Split cipher_update_ad() out or cipher_reset()
diff --git a/include/polarssl/cipher.h b/include/polarssl/cipher.h
index 93a0015..7dea1e2 100644
--- a/include/polarssl/cipher.h
+++ b/include/polarssl/cipher.h
@@ -454,7 +454,7 @@
const unsigned char *iv, size_t iv_len );
/**
- * \brief Reset the given context, setting the IV to iv
+ * \brief Finish preparation of the given context
*
* \param ctx generic cipher context
* \param ad Additional data for AEAD ciphers, or discarded.
@@ -464,8 +464,25 @@
* \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA
* if parameter verification fails.
*/
-int cipher_reset( cipher_context_t *ctx,
- const unsigned char *ad, size_t ad_len );
+int cipher_reset( cipher_context_t *ctx );
+
+/**
+ * \brief Add additional data (for AEAD ciphers).
+ * This function has no effect for non-AEAD ciphers.
+ * For AEAD ciphers, it may or may not be called
+ * repeatedly, and/or interleaved with calls to
+ * cipher_udpate(), depending on the cipher.
+ * E.g. for GCM is must be called exactly once, right
+ * after cipher_reset().
+ *
+ * \param ctx generic cipher context
+ * \param ad Additional data to use.
+ * \param ad_len Length of ad.
+ *
+ * \returns 0 on success, or a specific error code.
+ */
+int cipher_update_ad( cipher_context_t *ctx,
+ const unsigned char *ad, size_t ad_len );
/**
* \brief Generic cipher update function. Encrypts/decrypts
diff --git a/library/cipher.c b/library/cipher.c
index a5f6e11..f8e2841 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -415,14 +415,32 @@
return 0;
}
-int cipher_reset( cipher_context_t *ctx,
- const unsigned char *ad, size_t ad_len )
+int cipher_reset( cipher_context_t *ctx )
{
+ if( NULL == ctx || NULL == ctx->cipher_info )
+ return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA;
+
ctx->unprocessed_len = 0;
+ return 0;
+}
+
+int cipher_update_ad( cipher_context_t *ctx,
+ const unsigned char *ad, size_t ad_len )
+{
+ if( NULL == ctx || NULL == ctx->cipher_info )
+ return POLARSSL_ERR_CIPHER_BAD_INPUT_DATA;
+
#if defined(POLARSSL_GCM_C)
if( POLARSSL_MODE_GCM == ctx->cipher_info->mode )
{
+ /* Make sure we're called right after cipher_reset() */
+ if( ((gcm_context *) ctx->cipher_ctx)->len != 0 ||
+ ((gcm_context *) ctx->cipher_ctx)->add_len != 0 )
+ {
+ return POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE;
+ }
+
return gcm_starts( ctx->cipher_ctx, ctx->operation,
ctx->iv, ctx->iv_size, ad, ad_len );
}
diff --git a/library/pkcs12.c b/library/pkcs12.c
index cc59d68..98ebd88 100644
--- a/library/pkcs12.c
+++ b/library/pkcs12.c
@@ -187,7 +187,7 @@
if( ( ret = cipher_set_iv( &cipher_ctx, iv, cipher_info->iv_size ) ) != 0 )
goto exit;
- if( ( ret = cipher_reset( &cipher_ctx, NULL, 0 ) ) != 0 )
+ if( ( ret = cipher_reset( &cipher_ctx ) ) != 0 )
goto exit;
if( ( ret = cipher_update( &cipher_ctx, data, len,
diff --git a/library/pkcs5.c b/library/pkcs5.c
index 10adbb4..a27d4fb 100644
--- a/library/pkcs5.c
+++ b/library/pkcs5.c
@@ -190,7 +190,7 @@
if( ( ret = cipher_set_iv( &cipher_ctx, iv, enc_scheme_params.len ) ) != 0 )
goto exit;
- if( ( ret = cipher_reset( &cipher_ctx, NULL, 0 ) ) != 0 )
+ if( ( ret = cipher_reset( &cipher_ctx ) ) != 0 )
goto exit;
if( ( ret = cipher_update( &cipher_ctx, data, datalen,
diff --git a/programs/aes/crypt_and_hash.c b/programs/aes/crypt_and_hash.c
index 8ffdb9f..c46713d 100644
--- a/programs/aes/crypt_and_hash.c
+++ b/programs/aes/crypt_and_hash.c
@@ -311,7 +311,7 @@
fprintf( stderr, "cipher_set_iv() returned error\n");
goto exit;
}
- if( cipher_reset( &cipher_ctx, NULL, 0 ) != 0 )
+ if( cipher_reset( &cipher_ctx ) != 0 )
{
fprintf( stderr, "cipher_reset() returned error\n");
goto exit;
@@ -430,7 +430,7 @@
cipher_setkey( &cipher_ctx, digest, cipher_info->key_length,
POLARSSL_DECRYPT );
cipher_set_iv( &cipher_ctx, IV, 16 );
- cipher_reset( &cipher_ctx, NULL, 0 );
+ cipher_reset( &cipher_ctx );
md_hmac_starts( &md_ctx, digest, 32 );
diff --git a/tests/suites/test_suite_cipher.function b/tests/suites/test_suite_cipher.function
index d247bab..aa82daa 100644
--- a/tests/suites/test_suite_cipher.function
+++ b/tests/suites/test_suite_cipher.function
@@ -61,8 +61,11 @@
TEST_ASSERT( 0 == cipher_set_iv( &ctx_dec, iv, 16 ) );
TEST_ASSERT( 0 == cipher_set_iv( &ctx_enc, iv, 16 ) );
- TEST_ASSERT( 0 == cipher_reset( &ctx_dec, ad, 13 ) );
- TEST_ASSERT( 0 == cipher_reset( &ctx_enc, ad, 13 ) );
+ TEST_ASSERT( 0 == cipher_reset( &ctx_dec ) );
+ TEST_ASSERT( 0 == cipher_reset( &ctx_enc ) );
+
+ TEST_ASSERT( 0 == cipher_update_ad( &ctx_dec, ad, 13 ) );
+ TEST_ASSERT( 0 == cipher_update_ad( &ctx_enc, ad, 13 ) );
/* encode length number of bytes from inbuf */
TEST_ASSERT( 0 == cipher_update( &ctx_enc, inbuf, length, encbuf, &outlen ) );
@@ -137,7 +140,8 @@
TEST_ASSERT( 0 == cipher_setkey( &ctx, key, key_len, POLARSSL_ENCRYPT ) );
TEST_ASSERT( 0 == cipher_set_padding_mode( &ctx, pad_mode ) );
TEST_ASSERT( 0 == cipher_set_iv( &ctx, iv, 16 ) );
- TEST_ASSERT( 0 == cipher_reset( &ctx, NULL, 0 ) );
+ TEST_ASSERT( 0 == cipher_reset( &ctx ) );
+ TEST_ASSERT( 0 == cipher_update_ad( &ctx, NULL, 0 ) );
/* encode length number of bytes from inbuf */
TEST_ASSERT( 0 == cipher_update( &ctx, inbuf, length, encbuf, &outlen ) );
@@ -180,7 +184,9 @@
TEST_ASSERT( 0 == cipher_set_iv( &ctx_dec, iv, 16 ) );
- TEST_ASSERT( 0 == cipher_reset( &ctx_dec, NULL, 0 ) );
+ TEST_ASSERT( 0 == cipher_reset( &ctx_dec ) );
+
+ TEST_ASSERT( 0 == cipher_update_ad( &ctx_dec, NULL, 0 ) );
/* decode 0-byte string */
TEST_ASSERT( 0 == cipher_update( &ctx_dec, encbuf, 0, decbuf, &outlen ) );
@@ -237,8 +243,11 @@
TEST_ASSERT( 0 == cipher_set_iv( &ctx_dec, iv, 16 ) );
TEST_ASSERT( 0 == cipher_set_iv( &ctx_enc, iv, 16 ) );
- TEST_ASSERT( 0 == cipher_reset( &ctx_dec, NULL, 0 ) );
- TEST_ASSERT( 0 == cipher_reset( &ctx_enc, NULL, 0 ) );
+ TEST_ASSERT( 0 == cipher_reset( &ctx_dec ) );
+ TEST_ASSERT( 0 == cipher_reset( &ctx_enc ) );
+
+ TEST_ASSERT( 0 == cipher_update_ad( &ctx_dec, NULL, 0 ) );
+ TEST_ASSERT( 0 == cipher_update_ad( &ctx_enc, NULL, 0 ) );
/* encode length number of bytes from inbuf */
TEST_ASSERT( 0 == cipher_update( &ctx_enc, inbuf, first_length, encbuf, &outlen ) );