kazu-yamamoto/crypton
1
1
Fork 0
mirror of https://github.com/kazu-yamamoto/crypton.git synced 2024-10-05 08:17:16 +03:00
Code Issues Packages Projects Releases Wiki Activity

[random] re-use standard instruction

Browse Source
This commit is contained in:
Vincent Hanquez 2016-07-11 06:59:12 +01:00
parent ad559e02e6
commit 8e0d34ff4d
1 changed files with 16 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
cbits/cryptonite_rdrand.c
View File

@ -46,19 +46,6 @@ int cryptonite_cpu_has_rdrand()
return (cx & 0x40000000); return (cx & 0x40000000);
} }
/* sadly many people are still using an old binutils,
* leading to report that instruction is not recognized.
*/
#if 0
/* Returns 1 on success */
static inline int crypto_random_rdrand64_step(uint64_t *buffer)
{
unsigned char err;
asm volatile ("rdrand %0; setc %1" : "=r" (*buffer), "=qm" (err));
return (int) err;
}
#endif
/* inline encoding of 'rdrand %rax' to cover old binutils /* inline encoding of 'rdrand %rax' to cover old binutils
* - no inputs * - no inputs
* - 'cc' to the clobber list as we modify condition code. * - 'cc' to the clobber list as we modify condition code.
@ -84,11 +71,24 @@ static inline int crypto_random_rdrand64_step(uint64_t *buffer)
#ifdef __x86_64__ #ifdef __x86_64__
# define RDRAND_SZ 8 # define RDRAND_SZ 8
# define RDRAND_T uint64_t # define RDRAND_T uint64_t
#define inline_rdrand(val, err) inline_rdrand_rax(val, err) #define inline_rdrand(val, err) err = cryptonite_rdrand_step(&val)
#else #else
# define RDRAND_SZ 4 # define RDRAND_SZ 4
# define RDRAND_T uint32_t # define RDRAND_T uint32_t
#define inline_rdrand(val, err) inline_rdrand_eax(val, err) #define inline_rdrand(val, err) err = cryptonite_rdrand_step(&val)
#endif
/* sadly many people are still using an old binutils,
* leading to report that instruction is not recognized.
*/
#if 1
/* Returns 1 on success */
static inline int cryptonite_rdrand_step(RDRAND_T *buffer)
{
unsigned char err;
asm volatile ("rdrand %0; setc %1" : "=r" (*buffer), "=qm" (err));
return (int) err;
}
#endif #endif
/* Returns the number of bytes succesfully generated */ /* Returns the number of bytes succesfully generated */
@ -113,7 +113,7 @@ int cryptonite_get_rand_bytes(uint8_t *buffer, size_t len)
inline_rdrand(tmp, ok); inline_rdrand(tmp, ok);
if (!ok) if (!ok)
return (orig_len - len); return (orig_len - len);
*((uint64_t *) buffer) = tmp; *((RDRAND_T *) buffer) = tmp;
} }
if (len > 0) { if (len > 0) {