_t err;
   size_t hlen;
 
-  if ((err = hal_asn1_encode_header(ASN1_INTEGER, vlen, der, &hlen, der_max)) != HAL_OK)
-    return err;
+  err = hal_asn1_encode_header(ASN1_INTEGER, vlen, der, &hlen, der_max);
 
   if (der_len != NULL)
     *der_len = hlen + vlen;
 
-  if (der == NULL)
-    return HAL_OK;
+  if (der == NULL || err != HAL_OK)
+    return err;
 
-  if (hlen + vlen > der_max)
-    return HAL_ERROR_RESULT_TOO_LONG;
+  assert(hlen + vlen <= der_max);
 
   der += hlen;
   if (leading_zero)
diff --git a/csprng.c b/csprng.c
index 816aeae..235bd12 100644
--- a/csprng.c
+++ b/csprng.c
@@ -1,34 +1,34 @@
-/* 
+/*
  * csprng.c
  * --------
  * HAL interface to Cryptech CSPRNG.
- * 
+ *
  * Authors: Joachim Strömbergson, Paul Selkirk, Rob Austein
  * Copyright (c) 2014-2015, SUNET
- * 
- * Redistribution and use in source and binary forms, with or 
- * without modification, are permitted provided that the following 
- * conditions are met: 
- * 
- * 1. Redistributions of source code must retain the above copyright 
- *    notice, this list of conditions and the following disclaimer. 
- * 
- * 2. Redistributions in binary form must reproduce the above copyright 
- *    notice, this list of conditions and the following disclaimer in 
- *    the documentation and/or other materials provided with the 
- *    distribution. 
- * 
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
diff --git a/ecdsa.c b/ecdsa.c
index 8d9beb0..8799ece 100644
--- a/ecdsa.c
+++ b/ecdsa.c
@@ -250,7 +250,7 @@ static inline void ff_add(const ecdsa_curve_t * const curve,
 }
 
 static inline void ff_sub(const ecdsa_curve_t * const curve,
-                          const fp_int * const a, 
+                          const fp_int * const a,
                           const fp_int * const b,
                           fp_int *c)
 {
@@ -408,7 +408,7 @@ static inline void point_add(const ec_point_t * const P,
 
     if (fp_cmp(unconst_fp_int(P->y), unconst_fp_int(Q->y)) == FP_EQ)
       return point_double(P, R, curve);
-    
+
     fp_int Qy_neg[1];
     fp_sub(unconst_fp_int(curve->q), unconst_fp_int(Q->y), Qy_neg);
     const int zero_sum = fp_cmp(unconst_fp_int(P->y), Qy_neg) == FP_EQ;
@@ -717,7 +717,7 @@ static int point_is_on_curve(const ec_point_t * const P,
 {
   assert(P != NULL && curve != NULL);
 
-  fp_int t1[1]; fp_init(t1); 
+  fp_int t1[1]; fp_init(t1);
   fp_int t2[1]; fp_init(t2);
 
   /*
@@ -909,6 +909,117 @@ hal_error_t hal_ecdsa_key_load_private(hal_ecdsa_key_t **key_,
 }
 
 /*
+ * Write public key in X9.62 ECPoint format (ASN.1 OCTET STRING, first octet is compression flag).
+ */
+
+hal_error_t hal_ecdsa_key_to_ecpoint(const hal_ecdsa_key_t * const key,
+                                     uint8_t *der, size_t *der_len, const size_t der_max)
+{
+  if (key == NULL)
+    return HAL_ERROR_BAD_ARGUMENTS;
+
+  const ecdsa_curve_t * const curve = get_curve(key->curve);
+  if (curve == NULL)
+    return HAL_ERROR_IMPOSSIBLE;
+
+  const size_t q_len  = fp_unsigned_bin_size(unconst_fp_int(curve->q));
+  const size_t Qx_len = fp_unsigned_bin_size(unconst_fp_int(key->Q->x));
+  const size_t Qy_len = fp_unsigned_bin_size(unconst_fp_int(key->Q->y));
+  assert(q_len >= Qx_len && q_len >= Qy_len);
+
+  const size_t vlen = q_len * 2 + 1;
+  size_t hlen;
+
+  hal_error_t err = hal_asn1_encode_header(ASN1_OCTET_STRING, vlen, der, &hlen, der_max);
+
+  if (der_len != NULL)
+    *der_len = hlen + vlen;
+
+  if (der == NULL || err != HAL_OK)
+    return err;
+
+  assert(hlen + vlen <= der_max);
+
+  uint8_t *d = der + hlen;
+  memset(d, 0, vlen);
+
+  *d++ = 0x04;                  /* uncompressed */
+
+  fp_to_unsigned_bin(unconst_fp_int(key->Q->x), d + q_len - Qx_len);
+  d += q_len;
+
+  fp_to_unsigned_bin(unconst_fp_int(key->Q->y), d + q_len - Qy_len);
+  d += q_len;
+
+  assert(d <= der + der_max);
+
+  return HAL_OK;
+}
+
+/*
+ * Convenience wrapper to return how many bytes a key would take if
+ * encoded as an ECPoint.
+ */
+
+size_t hal_ecdsa_key_to_ecpoint_len(const hal_ecdsa_key_t * const key)
+{
+  size_t len;
+  return hal_ecdsa_key_to_ecpoint(key, NULL, &len, 0) == HAL_OK ? len : 0;
+}
+
+/*
+ * Read public key in X9.62 ECPoint format (ASN.1 OCTET STRING, first octet is compression flag).
+ * ECPoint format doesn't include a curve identifier, so caller has to supply one.
+ */
+
+hal_error_t hal_ecdsa_key_from_ecpoint(hal_ecdsa_key_t **key_,
+                                       void *keybuf, const size_t keybuf_len,
+                                       const uint8_t * const der, const size_t der_len,
+                                       const hal_ecdsa_curve_t curve)
+{
+  hal_ecdsa_key_t *key = keybuf;
+
+  if (key_ == NULL || key == NULL || keybuf_len < sizeof(*key) || get_curve(curve) == NULL)
+    return HAL_ERROR_BAD_ARGUMENTS;
+
+  memset(keybuf, 0, keybuf_len);
+  key->type = HAL_ECDSA_PUBLIC;
+  key->curve = curve;
+
+  size_t hlen, vlen;
+  hal_error_t err;
+
+  if ((err = hal_asn1_decode_header(ASN1_OCTET_STRING, der, der_len, &hlen, &vlen)) != HAL_OK)
+    return err;
+
+  const uint8_t * const der_end = der + hlen + vlen;
+  const uint8_t *d = der + hlen;
+
+  if (vlen < 3 || (vlen & 1) == 0 || *d++ != 0x04)
+    lose(HAL_ERROR_ASN1_PARSE_FAILED);
+
+  vlen = vlen/2 - 1;
+
+  fp_read_unsigned_bin(key->Q->x, unconst_uint8_t(d), vlen);
+  d += vlen;
+
+  fp_read_unsigned_bin(key->Q->y, unconst_uint8_t(d), vlen);
+  d += vlen;
+
+  fp_set(key->Q->z, 1);
+
+  if (d != der_end)
+    lose(HAL_ERROR_ASN1_PARSE_FAILED);
+
+  *key_ = key;
+  return HAL_OK;
+
+ fail:
+  memset(keybuf, 0, keybuf_len);
+  return err;
+}
+
+/*
  * Write private key in RFC 5915 ASN.1 DER format.
  *
  * This is hand-coded, and is approaching the limit where one should
@@ -945,20 +1056,19 @@ hal_error_t hal_ecdsa_key_to_der(const hal_ecdsa_key_t * const key,
       (err = hal_asn1_encode_header(ASN1_BIT_STRING,            (q_len + 1) * 2, NULL, &hlen_bit,    0)) != HAL_OK ||
       (err = hal_asn1_encode_header(ASN1_EXPLICIT_1, hlen_bit + (q_len + 1) * 2, NULL, &hlen_exp1,   0)) != HAL_OK)
     return err;
-  
+
   const size_t vlen = (version_len   +
                        hlen_oct + q_len +
                        hlen_oid + hlen_exp0 + curve->oid_len +
                        hlen_bit + hlen_exp1 + (q_len + 1) * 2);
 
-  if ((err = hal_asn1_encode_header(ASN1_SEQUENCE, vlen, der, &hlen, der_max)) != HAL_OK)
-    return err;
+  err = hal_asn1_encode_header(ASN1_SEQUENCE, vlen, der, &hlen, der_max);
 
   if (der_len != NULL)
     *der_len = hlen + vlen;
 
-  if (der == NULL)
-    return HAL_OK;
+  if (der == NULL || err != HAL_OK)
+    return err;
 
   uint8_t *d = der + hlen;
   memset(d, 0, vlen);
@@ -1067,7 +1177,7 @@ hal_error_t hal_ecdsa_key_from_der(hal_ecdsa_key_t **key_,
   if (curve == NULL)
     lose(HAL_ERROR_ASN1_PARSE_FAILED);
   d += vlen;
-  
+
   if ((err = hal_asn1_decode_header(ASN1_EXPLICIT_1, d, der_end - d, &hlen, &vlen)) != HAL_OK)
     return err;
   d += hlen;
@@ -1102,15 +1212,12 @@ hal_error_t hal_ecdsa_key_from_der(hal_ecdsa_key_t **key_,
  * to the byte length of the order of the base point.
  */
 
-hal_error_t encode_signature_pkcs11(const ecdsa_curve_t * const curve,
-                                    const fp_int * const r, const fp_int * const s,
-                                    uint8_t *signature, size_t *signature_len, const size_t signature_max)
+static hal_error_t encode_signature_pkcs11(const ecdsa_curve_t * const curve,
+                                           const fp_int * const r, const fp_int * const s,
+                                           uint8_t *signature, size_t *signature_len, const size_t signature_max)
 {
   assert(curve != NULL && r != NULL && s != NULL);
 
-  if (signature == NULL || signature_len == NULL)
-    return HAL_ERROR_BAD_ARGUMENTS;
-
   const size_t n_len = fp_unsigned_bin_size(unconst_fp_int(curve->n));
   const size_t r_len = fp_unsigned_bin_size(unconst_fp_int(r));
   const size_t s_len = fp_unsigned_bin_size(unconst_fp_int(s));
@@ -1118,13 +1225,18 @@ hal_error_t encode_signature_pkcs11(const ecdsa_curve_t * const curve,
   if (n_len < r_len || n_len < s_len)
     return HAL_ERROR_IMPOSSIBLE;
 
+  if (signature_len != NULL)
+    *signature_len = n_len * 2;
+
+  if (signature == NULL)
+    return HAL_OK;
+
   if (signature_max < n_len * 2)
     return HAL_ERROR_RESULT_TOO_LONG;
 
   memset(signature, 0, n_len * 2);
   fp_to_unsigned_bin(unconst_fp_int(r), signature + 1 * n_len - r_len);
   fp_to_unsigned_bin(unconst_fp_int(s), signature + 2 * n_len - s_len);
-  *signature_len = n_len * 2;
 
   return HAL_OK;
 }
@@ -1135,9 +1247,9 @@ hal_error_t encode_signature_pkcs11(const ecdsa_curve_t * const curve,
  * the octet string (which must therefore be of even length).
  */
 
-hal_error_t decode_signature_pkcs11(const ecdsa_curve_t * const curve,
-                                    fp_int *r, fp_int *s,
-                                    const uint8_t * const signature, const size_t signature_len)
+static hal_error_t decode_signature_pkcs11(const ecdsa_curve_t * const curve,
+                                           fp_int *r, fp_int *s,
+                                           const uint8_t * const signature, const size_t signature_len)
 {
   assert(curve != NULL && r != NULL && s != NULL);
 
@@ -1159,46 +1271,46 @@ hal_error_t decode_signature_pkcs11(const ecdsa_curve_t * const curve,
  * Encode a signature in ASN.1 format SEQUENCE { INTEGER r, INTEGER s }.
  */
 
-hal_error_t encode_signature_asn1(const ecdsa_curve_t * const curve,
-                                  const fp_int * const r, const fp_int * const s,
-                                  uint8_t *signature, size_t *signature_len, const size_t signature_max)
+static hal_error_t encode_signature_asn1(const ecdsa_curve_t * const curve,
+                                         const fp_int * const r, const fp_int * const s,
+                                         uint8_t *signature, size_t *signature_len, const size_t signature_max)
 {
   assert(curve != NULL && r != NULL && s != NULL);
 
-  if (signature == NULL || signature_len == NULL)
-    return HAL_ERROR_BAD_ARGUMENTS;
-
-  hal_error_t err = HAL_ERROR_IMPOSSIBLE;
-  size_t r_len, s_len;
+  size_t hlen, r_len, s_len;
+  hal_error_t err;
 
   if ((err = hal_asn1_encode_integer(r, NULL, &r_len, 0)) != HAL_OK ||
-      (err = hal_asn1_encode_integer(s, NULL, &s_len, 0)) != HAL_OK ||
-      (err = hal_asn1_encode_header(ASN1_SEQUENCE, r_len + s_len,
-                                    signature, signature_len, signature_max)) != HAL_OK)
-    goto fail;
+      (err = hal_asn1_encode_integer(s, NULL, &s_len, 0)) != HAL_OK)
+    return err;
+
+  const size_t vlen = r_len + s_len;
+
+  err = hal_asn1_encode_header(ASN1_SEQUENCE, vlen, signature, &hlen, signature_max);
+
+  if (signature_len != NULL)
+    *signature_len = hlen + vlen;
+
+  if (signature == NULL || err != HAL_OK)
+    return err;
 
-  uint8_t * const r_out = signature + *signature_len;
+  uint8_t * const r_out = signature + hlen;
   uint8_t * const s_out = r_out + r_len;
-  *signature_len += r_len + s_len;
-  assert(*signature_len <= signature_max);
 
   if ((err = hal_asn1_encode_integer(r, r_out, NULL, signature_max - (r_out - signature))) != HAL_OK ||
       (err = hal_asn1_encode_integer(s, s_out, NULL, signature_max - (s_out - signature))) != HAL_OK)
-    goto fail;
-
-  err = HAL_OK;
+    return err;
 
- fail:
-  return err;
+  return HAL_OK;
 }
 
 /*
  * Decode a signature from ASN.1 format SEQUENCE { INTEGER r, INTEGER s }.
  */
 
-hal_error_t decode_signature_asn1(const ecdsa_curve_t * const curve,
-                                  fp_int *r, fp_int *s,
-                                  const uint8_t * const signature, const size_t signature_len)
+static hal_error_t decode_signature_asn1(const ecdsa_curve_t * const curve,
+                                         fp_int *r, fp_int *s,
+                                         const uint8_t * const signature, const size_t signature_len)
 {
   assert(curve != NULL && r != NULL && s != NULL);
 
diff --git a/hal.h b/hal.h
index 5a3c592..547894e 100644
--- a/hal.h
+++ b/hal.h
@@ -39,23 +39,23 @@
  *   3 bits segment selector       | up to 8 segments
  *   5 bits core selector          | up to 32 cores/segment (see note below)
  *   8 bits register selector      | up to 256 registers/core (see modexp below)
- * 
+ *
  * i.e, the address is structured as:
  * sss ccccc rrrrrrrr
- * 
+ *
  * The I2C and UART communication channels use this 16-bit address format
  * directly in their read and write commands.
- * 
+ *
  * The EIM communications channel translates this 16-bit address into a
  * 32-bit memory-mapped address in the range 0x08000000..807FFFF:
  * 00001000000000 sss 0 ccccc rrrrrrrr 00
- * 
+ *
  * EIM, as implemented on the Novena, uses a 19-bit address space:
  *   Bits 18..16 are the semgent selector.
  *   Bits 15..10 are the core selector.
  *   Bits 9..2 are the register selector.
  *   Bits 1..0 are zero, because reads and writes are always word aligned.
- * 
+ *
  * Note that EIM can support 64 cores per segment, but we sacrifice one bit
  * in order to map it into a 16-bit address space.
  */
@@ -733,6 +733,16 @@ 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);
 
+extern hal_error_t hal_ecdsa_key_to_ecpoint(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_ecpoint_len(const hal_ecdsa_key_t * const key);
+
+extern hal_error_t hal_ecdsa_key_from_ecpoint(hal_ecdsa_key_t **key,
+                                              void *keybuf, const size_t keybuf_len,
+                                              const uint8_t * const der, const size_t der_len,
+                                              const hal_ecdsa_curve_t curve);
+
 extern hal_error_t hal_ecdsa_sign(const hal_ecdsa_key_t * const key,
                                   const uint8_t * const hash, const size_t hash_len,
                                   uint8_t *signature, size_t *signature_len, const size_t signature_max,
diff --git a/hal_io_eim.c b/hal_io_eim.c
index bdc3171..3687b95 100644
--- a/hal_io_eim.c
+++ b/hal_io_eim.c
@@ -1,11 +1,11 @@
-/* 
+/*
  * hal_io_eim.c
  * ------------
  * This module contains common code to talk to the FPGA over the EIM bus.
- * 
+ *
  * Author: Paul Selkirk
  * Copyright (c) 2014-2015, NORDUnet A/S All rights reserved.
- * 
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
diff --git a/hal_io_i2c.c b/hal_io_i2c.c
index c98ea7d..9788232 100644
--- a/hal_io_i2c.c
+++ b/hal_io_i2c.c
@@ -1,11 +1,11 @@
-/* 
+/*
  * hal_io_i2c.c
  * ------------
  * This module contains common code to talk to the FPGA over the I2C bus.
- * 
+ *
  * Author: Paul Selkirk
  * Copyright (c) 2014-2015, NORDUnet A/S All rights reserved.
- * 
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
diff --git a/hash.c b/hash.c
index 024b55b..ce086f4 100644
--- a/hash.c
+++ b/hash.c
@@ -1,34 +1,34 @@
-/* 
+/*
  * hashes.c
  * --------
  * HAL interface to Cryptech hash cores.
- * 
+ *
  * Authors: Joachim Strömbergson, Paul Selkirk, Rob Austein
  * Copyright (c) 2014-2015, SUNET
- * 
- * Redistribution and use in source and binary forms, with or 
- * without modification, are permitted provided that the following 
- * conditions are met: 
- * 
- * 1. Redistributions of source code must retain the above copyright 
- *    notice, this list of conditions and the following disclaimer. 
- * 
- * 2. Redistributions in binary form must reproduce the above copyright 
- *    notice, this list of conditions and the following disclaimer in 
- *    the documentation and/or other materials provided with the 
- *    distribution. 
- * 
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
@@ -306,7 +306,7 @@ static hal_error_t hash_write_block(hal_hash_state_t * const state)
     return err;
 
   ctrl_cmd[0] = ctrl_cmd[1] = ctrl_cmd[2] = 0;
-  ctrl_cmd[3] = state->block_count == 0 ? CTRL_INIT : CTRL_NEXT;  
+  ctrl_cmd[3] = state->block_count == 0 ? CTRL_INIT : CTRL_NEXT;
   ctrl_cmd[3] |= state->driver->ctrl_mode;
 
   /*
diff --git a/novena-eim.c b/novena-eim.c
index c8c47ad..b55b01c 100644
--- a/novena-eim.c
+++ b/novena-eim.c
@@ -1,12 +1,12 @@
-/* 
+/*
  * novena-eim.c
  * ------------
  * This module contains the userland magic to set up and use the EIM bus.
  *
- * 
+ *
  * Author: Pavel Shatov
  * Copyright (c) 2014-2015, NORDUnet A/S All rights reserved.
- * 
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
@@ -118,9 +118,9 @@ enum IMX6DQ_REGISTER_OFFSET
         IOMUXC_SW_PAD_CTL_PAD_EIM_AD15          = 0x020E0464,
         IOMUXC_SW_PAD_CTL_PAD_EIM_WAIT_B        = 0x020E0468,
         IOMUXC_SW_PAD_CTL_PAD_EIM_BCLK          = 0x020E046C,
-        
+
         CCM_CCGR6                               = 0x020C4080,
-        
+
         EIM_CS0GCR1                             = 0x021B8000,
         EIM_CS0GCR2                             = 0x021B8004,
         EIM_CS0RCR1                             = 0x021B8008,
@@ -166,17 +166,17 @@ struct CCM_CCGR6
         unsigned int    cg1_usdhc1              : 2;
         unsigned int    cg2_usdhc2              : 2;
         unsigned int    cg3_usdhc3              : 2;
-        
+
         unsigned int    cg3_usdhc4              : 2;
         unsigned int    cg5_eim_slow            : 2;
         unsigned int    cg6_vdoaxiclk           : 2;
         unsigned int    cg7_vpu                 : 2;
-        
+
         unsigned int    cg8_reserved            : 2;
         unsigned int    cg9_reserved            : 2;
         unsigned int    cg10_reserved           : 2;
         unsigned int    cg11_reserved           : 2;
-        
+
         unsigned int    cg12_reserved           : 2;
         unsigned int    cg13_reserved           : 2;
         unsigned int    cg14_reserved           : 2;
diff --git a/rsa.c b/rsa.c
index 8ac2d50..b863fdd 100644
--- a/rsa.c
+++ b/rsa.c
@@ -9,7 +9,7 @@
  * (but no simpler).
  *
  * Much of the code in this module is based, at least loosely, on Tom
- * St Denis's libtomcrypt code.  
+ * St Denis's libtomcrypt code.
  *
  * Authors: Rob Austein
  * Copyright (c) 2015, SUNET
@@ -394,7 +394,7 @@ hal_error_t hal_rsa_decrypt(const hal_rsa_key_t * const key,
     err = modexp(&i, &key->d, &key->n, &o);
   else
     err = rsa_crt(key, &i, &o);
-  
+
   if (err != HAL_OK || (err = unpack_fp(&o, output, output_len)) != HAL_OK)
     goto fail;
 
@@ -549,7 +549,7 @@ hal_error_t hal_rsa_key_get_public_exponent(const hal_rsa_key_t * const key,
 
 /*
  * Generate a prime factor for an RSA keypair.
- * 
+ *
  * Get random bytes, munge a few bits, and stuff into a bignum.  Keep
  * doing this until we find a result that's (probably) prime and for
  * which result - 1 is relatively prime with respect to e.
@@ -695,7 +695,7 @@ hal_error_t hal_rsa_key_to_der(const hal_rsa_key_t * const key,
    */
 
   der += hlen;
-  
+
 #define _(x) { size_t i; if ((err = hal_asn1_encode_integer(x, der, &i, vlen)) != HAL_OK) return err; der += i; vlen -= i; }
   RSAPrivateKey_fields;
 #undef _