ccm128.c: add CRYPTO_ccm128_[en|de]crypt_ccm64 and minor optimization.
authorAndy Polyakov <appro@openssl.org>
Sun, 24 Apr 2011 11:10:14 +0000 (11:10 +0000)
committerAndy Polyakov <appro@openssl.org>
Sun, 24 Apr 2011 11:10:14 +0000 (11:10 +0000)
crypto/modes/ccm128.c
crypto/modes/modes.h

index 8a833b2..001fdff 100644 (file)
@@ -58,7 +58,8 @@
 #endif
 #include <assert.h>
 
-/* First you setup M and L parameters and pass the key schedule */
+/* First you setup M and L parameters and pass the key schedule.
+ * This is called once per session setup... */
 void CRYPTO_ccm128_init(CCM128_CONTEXT *ctx,
        unsigned int M,unsigned int L,void *key,block128_f block)
 {
@@ -150,10 +151,13 @@ void CRYPTO_ccm128_aad(CCM128_CONTEXT *ctx,
 
 /* Finally you encrypt or decrypt the message */
 
-static void ctr128_inc(unsigned char *counter) {
-       unsigned int n=16;
+/* counter part of nonce may not be larger than L*8 bits,
+ * L is not larger than 8, therefore 64-bit counter... */
+static void ctr64_inc(unsigned char *counter) {
+       unsigned int n=8;
        u8  c;
 
+       counter += 8;
        do {
                --n;
                c = counter[n];
@@ -169,12 +173,13 @@ int CRYPTO_ccm128_encrypt(CCM128_CONTEXT *ctx,
 {
        size_t          n;
        unsigned int    i,L;
-       unsigned char   flags0 = ctx->nonce.c[0];
-       block128_f      block = ctx->block;
+       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,ctx->key),
+               (*block)(ctx->nonce.c,ctx->cmac.c,key),
                ctx->blocks++;
 
        ctx->nonce.c[0] = L = flags0&7;
@@ -202,9 +207,9 @@ int CRYPTO_ccm128_encrypt(CCM128_CONTEXT *ctx,
                ctx->cmac.u[0] ^= ((u64*)inp)[0];
                ctx->cmac.u[1] ^= ((u64*)inp)[1];
 #endif
-               (*block)(ctx->cmac.c,ctx->cmac.c,ctx->key);
-               (*block)(ctx->nonce.c,scratch.c,ctx->key);
-               ctr128_inc(ctx->nonce.c);
+               (*block)(ctx->cmac.c,ctx->cmac.c,key);
+               (*block)(ctx->nonce.c,scratch.c,key);
+               ctr64_inc(ctx->nonce.c);
 #if defined(STRICT_ALIGNMENT)
                temp.u[0] ^= scratch.u[0];
                temp.u[1] ^= scratch.u[1];
@@ -220,15 +225,15 @@ int CRYPTO_ccm128_encrypt(CCM128_CONTEXT *ctx,
 
        if (len) {
                for (i=0; i<len; ++i) ctx->cmac.c[i] ^= inp[i];
-               (*block)(ctx->cmac.c,ctx->cmac.c,ctx->key);
-               (*block)(ctx->nonce.c,scratch.c,ctx->key);
+               (*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,ctx->key);
+       (*block)(ctx->nonce.c,scratch.c,key);
        ctx->cmac.u[0] ^= scratch.u[0];
        ctx->cmac.u[1] ^= scratch.u[1];
 
@@ -243,12 +248,13 @@ int CRYPTO_ccm128_decrypt(CCM128_CONTEXT *ctx,
 {
        size_t          n;
        unsigned int    i,L;
-       unsigned char   flags0 = ctx->nonce.c[0];
-       block128_f      block = ctx->block;
+       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,ctx->key);
+               (*block)(ctx->nonce.c,ctx->cmac.c,key);
 
        ctx->nonce.c[0] = L = flags0&7;
        for (n=0,i=15-L;i<15;++i) {
@@ -265,8 +271,8 @@ int CRYPTO_ccm128_decrypt(CCM128_CONTEXT *ctx,
 #if defined(STRICT_ALIGNMENT)
                union { u64 u[2]; u8 c[16]; } temp;
 #endif
-               (*block)(ctx->nonce.c,scratch.c,ctx->key);
-               ctr128_inc(ctx->nonce.c);
+               (*block)(ctx->nonce.c,scratch.c,key);
+               ctr64_inc(ctx->nonce.c);
 #if defined(STRICT_ALIGNMENT)
                memcpy (temp.c,inp,16);
                ctx->cmac.u[0] ^= (scratch.u[0] ^= temp.u[0]);
@@ -276,7 +282,7 @@ int CRYPTO_ccm128_decrypt(CCM128_CONTEXT *ctx,
                ctx->cmac.u[0] ^= (((u64*)out)[0] = scratch.u[0]^((u64*)inp)[0]);
                ctx->cmac.u[1] ^= (((u64*)out)[1] = scratch.u[1]^((u64*)inp)[1]);
 #endif
-               (*block)(ctx->cmac.c,ctx->cmac.c,ctx->key);
+               (*block)(ctx->cmac.c,ctx->cmac.c,key);
 
                inp += 16;
                out += 16;
@@ -284,16 +290,139 @@ int CRYPTO_ccm128_decrypt(CCM128_CONTEXT *ctx,
        }
 
        if (len) {
-               (*block)(ctx->nonce.c,scratch.c,ctx->key);
+               (*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,ctx->key);
+               (*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,ctx->key);
+       (*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;
+}
+
+static void ctr64_add (unsigned char *counter,size_t inc)
+{      size_t n=8, val=0;
+
+       counter += 8;
+       do {
+               --n;
+               val += counter[n] + (inc&0xff);
+               counter[n] = (unsigned char)val;
+               val >>= 8;      /* carry bit */
+               inc >>= 8;
+       } while(n && (inc || val));
+}
+
+int CRYPTO_ccm128_encrypt_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->blocks++;
+
+       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;  /* 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) {
+               if (n) ctr64_add(ctx->nonce.c,n/16);
+               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) {
+               if (n) ctr64_add(ctx->nonce.c,n/16);
+               (*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];
 
index 5cf1935..f18215b 100644 (file)
@@ -19,6 +19,10 @@ typedef void (*ctr128_f)(const unsigned char *in, unsigned char *out,
                        size_t blocks, const void *key,
                        const unsigned char ivec[16]);
 
+typedef void (*ccm128_f)(const unsigned char *in, unsigned char *out,
+                       size_t blocks, const void *key,
+                       const unsigned char ivec[16],unsigned char cmac[16]);
+
 void CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
                        size_t len, const void *key,
                        unsigned char ivec[16], block128_f block);
@@ -100,9 +104,9 @@ int CRYPTO_gcm128_encrypt_ctr32(GCM128_CONTEXT *ctx,
 int CRYPTO_gcm128_decrypt_ctr32(GCM128_CONTEXT *ctx,
                        const unsigned char *in, unsigned char *out,
                        size_t len, ctr128_f stream);
-int  CRYPTO_gcm128_finish(GCM128_CONTEXT *ctx,const unsigned char *tag,
+int CRYPTO_gcm128_finish(GCM128_CONTEXT *ctx,const unsigned char *tag,
                        size_t len);
-void  CRYPTO_gcm128_tag(GCM128_CONTEXT *ctx, unsigned char *tag, size_t len);
+void CRYPTO_gcm128_tag(GCM128_CONTEXT *ctx, unsigned char *tag, size_t len);
 void CRYPTO_gcm128_release(GCM128_CONTEXT *ctx);
 
 typedef struct ccm128_context CCM128_CONTEXT;
@@ -117,6 +121,12 @@ int CRYPTO_ccm128_encrypt(CCM128_CONTEXT *ctx,
        const unsigned char *inp, unsigned char *out, size_t len);
 int CRYPTO_ccm128_decrypt(CCM128_CONTEXT *ctx,
        const unsigned char *inp, unsigned char *out, size_t len);
+int CRYPTO_ccm128_encrypt_ccm64(CCM128_CONTEXT *ctx,
+       const unsigned char *inp, unsigned char *out, size_t len,
+       ccm128_f stream);
+int CRYPTO_ccm128_decrypt_ccm64(CCM128_CONTEXT *ctx,
+       const unsigned char *inp, unsigned char *out, size_t len,
+       ccm128_f stream);
 size_t CRYPTO_ccm128_tag(CCM128_CONTEXT *ctx, unsigned char *tag, size_t len);
 
 typedef struct xts128_context XTS128_CONTEXT;