btrfs: Use real device structure to verify dev extent

[sfrench/cifs-2.6.git] / crypto / dh_helper.c

diff --git a/crypto/dh_helper.c b/crypto/dh_helper.c
index 24fdb2ecaa85dd9ad20d223898e94503f4307c3c..edacda5f6a4d3332395f3802752587190f58196c 100644 (file)
--- a/crypto/dh_helper.c
+++ b/crypto/dh_helper.c
@@ -14,10 +14,12 @@
 #include <crypto/dh.h>
 #include <crypto/kpp.h>
 
-#define DH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 3 * sizeof(int))
+#define DH_KPP_SECRET_MIN_SIZE (sizeof(struct kpp_secret) + 4 * sizeof(int))
 
-static inline u8 *dh_pack_data(void *dst, const void *src, size_t size)
+static inline u8 *dh_pack_data(u8 *dst, u8 *end, const void *src, size_t size)
 {
+       if (!dst || size > end - dst)
+               return NULL;
        memcpy(dst, src, size);
        return dst + size;
 }
@@ -30,7 +32,7 @@ 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->g_size;
+       return p->key_size + p->p_size + p->q_size + p->g_size;
 }
 
 unsigned int crypto_dh_key_len(const struct dh *p)
@@ -42,25 +44,27 @@ EXPORT_SYMBOL_GPL(crypto_dh_key_len);
 int crypto_dh_encode_key(char *buf, unsigned int len, const struct dh *params)
 {
        u8 *ptr = buf;
+       u8 * const end = ptr + len;
        struct kpp_secret secret = {
                .type = CRYPTO_KPP_SECRET_TYPE_DH,
                .len = len
        };
 
-       if (unlikely(!buf))
+       if (unlikely(!len))
                return -EINVAL;
 
-       if (len != crypto_dh_key_len(params))
+       ptr = dh_pack_data(ptr, end, &secret, sizeof(secret));
+       ptr = dh_pack_data(ptr, end, &params->key_size,
+                          sizeof(params->key_size));
+       ptr = dh_pack_data(ptr, end, &params->p_size, sizeof(params->p_size));
+       ptr = dh_pack_data(ptr, end, &params->q_size, sizeof(params->q_size));
+       ptr = dh_pack_data(ptr, end, &params->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;
-
-       ptr = dh_pack_data(ptr, &secret, sizeof(secret));
-       ptr = dh_pack_data(ptr, &params->key_size, sizeof(params->key_size));
-       ptr = dh_pack_data(ptr, &params->p_size, sizeof(params->p_size));
-       ptr = dh_pack_data(ptr, &params->g_size, sizeof(params->g_size));
-       ptr = dh_pack_data(ptr, params->key, params->key_size);
-       ptr = dh_pack_data(ptr, params->p, params->p_size);
-       dh_pack_data(ptr, params->g, params->g_size);
-
        return 0;
 }
 EXPORT_SYMBOL_GPL(crypto_dh_encode_key);
@@ -79,6 +83,7 @@ int crypto_dh_decode_key(const char *buf, unsigned int len, struct dh *params)
 
        ptr = dh_unpack_data(&params->key_size, ptr, sizeof(params->key_size));
        ptr = dh_unpack_data(&params->p_size, ptr, sizeof(params->p_size));
+       ptr = dh_unpack_data(&params->q_size, ptr, sizeof(params->q_size));
        ptr = dh_unpack_data(&params->g_size, ptr, sizeof(params->g_size));
        if (secret.len != crypto_dh_key_len(params))
                return -EINVAL;
@@ -88,7 +93,7 @@ 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->g_size > params->p_size || params->q_size > params->p_size)
                return -EINVAL;
 
        /* Don't allocate memory. Set pointers to data within
@@ -96,7 +101,9 @@ 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->g = (void *)(ptr + params->key_size + params->p_size);
+       params->q = (void *)(ptr + params->key_size + params->p_size);
+       params->g = (void *)(ptr + params->key_size + params->p_size +
+                            params->q_size);
 
        /*
         * Don't permit 'p' to be 0.  It's not a prime number, and it's subject
@@ -106,6 +113,10 @@ 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);