X-Git-Url: http://git.silcnet.org/gitweb/?a=blobdiff_plain;f=lib%2Fsilccrypt%2Frsa.c;h=7bacd1e098af114fd4663eb4c6b5f9c1720bb3fc;hb=413da0f8686910f5e627393157566ae729ca99c4;hp=47158aab0a4700fc79a31101a154bc5391229b2b;hpb=030955992dd0663ddb907a06fd92af62afb9a015;p=silc.git

diff --git a/lib/silccrypt/rsa.c b/lib/silccrypt/rsa.c
index 47158aab..7bacd1e0 100644
--- a/lib/silccrypt/rsa.c
+++ b/lib/silccrypt/rsa.c
@@ -66,6 +66,11 @@
      Use the SilcRng sent as argument to SILC_PKCS_API_INIT in prime 
      generation.
 
+   o Sat Sep 26 19:59:48 EEST 2002  Pekka
+
+     Fixed double free in public key setting.  Use a bit larger e as
+     starting point in key generation.
+
 */
 
 #include "silcincludes.h"
@@ -121,7 +126,7 @@ SILC_PKCS_API_INIT(rsa)
   silc_mp_uninit(&p);
   silc_mp_uninit(&q);
   
-  printf("\nKeys generated succesfully.\n");
+  printf("\nKeys generated successfully.\n");
 
   return TRUE;
 }
@@ -141,7 +146,7 @@ SILC_PKCS_API_GET_PUBLIC_KEY(rsa)
   unsigned char tmp[4];
 
   e = silc_mp_mp2bin(&key->e, 0, &e_len);
-  n = silc_mp_mp2bin(&key->n, key->bits / 8, &n_len);
+  n = silc_mp_mp2bin(&key->n, (key->bits + 7) / 8, &n_len);
 
   *ret_len = e_len + 4 + n_len + 4;
   ret = silc_calloc(*ret_len, sizeof(unsigned char));
@@ -180,7 +185,7 @@ SILC_PKCS_API_GET_PRIVATE_KEY(rsa)
   unsigned char tmp[4];
 
   e = silc_mp_mp2bin(&key->e, 0, &e_len);
-  n = silc_mp_mp2bin(&key->n, key->bits / 8, &n_len);
+  n = silc_mp_mp2bin(&key->n, (key->bits + 7) / 8, &n_len);
   d = silc_mp_mp2bin(&key->d, 0, &d_len);
 
   *ret_len = e_len + 4 + n_len + 4 + d_len + 4;
@@ -227,26 +232,35 @@ SILC_PKCS_API_SET_PUBLIC_KEY(rsa)
 
   if (key->pub_set) {
     silc_mp_uninit(&key->e);
-    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
     key->pub_set = FALSE;
   }
 
+  if (key_len < 4)
+    return 0;
+
   silc_mp_init(&key->e);
   silc_mp_init(&key->n);
 
   memcpy(tmp, key_data, 4);
   SILC_GET32_MSB(e_len, tmp);
-  if (e_len > key_len) {
+  if (!e_len || e_len + 4 > key_len) {
     silc_mp_uninit(&key->e);
     silc_mp_uninit(&key->n);
     return 0;
   }
 
   silc_mp_bin2mp(key_data + 4, e_len, &key->e);
-  
+
+  if (key_len < 4 + e_len + 4) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    return 0;
+  }
+
   memcpy(tmp, key_data + 4 + e_len, 4);
   SILC_GET32_MSB(n_len, tmp);
-  if (e_len + n_len > key_len) {
+  if (!n_len || e_len + 4 + n_len + 4 > key_len) {
     silc_mp_uninit(&key->e);
     silc_mp_uninit(&key->n);
     return 0;
@@ -254,7 +268,7 @@ SILC_PKCS_API_SET_PUBLIC_KEY(rsa)
 
   silc_mp_bin2mp(key_data + 4 + e_len + 4, n_len, &key->n);
 
-  key->bits = n_len * 8;
+  key->bits = silc_mp_sizeinbase(&key->n, 2);
   key->pub_set = TRUE;
 
   return key->bits;
@@ -281,13 +295,16 @@ SILC_PKCS_API_SET_PRIVATE_KEY(rsa)
     key->pub_set = FALSE;
   }
 
+  if (key_len < 4)
+    return FALSE;
+
   silc_mp_init(&key->e);
   silc_mp_init(&key->n);
   silc_mp_init(&key->d);
 
   memcpy(tmp, key_data, 4);
   SILC_GET32_MSB(e_len, tmp);
-  if (e_len > key_len) {
+  if (e_len + 4 > key_len) {
     silc_mp_uninit(&key->e);
     silc_mp_uninit(&key->n);
     silc_mp_uninit(&key->d);
@@ -296,9 +313,16 @@ SILC_PKCS_API_SET_PRIVATE_KEY(rsa)
 
   silc_mp_bin2mp(key_data + 4, e_len, &key->e);
   
+  if (key_len < e_len + 4 + 4) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    silc_mp_uninit(&key->d);
+    return FALSE;
+  }
+
   memcpy(tmp, key_data + 4 + e_len, 4);
   SILC_GET32_MSB(n_len, tmp);
-  if (e_len + n_len > key_len) {
+  if (e_len + 4 + n_len + 4 > key_len) {
     silc_mp_uninit(&key->e);
     silc_mp_uninit(&key->n);
     silc_mp_uninit(&key->d);
@@ -307,9 +331,16 @@ SILC_PKCS_API_SET_PRIVATE_KEY(rsa)
 
   silc_mp_bin2mp(key_data + 4 + e_len + 4, n_len, &key->n);
 
+  if (key_len < e_len + 4 + n_len + 4 + 4) {
+    silc_mp_uninit(&key->e);
+    silc_mp_uninit(&key->n);
+    silc_mp_uninit(&key->d);
+    return FALSE;
+  }
+
   memcpy(tmp, key_data + 4 + e_len + 4 + n_len, 4);
   SILC_GET32_MSB(d_len, tmp);
-  if (e_len + n_len + d_len > key_len) {
+  if (e_len + 4 + n_len + 4 + d_len + 4 > key_len) {
     silc_mp_uninit(&key->e);
     silc_mp_uninit(&key->n);
     silc_mp_uninit(&key->d);
@@ -318,11 +349,11 @@ SILC_PKCS_API_SET_PRIVATE_KEY(rsa)
 
   silc_mp_bin2mp(key_data + 4 + e_len + 4 + n_len + 4, d_len, &key->d);
 
-  key->bits = n_len * 8;
+  key->bits = silc_mp_sizeinbase(&key->n, 2);
   key->prv_set = TRUE;
   key->pub_set = TRUE;
 
-  return TRUE;
+  return key->bits;
 }
 
 SILC_PKCS_API_CONTEXT_LEN(rsa)
@@ -333,20 +364,15 @@ SILC_PKCS_API_CONTEXT_LEN(rsa)
 SILC_PKCS_API_ENCRYPT(rsa)
 {
   RsaKey *key = (RsaKey *)context;
-  int i, tmplen;
+  int tmplen;
   SilcMPInt mp_tmp;
   SilcMPInt mp_dst;
 
   silc_mp_init(&mp_tmp);
   silc_mp_init(&mp_dst);
-  silc_mp_set_ui(&mp_tmp, 0);
-  silc_mp_set_ui(&mp_dst, 0);
 
   /* Format the data into MP int */
-  for (i = 0; i < src_len; i++) {
-    silc_mp_mul_2exp(&mp_tmp, &mp_tmp, 8);
-    silc_mp_add_ui(&mp_tmp, &mp_tmp, src[i]);
-  }
+  silc_mp_bin2mp(src, src_len, &mp_tmp);
 
   /* Encrypt */
   rsa_en_de_crypt(&mp_dst, &mp_tmp, &key->e, &key->n);
@@ -354,10 +380,7 @@ SILC_PKCS_API_ENCRYPT(rsa)
   tmplen = (key->bits + 7) / 8;
 
   /* Format the MP int back into data */
-  for (i = tmplen; i > 0; i--) {
-    dst[i - 1] = (unsigned char)(silc_mp_get_ui(&mp_dst) & 0xff);
-    silc_mp_div_2exp(&mp_dst, &mp_dst, 8);
-  }
+  silc_mp_mp2bin_noalloc(&mp_dst, dst, tmplen);
   *dst_len = tmplen;
 
   silc_mp_uninit(&mp_tmp);
@@ -369,20 +392,15 @@ SILC_PKCS_API_ENCRYPT(rsa)
 SILC_PKCS_API_DECRYPT(rsa)
 {
   RsaKey *key = (RsaKey *)context;
-  int i, tmplen;
+  int tmplen;
   SilcMPInt mp_tmp;
   SilcMPInt mp_dst;
 
   silc_mp_init(&mp_tmp);
   silc_mp_init(&mp_dst);
-  silc_mp_set_ui(&mp_tmp, 0);
-  silc_mp_set_ui(&mp_dst, 0);
 
   /* Format the data into MP int */
-  for (i = 0; i < src_len; i++) {
-    silc_mp_mul_2exp(&mp_tmp, &mp_tmp, 8);
-    silc_mp_add_ui(&mp_tmp, &mp_tmp, src[i]);
-  }
+  silc_mp_bin2mp(src, src_len, &mp_tmp);
 
   /* Decrypt */
   rsa_en_de_crypt(&mp_dst, &mp_tmp, &key->d, &key->n);
@@ -390,10 +408,7 @@ SILC_PKCS_API_DECRYPT(rsa)
   tmplen = (key->bits + 7) / 8;
 
   /* Format the MP int back into data */
-  for (i = tmplen; i > 0; i--) {
-    dst[i - 1] = (unsigned char)(silc_mp_get_ui(&mp_dst) & 0xff);
-    silc_mp_div_2exp(&mp_dst, &mp_dst, 8);
-  }
+  silc_mp_mp2bin_noalloc(&mp_dst, dst, tmplen);
   *dst_len = tmplen;
 
   silc_mp_uninit(&mp_tmp);
@@ -405,20 +420,15 @@ SILC_PKCS_API_DECRYPT(rsa)
 SILC_PKCS_API_SIGN(rsa)
 {
   RsaKey *key = (RsaKey *)context;
-  int i, tmplen;
+  int tmplen;
   SilcMPInt mp_tmp;
   SilcMPInt mp_dst;
 
   silc_mp_init(&mp_tmp);
   silc_mp_init(&mp_dst);
-  silc_mp_set_ui(&mp_tmp, 0);
-  silc_mp_set_ui(&mp_dst, 0);
 
   /* Format the data into MP int */
-  for (i = 0; i < src_len; i++) {
-    silc_mp_mul_2exp(&mp_tmp, &mp_tmp, 8);
-    silc_mp_add_ui(&mp_tmp, &mp_tmp, src[i]);
-  }
+  silc_mp_bin2mp(src, src_len, &mp_tmp);
 
   /* Sign */
   rsa_en_de_crypt(&mp_dst, &mp_tmp, &key->d, &key->n);
@@ -426,10 +436,7 @@ SILC_PKCS_API_SIGN(rsa)
   tmplen = (key->bits + 7) / 8;
 
   /* Format the MP int back into data */
-  for (i = tmplen; i > 0; i--) {
-    dst[i - 1] = (unsigned char)(silc_mp_get_ui(&mp_dst) & 0xff);
-    silc_mp_div_2exp(&mp_dst, &mp_dst, 8);
-  }
+  silc_mp_mp2bin_noalloc(&mp_dst, dst, tmplen);
   *dst_len = tmplen;
 
   silc_mp_uninit(&mp_tmp);
@@ -441,31 +448,22 @@ SILC_PKCS_API_SIGN(rsa)
 SILC_PKCS_API_VERIFY(rsa)
 {
   RsaKey *key = (RsaKey *)context;
-  int i, ret;
+  int ret;
   SilcMPInt mp_tmp, mp_tmp2;
   SilcMPInt mp_dst;
 
   silc_mp_init(&mp_tmp);
   silc_mp_init(&mp_tmp2);
   silc_mp_init(&mp_dst);
-  silc_mp_set_ui(&mp_tmp, 0);
-  silc_mp_set_ui(&mp_tmp2, 0);
-  silc_mp_set_ui(&mp_dst, 0);
 
   /* Format the signature into MP int */
-  for (i = 0; i < signature_len; i++) {
-    silc_mp_mul_2exp(&mp_tmp2, &mp_tmp2, 8);
-    silc_mp_add_ui(&mp_tmp2, &mp_tmp2, signature[i]);
-  }
+  silc_mp_bin2mp(signature, signature_len, &mp_tmp2);
 
   /* Verify */
   rsa_en_de_crypt(&mp_dst, &mp_tmp2, &key->e, &key->n);
 
   /* Format the data into MP int */
-  for (i = 0; i < data_len; i++) {
-    silc_mp_mul_2exp(&mp_tmp, &mp_tmp, 8);
-    silc_mp_add_ui(&mp_tmp, &mp_tmp, data[i]);
-  }
+  silc_mp_bin2mp(data, data_len, &mp_tmp);
 
   ret = TRUE;
 
@@ -516,7 +514,7 @@ void rsa_generate_keys(RsaKey *key, SilcUInt32 bits,
   /* Set e, the public exponent. We try to use same public exponent
      for all keys. Also, to make encryption faster we use small 
      number. */
-  silc_mp_set_ui(&key->e, 127);
+  silc_mp_set_ui(&key->e, 65533);
  retry_e:
   /* See if e is relatively prime to phi. gcd == greates common divisor,
      if gcd equals 1 they are relatively prime. */
@@ -526,7 +524,7 @@ void rsa_generate_keys(RsaKey *key, SilcUInt32 bits,
     goto retry_e;
   }
   
-  /* Find d, the private exponent. */
+  /* Find d, the private exponent, e ^ -1 mod lcm(phi). */
   silc_mp_gcd(&div, &pm1, &qm1);
   silc_mp_div(&lcm, &phi, &div);
   silc_mp_modinv(&key->d, &key->e, &lcm);