common.c

   1 /*
   2  * Utility routines. This file is part of Shairport.
   3  * Copyright (c) James Laird 2013
   4  * All rights reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person
   7  * obtaining a copy of this software and associated documentation
   8  * files (the "Software"), to deal in the Software without
   9  * restriction, including without limitation the rights to use,
  10  * copy, modify, merge, publish, distribute, sublicense, and/or
  11  * sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be
  15  * included in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  19  * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  20  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  21  * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  22  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  24  * OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27 #include <stdio.h>
  28 #include <stdarg.h>
  29 #include <stdlib.h>
  30 #include <memory.h>
  31 #include <openssl/rsa.h>
  32 #include <openssl/pem.h>
  33 #include <openssl/evp.h>
  34 #include <openssl/bio.h>
  35 #include <openssl/buffer.h>
  36 #include "common.h"
  37
  38 shairport_cfg config;
  39
  40 int debuglev = 0;
  41
  42 void die(char *format, ...) {
  43     fprintf(stderr, "FATAL: ");
  44     va_list args;
  45     va_start(args, format);
  46     vfprintf(stderr, format, args);
  47     va_end(args);
  48     exit(1);
  49 }
  50
  51 void warn(char *format, ...) {
  52     fprintf(stderr, "WARNING: ");
  53     va_list args;
  54     va_start(args, format);
  55     vfprintf(stderr, format, args);
  56     va_end(args);
  57 }
  58
  59 void debug(char *format, ...) {
  60     if (!debuglev)
  61         return;
  62     fprintf(stderr, "DEBUG: ");
  63     va_list args;
  64     va_start(args, format);
  65     vfprintf(stderr, format, args);
  66     va_end(args);
  67 }
  68
  69
  70 char *base64_enc(uint8_t *input, int length) {
  71     BIO *bmem, *b64;
  72     BUF_MEM *bptr;
  73     b64 = BIO_new(BIO_f_base64());
  74     bmem = BIO_new(BIO_s_mem());
  75     b64 = BIO_push(b64, bmem);
  76     BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
  77     BIO_write(b64, input, length);
  78     BIO_flush(b64);
  79     BIO_get_mem_ptr(b64, &bptr);
  80
  81     char *buf = (char *)malloc(bptr->length);
  82     if (bptr->length) {
  83         memcpy(buf, bptr->data, bptr->length-1);
  84         buf[bptr->length-1] = 0;
  85     }
  86
  87     BIO_free_all(bmem);
  88
  89     return buf;
  90 }
  91
  92 uint8_t *base64_dec(char *input, int *outlen) {
  93     BIO *bmem, *b64;
  94     int inlen = strlen(input);
  95
  96     b64 = BIO_new(BIO_f_base64());
  97     BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
  98     bmem = BIO_new(BIO_s_mem());
  99     b64 = BIO_push(b64, bmem);
 100
 101     // Apple cut the padding off their challenges; restore it
 102     BIO_write(bmem, input, inlen);
 103     while (inlen++ & 3)
 104         BIO_write(bmem, "=", 1);
 105     BIO_flush(bmem);
 106
 107     int bufsize = strlen(input)*3/4 + 1;
 108     uint8_t *buf = malloc(bufsize);
 109     int nread;
 110
 111     nread = BIO_read(b64, buf, bufsize);
 112
 113     BIO_free_all(bmem);
 114
 115     *outlen = nread;
 116     return buf;
 117 }
 118
 119 static char super_secret_key[] =
 120 "-----BEGIN RSA PRIVATE KEY-----\n"
 121 "MIIEpQIBAAKCAQEA59dE8qLieItsH1WgjrcFRKj6eUWqi+bGLOX1HL3U3GhC/j0Qg90u3sG/1CUt\n"
 122 "wC5vOYvfDmFI6oSFXi5ELabWJmT2dKHzBJKa3k9ok+8t9ucRqMd6DZHJ2YCCLlDRKSKv6kDqnw4U\n"
 123 "wPdpOMXziC/AMj3Z/lUVX1G7WSHCAWKf1zNS1eLvqr+boEjXuBOitnZ/bDzPHrTOZz0Dew0uowxf\n"
 124 "/+sG+NCK3eQJVxqcaJ/vEHKIVd2M+5qL71yJQ+87X6oV3eaYvt3zWZYD6z5vYTcrtij2VZ9Zmni/\n"
 125 "UAaHqn9JdsBWLUEpVviYnhimNVvYFZeCXg/IdTQ+x4IRdiXNv5hEewIDAQABAoIBAQDl8Axy9XfW\n"
 126 "BLmkzkEiqoSwF0PsmVrPzH9KsnwLGH+QZlvjWd8SWYGN7u1507HvhF5N3drJoVU3O14nDY4TFQAa\n"
 127 "LlJ9VM35AApXaLyY1ERrN7u9ALKd2LUwYhM7Km539O4yUFYikE2nIPscEsA5ltpxOgUGCY7b7ez5\n"
 128 "NtD6nL1ZKauw7aNXmVAvmJTcuPxWmoktF3gDJKK2wxZuNGcJE0uFQEG4Z3BrWP7yoNuSK3dii2jm\n"
 129 "lpPHr0O/KnPQtzI3eguhe0TwUem/eYSdyzMyVx/YpwkzwtYL3sR5k0o9rKQLtvLzfAqdBxBurciz\n"
 130 "aaA/L0HIgAmOit1GJA2saMxTVPNhAoGBAPfgv1oeZxgxmotiCcMXFEQEWflzhWYTsXrhUIuz5jFu\n"
 131 "a39GLS99ZEErhLdrwj8rDDViRVJ5skOp9zFvlYAHs0xh92ji1E7V/ysnKBfsMrPkk5KSKPrnjndM\n"
 132 "oPdevWnVkgJ5jxFuNgxkOLMuG9i53B4yMvDTCRiIPMQ++N2iLDaRAoGBAO9v//mU8eVkQaoANf0Z\n"
 133 "oMjW8CN4xwWA2cSEIHkd9AfFkftuv8oyLDCG3ZAf0vrhrrtkrfa7ef+AUb69DNggq4mHQAYBp7L+\n"
 134 "k5DKzJrKuO0r+R0YbY9pZD1+/g9dVt91d6LQNepUE/yY2PP5CNoFmjedpLHMOPFdVgqDzDFxU8hL\n"
 135 "AoGBANDrr7xAJbqBjHVwIzQ4To9pb4BNeqDndk5Qe7fT3+/H1njGaC0/rXE0Qb7q5ySgnsCb3DvA\n"
 136 "cJyRM9SJ7OKlGt0FMSdJD5KG0XPIpAVNwgpXXH5MDJg09KHeh0kXo+QA6viFBi21y340NonnEfdf\n"
 137 "54PX4ZGS/Xac1UK+pLkBB+zRAoGAf0AY3H3qKS2lMEI4bzEFoHeK3G895pDaK3TFBVmD7fV0Zhov\n"
 138 "17fegFPMwOII8MisYm9ZfT2Z0s5Ro3s5rkt+nvLAdfC/PYPKzTLalpGSwomSNYJcB9HNMlmhkGzc\n"
 139 "1JnLYT4iyUyx6pcZBmCd8bD0iwY/FzcgNDaUmbX9+XDvRA0CgYEAkE7pIPlE71qvfJQgoA9em0gI\n"
 140 "LAuE4Pu13aKiJnfft7hIjbK+5kyb3TysZvoyDnb3HOKvInK7vXbKuU4ISgxB2bB3HcYzQMGsz1qJ\n"
 141 "2gG0N5hvJpzwwhbhXqFKA4zaaSrw622wDniAK5MlIE0tIAKKP4yxNGjoD2QYjhBGuhvkWKY=\n"
 142 "-----END RSA PRIVATE KEY-----";
 143
 144 uint8_t *rsa_apply(uint8_t *input, int inlen, int *outlen, int mode) {
 145     static RSA *rsa = NULL;
 146
 147     if (!rsa) {
 148         BIO *bmem = BIO_new_mem_buf(super_secret_key, -1);
 149         rsa = PEM_read_bio_RSAPrivateKey(bmem, NULL, NULL, NULL);
 150         BIO_free(bmem);
 151     }
 152
 153     uint8_t *out = malloc(RSA_size(rsa));
 154     switch (mode) {
 155         case RSA_MODE_AUTH:
 156             *outlen = RSA_private_encrypt(inlen, input, out, rsa,
 157                                           RSA_PKCS1_PADDING);
 158             break;
 159         case RSA_MODE_KEY:
 160             *outlen = RSA_private_decrypt(inlen, input, out, rsa,
 161                                           RSA_PKCS1_OAEP_PADDING);
 162             break;
 163         default:
 164             die("bad rsa mode");
 165     }
 166     return out;
 167 }