- Changed the used random function pointer to more flexible format. Renamed...

 - Changed the used random function pointer to more flexible format. Renamed havege_rand() to havege_random() to prevent mistakes. Lots of changes as a consequence in library code and programs

ChangeLog

@@ -29,6 +29,9 @@ Changes
      trade-off
    * Introduced POLARSSL_MPI_MAX_SIZE and POLARSSL_MPI_MAX_BITS for MPI size
      management (Closes ticket #44)
+   * Changed the used random function pointer to more flexible format. Renamed
+     havege_rand() to havege_random() to prevent mistakes. Lots of changes as
+	 a consequence in library code and programs
 
 Bugfix
    * Fixed faulty HMAC-MD2 implementation. Found by dibac. (Closes

include/polarssl/bignum.h

@@ -539,7 +539,9 @@ int mpi_exp_mod( mpi *X, const mpi *A, const mpi *E, const mpi *N, mpi *_RR );
  * \return         0 if successful,
  *                 1 if memory allocation failed
  */
-int mpi_fill_random( mpi *X, size_t size, int (*f_rng)(void *), void *p_rng );
+int mpi_fill_random( mpi *X, size_t size,
+                     int (*f_rng)(void *, unsigned char *, size_t),
+                     void *p_rng );
 
 /**
  * \brief          Greatest common divisor: G = gcd(A, B)
@@ -578,7 +580,9 @@ int mpi_inv_mod( mpi *X, const mpi *A, const mpi *N );
  *                 1 if memory allocation failed,
  *                 POLARSSL_ERR_MPI_NOT_ACCEPTABLE if X is not prime
  */
-int mpi_is_prime( mpi *X, int (*f_rng)(void *), void *p_rng );
+int mpi_is_prime( mpi *X,
+                  int (*f_rng)(void *, unsigned char *, size_t),
+                  void *p_rng );
 
 /**
  * \brief          Prime number generation
@@ -594,7 +598,8 @@ int mpi_is_prime( mpi *X, int (*f_rng)(void *), void *p_rng );
  *                 POLARSSL_ERR_MPI_BAD_INPUT_DATA if nbits is < 3
  */
 int mpi_gen_prime( mpi *X, size_t nbits, int dh_flag,
-                   int (*f_rng)(void *), void *p_rng );
+                   int (*f_rng)(void *, unsigned char *, size_t),
+                   void *p_rng );
 
 /**
  * \brief          Checkup routine

include/polarssl/dhm.h

@@ -90,7 +90,8 @@ int dhm_read_params( dhm_context *ctx,
  */
 int dhm_make_params( dhm_context *ctx, int x_size,
                      unsigned char *output, size_t *olen,
-                     int (*f_rng)(void *), void *p_rng );
+                     int (*f_rng)(void *, unsigned char *, size_t),
+                     void *p_rng );
 
 /**
  * \brief          Import the peer's public value G^Y
@@ -118,7 +119,8 @@ int dhm_read_public( dhm_context *ctx,
  */
 int dhm_make_public( dhm_context *ctx, int x_size,
                      unsigned char *output, size_t olen,
-                     int (*f_rng)(void *), void *p_rng );
+                     int (*f_rng)(void *, unsigned char *, size_t),
+                     void *p_rng );
 
 /**
  * \brief          Derive and export the shared secret (G^Y)^X mod P

include/polarssl/havege.h

@@ -27,6 +27,8 @@
 #ifndef POLARSSL_HAVEGE_H
 #define POLARSSL_HAVEGE_H
 
+#include <string.h>
+
 #define COLLECT_SIZE 1024
 
 /**
@@ -55,10 +57,12 @@ void havege_init( havege_state *hs );
  * \brief          HAVEGE rand function
  *
  * \param p_rng    A HAVEGE state
+ * \param output   Buffer to fill
+ * \param len      Length of buffer
  *
  * \return         A random int
  */
-int havege_rand( void *p_rng );
+int havege_random( void *p_rng, unsigned char *output, size_t len );
 
 #ifdef __cplusplus
 }

include/polarssl/rsa.h

@@ -186,7 +186,7 @@ void rsa_init( rsa_context *ctx,
  * \return         0 if successful, or an POLARSSL_ERR_RSA_XXX error code
  */
 int rsa_gen_key( rsa_context *ctx,
-                 int (*f_rng)(void *),
+                 int (*f_rng)(void *, unsigned char *, size_t),
                  void *p_rng,
                  unsigned int nbits, int exponent );
 
@@ -261,7 +261,7 @@ int rsa_private( rsa_context *ctx,
  *                 of ctx->N (eg. 128 bytes if RSA-1024 is used).
  */
 int rsa_pkcs1_encrypt( rsa_context *ctx,
-                       int (*f_rng)(void *),
+                       int (*f_rng)(void *, unsigned char *, size_t),
                        void *p_rng,
                        int mode, size_t ilen,
                        const unsigned char *input,
@@ -314,7 +314,7 @@ int rsa_pkcs1_decrypt( rsa_context *ctx,
  *                 keep both hashes the same.
  */
 int rsa_pkcs1_sign( rsa_context *ctx,
-                    int (*f_rng)(void *),
+                    int (*f_rng)(void *, unsigned char *, size_t),
                     void *p_rng,
                     int mode,
                     int hash_id,

include/polarssl/ssl.h

@@ -232,7 +232,7 @@ struct _ssl_context
     /*
      * Callbacks (RNG, debug, I/O, verification)
      */
-    int  (*f_rng)(void *);
+    int  (*f_rng)(void *, unsigned char *, size_t);
     void (*f_dbg)(void *, int, const char *);
     int (*f_recv)(void *, unsigned char *, size_t);
     int (*f_send)(void *, const unsigned char *, size_t);
@@ -438,7 +438,7 @@ void ssl_set_verify( ssl_context *ssl,
  * \param p_rng    RNG parameter
  */
 void ssl_set_rng( ssl_context *ssl,
-                  int (*f_rng)(void *),
+                  int (*f_rng)(void *, unsigned char *, size_t),
                   void *p_rng );
 
 /**

library/bignum.c

@@ -1608,18 +1608,16 @@ cleanup:
     return( ret );
 }
 
-int mpi_fill_random( mpi *X, size_t size, int (*f_rng)(void *), void *p_rng )
+int mpi_fill_random( mpi *X, size_t size,
+                     int (*f_rng)(void *, unsigned char *, size_t),
+                     void *p_rng )
 {
     int ret;
-    size_t k;
-    unsigned char *p;
 
     MPI_CHK( mpi_grow( X, size ) );
     MPI_CHK( mpi_lset( X, 0 ) );
 
-    p = (unsigned char *) X->p;
-    for( k = 0; k < X->n * ciL; k++ )
-        *p++ = (unsigned char) f_rng( p_rng );
+    MPI_CHK( f_rng( p_rng, (unsigned char *) X->p, X->n * ciL ) );
 
 cleanup:
     return( ret );
@@ -1750,7 +1748,9 @@ static const int small_prime[] =
 /*
  * Miller-Rabin primality test  (HAC 4.24)
  */
-int mpi_is_prime( mpi *X, int (*f_rng)(void *), void *p_rng )
+int mpi_is_prime( mpi *X,
+                  int (*f_rng)(void *, unsigned char *, size_t),
+                  void *p_rng )
 {
     int ret, xs;
     size_t i, j, n, s;
@@ -1809,7 +1809,7 @@ int mpi_is_prime( mpi *X, int (*f_rng)(void *), void *p_rng )
         /*
          * pick a random A, 1 < A < |X| - 1
          */
-        mpi_fill_random( &A, X->n, f_rng, p_rng );
+        MPI_CHK( mpi_fill_random( &A, X->n, f_rng, p_rng ) );
 
         if( mpi_cmp_mpi( &A, &W ) >= 0 )
         {
@@ -1867,7 +1867,8 @@ cleanup:
  * Prime number generation
  */
 int mpi_gen_prime( mpi *X, size_t nbits, int dh_flag,
-                   int (*f_rng)(void *), void *p_rng )
+                   int (*f_rng)(void *, unsigned char *, size_t),
+                   void *p_rng )
 {
     int ret;
     size_t k, n;
@@ -1880,7 +1881,7 @@ int mpi_gen_prime( mpi *X, size_t nbits, int dh_flag,
 
     n = BITS_TO_LIMBS( nbits );
 
-    mpi_fill_random( X, n, f_rng, p_rng );
+    MPI_CHK( mpi_fill_random( X, n, f_rng, p_rng ) );
 
     k = mpi_msb( X );
     if( k < nbits ) MPI_CHK( mpi_shift_l( X, nbits - k ) );

library/dhm.c

@@ -127,7 +127,8 @@ int dhm_read_params( dhm_context *ctx,
  */
 int dhm_make_params( dhm_context *ctx, int x_size,
                      unsigned char *output, size_t *olen,
-                     int (*f_rng)(void *), void *p_rng )
+                     int (*f_rng)(void *, unsigned char *, size_t),
+                     void *p_rng )
 {
     int ret, n;
     size_t n1, n2, n3;
@@ -203,7 +204,8 @@ int dhm_read_public( dhm_context *ctx,
  */
 int dhm_make_public( dhm_context *ctx, int x_size,
                      unsigned char *output, size_t olen,
-                     int (*f_rng)(void *), void *p_rng )
+                     int (*f_rng)(void *, unsigned char *, size_t),
+                     void *p_rng )
 {
     int ret, n;
 

library/havege.c

@@ -200,18 +200,32 @@ void havege_init( havege_state *hs )
 /*
  * HAVEGE rand function
  */
-int havege_rand( void *p_rng )
+int havege_random( void *p_rng, unsigned char *buf, size_t len )
 {
-    int ret;
+    int val;
+    size_t use_len;
     havege_state *hs = (havege_state *) p_rng;
+    unsigned char *p = buf;
 
-    if( hs->offset[1] >= COLLECT_SIZE )
-        havege_fill( hs );
+    while( len > 0 )
+    {
+        use_len = len;
+        if( use_len > sizeof(int) )
+            use_len = sizeof(int);
+
+        if( hs->offset[1] >= COLLECT_SIZE )
+            havege_fill( hs );
 
-    ret  = hs->pool[hs->offset[0]++];
-    ret ^= hs->pool[hs->offset[1]++];
+        val  = hs->pool[hs->offset[0]++];
+        val ^= hs->pool[hs->offset[1]++];
+
+        memcpy( p, &val, use_len );
+        
+        len -= use_len;
+        p += use_len;
+    }
 
-    return( ret );
+    return( 0 );
 }
 
 #endif

library/rsa.c

@@ -58,9 +58,9 @@ void rsa_init( rsa_context *ctx,
  * Generate an RSA keypair
  */
 int rsa_gen_key( rsa_context *ctx,
-        int (*f_rng)(void *),
-        void *p_rng,
-        unsigned int nbits, int exponent )
+                 int (*f_rng)(void *, unsigned char *, size_t),
+                 void *p_rng,
+                 unsigned int nbits, int exponent )
 {
     int ret;
     mpi P1, Q1, H, G;
@@ -356,16 +356,16 @@ static void mgf_mask( unsigned char *dst, size_t dlen, unsigned char *src, size_
  * Add the message padding, then do an RSA operation
  */
 int rsa_pkcs1_encrypt( rsa_context *ctx,
-                       int (*f_rng)(void *),
+                       int (*f_rng)(void *, unsigned char *, size_t),
                        void *p_rng,
                        int mode, size_t ilen,
                        const unsigned char *input,
                        unsigned char *output )
 {
-    size_t nb_pad, olen;
+    size_t nb_pad, olen, ret;
     unsigned char *p = output;
 #if defined(POLARSSL_PKCS1_V21)
-    unsigned int i, hlen;
+    unsigned int hlen;
     const md_info_t *md_info;
     md_context_t md_ctx;
 #endif
@@ -392,13 +392,13 @@ int rsa_pkcs1_encrypt( rsa_context *ctx,
                 int rng_dl = 100;
 
                 do {
-                    *p = (unsigned char) f_rng( p_rng );
-                } while( *p == 0 && --rng_dl );
+                    ret = f_rng( p_rng, p, 1 );
+                } while( *p == 0 && --rng_dl && ret == 0 );
 
                 // Check if RNG failed to generate data
                 //
-                if( rng_dl == 0 )
-                    return POLARSSL_ERR_RSA_RNG_FAILED;
+                if( rng_dl == 0 || ret != 0)
+                    return POLARSSL_ERR_RSA_RNG_FAILED + ret;
 
                 p++;
             }
@@ -427,8 +427,10 @@ int rsa_pkcs1_encrypt( rsa_context *ctx,
 
             // Generate a random octet string seed
             //
-            for( i = 0; i < hlen; ++i )
-                *p++ = (unsigned char) f_rng( p_rng ); 
+            if( ( ret = f_rng( p_rng, p, hlen ) ) != 0 )
+                return( POLARSSL_ERR_RSA_RNG_FAILED + ret );
+
+            p += hlen;
 
             // Construct DB
             //
@@ -578,7 +580,7 @@ int rsa_pkcs1_decrypt( rsa_context *ctx,
  * Do an RSA operation to sign the message digest
  */
 int rsa_pkcs1_sign( rsa_context *ctx,
-                    int (*f_rng)(void *),
+                    int (*f_rng)(void *, unsigned char *, size_t),
                     void *p_rng,
                     int mode,
                     int hash_id,
@@ -590,7 +592,7 @@ int rsa_pkcs1_sign( rsa_context *ctx,
     unsigned char *p = sig;
 #if defined(POLARSSL_PKCS1_V21)
     unsigned char salt[POLARSSL_MD_MAX_SIZE];
-    unsigned int i, slen, hlen, offset = 0;
+    unsigned int slen, hlen, offset = 0, ret;
     size_t msb;
     const md_info_t *md_info;
     md_context_t md_ctx;
@@ -757,8 +759,8 @@ int rsa_pkcs1_sign( rsa_context *ctx,
 
             // Generate salt of length slen
             //
-            for( i = 0; i < slen; ++i )
-                salt[i] = (unsigned char) f_rng( p_rng ); 
+            if( ( ret = f_rng( p_rng, salt, slen ) ) != 0 )
+                return( POLARSSL_ERR_RSA_RNG_FAILED + ret );
 
             // Note: EMSA-PSS encoding is over the length of N - 1 bits
             //
@@ -1080,12 +1082,17 @@ void rsa_free( rsa_context *ctx )
 #define RSA_PT  "\xAA\xBB\xCC\x03\x02\x01\x00\xFF\xFF\xFF\xFF\xFF" \
                 "\x11\x22\x33\x0A\x0B\x0C\xCC\xDD\xDD\xDD\xDD\xDD"
 
-static int myrand( void *rng_state )
+static int myrand( void *rng_state, unsigned char *output, size_t len )
 {
+    size_t i;
+
     if( rng_state != NULL )
         rng_state  = NULL;
 
-    return( rand() );
+    for( i = 0; i < len; ++i )
+        output[i] = rand();
+    
+    return( 0 );
 }
 
 /*

library/ssl_cli.c

@@ -81,8 +81,10 @@ static int ssl_write_client_hello( ssl_context *ssl )
 
     SSL_DEBUG_MSG( 3, ( "client hello, current time: %lu", t ) );
 
-    for( i = 28; i > 0; i-- )
-        *p++ = (unsigned char) ssl->f_rng( ssl->p_rng );
+    if( ( ret = ssl->f_rng( ssl->p_rng, p, 28 ) ) != 0 )
+        return( ret );
+
+    p += 28;
 
     memcpy( ssl->randbytes, buf + 6, 32 );
 
@@ -583,8 +585,9 @@ static int ssl_write_client_key_exchange( ssl_context *ssl )
         ssl->premaster[1] = (unsigned char) ssl->max_minor_ver;
         ssl->pmslen = 48;
 
-        for( i = 2; i < ssl->pmslen; i++ )
-            ssl->premaster[i] = (unsigned char) ssl->f_rng( ssl->p_rng );
+        ret = ssl->f_rng( ssl->p_rng, ssl->premaster + 2, ssl->pmslen - 2 );
+        if( ret != 0 )
+            return( ret );
 
         i = 4;
         n = ssl->peer_cert->rsa.len;

library/ssl_srv.c

@@ -359,7 +359,7 @@ have_ciphersuite:
 static int ssl_write_server_hello( ssl_context *ssl )
 {
     time_t t;
-    int ret, i, n;
+    int ret, n;
     unsigned char *buf, *p;
 
     SSL_DEBUG_MSG( 2, ( "=> write server hello" ) );
@@ -388,8 +388,10 @@ static int ssl_write_server_hello( ssl_context *ssl )
 
     SSL_DEBUG_MSG( 3, ( "server hello, current time: %lu", t ) );
 
-    for( i = 28; i > 0; i-- )
-        *p++ = (unsigned char) ssl->f_rng( ssl->p_rng );
+    if( ( ret = ssl->f_rng( ssl->p_rng, p, 28 ) ) != 0 )
+        return( ret );
+
+    p += 28;
 
     memcpy( ssl->randbytes + 32, buf + 6, 32 );
 
@@ -413,9 +415,8 @@ static int ssl_write_server_hello( ssl_context *ssl )
         ssl->resume = 0;
         ssl->state++;
 
-        for( i = 0; i < n; i++ )
-            ssl->session->id[i] =
-                (unsigned char) ssl->f_rng( ssl->p_rng );
+        if( ( ret = ssl->f_rng( ssl->p_rng, ssl->session->id, n ) ) != 0 )
+            return( ret );
     }
     else
     {
@@ -823,8 +824,9 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
              */
             ssl->pmslen = 48;
 
-            for( i = 0; i < ssl->pmslen; i++ )
-                ssl->premaster[i] = (unsigned char) ssl->f_rng( ssl->p_rng );
+            ret = ssl->f_rng( ssl->p_rng, ssl->premaster, ssl->pmslen );
+            if( ret != 0 )
+                return( ret );
         }
     }
 

library/ssl_tls.c

@@ -578,8 +578,9 @@ static int ssl_encrypt_buf( ssl_context *ssl )
             /*
              * Generate IV
              */
-            for( i = 0; i < ssl->ivlen; i++ )
-                ssl->iv_enc[i] = ssl->f_rng( ssl->p_rng );
+            int ret = ssl->f_rng( ssl->p_rng, ssl->iv_enc, ssl->ivlen );
+            if( ret != 0 )
+                return( ret );
 
             /*
              * Shift message for ivlen bytes and prepend IV
@@ -1796,7 +1797,7 @@ void ssl_set_verify( ssl_context *ssl,
 }
 
 void ssl_set_rng( ssl_context *ssl,
-                  int (*f_rng)(void *),
+                  int (*f_rng)(void *, unsigned char *, size_t),
                   void *p_rng )
 {
     ssl->f_rng      = f_rng;

programs/pkey/dh_client.c

@@ -207,7 +207,7 @@ int main( int argc, char *argv[] )
 
     n = dhm.len;
     if( ( ret = dhm_make_public( &dhm, 256, buf, n,
-                                 havege_rand, &hs ) ) != 0 )
+                                 havege_random, &hs ) ) != 0 )
     {
         printf( " failed\n  ! dhm_make_public returned %d\n\n", ret );
         goto exit;

programs/pkey/dh_genprime.c

@@ -80,7 +80,7 @@ int main( int argc, char *argv[] )
      * This can take a long time...
      */
     if( ( ret = mpi_gen_prime( &P, DH_P_SIZE, 1,
-                               havege_rand, &hs ) ) != 0 )
+                               havege_random, &hs ) ) != 0 )
     {
         printf( " failed\n  ! mpi_gen_prime returned %d\n\n", ret );
         goto exit;
@@ -101,7 +101,7 @@ int main( int argc, char *argv[] )
         goto exit;
     }
 
-    if( ( ret = mpi_is_prime( &Q, havege_rand, &hs ) ) != 0 )
+    if( ( ret = mpi_is_prime( &Q, havege_random, &hs ) ) != 0 )
     {
         printf( " failed\n  ! mpi_is_prime returned %d\n\n", ret );
         goto exit;

programs/pkey/dh_server.c

@@ -172,7 +172,7 @@ int main( int argc, char *argv[] )
     memset( buf, 0, sizeof( buf ) );
 
     if( ( ret = dhm_make_params( &dhm, 256, buf, &n,
-                                 havege_rand, &hs ) ) != 0 )
+                                 havege_random, &hs ) ) != 0 )
     {
         printf( " failed\n  ! dhm_make_params returned %d\n\n", ret );
         goto exit;

programs/pkey/rsa_encrypt.c

@@ -110,7 +110,7 @@ int main( int argc, char *argv[] )
     printf( "\n  . Generating the RSA encrypted value" );
     fflush( stdout );
 
-    if( ( ret = rsa_pkcs1_encrypt( &rsa, havege_rand, &hs, RSA_PUBLIC, strlen( argv[1] ), input, buf ) ) != 0 )
+    if( ( ret = rsa_pkcs1_encrypt( &rsa, havege_random, &hs, RSA_PUBLIC, strlen( argv[1] ), input, buf ) ) != 0 )
     {
         printf( " failed\n  ! rsa_pkcs1_encrypt returned %d\n\n", ret );
         goto exit;

programs/pkey/rsa_genkey.c

@@ -74,7 +74,7 @@ int main( int argc, char *argv[] )
 
     rsa_init( &rsa, RSA_PKCS_V15, 0 );
     
-    if( ( ret = rsa_gen_key( &rsa, havege_rand, &hs, KEY_SIZE, EXPONENT ) ) != 0 )
+    if( ( ret = rsa_gen_key( &rsa, havege_random, &hs, KEY_SIZE, EXPONENT ) ) != 0 )
     {
         printf( " failed\n  ! rsa_gen_key returned %d\n\n", ret );
         goto exit;

programs/pkey/rsa_sign_pss.c

@@ -105,7 +105,7 @@ int main( int argc, char *argv[] )
         goto exit;
     }
 
-    if( ( ret = rsa_pkcs1_sign( &rsa, havege_rand, &hs, RSA_PRIVATE, SIG_RSA_SHA1,
+    if( ( ret = rsa_pkcs1_sign( &rsa, havege_random, &hs, RSA_PRIVATE, SIG_RSA_SHA1,
                                 20, hash, buf ) ) != 0 )
     {
         printf( " failed\n  ! rsa_pkcs1_sign returned %d\n\n", ret );

programs/random/gen_random.c

@@ -44,7 +44,7 @@ int main( int argc, char *argv[] )
 {
     FILE *f;
     time_t t;
-    int i, j, k;
+    int i, k;
     havege_state hs;
     unsigned char buf[1024];
 
@@ -66,8 +66,12 @@ int main( int argc, char *argv[] )
 
     for( i = 0, k = 768; i < k; i++ )
     {
-        for( j = 0; j < (int) sizeof( buf ); j++ )
-            buf[j] = havege_rand( &hs );
+        if( havege_random( &hs, buf, sizeof( buf ) ) != 0 )
+        {
+            printf( "Failed to get random from source.\n" );
+            fclose( f );
+            return( 1 );
+        }
 
         fwrite( buf, sizeof( buf ), 1, f );