The AES CTR API was buggy, we need to save the encrypted counter as well

between calls, or that will be lost if it returned with *num non-zero.

diff --git a/crypto/aes/aes.h b/crypto/aes/aes.h
index e8da921ec50472067ca0cad91e66d8cc920d4490..f708f6f34b17f33e57888a6160d1a5f1a1d8d76e 100644 (file)
--- a/crypto/aes/aes.h
+++ b/crypto/aes/aes.h
@@ -99,7 +99,9 @@ void AES_ofb128_encrypt(const unsigned char *in, unsigned char *out,
        unsigned char *ivec, int *num);
 void AES_ctr128_encrypt(const unsigned char *in, unsigned char *out,
        const unsigned long length, const AES_KEY *key,
-       unsigned char *counter, unsigned int *num);
+       unsigned char counter[AES_BLOCK_SIZE],
+       unsigned char ecount_buf[AES_BLOCK_SIZE],
+       unsigned int *num);
 
 
 #ifdef  __cplusplus

diff --git a/crypto/aes/aes_ctr.c b/crypto/aes/aes_ctr.c
index aea3db209272189e4e8fcd6638a3e3ed51048e10..6a89f4def2466617f0fe4bd2ea6206a5c133092d 100644 (file)
--- a/crypto/aes/aes_ctr.c
+++ b/crypto/aes/aes_ctr.c
@@ -94,11 +94,12 @@ static void AES_ctr128_inc(unsigned char *counter) {
  */
 void AES_ctr128_encrypt(const unsigned char *in, unsigned char *out,
        const unsigned long length, const AES_KEY *key,
-       unsigned char *counter, unsigned int *num) {
+       unsigned char counter[AES_BLOCK_SIZE],
+       unsigned char ecount_buf[AES_BLOCK_SIZE],
+       unsigned int *num) {
 
        unsigned int n;
        unsigned long l=length;
-       unsigned char tmp[AES_BLOCK_SIZE];
 
        assert(in && out && key && counter && num);
 
@@ -106,10 +107,10 @@ void AES_ctr128_encrypt(const unsigned char *in, unsigned char *out,
 
        while (l--) {
                if (n == 0) {
-                       AES_encrypt(counter, tmp, key);
+                       AES_encrypt(counter, ecount_buf, key);
                        AES_ctr128_inc(counter);
                }
-               *(out++) = *(in++) ^ tmp[n];
+               *(out++) = *(in++) ^ ecount_buf[n];
                n = (n+1) % AES_BLOCK_SIZE;
        }