From 48c6d8b878c1d811015cfba1a302d8474a9aace6 Mon Sep 17 00:00:00 2001 From: Nicolai Stange Date: Mon, 21 Feb 2022 13:10:49 +0100 Subject: crypto: dh - remove struct dh's ->q member The only current user of the DH KPP algorithm, the keyctl(KEYCTL_DH_COMPUTE) syscall, doesn't set the domain parameter ->q in struct dh. Remove it and any associated (de)serialization code in crypto_dh_encode_key() and crypto_dh_decode_key. Adjust the encoded ->secret values in testmgr's DH test vectors accordingly. Note that the dh-generic implementation would have initialized its struct dh_ctx's ->q from the decoded struct dh's ->q, if present. If this struct dh_ctx's ->q would ever have been non-NULL, it would have enabled a full key validation as specified in NIST SP800-56A in dh_is_pubkey_valid(). However, as outlined above, ->q is always NULL in practice and the full key validation code is effectively dead. A later patch will make dh_is_pubkey_valid() to calculate Q from P on the fly, if possible, so don't remove struct dh_ctx's ->q now, but leave it there until that has happened. Signed-off-by: Nicolai Stange Reviewed-by: Hannes Reinecke Signed-off-by: Herbert Xu --- crypto/dh_helper.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) (limited to 'crypto/dh_helper.c') diff --git a/crypto/dh_helper.c b/crypto/dh_helper.c index 9fd5a42eea15..aabc91e4f63f 100644 --- a/crypto/dh_helper.c +++ b/crypto/dh_helper.c @@ -10,7 +10,7 @@ #include #include -#define DH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 4 * sizeof(int)) +#define DH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 3 * sizeof(int)) static inline u8 *dh_pack_data(u8 *dst, u8 *end, const void *src, size_t size) { @@ -28,7 +28,7 @@ static inline const u8 *dh_unpack_data(void *dst, const void *src, size_t size) static inline unsigned int dh_data_size(const struct dh *p) { - return p->key_size + p->p_size + p->q_size + p->g_size; + return p->key_size + p->p_size + p->g_size; } unsigned int crypto_dh_key_len(const struct dh *p) @@ -53,11 +53,9 @@ int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params) ptr = dh_pack_data(ptr, end, ¶ms->key_size, sizeof(params->key_size)); ptr = dh_pack_data(ptr, end, ¶ms->p_size, sizeof(params->p_size)); - ptr = dh_pack_data(ptr, end, ¶ms->q_size, sizeof(params->q_size)); ptr = dh_pack_data(ptr, end, ¶ms->g_size, sizeof(params->g_size)); ptr = dh_pack_data(ptr, end, params->key, params->key_size); ptr = dh_pack_data(ptr, end, params->p, params->p_size); - ptr = dh_pack_data(ptr, end, params->q, params->q_size); ptr = dh_pack_data(ptr, end, params->g, params->g_size); if (ptr != end) return -EINVAL; @@ -79,7 +77,6 @@ int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params) ptr = dh_unpack_data(¶ms->key_size, ptr, sizeof(params->key_size)); ptr = dh_unpack_data(¶ms->p_size, ptr, sizeof(params->p_size)); - ptr = dh_unpack_data(¶ms->q_size, ptr, sizeof(params->q_size)); ptr = dh_unpack_data(¶ms->g_size, ptr, sizeof(params->g_size)); if (secret.len != crypto_dh_key_len(params)) return -EINVAL; @@ -89,7 +86,7 @@ int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params) * some drivers assume otherwise. */ if (params->key_size > params->p_size || - params->g_size > params->p_size || params->q_size > params->p_size) + params->g_size > params->p_size) return -EINVAL; /* Don't allocate memory. Set pointers to data within @@ -97,9 +94,7 @@ int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params) */ params->key = (void *)ptr; params->p = (void *)(ptr + params->key_size); - params->q = (void *)(ptr + params->key_size + params->p_size); - params->g = (void *)(ptr + params->key_size + params->p_size + - params->q_size); + params->g = (void *)(ptr + params->key_size + params->p_size); /* * Don't permit 'p' to be 0. It's not a prime number, and it's subject @@ -109,10 +104,6 @@ int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params) if (memchr_inv(params->p, 0, params->p_size) == NULL) return -EINVAL; - /* It is permissible to not provide Q. */ - if (params->q_size == 0) - params->q = NULL; - return 0; } EXPORT_SYMBOL_GPL(crypto_dh_decode_key); -- cgit v1.2.3