[PATCH 15/17] crypto: testmgr - Teach test_cprng to handle non-default seed sizes

[George Spelvin]

crypto_rng_seedsize() isn't necessarily enough.

Also (while we're at it), dynamically allocate the result (in the
same buffer) as well.

Signed-off-by: George Spelvin <li...@horizon.com>
---
 crypto/testmgr.c | 27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

Much of this gets undone in the next patch, but I wanted to show the idea.

diff --git a/crypto/testmgr.c b/crypto/testmgr.c
index 29a0cbdd..b81e593d 100644
--- a/crypto/testmgr.c
+++ b/crypto/testmgr.c
@@ -1449,9 +1449,19 @@ static int test_cprng(struct crypto_rng *tfm, struct 
cprng_testvec *template,
        const char *algo = crypto_tfm_alg_driver_name(crypto_rng_tfm(tfm));
        int err = 0, i, j, seedsize;
        u8 *seed;
-       char result[32];
 
-       seedsize = crypto_rng_seedsize(tfm);
+       /*
+        * How big a seed + result buffer do we need?  Note that some
+        * tests use a non-default seed size, so crypto_rng_seedsize(tfm)
+        * isn't necessarily enough.
+        */
+       seedsize = 0;
+       for (i = 0; i < tcount; i++) {
+               j = template[i].vlen + template[i].klen +
+                   template[i].dtlen + template[i].rlen;
+               if (j > seedsize)
+                       seedsize = j;
+       }
 
        seed = kmalloc(seedsize, GFP_KERNEL);
        if (!seed) {
@@ -1461,13 +1471,16 @@ static int test_cprng(struct crypto_rng *tfm, struct 
cprng_testvec *template,
        }
 
        for (i = 0; i < tcount; i++) {
-               memset(result, 0, 32);
 
                memcpy(seed, template[i].v, template[i].vlen);
                memcpy(seed + template[i].vlen, template[i].key,
                       template[i].klen);
                memcpy(seed + template[i].vlen + template[i].klen,
                       template[i].dt, template[i].dtlen);
+               seedsize = template[i].vlen + template[i].klen +
+                          template[i].dtlen +
+
+               memset(seed+seedsize, 0, template[i].rlen);
 
                err = crypto_rng_reset(tfm, seed, seedsize);
                if (err) {
@@ -1477,7 +1490,7 @@ static int test_cprng(struct crypto_rng *tfm, struct 
cprng_testvec *template,
                }
 
                for (j = 0; j < template[i].loops; j++) {
-                       err = crypto_rng_get_bytes(tfm, result,
+                       err = crypto_rng_get_bytes(tfm, seed + seedsize,
                                                   template[i].rlen);
                        if (err != template[i].rlen) {
                                printk(KERN_ERR "alg: cprng: Failed to obtain "
@@ -1488,12 +1501,12 @@ static int test_cprng(struct crypto_rng *tfm, struct 
cprng_testvec *template,
                        }
                }
 
-               err = memcmp(result, template[i].result,
+               err = memcmp(seed + seedsize, template[i].result,
                             template[i].rlen);
                if (err) {
                        printk(KERN_ERR "alg: cprng: Test %d failed for %s\n",
                               i, algo);
-                       hexdump(result, template[i].rlen);
+                       hexdump(seed + seedsize, template[i].rlen);
                        err = -EINVAL;
                        goto out;
                }
@@ -1722,6 +1735,8 @@ static int alg_test_cprng(const struct alg_test_desc 
*desc, const char *driver,
 
        crypto_free_rng(rng);
 
+printk("alg_test_cprng: testing %s: err %d\n", driver, err);
+
        return err;
 }
 
-- 
2.1.3

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