simple: Handle encrypt/decrypt block sizes properly

- Calculate output block sizes properly
- Resize output allocations to size output

Change-Id: I58cc4530f9b832375c20c79c9883910adaaccc67
Signed-off-by: Mateusz Kulikowski <m.kulikowski@samsung.com>

diff --git a/src/simple.c b/src/simple.c
index ce1d5f3..ff7f19e 100644 (file)
--- a/src/simple.c
+++ b/src/simple.c
@@ -90,6 +90,7 @@ API int yaca_encrypt(yaca_enc_algo_e algo,
        yaca_ctx_h ctx;
        int ret;
        char *lcipher;
+       char *rcipher;
        size_t out_len, lcipher_len, written;
 
        if (plain == NULL || plain_len == 0 || cipher == NULL || cipher_len == NULL ||
@@ -100,21 +101,28 @@ API int yaca_encrypt(yaca_enc_algo_e algo,
                return YACA_ERROR_TOO_BIG_ARGUMENT;
 
        ret = yaca_encrypt_init(&ctx, algo, bcm, sym_key, iv);
-       if (ret < 0)
+       if (ret != 0)
                return ret;
 
-       ret = yaca_get_output_length(ctx, plain_len);
-       if (ret < 0)
+       ret = yaca_get_block_length(ctx);
+       if (ret <= 0)
                goto err;
 
        lcipher_len = ret;
+
+       ret = yaca_get_output_length(ctx, plain_len);
+       if (ret <= 0)
+               goto err;
+
+       lcipher_len += ret;
+
        lcipher = yaca_malloc(lcipher_len);
        if (lcipher == NULL)
                goto err;
 
        out_len = lcipher_len;
        ret = yaca_encrypt_update(ctx, plain, plain_len, lcipher, &out_len);
-       if (ret < 0)
+       if (ret != 0)
                goto err_free;
 
        assert (out_len <= lcipher_len);
@@ -122,15 +130,22 @@ API int yaca_encrypt(yaca_enc_algo_e algo,
        written = out_len;
        out_len = lcipher_len - written;
        ret = yaca_encrypt_final(ctx, lcipher + written, &out_len);
-       if (ret < 0)
+       if (ret != 0)
                goto err_free;
 
-       assert (out_len + written == lcipher_len);
+       written += out_len;
+       assert (written <= lcipher_len);
+
+       rcipher = yaca_realloc(lcipher, written);
+       if (rcipher == NULL) {
+               ret = YACA_ERROR_OUT_OF_MEMORY;
+               goto err_free;
+       }
 
        yaca_ctx_free(ctx);
 
-       *cipher = lcipher;
-       *cipher_len = lcipher_len;
+       *cipher = rcipher;
+       *cipher_len = written;
        return 0;
 
 err_free:
@@ -152,6 +167,7 @@ API int yaca_decrypt(yaca_enc_algo_e algo,
        yaca_ctx_h ctx;
        int ret;
        char *lplain;
+       char *rplain;
        size_t out_len, lplain_len, written;
 
        if (cipher == NULL || cipher_len == 0 || plain == NULL || plain_len == NULL ||
@@ -162,21 +178,28 @@ API int yaca_decrypt(yaca_enc_algo_e algo,
                return YACA_ERROR_TOO_BIG_ARGUMENT;
 
        ret = yaca_decrypt_init(&ctx, algo, bcm, sym_key, iv);
-       if (ret < 0)
+       if (ret != 0)
                return ret;
 
-       ret = yaca_get_output_length(ctx, cipher_len);
-       if (ret < 0)
+       ret = yaca_get_block_length(ctx);
+       if (ret <= 0)
                goto err;
 
        lplain_len = ret;
+
+       ret = yaca_get_output_length(ctx, cipher_len);
+       if (ret <= 0)
+               goto err;
+
+       lplain_len += ret;
+
        lplain = yaca_malloc(lplain_len);
        if (!lplain)
                goto err;
 
        out_len = lplain_len;
        ret = yaca_decrypt_update(ctx, cipher, cipher_len, lplain, &out_len);
-       if (ret < 0)
+       if (ret != 0)
                goto err_free;
 
        assert(out_len <= lplain_len);
@@ -184,15 +207,22 @@ API int yaca_decrypt(yaca_enc_algo_e algo,
        written = out_len;
        out_len = lplain_len - written;
        ret = yaca_decrypt_final(ctx, lplain + written, &out_len);
-       if (ret < 0)
+       if (ret != 0)
                goto err_free;
 
-       assert(out_len + written == lplain_len);
+       written += out_len;
+       assert(written <= lplain_len);
+
+       rplain = yaca_realloc(lplain, written);
+       if (rplain == NULL) {
+               ret = YACA_ERROR_OUT_OF_MEMORY;
+               goto err_free;
+       }
 
        yaca_ctx_free(ctx);
 
-       *plain = lplain;
-       *plain_len = lplain_len;
+       *plain = rplain;
+       *plain_len = written;
        return 0;
 
 err_free: