mirror of
				https://gitlab.labs.nic.cz/labs/bird.git
				synced 2024-05-11 16:54:54 +00:00 
			
		
		
		
	Add generic interface for generating and verifying MACs (message authentication codes). Replace multiple HMAC implementation with a generic one.
		
			
				
	
	
		
			328 lines
		
	
	
		
			7.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			328 lines
		
	
	
		
			7.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  *	BIRD Library -- SHA-256 and SHA-224 Hash Functions
 | |
|  *
 | |
|  *	(c) 2015 CZ.NIC z.s.p.o.
 | |
|  *
 | |
|  *	Based on the code from libgcrypt-1.6.0, which is
 | |
|  *	(c) 2003, 2006, 2008, 2009 Free Software Foundation, Inc.
 | |
|  *
 | |
|  *	Can be freely distributed and used under the terms of the GNU GPL.
 | |
|  */
 | |
| 
 | |
| #include "lib/sha256.h"
 | |
| #include "lib/unaligned.h"
 | |
| 
 | |
| 
 | |
| // #define SHA256_UNROLLED
 | |
| 
 | |
| void
 | |
| sha256_init(struct hash_context *CTX)
 | |
| {
 | |
|   struct sha256_context *ctx = (void *) CTX;
 | |
| 
 | |
|   ctx->h0 = 0x6a09e667;
 | |
|   ctx->h1 = 0xbb67ae85;
 | |
|   ctx->h2 = 0x3c6ef372;
 | |
|   ctx->h3 = 0xa54ff53a;
 | |
|   ctx->h4 = 0x510e527f;
 | |
|   ctx->h5 = 0x9b05688c;
 | |
|   ctx->h6 = 0x1f83d9ab;
 | |
|   ctx->h7 = 0x5be0cd19;
 | |
| 
 | |
|   ctx->nblocks = 0;
 | |
|   ctx->count = 0;
 | |
| }
 | |
| 
 | |
| void
 | |
| sha224_init(struct hash_context *CTX)
 | |
| {
 | |
|   struct sha224_context *ctx = (void *) CTX;
 | |
| 
 | |
|   ctx->h0 = 0xc1059ed8;
 | |
|   ctx->h1 = 0x367cd507;
 | |
|   ctx->h2 = 0x3070dd17;
 | |
|   ctx->h3 = 0xf70e5939;
 | |
|   ctx->h4 = 0xffc00b31;
 | |
|   ctx->h5 = 0x68581511;
 | |
|   ctx->h6 = 0x64f98fa7;
 | |
|   ctx->h7 = 0xbefa4fa4;
 | |
| 
 | |
|   ctx->nblocks = 0;
 | |
|   ctx->count = 0;
 | |
| }
 | |
| 
 | |
| /* (4.2) same as SHA-1's F1.  */
 | |
| static inline u32
 | |
| f1(u32 x, u32 y, u32 z)
 | |
| {
 | |
|   return (z ^ (x & (y ^ z)));
 | |
| }
 | |
| 
 | |
| /* (4.3) same as SHA-1's F3 */
 | |
| static inline u32
 | |
| f3(u32 x, u32 y, u32 z)
 | |
| {
 | |
|   return ((x & y) | (z & (x|y)));
 | |
| }
 | |
| 
 | |
| /* Bitwise rotation of an uint to the right */
 | |
| static inline u32 ror(u32 x, int n)
 | |
| {
 | |
|   return ((x >> (n&(32-1))) | (x << ((32-n)&(32-1))));
 | |
| }
 | |
| 
 | |
| /* (4.4) */
 | |
| static inline u32
 | |
| sum0(u32 x)
 | |
| {
 | |
|   return (ror(x, 2) ^ ror(x, 13) ^ ror(x, 22));
 | |
| }
 | |
| 
 | |
| /* (4.5) */
 | |
| static inline u32
 | |
| sum1(u32 x)
 | |
| {
 | |
|   return (ror(x, 6) ^ ror(x, 11) ^ ror(x, 25));
 | |
| }
 | |
| 
 | |
| /*
 | |
|   Transform the message X which consists of 16 32-bit-words. See FIPS
 | |
|   180-2 for details.  */
 | |
| #define S0(x) (ror((x),  7) ^ ror((x), 18) ^ ((x) >>  3))	/* (4.6) */
 | |
| #define S1(x) (ror((x), 17) ^ ror((x), 19) ^ ((x) >> 10))	/* (4.7) */
 | |
| #define R(a,b,c,d,e,f,g,h,k,w)					\
 | |
|     do								\
 | |
|     {								\
 | |
|       t1 = (h) + sum1((e)) + f1((e),(f),(g)) + (k) + (w);	\
 | |
|       t2 = sum0((a)) + f3((a),(b),(c));				\
 | |
|       h = g;							\
 | |
|       g = f;							\
 | |
|       f = e;							\
 | |
|       e = d + t1;						\
 | |
|       d = c;							\
 | |
|       c = b;							\
 | |
|       b = a;							\
 | |
|       a = t1 + t2;						\
 | |
|     } while (0)
 | |
| 
 | |
| /*
 | |
|     The SHA-256 core: Transform the message X which consists of 16
 | |
|     32-bit-words. See FIPS 180-2 for details.
 | |
|  */
 | |
| static uint
 | |
| sha256_transform(struct sha256_context *ctx, const byte *data)
 | |
| {
 | |
|   static const u32 K[64] = {
 | |
|       0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
 | |
|       0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
 | |
|       0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
 | |
|       0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
 | |
|       0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
 | |
|       0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
 | |
|       0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
 | |
|       0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
 | |
|       0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
 | |
|       0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
 | |
|       0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
 | |
|       0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
 | |
|       0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
 | |
|       0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
 | |
|       0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
 | |
|       0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
 | |
|   };
 | |
| 
 | |
|   u32 a,b,c,d,e,f,g,h,t1,t2;
 | |
|   u32 w[64];
 | |
|   int i;
 | |
| 
 | |
|   a = ctx->h0;
 | |
|   b = ctx->h1;
 | |
|   c = ctx->h2;
 | |
|   d = ctx->h3;
 | |
|   e = ctx->h4;
 | |
|   f = ctx->h5;
 | |
|   g = ctx->h6;
 | |
|   h = ctx->h7;
 | |
| 
 | |
|   for (i = 0; i < 16; i++)
 | |
|     w[i] = get_u32(data + i * 4);
 | |
| 
 | |
|   for (; i < 64; i++)
 | |
|     w[i] = S1(w[i-2]) + w[i-7] + S0(w[i-15]) + w[i-16];
 | |
| 
 | |
|   for (i = 0; i < 64;)
 | |
|   {
 | |
| #ifndef SHA256_UNROLLED
 | |
|     R(a,b,c,d,e,f,g,h,K[i],w[i]);
 | |
|     i++;
 | |
| #else /* Unrolled */
 | |
|     t1 = h + sum1(e) + f1(e, f, g) + K[i] + w[i];
 | |
|     t2 = sum0(a) + f3(a, b, c);
 | |
|     d += t1;
 | |
|     h  = t1 + t2;
 | |
| 
 | |
|     t1 = g + sum1(d) + f1(d, e, f) + K[i+1] + w[i+1];
 | |
|     t2 = sum0(h) + f3(h, a, b);
 | |
|     c += t1;
 | |
|     g  = t1 + t2;
 | |
| 
 | |
|     t1 = f + sum1(c) + f1(c, d, e) + K[i+2] + w[i+2];
 | |
|     t2 = sum0(g) + f3(g, h, a);
 | |
|     b += t1;
 | |
|     f  = t1 + t2;
 | |
| 
 | |
|     t1 = e + sum1(b) + f1(b, c, d) + K[i+3] + w[i+3];
 | |
|     t2 = sum0(f) + f3(f, g, h);
 | |
|     a += t1;
 | |
|     e  = t1 + t2;
 | |
| 
 | |
|     t1 = d + sum1(a) + f1(a, b, c) + K[i+4] + w[i+4];
 | |
|     t2 = sum0(e) + f3(e, f, g);
 | |
|     h += t1;
 | |
|     d  = t1 + t2;
 | |
| 
 | |
|     t1 = c + sum1(h) + f1(h, a, b) + K[i+5] + w[i+5];
 | |
|     t2 = sum0(d) + f3(d, e, f);
 | |
|     g += t1;
 | |
|     c  = t1 + t2;
 | |
| 
 | |
|     t1 = b + sum1(g) + f1(g, h, a) + K[i+6] + w[i+6];
 | |
|     t2 = sum0(c) + f3(c, d, e);
 | |
|     f += t1;
 | |
|     b  = t1 + t2;
 | |
| 
 | |
|     t1 = a + sum1(f) + f1(f, g, h) + K[i+7] + w[i+7];
 | |
|     t2 = sum0(b) + f3(b, c, d);
 | |
|     e += t1;
 | |
|     a  = t1 + t2;
 | |
| 
 | |
|     i += 8;
 | |
| #endif
 | |
|   }
 | |
| 
 | |
|   ctx->h0 += a;
 | |
|   ctx->h1 += b;
 | |
|   ctx->h2 += c;
 | |
|   ctx->h3 += d;
 | |
|   ctx->h4 += e;
 | |
|   ctx->h5 += f;
 | |
|   ctx->h6 += g;
 | |
|   ctx->h7 += h;
 | |
| 
 | |
|   return /*burn_stack*/ 74*4+32;
 | |
| }
 | |
| #undef S0
 | |
| #undef S1
 | |
| #undef R
 | |
| 
 | |
| /* Common function to write a chunk of data to the transform function
 | |
|    of a hash algorithm.  Note that the use of the term "block" does
 | |
|    not imply a fixed size block.  Note that we explicitly allow to use
 | |
|    this function after the context has been finalized; the result does
 | |
|    not have any meaning but writing after finalize is sometimes
 | |
|    helpful to mitigate timing attacks. */
 | |
| void
 | |
| sha256_update(struct hash_context *CTX, const byte *buf, uint len)
 | |
| {
 | |
|   struct sha256_context *ctx = (void *) CTX;
 | |
| 
 | |
|   if (ctx->count)
 | |
|   {
 | |
|     /* Fill rest of internal buffer */
 | |
|     for (; len && ctx->count < SHA256_BLOCK_SIZE; len--)
 | |
|       ctx->buf[ctx->count++] = *buf++;
 | |
| 
 | |
|     if (ctx->count < SHA256_BLOCK_SIZE)
 | |
|       return;
 | |
| 
 | |
|     /* Process data from internal buffer */
 | |
|     sha256_transform(ctx, ctx->buf);
 | |
|     ctx->nblocks++;
 | |
|     ctx->count = 0;
 | |
|   }
 | |
| 
 | |
|   if (!len)
 | |
|     return;
 | |
| 
 | |
|   /* Process data from input buffer */
 | |
|   while (len >= SHA256_BLOCK_SIZE)
 | |
|   {
 | |
|     sha256_transform(ctx, buf);
 | |
|     ctx->nblocks++;
 | |
|     buf += SHA256_BLOCK_SIZE;
 | |
|     len -= SHA256_BLOCK_SIZE;
 | |
|   }
 | |
| 
 | |
|   /* Copy remaining data to internal buffer */
 | |
|   memcpy(ctx->buf, buf, len);
 | |
|   ctx->count = len;
 | |
| }
 | |
| 
 | |
| /*
 | |
|  * The routine finally terminates the computation and returns the digest.  The
 | |
|  * handle is prepared for a new cycle, but adding bytes to the handle will the
 | |
|  * destroy the returned buffer.
 | |
|  *
 | |
|  * Returns: 32 bytes with the message the digest. 28 bytes for SHA-224.
 | |
|  */
 | |
| byte *
 | |
| sha256_final(struct hash_context *CTX)
 | |
| {
 | |
|   struct sha256_context *ctx = (void *) CTX;
 | |
|   u32 t, th, msb, lsb;
 | |
| 
 | |
|   sha256_update(CTX, NULL, 0);	/* flush */
 | |
| 
 | |
|   t = ctx->nblocks;
 | |
|   th = 0;
 | |
| 
 | |
|   /* multiply by 64 to make a byte count */
 | |
|   lsb = t << 6;
 | |
|   msb = (th << 6) | (t >> 26);
 | |
|   /* add the count */
 | |
|   t = lsb;
 | |
|   if ((lsb += ctx->count) < t)
 | |
|     msb++;
 | |
|   /* multiply by 8 to make a bit count */
 | |
|   t = lsb;
 | |
|   lsb <<= 3;
 | |
|   msb <<= 3;
 | |
|   msb |= t >> 29;
 | |
| 
 | |
|   if (ctx->count < 56)
 | |
|   {
 | |
|     /* enough room */
 | |
|     ctx->buf[ctx->count++] = 0x80; /* pad */
 | |
|     while (ctx->count < 56)
 | |
|       ctx->buf[ctx->count++] = 0;  /* pad */
 | |
|   }
 | |
|   else
 | |
|   {
 | |
|     /* need one extra block */
 | |
|     ctx->buf[ctx->count++] = 0x80; /* pad character */
 | |
|     while (ctx->count < 64)
 | |
|       ctx->buf[ctx->count++] = 0;
 | |
|     sha256_update(CTX, NULL, 0);  /* flush */;
 | |
|     memset(ctx->buf, 0, 56 ); /* fill next block with zeroes */
 | |
|   }
 | |
| 
 | |
|   /* append the 64 bit count */
 | |
|   put_u32(ctx->buf + 56, msb);
 | |
|   put_u32(ctx->buf + 60, lsb);
 | |
|   sha256_transform(ctx, ctx->buf);
 | |
| 
 | |
|   byte *p = ctx->buf;
 | |
| #define X(a) do { put_u32(p, ctx->h##a); p += 4; } while(0)
 | |
|   X(0);
 | |
|   X(1);
 | |
|   X(2);
 | |
|   X(3);
 | |
|   X(4);
 | |
|   X(5);
 | |
|   X(6);
 | |
|   X(7);
 | |
| #undef X
 | |
| 
 | |
|   return ctx->buf;
 | |
| }
 |