Properly handle a partial block in OCB mode

[openssl.git] / crypto / evp / e_aes.c

diff --git a/crypto/evp/e_aes.c b/crypto/evp/e_aes.c
index f504c688863a6d862911ae181eab1c731c706de8..d3be6a086aaaefe872fd85af9feaaed9dc2f1514 100644 (file)
--- a/crypto/evp/e_aes.c
+++ b/crypto/evp/e_aes.c
@@ -135,10 +135,10 @@ void AES_ctr32_encrypt(const unsigned char *in, unsigned char *out,
                        const unsigned char ivec[AES_BLOCK_SIZE]);
 #endif
 #ifdef AES_XTS_ASM
-void AES_xts_encrypt(const char *inp, char *out, size_t len,
+void AES_xts_encrypt(const unsigned char *inp, unsigned char *out, size_t len,
                      const AES_KEY *key1, const AES_KEY *key2,
                      const unsigned char iv[16]);
-void AES_xts_decrypt(const char *inp, char *out, size_t len,
+void AES_xts_decrypt(const unsigned char *inp, unsigned char *out, size_t len,
                      const AES_KEY *key1, const AES_KEY *key2,
                      const unsigned char iv[16]);
 #endif
@@ -2536,7 +2536,7 @@ static int aes_ocb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
     if (!octx->key_set)
         return -1;
 
-    if (in) {
+    if (in != NULL) {
         /*
          * Need to ensure we are only passing full blocks to low level OCB
          * routines. We do it here rather than in EVP_EncryptUpdate/
@@ -2557,10 +2557,10 @@ static int aes_ocb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
          * If we've got a partially filled buffer from a previous call then
          * use that data first
          */
-        if (*buf_len) {
+        if (*buf_len > 0) {
             unsigned int remaining;
 
-            remaining = 16 - (*buf_len);
+            remaining = AES_BLOCK_SIZE - (*buf_len);
             if (remaining > len) {
                 memcpy(buf + (*buf_len), in, len);
                 *(buf_len) += len;
@@ -2574,21 +2574,25 @@ static int aes_ocb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
             len -= remaining;
             in += remaining;
             if (out == NULL) {
-                if (!CRYPTO_ocb128_aad(&octx->ocb, buf, 16))
+                if (!CRYPTO_ocb128_aad(&octx->ocb, buf, AES_BLOCK_SIZE))
                     return -1;
             } else if (EVP_CIPHER_CTX_encrypting(ctx)) {
-                if (!CRYPTO_ocb128_encrypt(&octx->ocb, buf, out, 16))
+                if (!CRYPTO_ocb128_encrypt(&octx->ocb, buf, out,
+                                           AES_BLOCK_SIZE))
                     return -1;
             } else {
-                if (!CRYPTO_ocb128_decrypt(&octx->ocb, buf, out, 16))
+                if (!CRYPTO_ocb128_decrypt(&octx->ocb, buf, out,
+                                           AES_BLOCK_SIZE))
                     return -1;
             }
-            written_len = 16;
+            written_len = AES_BLOCK_SIZE;
             *buf_len = 0;
+            if (out != NULL)
+                out += AES_BLOCK_SIZE;
         }
 
         /* Do we have a partial block to handle at the end? */
-        trailing_len = len % 16;
+        trailing_len = len % AES_BLOCK_SIZE;
 
         /*
          * If we've got some full blocks to handle, then process these first
@@ -2611,7 +2615,7 @@ static int aes_ocb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
         }
 
         /* Handle any trailing partial block */
-        if (trailing_len) {
+        if (trailing_len > 0) {
             memcpy(buf, in, trailing_len);
             *buf_len = trailing_len;
         }
@@ -2622,7 +2626,7 @@ static int aes_ocb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
          * First of all empty the buffer of any partial block that we might
          * have been provided - both for data and AAD
          */
-        if (octx->data_buf_len) {
+        if (octx->data_buf_len > 0) {
             if (EVP_CIPHER_CTX_encrypting(ctx)) {
                 if (!CRYPTO_ocb128_encrypt(&octx->ocb, octx->data_buf, out,
                                            octx->data_buf_len))
@@ -2635,7 +2639,7 @@ static int aes_ocb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
             written_len = octx->data_buf_len;
             octx->data_buf_len = 0;
         }
-        if (octx->aad_buf_len) {
+        if (octx->aad_buf_len > 0) {
             if (!CRYPTO_ocb128_aad
                 (&octx->ocb, octx->aad_buf, octx->aad_buf_len))
                 return -1;