[openssl-commits] [openssl] OpenSSL_1_0_2-stable update

[Matt Caswell]

The branch OpenSSL_1_0_2-stable has been updated
       via  32492093722636596018a799c438bfc04c343b40 (commit)
      from  950d49d43900e67a1f9d02bc1a053a9fdc5c4257 (commit)


- Log -----------------------------------------------------------------
commit 32492093722636596018a799c438bfc04c343b40
Author: Rich Salz <rsalz at openssl.org>
Date:   Mon Mar 6 09:54:17 2017 -0500

    Fix an endless loop in rsa_builtin_keygen.
    
    Cherry-picked by Matt Caswell from 69795831.
    
    Reviewed-by: Richard Levitte <levitte at openssl.org>
    Reviewed-by: Matt Caswell <matt at openssl.org>
    (Merged from https://github.com/openssl/openssl/pull/4670)

-----------------------------------------------------------------------

Summary of changes:
 crypto/rsa/rsa_gen.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/crypto/rsa/rsa_gen.c b/crypto/rsa/rsa_gen.c
index 082c8da..a85493d 100644
--- a/crypto/rsa/rsa_gen.c
+++ b/crypto/rsa/rsa_gen.c
@@ -110,6 +110,16 @@ static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
     int bitsp, bitsq, ok = -1, n = 0;
     BN_CTX *ctx = NULL;
 
+    /*
+     * When generating ridiculously small keys, we can get stuck
+     * continually regenerating the same prime values.
+     */
+    if (bits < 16) {
+        ok = 0;             /* we set our own err */
+        RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_SIZE_TOO_SMALL);
+        goto err;
+    }
+
     ctx = BN_CTX_new();
     if (ctx == NULL)
         goto err;
@@ -161,21 +171,10 @@ static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
     if (!BN_GENCB_call(cb, 3, 0))
         goto err;
     for (;;) {
-        /*
-         * When generating ridiculously small keys, we can get stuck
-         * continually regenerating the same prime values. Check for this and
-         * bail if it happens 3 times.
-         */
-        unsigned int degenerate = 0;
         do {
             if (!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb))
                 goto err;
-        } while ((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3));
-        if (degenerate == 3) {
-            ok = 0;             /* we set our own err */
-            RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_SIZE_TOO_SMALL);
-            goto err;
-        }
+        } while (BN_cmp(rsa->p, rsa->q) == 0);
         if (!BN_sub(r2, rsa->q, BN_value_one()))
             goto err;
         if (!BN_gcd(r1, r2, rsa->e, ctx))