+ n <<= 8;
+ }
+ n |= ctx->nonce.c[15]; /* reconstructed length */
+ ctx->nonce.c[15]=1;
+
+ if (n!=len) return -1; /* length mismatch */
+
+ ctx->blocks += ((len+15)>>3)|1;
+ if (ctx->blocks > (U64(1)<<61)) return -2; /* too much data */
+
+ if ((n=len/16)) {
+ (*stream)(inp,out,n,key,ctx->nonce.c,ctx->cmac.c);
+ n *= 16;
+ inp += n;
+ out += n;
+ len -= n;
+ if (len) ctr64_add(ctx->nonce.c,n/16);
+ }
+
+ if (len) {
+ for (i=0; i<len; ++i) ctx->cmac.c[i] ^= inp[i];
+ (*block)(ctx->cmac.c,ctx->cmac.c,key);
+ (*block)(ctx->nonce.c,scratch.c,key);
+ for (i=0; i<len; ++i) out[i] = scratch.c[i]^inp[i];
+ }
+
+ for (i=15-L;i<16;++i)
+ ctx->nonce.c[i]=0;
+
+ (*block)(ctx->nonce.c,scratch.c,key);
+ ctx->cmac.u[0] ^= scratch.u[0];
+ ctx->cmac.u[1] ^= scratch.u[1];
+
+ ctx->nonce.c[0] = flags0;
+
+ return 0;
+}
+
+int CRYPTO_ccm128_decrypt_ccm64(CCM128_CONTEXT *ctx,
+ const unsigned char *inp, unsigned char *out,
+ size_t len,ccm128_f stream)
+{
+ size_t n;
+ unsigned int i,L;
+ unsigned char flags0 = ctx->nonce.c[0];
+ block128_f block = ctx->block;
+ void * key = ctx->key;
+ union { u64 u[2]; u8 c[16]; } scratch;
+
+ if (!(flags0&0x40))
+ (*block)(ctx->nonce.c,ctx->cmac.c,key);
+
+ ctx->nonce.c[0] = L = flags0&7;
+ for (n=0,i=15-L;i<15;++i) {
+ n |= ctx->nonce.c[i];
+ ctx->nonce.c[i]=0;
+ n <<= 8;
+ }
+ n |= ctx->nonce.c[15]; /* reconstructed length */
+ ctx->nonce.c[15]=1;
+
+ if (n!=len) return -1;
+
+ if ((n=len/16)) {
+ (*stream)(inp,out,n,key,ctx->nonce.c,ctx->cmac.c);
+ n *= 16;
+ inp += n;
+ out += n;
+ len -= n;
+ if (len) ctr64_add(ctx->nonce.c,n/16);
+ }
+
+ if (len) {
+ (*block)(ctx->nonce.c,scratch.c,key);
+ for (i=0; i<len; ++i)
+ ctx->cmac.c[i] ^= (out[i] = scratch.c[i]^inp[i]);
+ (*block)(ctx->cmac.c,ctx->cmac.c,key);
+ }
+
+ for (i=15-L;i<16;++i)
+ ctx->nonce.c[i]=0;
+
+ (*block)(ctx->nonce.c,scratch.c,key);
+ ctx->cmac.u[0] ^= scratch.u[0];
+ ctx->cmac.u[1] ^= scratch.u[1];