From cde001e4c3c3625c60b68a83eb1f1c2572dee07a Mon Sep 17 00:00:00 2001 From: Stephan Mueller Date: Fri, 6 Mar 2015 08:26:31 +0100 Subject: [PATCH] crypto: rng - RNGs must return 0 in success case Change the RNGs to always return 0 in success case. This patch ensures that seqiv.c works with RNGs other than krng. seqiv expects that any return code other than 0 is an error. Without the patch, rfc4106(gcm(aes)) will not work when using a DRBG or an ANSI X9.31 RNG. Signed-off-by: Stephan Mueller Signed-off-by: Herbert Xu --- crypto/ansi_cprng.c | 6 +++++- crypto/drbg.c | 7 ++++++- include/crypto/rng.h | 3 +-- 3 files changed, 12 insertions(+), 4 deletions(-) diff --git a/crypto/ansi_cprng.c b/crypto/ansi_cprng.c index 6f5bebc9bf01..765fe7609348 100644 --- a/crypto/ansi_cprng.c +++ b/crypto/ansi_cprng.c @@ -210,7 +210,11 @@ static int get_prng_bytes(char *buf, size_t nbytes, struct prng_context *ctx, byte_count = DEFAULT_BLK_SZ; } - err = byte_count; + /* + * Return 0 in case of success as mandated by the kernel + * crypto API interface definition. + */ + err = 0; dbgprint(KERN_CRIT "getting %d random bytes for context %p\n", byte_count, ctx); diff --git a/crypto/drbg.c b/crypto/drbg.c index 56c1d7ec3d9e..b69409cb7e6a 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -1280,7 +1280,7 @@ static void drbg_restore_shadow(struct drbg_state *drbg, * as defined in SP800-90A. The additional input is mixed into * the state in addition to the pulled entropy. * - * return: generated number of bytes + * return: 0 when all bytes are generated; < 0 in case of an error */ static int drbg_generate(struct drbg_state *drbg, unsigned char *buf, unsigned int buflen, @@ -1419,6 +1419,11 @@ static int drbg_generate(struct drbg_state *drbg, } #endif + /* + * All operations were successful, return 0 as mandated by + * the kernel crypto API interface. + */ + len = 0; err: shadow->d_ops->crypto_fini(shadow); drbg_restore_shadow(drbg, &shadow); diff --git a/include/crypto/rng.h b/include/crypto/rng.h index a16fb10142bf..6e28ea5be9f1 100644 --- a/include/crypto/rng.h +++ b/include/crypto/rng.h @@ -103,8 +103,7 @@ static inline void crypto_free_rng(struct crypto_rng *tfm) * This function fills the caller-allocated buffer with random numbers using the * random number generator referenced by the cipher handle. * - * Return: > 0 function was successful and returns the number of generated - * bytes; < 0 if an error occurred + * Return: 0 function was successful; < 0 if an error occurred */ static inline int crypto_rng_get_bytes(struct crypto_rng *tfm, u8 *rdata, unsigned int dlen) -- 2.20.1