diff options
| -rw-r--r-- | crypto/ansi_cprng.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c index 486aa93646f..1b3b1da1fd3 100644 --- a/crypto/ansi_cprng.c +++ b/crypto/ansi_cprng.c @@ -223,9 +223,10 @@ remainder: } /* - * Copy up to the next whole block size + * Copy any data less than an entire block */ if (byte_count < DEFAULT_BLK_SZ) { +empty_rbuf: for (; ctx->rand_data_valid < DEFAULT_BLK_SZ; ctx->rand_data_valid++) { *ptr = ctx->rand_data[ctx->rand_data_valid]; @@ -240,18 +241,22 @@ remainder: * Now copy whole blocks */ for (; byte_count >= DEFAULT_BLK_SZ; byte_count -= DEFAULT_BLK_SZ) { - if (_get_more_prng_bytes(ctx) < 0) { - memset(buf, 0, nbytes); - err = -EINVAL; - goto done; + if (ctx->rand_data_valid == DEFAULT_BLK_SZ) { + if (_get_more_prng_bytes(ctx) < 0) { + memset(buf, 0, nbytes); + err = -EINVAL; + goto done; + } } + if (ctx->rand_data_valid > 0) + goto empty_rbuf; memcpy(ptr, ctx->rand_data, DEFAULT_BLK_SZ); ctx->rand_data_valid += DEFAULT_BLK_SZ; ptr += DEFAULT_BLK_SZ; } /* - * Now copy any extra partial data + * Now go back and get any remaining partial block */ if (byte_count) goto remainder; |