[PATCH 01/17] crypto: ansi_cprng - Rename rand_data_valid more sensibly

[George Spelvin]

It's more like rand_data_invalid (data which has already been output),
so it's a pretty bad misnomer.  But rand_data_pos is even better.

Signed-off-by: George Spelvin <li...@horizon.com>
---
 crypto/ansi_cprng.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c
index 97fe3110..c9e1684b 100644
--- a/crypto/ansi_cprng.c
+++ b/crypto/ansi_cprng.c
@@ -50,7 +50,7 @@ struct prng_context {
        unsigned char DT[DEFAULT_BLK_SZ];
        unsigned char I[DEFAULT_BLK_SZ];
        unsigned char V[DEFAULT_BLK_SZ];
-       u32 rand_data_valid;
+       u32 rand_read_pos;      /* Offset into rand_data[] */
        struct crypto_cipher *tfm;
        u32 flags;
 };
@@ -174,7 +174,7 @@ static int _get_more_prng_bytes(struct prng_context *ctx, 
int cont_test)
        }
 
        dbgprint("Returning new block for context %p\n", ctx);
-       ctx->rand_data_valid = 0;
+       ctx->rand_read_pos = 0;
 
        hexdump("Output DT: ", ctx->DT, DEFAULT_BLK_SZ);
        hexdump("Output I: ", ctx->I, DEFAULT_BLK_SZ);
@@ -217,7 +217,7 @@ static int get_prng_bytes(char *buf, size_t nbytes, struct 
prng_context *ctx,
 
 
 remainder:
-       if (ctx->rand_data_valid == DEFAULT_BLK_SZ) {
+       if (ctx->rand_read_pos == DEFAULT_BLK_SZ) {
                if (_get_more_prng_bytes(ctx, do_cont_test) < 0) {
                        memset(buf, 0, nbytes);
                        err = -EINVAL;
@@ -230,12 +230,9 @@ remainder:
         */
        if (byte_count < DEFAULT_BLK_SZ) {
 empty_rbuf:
-               while (ctx->rand_data_valid < DEFAULT_BLK_SZ) {
-                       *ptr = ctx->rand_data[ctx->rand_data_valid];
-                       ptr++;
-                       byte_count--;
-                       ctx->rand_data_valid++;
-                       if (byte_count == 0)
+               while (ctx->rand_read_pos < DEFAULT_BLK_SZ) {
+                       *ptr++ = ctx->rand_data[ctx->rand_read_pos++];
+                       if (--byte_count == 0)
                                goto done;
                }
        }
@@ -244,17 +241,17 @@ empty_rbuf:
         * Now copy whole blocks
         */
        for (; byte_count >= DEFAULT_BLK_SZ; byte_count -= DEFAULT_BLK_SZ) {
-               if (ctx->rand_data_valid == DEFAULT_BLK_SZ) {
+               if (ctx->rand_read_pos == DEFAULT_BLK_SZ) {
                        if (_get_more_prng_bytes(ctx, do_cont_test) < 0) {
                                memset(buf, 0, nbytes);
                                err = -EINVAL;
                                goto done;
                        }
                }
-               if (ctx->rand_data_valid > 0)
+               if (ctx->rand_read_pos > 0)
                        goto empty_rbuf;
                memcpy(ptr, ctx->rand_data, DEFAULT_BLK_SZ);
-               ctx->rand_data_valid += DEFAULT_BLK_SZ;
+               ctx->rand_read_pos += DEFAULT_BLK_SZ;
                ptr += DEFAULT_BLK_SZ;
        }
 
@@ -304,7 +301,7 @@ static int reset_prng_context(struct prng_context *ctx,
        memset(ctx->rand_data, 0, DEFAULT_BLK_SZ);
        memset(ctx->last_rand_data, 0, DEFAULT_BLK_SZ);
 
-       ctx->rand_data_valid = DEFAULT_BLK_SZ;
+       ctx->rand_read_pos = DEFAULT_BLK_SZ;    /* Force immediate refill */
 
        ret = crypto_cipher_setkey(ctx->tfm, prng_key, klen);
        if (ret) {
@@ -413,7 +410,7 @@ static int fips_cprng_reset(struct crypto_rng *tfm, u8 
*seed, unsigned int slen)
 
        /* this primes our continuity test */
        rc = get_prng_bytes(rdata, DEFAULT_BLK_SZ, prng, 0);
-       prng->rand_data_valid = DEFAULT_BLK_SZ;
+       prng->rand_read_pos = DEFAULT_BLK_SZ;
 
 out:
        return rc;
-- 
2.1.3

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