2 files changed, 26 insertions, 0 deletions
diff --git a/lib/crypto/aes.c b/lib/crypto/aes.c
index 7735e8ff37..a47a456593 100644
--- a/lib/crypto/aes.c
+++ b/lib/crypto/aes.c
@@ -112,3 +112,25 @@ AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
 	}
     }
 }
+
+void aes_cfb8_encrypt(const uint8_t *in, uint8_t *out,
+		      size_t length, const AES_KEY *key,
+		      uint8_t *iv, int forward)
+{
+	size_t i;
+
+	for (i=0; i < length; i++) {
+		uint8_t tiv[AES_BLOCK_SIZE*2];
+
+		memcpy(tiv, iv, AES_BLOCK_SIZE);
+		AES_encrypt(iv, iv, key);
+		if (!forward) {
+			tiv[AES_BLOCK_SIZE] = in[i];
+		}
+		out[i] = in[i] ^ iv[0];
+		if (forward) {
+			tiv[AES_BLOCK_SIZE] = out[i];
+		}
+		memcpy(iv, tiv+1, AES_BLOCK_SIZE);
+	}
+}
diff --git a/lib/crypto/aes.h b/lib/crypto/aes.h
index e74d345215..a2b6c077e6 100644
--- a/lib/crypto/aes.h
+++ b/lib/crypto/aes.h
@@ -72,6 +72,10 @@ void AES_cbc_encrypt(const unsigned char *, unsigned char *,
 		     const unsigned long, const AES_KEY *,
 		     unsigned char *, int);
 
+void aes_cfb8_encrypt(const uint8_t *in, uint8_t *out,
+		      size_t length, const AES_KEY *key,
+		      uint8_t *iv, int forward);
+
 #ifdef  __cplusplus
 }
 #endif