Commit 69ce48c3 authored by Richard Levitte's avatar Richard Levitte
Browse files

Make the CBC mode od AES accept lengths that aren't multiples of 16. 

PR: 330
parent 06b7c8d5

crypto/aes/aes_cbc.c

+21 −5
Original line number Diff line number Diff line
@@ -62,11 +62,10 @@ void AES_cbc_encrypt(const unsigned char *in, unsigned char *out, 
	unsigned char tmp[16];



	assert(in && out && key && ivec);

	assert(length % AES_BLOCK_SIZE == 0);

	assert((AES_ENCRYPT == enc)||(AES_DECRYPT == enc));



	if (AES_ENCRYPT == enc)

		while (len > 0) {

	if (AES_ENCRYPT == enc) {

		while (len >= AES_BLOCK_SIZE) {

			for(n=0; n < 16; ++n)

				tmp[n] = in[n] ^ ivec[n];

			AES_encrypt(tmp, out, key);
@@ -75,8 +74,17 @@ void AES_cbc_encrypt(const unsigned char *in, unsigned char *out, 
			in += 16;

			out += 16;

		}

	else

		while (len > 0) {

		if (len) {

			for(n=0; n < len; ++n)

				tmp[n] = in[n] ^ ivec[n];

			for(n=len; n < AES_BLOCK_SIZE; ++n)

				tmp[n] = ivec[n];

			AES_encrypt(tmp, tmp, key);

			memcpy(out, tmp, len);

			memcpy(ivec, tmp, 16);

		}			

	} else {

		while (len >= AES_BLOCK_SIZE) {

			memcpy(tmp, in, 16);

			AES_decrypt(in, out, key);

			for(n=0; n < 16; ++n)
@@ -86,4 +94,12 @@ void AES_cbc_encrypt(const unsigned char *in, unsigned char *out, 
			in += 16;

			out += 16;

		}

		if (len) {

			memcpy(tmp, in, 16);

			AES_decrypt(tmp, tmp, key);

			for(n=0; n < len; ++n)

				out[n] ^= ivec[n];

			memcpy(ivec, tmp, 16);

		}			

	}

}