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Diffstat (limited to 'thirdparty/mbedtls/library/hmac_drbg.c')
-rw-r--r--thirdparty/mbedtls/library/hmac_drbg.c25
1 files changed, 14 insertions, 11 deletions
diff --git a/thirdparty/mbedtls/library/hmac_drbg.c b/thirdparty/mbedtls/library/hmac_drbg.c
index 50d88bd54b..284c9b4e96 100644
--- a/thirdparty/mbedtls/library/hmac_drbg.c
+++ b/thirdparty/mbedtls/library/hmac_drbg.c
@@ -273,16 +273,19 @@ int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
ctx->reseed_interval = MBEDTLS_HMAC_DRBG_RESEED_INTERVAL;
- /*
- * See SP800-57 5.6.1 (p. 65-66) for the security strength provided by
- * each hash function, then according to SP800-90A rev1 10.1 table 2,
- * min_entropy_len (in bits) is security_strength.
- *
- * (This also matches the sizes used in the NIST test vectors.)
- */
- ctx->entropy_len = md_size <= 20 ? 16 : /* 160-bits hash -> 128 bits */
- md_size <= 28 ? 24 : /* 224-bits hash -> 192 bits */
- 32; /* better (256+) -> 256 bits */
+ if( ctx->entropy_len == 0 )
+ {
+ /*
+ * See SP800-57 5.6.1 (p. 65-66) for the security strength provided by
+ * each hash function, then according to SP800-90A rev1 10.1 table 2,
+ * min_entropy_len (in bits) is security_strength.
+ *
+ * (This also matches the sizes used in the NIST test vectors.)
+ */
+ ctx->entropy_len = md_size <= 20 ? 16 : /* 160-bits hash -> 128 bits */
+ md_size <= 28 ? 24 : /* 224-bits hash -> 192 bits */
+ 32; /* better (256+) -> 256 bits */
+ }
if( ( ret = hmac_drbg_reseed_core( ctx, custom, len,
1 /* add nonce */ ) ) != 0 )
@@ -303,7 +306,7 @@ void mbedtls_hmac_drbg_set_prediction_resistance( mbedtls_hmac_drbg_context *ctx
}
/*
- * Set entropy length grabbed for reseeds
+ * Set entropy length grabbed for seeding
*/
void mbedtls_hmac_drbg_set_entropy_len( mbedtls_hmac_drbg_context *ctx, size_t len )
{