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-rw-r--r--Makefile35
-rw-r--r--aes.c68
-rw-r--r--aes.h10
-rw-r--r--test.c31
4 files changed, 69 insertions, 75 deletions
diff --git a/Makefile b/Makefile
index 55af9bc..3b875af 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,11 @@
#CFLAGS = -Wall -mmcu=atmega16 -Os -Wl,-Map,test.map
#OBJCOPY = avr-objcopy
CC = gcc
-CFLAGS = -Wall -Os -Wl,-Map,test.map
+LD = gcc
+CFLAGS = -Wall -Os -c
+LDFLAGS = -Wall -Os -Wl,-Map,test.map
+
+OBJCOPYFLAFS = -j .text -O ihex
OBJCOPY = objcopy
# include path to AVR library
@@ -10,28 +14,27 @@ INCLUDE_PATH = /usr/lib/avr/include
# splint static check
SPLINT = splint test.c aes.c -I$(INCLUDE_PATH) +charindex -unrecog
+default: test.elf
+
.SILENT:
.PHONY: lint clean
+test.hex : test.elf
+ echo copy object-code to new image and format in hex
+ $(OBJCOPY) ${OBJCOPYFLAFS} $< $@
-rom.hex : test.out
- # copy object-code to new image and format in hex
- $(OBJCOPY) -j .text -O ihex test.out rom.hex
-
-test.o : test.c
- # compiling test.c
- $(CC) $(CFLAGS) -c test.c -o test.o
+test.o : test.c aes.h aes.o
+ echo [CC] $@
+ $(CC) $(CFLAGS) -o $@ $<
-aes.o : aes.h aes.c
- # compiling aes.c
- $(CC) $(CFLAGS) -c aes.c -o aes.o
+aes.o : aes.c aes.h
+ echo [CC] $@
+ $(CC) $(CFLAGS) -o $@ $<
-test.out : aes.o test.o
- # linking object code to binary
- $(CC) $(CFLAGS) aes.o test.o -o test.out
+test.elf : aes.o test.o
+ echo [LD] $@
+ $(LD) $(LDFLAGS) -o $@ $^
-small: test.out
- $(OBJCOPY) -j .text -O ihex test.out rom.hex
clean:
rm -f *.OBJ *.LST *.o *.gch *.out *.hex *.map
diff --git a/aes.c b/aes.c
index c42620b..030e8b1 100644
--- a/aes.c
+++ b/aes.c
@@ -482,21 +482,16 @@ static void InvCipher(state_t *state,uint8_t*RoundKey)
#if defined(ECB) && (ECB == 1)
-void AES_ECB_encrypt(struct AES_ctx *ctx,const uint8_t* input, uint8_t* output)
+void AES_ECB_encrypt(struct AES_ctx *ctx,const uint8_t* buf)
{
- // Copy input to output, and work in-memory on output
- memcpy(output, input, AES_BLOCKLEN);
-
// The next function call encrypts the PlainText with the Key using AES algorithm.
- Cipher((state_t*)output,ctx->RoundKey);
+ Cipher((state_t*)buf,ctx->RoundKey);
}
-void AES_ECB_decrypt(struct AES_ctx *ctx,const uint8_t* input, uint8_t *output)
+void AES_ECB_decrypt(struct AES_ctx *ctx,const uint8_t* buf)
{
- // Copy input to output, and work in-memory on output
- memcpy(output, input, AES_BLOCKLEN);
-
- InvCipher((state_t*)output,ctx->RoundKey);
+ // The next function call decrypts the PlainText with the Key using AES algorithm.
+ InvCipher((state_t*)buf,ctx->RoundKey);
}
@@ -518,35 +513,33 @@ static void XorWithIv(uint8_t* buf,uint8_t*Iv)
}
}
-void AES_CBC_encrypt_buffer(struct AES_ctx *ctx,uint8_t* output, uint8_t* input, uint32_t length)
+void AES_CBC_encrypt_buffer(struct AES_ctx *ctx,uint8_t* buf, uint32_t length)
{
uintptr_t i;
uint8_t *Iv=ctx->Iv;
- memcpy(output, input, length);
for (i = 0; i < length; i += AES_BLOCKLEN)
{
- XorWithIv(output,Iv);
- Cipher((state_t*)output,ctx->RoundKey);
- Iv = output;
- output += AES_BLOCKLEN;
+ XorWithIv(buf,Iv);
+ Cipher((state_t*)buf,ctx->RoundKey);
+ Iv = buf;
+ buf += AES_BLOCKLEN;
//printf("Step %d - %d", i/16, i);
}
//store Iv in ctx for next call
memcpy(ctx->Iv,Iv,AES_BLOCKLEN);
}
-void AES_CBC_decrypt_buffer(struct AES_ctx *ctx, uint8_t* output, uint8_t* input, uint32_t length)
+void AES_CBC_decrypt_buffer(struct AES_ctx *ctx, uint8_t* buf, uint32_t length)
{
uintptr_t i;
- uint8_t *Iv=ctx->Iv;
- memcpy(output, input, length);
+ uint8_t storeNextIv[AES_BLOCKLEN];
for (i = 0; i < length; i += AES_BLOCKLEN)
{
- InvCipher((state_t*)output,ctx->RoundKey);
- XorWithIv(output,Iv);
- Iv = input; //we DO need original input stored here
- input += AES_BLOCKLEN;
- output += AES_BLOCKLEN;
+ memcpy(storeNextIv, buf, AES_BLOCKLEN);
+ InvCipher((state_t*)buf,ctx->RoundKey);
+ XorWithIv(buf,ctx->Iv);
+ memcpy(ctx->Iv, storeNextIv, AES_BLOCKLEN);
+ buf += AES_BLOCKLEN;
}
}
@@ -558,34 +551,35 @@ void AES_CBC_decrypt_buffer(struct AES_ctx *ctx, uint8_t* output, uint8_t* input
#if defined(CTR) && (CTR == 1)
/* Symmetrical operation: same function for encrypting as for decrypting. Note any IV/nonce should never be reused with the same key */
-void AES_CTR_xcrypt_buffer(struct AES_ctx *ctx,uint8_t* output, uint8_t* input, uint32_t length)
+void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length)
{
uint8_t buffer[AES_BLOCKLEN];
- int j;
unsigned i;
- for (i = 0; i < length; ++i)
+ int bi;
+ for (i = 0,bi=AES_BLOCKLEN; i < length; ++i,bi++)
{
- if ((i & (AES_BLOCKLEN - 1)) == 0) //we need to regen xor compliment in buff
+ if (bi == AES_BLOCKLEN) //we need to regen xor compliment in buffer
{
memcpy(buffer, ctx->Iv, AES_BLOCKLEN);
Cipher((state_t*)buffer,ctx->RoundKey);
- /* Increment counter and handle overflow */
- for (j = (AES_BLOCKLEN - 1); j >= 0; --j)
+ /* Increment Iv and handle overflow */
+ for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi)
{
- ctx->Iv[j] += 1;
+ if (ctx->Iv[bi] == 255) { //inc will owerflow
+ ctx->Iv[bi]=0;
+ continue;
+ }
+ ctx->Iv[bi] += 1;
+ break;
- /* Break if no overflow, keep going otherwise */
- if (ctx->Iv[j] != 0)
- {
- break;
- }
}
+ bi=0;
}
- output[i] = (input[i] ^ buffer[(i & (AES_BLOCKLEN - 1))]);
+ buf[i] = (buf[i] ^ buffer[bi]);
}
}
diff --git a/aes.h b/aes.h
index 021f0c2..54d994a 100644
--- a/aes.h
+++ b/aes.h
@@ -58,8 +58,8 @@ void AES_ctx_set_iv(struct AES_ctx *ctx,const uint8_t* iv);
// buffer size is exactly AES_BLOCKLEN bytes;
// you need only AES_init_ctx as Iv is not used in ECB
// NB: ECB s considered insecure
-void AES_ECB_encrypt(struct AES_ctx *ctx, const uint8_t* input, uint8_t *output);
-void AES_ECB_decrypt(struct AES_ctx *ctx, const uint8_t* input, uint8_t *output);
+void AES_ECB_encrypt(struct AES_ctx *ctx, const uint8_t* buf);
+void AES_ECB_decrypt(struct AES_ctx *ctx, const uint8_t* buf);
#endif // #if defined(ECB) && (ECB == !)
@@ -69,8 +69,8 @@ void AES_ECB_decrypt(struct AES_ctx *ctx, const uint8_t* input, uint8_t *output)
// We suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 if you need one
// you need to set iv in ctx via AES_init_ctx_iv or AES_ctx_set_iv
// NB: no IV should ever be reused with the same key
-void AES_CBC_encrypt_buffer(struct AES_ctx *ctx, uint8_t* output, uint8_t* input, uint32_t length);
-void AES_CBC_decrypt_buffer(struct AES_ctx *ctx, uint8_t* output, uint8_t* input, uint32_t length);
+void AES_CBC_encrypt_buffer(struct AES_ctx *ctx, uint8_t* buf, uint32_t length);
+void AES_CBC_decrypt_buffer(struct AES_ctx *ctx, uint8_t* buf, uint32_t length);
#endif // #if defined(CBC) && (CBC == 1)
@@ -83,7 +83,7 @@ void AES_CBC_decrypt_buffer(struct AES_ctx *ctx, uint8_t* output, uint8_t* input
// We suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 if you need one
// you need to set iv in ctx via AES_init_ctx_iv or AES_ctx_set_iv
// NB: no IV should ever be reused with the same key
-void AES_CTR_xcrypt_buffer(struct AES_ctx *ctx, uint8_t* output, uint8_t* input, uint32_t length);
+void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length);
#endif // #if defined(CTR) && (CTR == 1)
diff --git a/test.c b/test.c
index 2bd2159..1460003 100644
--- a/test.c
+++ b/test.c
@@ -101,8 +101,8 @@ static void test_encrypt_ecb_verbose(void)
AES_init_ctx(&ctx,key);
for(i = 0; i < 4; ++i)
{
- AES_ECB_encrypt(&ctx,plain_text + (i*16), buf+(i*16));
- phex(buf + (i*16));
+ AES_ECB_encrypt(&ctx,plain_text + (i*16));
+ phex(plain_text + (i*16));
}
printf("\n");
}
@@ -124,14 +124,13 @@ static void test_encrypt_ecb(void)
#endif
uint8_t in[] = {0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a};
- uint8_t buffer[16];
struct AES_ctx ctx; AES_init_ctx(&ctx,key);
- AES_ECB_encrypt(&ctx,in, buffer);
+ AES_ECB_encrypt(&ctx,in);
printf("ECB encrypt: ");
- if(0 == memcmp((char*) out, (char*) buffer, 16))
+ if(0 == memcmp((char*) out, (char*) in, 16))
{
printf("SUCCESS!\n");
}
@@ -169,14 +168,14 @@ static void test_decrypt_cbc(void)
0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10 };
- uint8_t buffer[64];
+// uint8_t buffer[64];
struct AES_ctx ctx;
AES_init_ctx_iv(&ctx,key,iv);
- AES_CBC_decrypt_buffer(&ctx,buffer, in, 64);
+ AES_CBC_decrypt_buffer(&ctx,in, 64);
printf("CBC decrypt: ");
- if(0 == memcmp((char*) out, (char*) buffer, 64))
+ if(0 == memcmp((char*) out, (char*) in, 64))
{
printf("SUCCESS!\n");
}
@@ -214,14 +213,13 @@ static void test_encrypt_cbc(void)
0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10 };
- uint8_t buffer[64];
struct AES_ctx ctx;
AES_init_ctx_iv(&ctx,key,iv);
- AES_CBC_encrypt_buffer(&ctx,buffer, in, 64);
+ AES_CBC_encrypt_buffer(&ctx, in, 64);
printf("CBC encrypt: ");
- if(0 == memcmp((char*) out, (char*) buffer, 64))
+ if(0 == memcmp((char*) out, (char*) in, 64))
{
printf("SUCCESS!\n");
}
@@ -270,16 +268,15 @@ static void test_xcrypt_ctr(const char* xcrypt)
0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10 };
- uint8_t buffer[64];
struct AES_ctx ctx;
AES_init_ctx_iv(&ctx,key,iv);
- AES_CTR_xcrypt_buffer(&ctx,buffer, in, 64);
+ AES_CTR_xcrypt_buffer(&ctx, in, 64);
printf("CTR %s: ", xcrypt);
- if (0 == memcmp((char *) out, (char *) buffer, 64))
+ if (0 == memcmp((char *) out, (char *) in, 64))
{
printf("SUCCESS!\n");
}
@@ -306,14 +303,14 @@ static void test_decrypt_ecb(void)
#endif
uint8_t out[] = {0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a};
- uint8_t buffer[16];
+
struct AES_ctx ctx;
AES_init_ctx(&ctx,key);
- AES_ECB_decrypt(&ctx,in, buffer);
+ AES_ECB_decrypt(&ctx,in);
printf("ECB decrypt: ");
- if(0 == memcmp((char*) out, (char*) buffer, 16))
+ if(0 == memcmp((char*) out, (char*) in, 16))
{
printf("SUCCESS!\n");
}