diff --git a/crypto/drbg.c b/crypto/drbg.c index 99fa8f89fb3e..3f0b7e0f8bac 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -446,8 +446,16 @@ static int drbg_ctr_bcc(struct drbg_state *drbg, * length: drbg_blocklen(drbg) * temp * start: iv + drbg_blocklen(drbg) - * length: (drbg_keylen(drbg) + drbg_blocklen(drbg) == - * drbg_statelen(drbg)) + * length: drbg_satelen(drbg) + drbg_blocklen(drbg) + * note: temp is the buffer that the BCC function operates + * on. BCC operates blockwise. drbg_statelen(drbg) + * is sufficient when the DRBG state length is a multiple + * of the block size. For AES192 (and maybe other ciphers) + * this is not correct and the length for temp is + * insufficient (yes, that also means for such ciphers, + * the final output of all BCC rounds are truncated). + * Therefore, add drbg_blocklen(drbg) to cover all + * possibilities. */ /* Derivation Function for CTR DRBG as defined in 10.4.2 */ @@ -1205,7 +1213,7 @@ static inline int drbg_alloc_state(struct drbg_state *drbg) drbg_statelen(drbg) + /* df_data */ drbg_blocklen(drbg) + /* pad */ drbg_blocklen(drbg) + /* iv */ - drbg_statelen(drbg); /* temp */ + drbg_statelen(drbg) + drbg_blocklen(drbg); /* temp */ else sb_size = drbg_statelen(drbg) + drbg_blocklen(drbg);