Remove tor-checkkey as obsolete

CVE-2008-0166 is long gone, and we no longer need a helper tool to
dump out public key moduli so folks can detect it.

Closes ticket 21842.

changes/ticket21842

@@ -0,0 +1,6 @@
+  o Removed features:
+    - We've removed the tor-checkkey tool from src/tools. Long ago, we
+      used it to help people detect RSA keys that were generated by
+      versions of Debian affected by CVE-2008-0166. But those keys
+      have been out of circulation for ages, and this tool is no
+      longer required.  Closes ticket 21842.

src/common/crypto.c

@@ -467,7 +467,7 @@ crypto_new_pk_from_rsa_(RSA *rsa)
   return env;
 }
 
-/** Helper, used by tor-checkkey.c and tor-gencert.c.  Return the RSA from a
+/** Helper, used by tor-gencert.c.  Return the RSA from a
  * crypto_pk_t. */
 RSA *
 crypto_pk_get_rsa_(crypto_pk_t *env)

src/tools/include.am

@@ -1,5 +1,4 @@
 bin_PROGRAMS+= src/tools/tor-resolve src/tools/tor-gencert
-noinst_PROGRAMS+=  src/tools/tor-checkkey
 
 if COVERAGE_ENABLED
 noinst_PROGRAMS+= src/tools/tor-cov-resolve src/tools/tor-cov-gencert
@@ -43,14 +42,4 @@ src_tools_tor_cov_gencert_LDADD = src/common/libor-testing.a \
     @TOR_LIB_WS32@ @TOR_LIB_GDI@ @CURVE25519_LIBS@
 endif
 
-src_tools_tor_checkkey_SOURCES = src/tools/tor-checkkey.c
-src_tools_tor_checkkey_LDFLAGS = @TOR_LDFLAGS_zlib@ @TOR_LDFLAGS_openssl@
-src_tools_tor_checkkey_LDADD = src/common/libor.a \
-    src/common/libor-ctime.a \
-    src/common/libor-crypto.a \
-    $(LIBKECCAK_TINY) \
-    $(LIBDONNA) \
-    @TOR_LIB_MATH@ @TOR_ZLIB_LIBS@ @TOR_OPENSSL_LIBS@ \
-    @TOR_LIB_WS32@ @TOR_LIB_GDI@ @CURVE25519_LIBS@
-
 EXTRA_DIST += src/tools/tor-fw-helper/README

src/tools/tor-checkkey.c

@@ -1,89 +0,0 @@
-/* Copyright (c) 2008-2017, The Tor Project, Inc. */
-/* See LICENSE for licensing information */
-
-#include "orconfig.h"
-
-#include <stdio.h>
-#include <stdlib.h>
-#include "crypto.h"
-#include "torlog.h"
-#include "util.h"
-#include "compat.h"
-#include "compat_openssl.h"
-#include <openssl/bn.h>
-#include <openssl/rsa.h>
-
-int
-main(int c, char **v)
-{
-  crypto_pk_t *env;
-  char *str;
-  RSA *rsa;
-  int wantdigest=0;
-  int fname_idx;
-  char *fname=NULL;
-  init_logging(1);
-
-  if (c < 2) {
-    fprintf(stderr, "Hi. I'm tor-checkkey.  Tell me a filename that "
-            "has a PEM-encoded RSA public key (like in a cert) and I'll "
-            "dump the modulus.  Use the --digest option too and I'll "
-            "dump the digest.\n");
-    return 1;
-  }
-
-  if (crypto_global_init(0, NULL, NULL)) {
-    fprintf(stderr, "Couldn't initialize crypto library.\n");
-    return 1;
-  }
-
-  if (!strcmp(v[1], "--digest")) {
-    wantdigest = 1;
-    fname_idx = 2;
-    if (c<3) {
-      fprintf(stderr, "too few arguments");
-      return 1;
-    }
-  } else {
-    wantdigest = 0;
-    fname_idx = 1;
-  }
-
-  fname = expand_filename(v[fname_idx]);
-  str = read_file_to_str(fname, 0, NULL);
-  tor_free(fname);
-  if (!str) {
-    fprintf(stderr, "Couldn't read %s\n", v[fname_idx]);
-    return 1;
-  }
-
-  env = crypto_pk_new();
-  if (crypto_pk_read_public_key_from_string(env, str, strlen(str))<0) {
-    fprintf(stderr, "Couldn't parse key.\n");
-    return 1;
-  }
-  tor_free(str);
-
-  if (wantdigest) {
-    char digest[HEX_DIGEST_LEN+1];
-    if (crypto_pk_get_fingerprint(env, digest, 0)<0)
-      return 1;
-    printf("%s\n",digest);
-  } else {
-    rsa = crypto_pk_get_rsa_(env);
-
-    const BIGNUM *rsa_n;
-#ifdef OPENSSL_1_1_API
-    const BIGNUM *rsa_e, *rsa_d;
-    RSA_get0_key(rsa, &rsa_n, &rsa_e, &rsa_d);
-#else
-    rsa_n = rsa->n;
-#endif
-    str = BN_bn2hex(rsa_n);
-
-    printf("%s\n", str);
-  }
-
-  return 0;
-}
-