From c493a2a0a3cb3a5d05eb96f7d08200a8de193a76 Mon Sep 17 00:00:00 2001
From: Steffen Jaeckel <s@jaeckel.eu>
Date: Tue, 27 Jun 2017 22:09:21 +0200
Subject: [PATCH] re-factor dh_export_radix() to dh_export_key()

---
 src/headers/tomcrypt_pk.h   |  5 ++---
 src/pk/dh/dh_export_radix.c | 29 ++++-------------------------
 tests/dh_test.c             | 20 +++-----------------
 3 files changed, 9 insertions(+), 45 deletions(-)

diff --git a/src/headers/tomcrypt_pk.h b/src/headers/tomcrypt_pk.h
index fcb74da..b73b8c0 100644
--- a/src/headers/tomcrypt_pk.h
+++ b/src/headers/tomcrypt_pk.h
@@ -236,9 +236,8 @@ int dh_shared_secret(dh_key        *private_key, dh_key        *public_key,
 
 void dh_free(dh_key *key);
 
-int dh_export_radix(int radix,
-                    void *out, unsigned long *outlen,
-                    int type, dh_key *key);
+int dh_export_key(void *out, unsigned long *outlen,
+                  int type, dh_key *key);
 
 #ifdef LTC_SOURCE
 /* internal helper functions */
diff --git a/src/pk/dh/dh_export_radix.c b/src/pk/dh/dh_export_radix.c
index 301fd7f..d48c011 100644
--- a/src/pk/dh/dh_export_radix.c
+++ b/src/pk/dh/dh_export_radix.c
@@ -11,35 +11,15 @@
 
 #ifdef LTC_MDH
 
-static unsigned long _count_digits(int radix, void *num)
-{
-   void *r, *t;
-   unsigned long digits = 0;
-
-   if (mp_iszero(num) == LTC_MP_YES) return 1;
-   if (mp_init_multi(&t, &r, NULL) != CRYPT_OK) return 0;
-   mp_copy(num, t);
-   mp_set_int(r, radix);
-   while (mp_iszero(t) == LTC_MP_NO) {
-      if (mp_div(t, r, t, NULL) != CRYPT_OK) {
-         mp_clear_multi(t, r, NULL);
-         return 0;
-      }
-      digits++;
-   }
-   mp_clear_multi(t, r, NULL);
-   return digits;
-}
-
 /**
-  Export a DH key to a binary packet
+  Binary export a DH key to a buffer
   @param out    [out] The destination for the key
   @param outlen [in/out] The max size and resulting size of the DH key
   @param type   Which type of key (PK_PRIVATE or PK_PUBLIC)
   @param key    The key you wish to export
   @return CRYPT_OK if successful
 */
-int dh_export_radix(int radix, void *out, unsigned long *outlen, int type, dh_key *key)
+int dh_export_key(void *out, unsigned long *outlen, int type, dh_key *key)
 {
    unsigned long len;
    void *k;
@@ -47,10 +27,9 @@ int dh_export_radix(int radix, void *out, unsigned long *outlen, int type, dh_ke
    LTC_ARGCHK(out    != NULL);
    LTC_ARGCHK(outlen != NULL);
    LTC_ARGCHK(key    != NULL);
-   LTC_ARGCHK((radix >= 2 && radix <= 64) || radix == 256);
 
    k = (type == PK_PRIVATE) ? key->x : key->y;
-   len = (radix == 256) ? mp_unsigned_bin_size(k) : _count_digits(radix, k) + 1;
+   len = mp_unsigned_bin_size(k);
 
    if (*outlen < len) {
       *outlen = len;
@@ -58,7 +37,7 @@ int dh_export_radix(int radix, void *out, unsigned long *outlen, int type, dh_ke
    }
    *outlen = len;
 
-   return (radix == 256) ? mp_to_unsigned_bin(k, out) : mp_toradix(k, out, radix);
+   return mp_to_unsigned_bin(k, out);
 }
 
 #endif /* LTC_MDH */
diff --git a/tests/dh_test.c b/tests/dh_test.c
index 077157c..1cf6c22 100644
--- a/tests/dh_test.c
+++ b/tests/dh_test.c
@@ -350,33 +350,19 @@ static int _radix_test(void)
          return CRYPT_ERROR;
       }
       len = sizeof(buf);
-      DO(dh_export_radix(256, buf, &len, PK_PRIVATE, &k1));
+      DO(dh_export_key(buf, &len, PK_PRIVATE, &k1));
       if (compare_testvector(buf, len, xbin, sizeof(xbin), "radix_test", i*10 + 2)) {
          printf("radix_test: dh_export+PK_PRIVATE mismatch\n");
          dh_free(&k1);
          return CRYPT_ERROR;
       }
       len = sizeof(buf);
-      DO(dh_export_radix(256, buf, &len, PK_PUBLIC, &k1));
+      DO(dh_export_key(buf, &len, PK_PUBLIC, &k1));
       if (compare_testvector(buf, len, ybin, sizeof(ybin), "radix_test", i*10 + 3)) {
          printf("radix_test: dh_export+PK_PUBLIC mismatch\n");
          dh_free(&k1);
          return CRYPT_ERROR;
       }
-      len = sizeof(buf);
-      DO(dh_export_radix(47, buf, &len, PK_PRIVATE, &k1));
-      if (compare_testvector(buf, len, xr47, strlen(xr47)+1, "radix_test", i*10 + 4)) {
-         printf("radix_test: dh_export+PK_PRIVATE mismatch\n");
-         dh_free(&k1);
-         return CRYPT_ERROR;
-      }
-      len = sizeof(buf);
-      DO(dh_export_radix(47, buf, &len, PK_PUBLIC, &k1));
-      if (compare_testvector(buf, len, yr47, strlen(yr47)+1, "radix_test", i*10 + 5)) {
-         printf("radix_test: dh_export+PK_PUBLIC mismatch\n");
-         dh_free(&k1);
-         return CRYPT_ERROR;
-      }
       dh_free(&k1);
 
       if(test[i].radix != 256) {
@@ -396,7 +382,7 @@ static int _radix_test(void)
          return CRYPT_ERROR;
       }
       len = sizeof(buf);
-      DO(dh_export_radix(256, buf, &len, PK_PUBLIC, &k2));
+      DO(dh_export_key(buf, &len, PK_PUBLIC, &k2));
       if (compare_testvector(buf, len, ybin, sizeof(ybin), "radix_test", i*10 + 7)) {
          printf("radix_test: dh_export+PK_PUBLIC mismatch\n");
          dh_free(&k2);