rev180: Add missing entry to sieveMarks array

Add the missing entry to the sieveMarks array. The new entry would only
be used for RSA 3072 keys but due to the following change in
RsaAdjustPrimeLimit it will not be used.

  primeLimit = s_LastPrimeInTable - 2;  // libtpms: Fix for 3072 bit keys to avoid mark=5

If it was to be used (above change removed) it would occasionally produce
different RSA 3072 prime numbers from the TPM's seeds and therefore any
change to the above will have to depend on the SEED_COMPAT_LEVEL so that
the same keys are always produced.

Use the full sieveMarks array to generate RSA 3072 keys when
SEED_COMPAT_LEVEL > SEED_COMPAT_LEVEL_RSA_PRIME_ADJUST_PREREV169,
otherwise keep the previous adjustment to avoid mark=5.

Signed-off-by: Stefan Berger <[email protected]>

src/tpm2/crypto/CryptPrimeSieve_fp.h

@@ -75,7 +75,9 @@
 // limit (primeLimit) set up by this function. This causes the sieve
 // process to stop when an appropriate number of primes have been
 // sieved.
-LIB_EXPORT void RsaAdjustPrimeLimit(uint32_t requestedPrimes);
+LIB_EXPORT void RsaAdjustPrimeLimit(uint32_t requestedPrimes,
+				    RAND_STATE* rand		// libtpms added
+				    );
 
 //*** RsaNextPrime()
 // This the iterator used during the sieve process. The input is the

src/tpm2/crypto/openssl/CryptPrimeSieve.c

@@ -94,15 +94,19 @@ uint32_t       primeLimit;
 // limit (primeLimit) set up by this function. This causes the sieve
 // process to stop when an appropriate number of primes have been
 // sieved.
-LIB_EXPORT void RsaAdjustPrimeLimit(uint32_t requestedPrimes)
+LIB_EXPORT void RsaAdjustPrimeLimit(uint32_t requestedPrimes,
+				    RAND_STATE* rand)
 {
     if(requestedPrimes == 0 || requestedPrimes > s_PrimesInTable)
 	requestedPrimes = s_PrimesInTable;
     requestedPrimes = (requestedPrimes - 1) / 1024;
     if(requestedPrimes < s_PrimeMarkersCount)
 	primeLimit = s_PrimeMarkers[requestedPrimes];
-    else
-	primeLimit = s_LastPrimeInTable - 2;  // libtpms: Fix for 3072 bit keys to avoid mark=5
+    else {					// libtpms changed begin
+	primeLimit = s_LastPrimeInTable;
+	if (DRBG_GetSeedCompatLevel(rand) <= SEED_COMPAT_LEVEL_RSA_PRIME_ADJUST_FIX)
+	    primeLimit = s_LastPrimeInTable - 2;  // Previous 'fix' for 3072 bit keys to avoid mark=5
+    }						// libtpms changed end
     primeLimit >>= 1;
 }
 
@@ -241,11 +245,13 @@ typedef struct
     UINT32 prime;
     UINT16 count;
 } SIEVE_MARKS;
-const SIEVE_MARKS sieveMarks[5] = {{31, 7},
+
+const SIEVE_MARKS sieveMarks[6] = {{31, 7},
 				   {73, 5},
 				   {241, 4},
 				   {1621, 3},
-				   {UINT16_MAX, 2}};
+				   {UINT16_MAX, 2},
+				   {UINT32_MAX, 1}};
 
 const size_t MAX_SIEVE_MARKS = (sizeof(sieveMarks) / sizeof(sieveMarks[0]));
 
@@ -449,15 +455,15 @@ LIB_EXPORT TPM_RC PrimeSelectWithSieve(
 
     if(primeSize <= 512)
 	{
-	    RsaAdjustPrimeLimit(1024);  // Use just the first 1024 primes
+	    RsaAdjustPrimeLimit(1024, rand);  // Use just the first 1024 primes	// libtpms added rand
 	}
     else if(primeSize <= 1024)
 	{
-	    RsaAdjustPrimeLimit(4096);  // Use just the first 4K primes
+	    RsaAdjustPrimeLimit(4096, rand);  // Use just the first 4K primes	// libtpms added rand
 	}
     else
 	{
-	    RsaAdjustPrimeLimit(0);  // Use all available
+	    RsaAdjustPrimeLimit(0, rand);  // Use all available			// libtpms added rand
 	}
 
     // Save the low-order word to use as a search generator and make sure that