fuzz against slow aez-ref, not fast aez-ni

Two reasons:

First, this allows us to test more of the algorithm, as the (slow)
reference implementation supports multiple associated data items, large
values for tau, ...

Second, this avoids the segfault crash, which is a limit of the fast
implementation (the assumption there is that data is aligned properly,
and even a read out-of-bounds will not cause a segfault).

1 files changed, 440 insertions, 0 deletions

diff --git a/aezref/aezv5/ref/encrypt.c b/aezref/aezv5/ref/encrypt.c
new file mode 100644
index 0000000..9e4eb1a
--- /dev/null
+++ b/aezref/aezv5/ref/encrypt.c
@@ -0,0 +1,440 @@
+/*
+// AEZ v5 reference code. AEZ info: http://www.cs.ucdavis.edu/~rogaway/aez
+//
+// ** This version is slow and susceptible to side-channel attacks. **
+// ** Do not use for any purpose other than to understand AEZ.      **
+//
+// Written by Ted Krovetz (ted@krovetz.net). Last modified 21 March 2017.
+//
+// This is free and unencumbered software released into the public domain.
+//
+// Anyone is free to copy, modify, publish, use, compile, sell, or
+// distribute this software, either in source code form or as a compiled
+// binary, for any purpose, commercial or non-commercial, and by any
+// means.
+//
+// In jurisdictions that recognize copyright laws, the author or authors
+// of this software dedicate any and all copyright interest in the
+// software to the public domain. We make this dedication for the benefit
+// of the public at large and to the detriment of our heirs and
+// successors. We intend this dedication to be an overt act of
+// relinquishment in perpetuity of all present and future rights to this
+// software under copyright law.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+// IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+// OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+// For more information, please refer to <http://unlicense.org/>
+*/
+#include <stdlib.h>
+#include <string.h>
+/* BLAKE2b384 is used in Extract(). We use Saarinen's reference version      */
+/* http://github.com/mjosaarinen/blake2_mjosref  (accessed 02SEP2015)        */
+#include "blake2b.h"
+/* We us Rijmen, Bosselaers and Barreto's AES reference code, with           */
+/* rijndael-alg-fst.h modified to define INTERMEDIATE_VALUE_KAT. This gives  */
+/* access to AES4 and AES10, and allows the forcing of MixColumns in the     */
+/* final round. It also defines "u32", used for internal AES keys.           */
+#include "rijndael-alg-fst.h"
+#include "crypto_aead.h"
+
+typedef unsigned char byte;
+
+/* ------------------------------------------------------------------------- */
+
+static void write32_big_endian(unsigned x, void *ptr) {
+    byte *p = (byte *)ptr;
+    p[0] = (byte)(x>>24); p[1] = (byte)(x>>16);
+    p[2] = (byte)(x>> 8); p[3] = (byte)(x>> 0);
+}
+
+/* ------------------------------------------------------------------------- */
+
+/* Adjust our constructed round keys to be compatible with rijndael-alg-fst  */
+static void correct_key(u32 *p, unsigned nbytes) {
+    unsigned i;
+    for (i=0; i<nbytes/4; i++) write32_big_endian(p[i], p+i);
+}
+
+/* ------------------------------------------------------------------------- */
+
+static void xor_bytes(byte *src1, byte *src2, unsigned n, byte *dst) {
+    while (n) { n--; dst[n] = src1[n] ^ src2[n]; }
+}
+
+/* ------------------------------------------------------------------------- */
+
+static void double_block(byte *p) {
+    byte i, tmp = p[0];
+    for (i=0; i<15; i++)
+        p[i] = (p[i] << 1) | (p[i+1] >> 7);
+    p[15] = (p[15] << 1) ^ ((tmp >> 7)?135:0);
+}
+
+/* ------------------------------------------------------------------------- */
+
+static void mult_block(unsigned x, byte *src, byte *dst) {
+    byte t[16], r[16];
+    memcpy(t,src,16); memset(r,0,16);
+    while (x != 0) {
+        if (x&1) xor_bytes(r,t,16,r);
+        double_block(t);
+        x>>=1;
+    }
+    memcpy(dst,r,16);
+}
+
+/* ------------------------------------------------------------------------- */
+
+static void Extract(byte *K, unsigned kbytes, byte extracted_key[3*16]) {
+    if (kbytes==48) memcpy(extracted_key, K, 48);
+    else            blake2b(extracted_key, 48, NULL, 0, K, kbytes);
+}
+
+/* ------------------------------------------------------------------------- */
+
+static void E(byte *K, unsigned kbytes, int j, unsigned i,
+                                                byte src[16], byte dst[16]) {
+    byte extracted_key[3*16], buf[16], delta[16], I[16], J[16], L[16];
+
+    Extract(K, kbytes, extracted_key);
+    memcpy(I,extracted_key,16);
+    memcpy(J,extracted_key+16,16);
+    memcpy(L,extracted_key+32,16);
+
+    /* Encipher */
+    if (j == -1) {
+        u32 aes_key[4*11];
+        memset(aes_key,0,16);                                  /* 0        */
+        memcpy((byte*)aes_key+ 16, extracted_key, 48);         /* I J L    */
+        correct_key(aes_key+4,3*16);
+        memcpy((byte*)aes_key+ 64, (byte*)aes_key+16, 48);     /* I J L    */
+        memcpy((byte*)aes_key+112, (byte*)aes_key+16, 48);     /* I J L    */
+        memcpy((byte*)aes_key+160, (byte*)aes_key+16, 16);     /* I        */
+        mult_block(i,L,delta); xor_bytes(delta,src,16,buf);
+        rijndaelEncryptRound(aes_key, 99, buf, 10); /*incl final MixColumns*/
+    } else {
+        u32 aes4_key[4*5];
+	    memset(aes4_key,0,16);
+        memcpy((byte*)aes4_key+16, J, 16);
+      	memcpy((byte*)aes4_key+32, I, 16);
+       	memcpy((byte*)aes4_key+48, L, 16);
+        memset((byte*)aes4_key+64,0,16);
+        correct_key(aes4_key+4,3*16);
+        mult_block(j,J,delta);
+        mult_block(i%8,L,buf); xor_bytes(delta, buf, 16, delta);
+        for (i=(i+7)/8; i>0; i--) mult_block(2,I,I);
+        xor_bytes(delta, I, 16, delta);
+        xor_bytes(delta, src, 16, buf);
+        rijndaelEncryptRound(aes4_key, 99, buf, 4);
+    }
+    memcpy(dst, buf, 16);
+}
+
+/* ------------------------------------------------------------------------- */
+
+static void AEZhash(byte *K, unsigned kbytes, byte *N, unsigned nbytes,
+    byte *A[], unsigned abytes[], unsigned veclen, unsigned tau, byte *result) {
+
+    byte buf[16], sum[16], *p;
+    unsigned i, k, bytes, empty;
+
+    /* Initialize sum with hash of tau */
+    memset(buf,0,12); write32_big_endian(tau, buf+12);
+    E(K,kbytes,3,1,buf,sum);
+
+    /* Hash nonce, accumulate into sum */
+    empty = (nbytes==0);
+    for (i=1; nbytes>=16; i++, nbytes-=16, N+=16) {
+        E(K,kbytes,4,i,N,buf); xor_bytes(sum, buf, 16, sum);
+    }
+    if (nbytes || empty) {
+        memset(buf,0,16); memcpy(buf,N,nbytes); buf[nbytes]=0x80;
+        E(K,kbytes,4,0,buf,buf);
+        xor_bytes(sum, buf, 16, sum);
+    }
+
+    /* Hash each vector element, accumulate into sum */
+    for (k=0; k<veclen; k++) {
+        p = A[k]; bytes = abytes[k]; empty = (bytes==0);
+        for (i=1; bytes>=16; i++, bytes-=16, p+=16) {
+            E(K,kbytes,5+k,i,p,buf); xor_bytes(sum, buf, 16, sum);
+        }
+        if (bytes || empty) {
+            memset(buf,0,16); memcpy(buf,p,bytes); buf[bytes]=0x80;
+            E(K,kbytes,5+k,0,buf,buf);
+            xor_bytes(sum, buf, 16, sum);
+        }
+    }
+    memcpy(result,sum,16);
+}
+
+/* ------------------------------------------------------------------------- */
+
+static void AEZprf(byte *K, unsigned kbytes, byte delta[16],
+                                        unsigned bytes, byte *result) {
+
+    byte buf[16], ctr[16];
+    memset(ctr,0,16);
+    for ( ; bytes >= 16; bytes-=16, result+=16) {
+        unsigned i=15;
+        xor_bytes(delta, ctr, 16, buf);
+        E(K,kbytes,-1,3,buf,result);
+        do { ctr[i]++; i--; } while (ctr[i+1]==0);   /* ctr+=1 */
+    }
+    if (bytes) {
+        xor_bytes(delta, ctr, 16, buf);
+        E(K,kbytes,-1,3,buf,buf);
+        memcpy(result, buf, bytes);
+    }
+}
+
+/* ------------------------------------------------------------------------- */
+
+/* Set d=0 for EncipherAEZcore and d=1 for DecipherAEZcore */
+static void AEZcore(byte *K, unsigned kbytes, byte delta[16],
+                        byte *in, unsigned inbytes, unsigned d, byte *out) {
+    byte tmp[16], X[16], Y[16], S[16];
+    byte *in_orig = in, *out_orig = out;
+    unsigned i, inbytes_orig = inbytes;
+
+    memset(X,0,16); memset(Y,0,16);
+
+    /* Pass 1 over in[0:-32], store intermediate values in out[0:-32] */
+    for (i=1; inbytes >= 64; i++, inbytes-=32, in+=32, out+=32) {
+        E(K, kbytes, 1, i, in+16, tmp); xor_bytes(in, tmp, 16, out);
+        E(K, kbytes, 0, 0, out, tmp); xor_bytes(in+16, tmp, 16, out+16);
+        xor_bytes(out+16, X, 16, X);
+    }
+
+    /* Finish X calculation */
+    inbytes -= 32;                /* inbytes now has fragment length 0..31 */
+    if (inbytes >= 16) {
+        E(K, kbytes, 0, 4, in, tmp); xor_bytes(X, tmp, 16, X);
+        inbytes -= 16; in += 16; out += 16;
+        memset(tmp,0,16); memcpy(tmp,in,inbytes); tmp[inbytes] = 0x80;
+        E(K, kbytes, 0, 5, tmp, tmp); xor_bytes(X, tmp, 16, X);
+    } else if (inbytes > 0) {
+        memset(tmp,0,16); memcpy(tmp,in,inbytes); tmp[inbytes] = 0x80;
+        E(K, kbytes, 0, 4, tmp, tmp); xor_bytes(X, tmp, 16, X);
+    }
+    in += inbytes; out += inbytes;
+
+    /* Calculate S */
+    E(K, kbytes, 0, 1+d, in+16, tmp);
+    xor_bytes(X, in, 16, out);
+    xor_bytes(delta, out, 16, out);
+    xor_bytes(tmp, out, 16, out);
+    E(K, kbytes, -1, 1+d, out, tmp);
+    xor_bytes(in+16, tmp, 16, out+16);
+    xor_bytes(out, out+16, 16, S);
+
+    /* Pass 2 over intermediate values in out[32..]. Final values written */
+    inbytes = inbytes_orig; out = out_orig; in = in_orig;
+    for (i=1; inbytes >= 64; i++, inbytes-=32, in+=32, out+=32) {
+        E(K, kbytes, 2, i, S, tmp);
+        xor_bytes(out, tmp, 16, out); xor_bytes(out+16, tmp, 16, out+16);
+        xor_bytes(out, Y, 16, Y);
+        E(K, kbytes, 0, 0, out+16, tmp); xor_bytes(out, tmp, 16, out);
+        E(K, kbytes, 1, i, out, tmp); xor_bytes(out+16, tmp, 16, out+16);
+        memcpy(tmp, out, 16); memcpy(out, out+16, 16); memcpy(out+16, tmp, 16);
+    }
+
+    /* Finish Y calculation and finish encryption of fragment bytes */
+    inbytes -= 32;                /* inbytes now has fragment length 0..31 */
+    if (inbytes >= 16) {
+        E(K, kbytes, -1, 4, S, tmp); xor_bytes(in, tmp, 16, out);
+        E(K, kbytes, 0, 4, out, tmp); xor_bytes(Y, tmp, 16, Y);
+        inbytes -= 16; in += 16; out += 16;
+        E(K, kbytes, -1, 5, S, tmp); xor_bytes(in, tmp, inbytes, tmp);
+        memcpy(out,tmp,inbytes);
+        memset(tmp+inbytes,0,16-inbytes); tmp[inbytes] = 0x80;
+        E(K, kbytes, 0, 5, tmp, tmp); xor_bytes(Y, tmp, 16, Y);
+    } else if (inbytes > 0) {
+        E(K, kbytes, -1, 4, S, tmp); xor_bytes(in, tmp, inbytes, tmp);
+        memcpy(out,tmp,inbytes);
+        memset(tmp+inbytes,0,16-inbytes); tmp[inbytes] = 0x80;
+        E(K, kbytes, 0, 4, tmp, tmp); xor_bytes(Y, tmp, 16, Y);
+    }
+    in += inbytes; out += inbytes;
+
+    /* Finish encryption of last two blocks */
+    E(K, kbytes, -1, 2-d, out+16, tmp);
+    xor_bytes(out, tmp, 16, out);
+    E(K, kbytes, 0, 2-d, out, tmp);
+    xor_bytes(tmp, out+16, 16, out+16);
+    xor_bytes(delta, out+16, 16, out+16);
+    xor_bytes(Y, out+16, 16, out+16);
+    memcpy(tmp, out, 16); memcpy(out, out+16, 16); memcpy(out+16, tmp, 16);
+}
+
+/* ------------------------------------------------------------------------- */
+
+/* Set d=0 for EncipherAEZtiny and d=1 for DecipherAEZtiny */
+static void AEZtiny(byte *K, unsigned kbytes, byte delta[16],
+                        byte *in, unsigned inbytes, unsigned d, byte *out) {
+    unsigned rounds,i=7,j,k;
+    int step;
+    byte mask=0x00, pad=0x80, L[16], R[16], buf[32];
+    if      (inbytes==1) rounds=24;
+    else if (inbytes==2) rounds=16;
+    else if (inbytes<16) rounds=10;
+    else {          i=6; rounds=8; }
+    /* Split (inbytes*8)/2 bits into L and R. Beware: May end in nibble. */
+    memcpy(L, in,           (inbytes+1)/2);
+    memcpy(R, in+inbytes/2, (inbytes+1)/2);
+    if (inbytes&1) {                     /* Must shift R left by half a byte */
+        for (k=0; k<inbytes/2; k++)
+            R[k] = (byte)((R[k] << 4) | (R[k+1] >> 4));
+        R[inbytes/2] = (byte)(R[inbytes/2] << 4);
+        pad = 0x08; mask = 0xf0;
+    }
+    if (d) {
+        if (inbytes < 16) {
+            memset(buf,0,16); memcpy(buf,in,inbytes); buf[0] |= 0x80;
+            xor_bytes(delta, buf, 16, buf);
+            E(K, kbytes,0,3,buf,buf);
+            L[0] ^= (buf[0] & 0x80);
+        }
+        j = rounds-1; step = -1;
+    } else {
+        j = 0; step = 1;
+    }
+    for (k=0; k<rounds/2; k++,j=(unsigned)((int)j+2*step)) {
+        memset(buf, 0, 16);
+        memcpy(buf,R,(inbytes+1)/2);
+        buf[inbytes/2] = (buf[inbytes/2] & mask) | pad;
+        xor_bytes(buf, delta, 16, buf);
+        buf[15] ^= (byte)j;
+        E(K, kbytes,0,i,buf,buf);
+        xor_bytes(L, buf, 16, L);
+
+        memset(buf, 0, 16);
+        memcpy(buf,L,(inbytes+1)/2);
+        buf[inbytes/2] = (buf[inbytes/2] & mask) | pad;
+        xor_bytes(buf, delta, 16, buf);
+        buf[15] ^= (byte)((int)j+step);
+        E(K, kbytes,0,i,buf,buf);
+        xor_bytes(R, buf, 16, R);
+    }
+    memcpy(buf,           R, inbytes/2);
+    memcpy(buf+inbytes/2, L, (inbytes+1)/2);
+    if (inbytes&1) {
+        for (k=inbytes-1; k>inbytes/2; k--)
+            buf[k] = (byte)((buf[k] >> 4) | (buf[k-1] << 4));
+        buf[inbytes/2] = (byte)((L[0] >> 4) | (R[inbytes/2] & 0xf0));
+    }
+    memcpy(out,buf,inbytes);
+    if ((inbytes < 16) && !d) {
+        memset(buf+inbytes,0,16-inbytes); buf[0] |= 0x80;
+        xor_bytes(delta, buf, 16, buf);
+        E(K, kbytes,0,3,buf,buf);
+        out[0] ^= (buf[0] & 0x80);
+    }
+}
+
+/* ------------------------------------------------------------------------- */
+
+static void Encipher(byte *K, unsigned kbytes, byte delta[16],
+                                    byte *in, unsigned inbytes, byte *out) {
+    if (inbytes == 0) return;
+    if (inbytes < 32) AEZtiny(K, kbytes, delta, in, inbytes, 0, out);
+    else              AEZcore(K, kbytes, delta, in, inbytes, 0, out);
+}
+
+/* ------------------------------------------------------------------------- */
+
+static void Decipher(byte *K, unsigned kbytes, byte delta[16],
+                                    byte *in, unsigned inbytes, byte *out) {
+    if (inbytes == 0) return;
+    if (inbytes < 32) AEZtiny(K, kbytes, delta, in, inbytes, 1, out);
+    else              AEZcore(K, kbytes, delta, in, inbytes, 1, out);
+}
+
+/* ------------------------------------------------------------------------- */
+
+int Decrypt(byte *K, unsigned kbytes,
+            byte *N, unsigned nbytes,
+            byte *AD[], unsigned adbytes[],
+            unsigned veclen, unsigned abytes,
+            byte *C, unsigned cbytes, byte *M) {
+    byte delta[16], *X, sum=0;
+    unsigned i;
+    if (cbytes < abytes) return -1;
+    AEZhash(K, kbytes, N, nbytes, AD, adbytes, veclen, abytes*8, delta);
+    X = (byte *)malloc(cbytes);
+    if (cbytes==abytes) {
+        AEZprf(K, kbytes, delta, abytes, X);
+        for (i=0; i<abytes; i++) sum |= (X[i] ^ C[i]);
+    } else {
+        Decipher(K, kbytes, delta, C, cbytes, X);
+        for (i=0; i<abytes; i++) sum |= X[cbytes-abytes+i];
+        if (sum==0) memcpy(M,X,cbytes-abytes);
+    }
+    free(X);
+    return (sum == 0 ? 0 : -1);  /* return 0 if valid, -1 if invalid */
+}
+
+/* ------------------------------------------------------------------------- */
+
+void Encrypt(byte *K, unsigned kbytes,
+             byte *N, unsigned nbytes,
+             byte *AD[], unsigned adbytes[],
+             unsigned veclen, unsigned abytes,
+             byte *M, unsigned mbytes, byte *C) {
+    byte delta[16], *X;
+    AEZhash(K, kbytes, N, nbytes, AD, adbytes, veclen, abytes*8, delta);
+    if (mbytes==0) {
+        AEZprf(K, kbytes, delta, abytes, C);
+    } else {
+        X = (byte *)malloc(mbytes+abytes);
+        memcpy(X, M, mbytes); memset(X+mbytes,0,abytes);
+        Encipher(K, kbytes, delta, X, mbytes+abytes, X);
+        memcpy(C, X, mbytes+abytes);
+        free(X);
+    }
+}
+
+/* ------------------------------------------------------------------------- */
+/* aez mapping for CAESAR competition                                        */
+
+int crypto_aead_encrypt(
+    unsigned char *c,unsigned long long *clen,
+    const unsigned char *m,unsigned long long mlen,
+    const unsigned char *ad,unsigned long long adlen,
+    const unsigned char *nsec,
+    const unsigned char *npub,
+    const unsigned char *k
+)
+{
+    byte *AD[] = {(byte*)ad};
+    unsigned adbytes[] = {(unsigned)adlen};
+    (void)nsec;
+    if (clen) *clen = mlen+16;
+    Encrypt((byte*)k, 48, (byte*)npub, 12, AD,
+                adbytes, 1, 16, (byte*)m, mlen, (byte*)c);
+    return 0;
+}
+
+int crypto_aead_decrypt(
+    unsigned char *m,unsigned long long *mlen,
+    unsigned char *nsec,
+    const unsigned char *c,unsigned long long clen,
+    const unsigned char *ad,unsigned long long adlen,
+    const unsigned char *npub,
+    const unsigned char *k
+)
+{
+    byte *AD[] = {(byte*)ad};
+    unsigned adbytes[] = {(unsigned)adlen};
+    (void)nsec;
+    if (mlen) *mlen = clen-16;
+    return Decrypt((byte*)k, 48, (byte*)npub, 12, AD,
+                    adbytes, 1, 16, (byte*)c, clen, (byte*)m);
+}
+