From 41a84982a1d728165554be3e2be845f2caf83b55 Mon Sep 17 00:00:00 2001 From: Stephan Mueller Date: Tue, 14 Oct 2014 21:50:13 +0200 Subject: [PATCH] crypto: drbg - use crypto_inc The DRBG internal buffer addition function is replaced with crypto_inc when a buffer is to be incremented by one. The function drbg_add_buf is moved to the CONFIG_CRYPTO_DRBG_HASH ifdef area as it is now only needed for the Hash DRBG. Signed-off-by: Stephan Mueller Signed-off-by: Herbert Xu --- crypto/drbg.c | 79 +++++++++++++++++++++++++-------------------------- 1 file changed, 38 insertions(+), 41 deletions(-) diff --git a/crypto/drbg.c b/crypto/drbg.c index 54cfd4820abc..8c0a742b60f6 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -283,38 +283,6 @@ static inline void drbg_cpu_to_be32(__u32 val, unsigned char *buf) conversion->conv = cpu_to_be32(val); } - -/* - * Increment buffer - * - * @dst buffer to increment - * @add value to add - */ -static inline void drbg_add_buf(unsigned char *dst, size_t dstlen, - const unsigned char *add, size_t addlen) -{ - /* implied: dstlen > addlen */ - unsigned char *dstptr; - const unsigned char *addptr; - unsigned int remainder = 0; - size_t len = addlen; - - dstptr = dst + (dstlen-1); - addptr = add + (addlen-1); - while (len) { - remainder += *dstptr + *addptr; - *dstptr = remainder & 0xff; - remainder >>= 8; - len--; dstptr--; addptr--; - } - len = dstlen - addlen; - while (len && remainder > 0) { - remainder = *dstptr + 1; - *dstptr = remainder & 0xff; - remainder >>= 8; - len--; dstptr--; - } -} #endif /* defined(CONFIG_CRYPTO_DRBG_HASH) || defined(CONFIG_CRYPTO_DRBG_CTR) */ /****************************************************************** @@ -554,7 +522,6 @@ static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed, unsigned char *temp_p, *df_data_p; /* pointer to iterate over buffers */ unsigned int len = 0; struct drbg_string cipherin; - unsigned char prefix = DRBG_PREFIX1; memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); if (3 > reseed) @@ -574,7 +541,7 @@ static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed, */ while (len < (drbg_statelen(drbg))) { /* 10.2.1.2 step 2.1 */ - drbg_add_buf(drbg->V, drbg_blocklen(drbg), &prefix, 1); + crypto_inc(drbg->V, drbg_blocklen(drbg)); /* * 10.2.1.2 step 2.2 */ ret = drbg_kcapi_sym(drbg, drbg->C, temp + len, &cipherin); @@ -617,7 +584,6 @@ static int drbg_ctr_generate(struct drbg_state *drbg, int len = 0; int ret = 0; struct drbg_string data; - unsigned char prefix = DRBG_PREFIX1; memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); @@ -629,7 +595,7 @@ static int drbg_ctr_generate(struct drbg_state *drbg, } /* 10.2.1.5.2 step 4.1 */ - drbg_add_buf(drbg->V, drbg_blocklen(drbg), &prefix, 1); + crypto_inc(drbg->V, drbg_blocklen(drbg)); drbg_string_fill(&data, drbg->V, drbg_blocklen(drbg)); while (len < buflen) { int outlen = 0; @@ -643,7 +609,7 @@ static int drbg_ctr_generate(struct drbg_state *drbg, drbg_blocklen(drbg) : (buflen - len); if (!drbg_fips_continuous_test(drbg, drbg->scratchpad)) { /* 10.2.1.5.2 step 6 */ - drbg_add_buf(drbg->V, drbg_blocklen(drbg), &prefix, 1); + crypto_inc(drbg->V, drbg_blocklen(drbg)); continue; } /* 10.2.1.5.2 step 4.3 */ @@ -651,7 +617,7 @@ static int drbg_ctr_generate(struct drbg_state *drbg, len += outlen; /* 10.2.1.5.2 step 6 */ if (len < buflen) - drbg_add_buf(drbg->V, drbg_blocklen(drbg), &prefix, 1); + crypto_inc(drbg->V, drbg_blocklen(drbg)); } /* 10.2.1.5.2 step 6 */ @@ -796,6 +762,38 @@ static struct drbg_state_ops drbg_hmac_ops = { #ifdef CONFIG_CRYPTO_DRBG_HASH #define CRYPTO_DRBG_HASH_STRING "HASH " +/* + * Increment buffer + * + * @dst buffer to increment + * @add value to add + */ +static inline void drbg_add_buf(unsigned char *dst, size_t dstlen, + const unsigned char *add, size_t addlen) +{ + /* implied: dstlen > addlen */ + unsigned char *dstptr; + const unsigned char *addptr; + unsigned int remainder = 0; + size_t len = addlen; + + dstptr = dst + (dstlen-1); + addptr = add + (addlen-1); + while (len) { + remainder += *dstptr + *addptr; + *dstptr = remainder & 0xff; + remainder >>= 8; + len--; dstptr--; addptr--; + } + len = dstlen - addlen; + while (len && remainder > 0) { + remainder = *dstptr + 1; + *dstptr = remainder & 0xff; + remainder >>= 8; + len--; dstptr--; + } +} + /* * scratchpad usage: as drbg_hash_update and drbg_hash_df are used * interlinked, the scratchpad is used as follows: @@ -942,7 +940,6 @@ static int drbg_hash_hashgen(struct drbg_state *drbg, unsigned char *dst = drbg->scratchpad + drbg_statelen(drbg); struct drbg_string data; LIST_HEAD(datalist); - unsigned char prefix = DRBG_PREFIX1; memset(src, 0, drbg_statelen(drbg)); memset(dst, 0, drbg_blocklen(drbg)); @@ -963,7 +960,7 @@ static int drbg_hash_hashgen(struct drbg_state *drbg, outlen = (drbg_blocklen(drbg) < (buflen - len)) ? drbg_blocklen(drbg) : (buflen - len); if (!drbg_fips_continuous_test(drbg, dst)) { - drbg_add_buf(src, drbg_statelen(drbg), &prefix, 1); + crypto_inc(src, drbg_statelen(drbg)); continue; } /* 10.1.1.4 step hashgen 4.2 */ @@ -971,7 +968,7 @@ static int drbg_hash_hashgen(struct drbg_state *drbg, len += outlen; /* 10.1.1.4 hashgen step 4.3 */ if (len < buflen) - drbg_add_buf(src, drbg_statelen(drbg), &prefix, 1); + crypto_inc(src, drbg_statelen(drbg)); } out: