random.c for Intel rdseed/rdrand

wolfcrypt/src/random.c

@@ -22,7 +22,7 @@
 #ifdef HAVE_CONFIG_H
     #include <config.h>
 #endif
-
+ 
 #include <wolfssl/wolfcrypt/settings.h>
 
 /* on HPUX 11 you may need to install /dev/random see
@@ -570,6 +570,83 @@ int wc_RNG_HealthTest(int reseed, const byte* entropyA, word32 entropyASz,
     return 0;
 }
 
+#elif defined(HAVE_INTEL_RDGEN)
+
+#ifndef _MSC_VER
+    #define cpuid(reg, leaf, sub)\
+            __asm__ __volatile__ ("cpuid":\
+             "=a" (reg[0]), "=b" (reg[1]), "=c" (reg[2]), "=d" (reg[3]) :\
+             "a" (leaf), "c"(sub));
+
+    #define XASM_LINK(f) asm(f)
+#else
+
+    #include <intrin.h>
+    #define cpuid(a,b) __cpuid((int*)a,b)
+
+    #define XASM_LINK(f)
+
+#endif /* _MSC_VER */
+
+#define EAX 0
+#define EBX 1
+#define ECX 2 
+#define EDX 3
+    
+#define CPUID_AVX1   0x1
+#define CPUID_AVX2   0x2
+#define CPUID_RDRAND 0x4
+#define CPUID_RDSEED 0x8
+
+#define IS_INTEL_RDRAND     (cpuid_flags&CPUID_RDRAND)
+#define IS_INTEL_RDSEED     (cpuid_flags&CPUID_RDSEED)
+
+static word32 cpuid_flags = 0 ;
+
+static word32 cpuid_flag(word32 leaf, word32 sub, word32 num, word32 bit) {
+    int got_intel_cpu=0;
+    unsigned int reg[5]; 
+    
+    reg[4] = '\0' ;
+    cpuid(reg, 0, 0);  
+    if(memcmp((char *)&(reg[EBX]), "Genu", 4) == 0 &&  
+                memcmp((char *)&(reg[EDX]), "ineI", 4) == 0 &&  
+                memcmp((char *)&(reg[ECX]), "ntel", 4) == 0) {  
+        got_intel_cpu = 1;  
+    }    
+    if (got_intel_cpu) {
+        cpuid(reg, leaf, sub);
+        return((reg[num]>>bit)&0x1) ;
+    }
+    return 0 ;
+}
+
+static int set_cpuid_flags(void) {  
+    if(cpuid_flag(1, 0, ECX, 30)){ cpuid_flags |= CPUID_RDRAND ;} 
+    if(cpuid_flag(7, 0, EBX, 18)){ cpuid_flags |= CPUID_RDSEED ;}
+
+    if(cpuid_flags == 0)return 1 ;
+    else               return 0 ;
+}
+
+int wc_InitRng(RNG* rng)
+{
+    (void) rng ;
+    return set_cpuid_flags() ;
+}
+
+int wc_RNG_GenerateBlock(RNG* rng, byte* output, word32 sz)
+{
+    (void) rng ;
+    return wc_GenerateSeed(NULL, output, sz) ;
+}
+
+
+int wc_RNG_GenerateByte(RNG* rng, byte* b)
+{
+    (void) rng ;
+    return wc_GenerateSeed(NULL, b, 1) ;
+}
 
 #else /* HAVE_HASHDRBG || NO_RC4 */
 
@@ -978,6 +1055,56 @@ int wc_GenerateSeed(OS_Seed* os, byte* output, word32 sz)
         return 0;
     }
 
+#elif defined(HAVE_INTEL_RDGEN)
+
+static inline int IntelRNrand32(unsigned int *rnd)  
+{  
+	int rdrand;  
+
+    __asm__ volatile("rdrand %0":"=r"(rdrand));  
+	if(rdrand){
+		*rnd = rdrand ;
+		return 0 ;
+	} else
+		return 1;  
+}
+
+
+static inline int IntelRNseed32(unsigned int *seed)  
+{  
+	int rdseed;  
+
+    __asm__ volatile("rdseed %0":"=r"(rdseed));  
+	if(rdseed){
+		*seed = rdseed ;
+		return 0 ;
+	} else
+		return 1;
+}
+
+int wc_GenerateSeed(OS_Seed* os, byte* output, word32 sz)
+{
+    (void) os ;
+    int ret ; byte buff[4] ;
+
+    for(  ; sz/4 > 0; sz-=4, output+=4) {
+        if     (IS_INTEL_RDSEED)ret = IntelRNseed32((word32 *)output) ;
+        else if(IS_INTEL_RDRAND)ret = IntelRNrand32((word32 *)output);
+        else return 1 ;
+        if(ret)
+             return 1 ;
+    }
+    if(sz == 0)return 0 ;
+
+    if     (IS_INTEL_RDSEED)ret = IntelRNseed32((word32 *)buff) ;
+    else if(IS_INTEL_RDRAND)ret = IntelRNrand32((word32 *)buff);
+    else return 1 ;
+    if(ret)
+         return 1 ;
+    XMEMCPY(output, buff, sz) ;
+    return 0;
+}
+
 #elif defined(CUSTOM_RAND_GENERATE)
 
    /* Implement your own random generation function