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-rw-r--r--src/box.c237
-rw-r--r--src/box_aes.c47
-rw-r--r--src/error.c14
-rw-r--r--src/padding.c87
4 files changed, 256 insertions, 129 deletions
diff --git a/src/box.c b/src/box.c
index 9610a93..d67eeb7 100644
--- a/src/box.c
+++ b/src/box.c
@@ -9,6 +9,7 @@
#include <aesni/all.h>
#include <stdlib.h>
+#include <string.h>
static const AesNI_BoxAlgorithmInterface* aesni_box_algorithms[] =
{
@@ -19,9 +20,9 @@ static const AesNI_BoxAlgorithmInterface* aesni_box_algorithms[] =
AesNI_StatusCode aesni_box_init(
AesNI_Box* box,
- AesNI_BoxAlgorithm algorithm,
+ AesNI_Algorithm algorithm,
const AesNI_BoxAlgorithmParams* algorithm_params,
- AesNI_BoxMode mode,
+ AesNI_Mode mode,
const AesNI_BoxBlock* iv,
AesNI_ErrorDetails* err_details)
{
@@ -298,6 +299,92 @@ static AesNI_StatusCode aesni_box_encrypt_buffer_block(
return status;
}
+static AesNI_StatusCode aesni_box_encrypt_buffer_partial_block_with_padding(
+ AesNI_Box* box,
+ const void* src,
+ size_t src_size,
+ void* dest,
+ size_t padding_size,
+ AesNI_ErrorDetails* err_details)
+{
+ AesNI_StatusCode status = AESNI_SUCCESS;
+
+ size_t block_size;
+
+ if (aesni_is_error(status = box->algorithm->get_block_size(
+ &block_size, err_details)))
+ return status;
+
+ void* plaintext_buf = malloc(block_size);
+ if (plaintext_buf == NULL)
+ return status = aesni_error_memory_allocation(err_details);
+
+ memcpy(plaintext_buf, src, src_size);
+
+ if (aesni_is_error(status = aesni_fill_with_padding(
+ AESNI_PADDING_PKCS7,
+ (char*) plaintext_buf + src_size,
+ padding_size,
+ err_details)))
+ goto FREE_PLAINTEXT_BUF;
+
+ if (aesni_is_error(status = aesni_box_encrypt_buffer_block(
+ box, plaintext_buf, dest, err_details)))
+ goto FREE_PLAINTEXT_BUF;
+
+FREE_PLAINTEXT_BUF:
+ free(plaintext_buf);
+
+ return status;
+}
+
+static AesNI_StatusCode aesni_box_encrypt_buffer_partial_block(
+ AesNI_Box* box,
+ const void* src,
+ size_t src_size,
+ void* dest,
+ AesNI_ErrorDetails* err_details)
+{
+ AesNI_StatusCode status = AESNI_SUCCESS;
+
+ if (src_size == 0)
+ return status;
+
+ size_t block_size;
+
+ if (aesni_is_error(status = box->algorithm->get_block_size(
+ &block_size, err_details)))
+ return status;
+
+ void* plaintext_buf = malloc(block_size);
+ if (plaintext_buf == NULL)
+ return status = aesni_error_memory_allocation(err_details);
+
+ memset(plaintext_buf, 0x00, block_size);
+ memcpy(plaintext_buf, src, src_size);
+
+ void* ciphertext_buf = malloc(block_size);
+ if (ciphertext_buf == NULL)
+ {
+ status = aesni_error_memory_allocation(err_details);
+ goto FREE_PLAINTEXT_BUF;
+ }
+
+ if (aesni_is_error(status = aesni_box_encrypt_buffer_block(
+ box, plaintext_buf, ciphertext_buf, err_details)))
+ goto FREE_CIPHERTEXT_BUF;
+
+ memcpy(dest, ciphertext_buf, src_size);
+
+FREE_CIPHERTEXT_BUF:
+ free(ciphertext_buf);
+
+FREE_PLAINTEXT_BUF:
+ free(plaintext_buf);
+
+ return status;
+}
+
AesNI_StatusCode aesni_box_encrypt_buffer(
AesNI_Box* box,
const void* src,
@@ -320,7 +407,7 @@ AesNI_StatusCode aesni_box_encrypt_buffer(
if (dest == NULL)
return AESNI_SUCCESS;
- if (src == NULL)
+ if (src == NULL && src_size != 0)
return aesni_error_null_argument(err_details, "src");
size_t block_size;
@@ -337,48 +424,11 @@ AesNI_StatusCode aesni_box_encrypt_buffer(
return status;
if (padding_size == 0)
- {
- const size_t partial_block_size = src_size % block_size;
-
- if (partial_block_size != 0)
- {
- AesNI_BoxBlock plaintext;
-
- if (aesni_is_error(status = box->algorithm->load_partial_block(
- &plaintext, src, partial_block_size, err_details)))
- return status;
-
- AesNI_BoxBlock ciphertext;
-
- if (aesni_is_error(status = aesni_box_encrypt_block(
- box, &plaintext, &ciphertext, err_details)))
- return status;
-
- if (aesni_is_error(status = box->algorithm->store_partial_block(
- dest, &ciphertext, partial_block_size, err_details)))
- return status;
- }
- }
+ return aesni_box_encrypt_buffer_partial_block(
+ box, src, src_size % block_size, dest, err_details);
else
- {
- AesNI_BoxBlock plaintext;
-
- if (aesni_is_error(status = box->algorithm->load_block_with_padding(
- &plaintext, src, src_size % block_size, err_details)))
- return status;
-
- AesNI_BoxBlock ciphertext;
-
- if (aesni_is_error(status = aesni_box_encrypt_block(
- box, &plaintext, &ciphertext, err_details)))
- return status;
-
- if (aesni_is_error(status = box->algorithm->store_block(
- dest, &ciphertext, err_details)))
- return status;
- }
-
- return status;
+ return aesni_box_encrypt_buffer_partial_block_with_padding(
+ box, src, src_size % block_size, dest, padding_size, err_details);
}
static AesNI_StatusCode aesni_box_get_decrypted_buffer_size(
@@ -401,8 +451,8 @@ static AesNI_StatusCode aesni_box_get_decrypted_buffer_size(
&block_size, err_details)))
return status;
- if (src_size % block_size != 0)
- return aesni_error_invalid_plaintext_length(err_details);
+ if (src_size == 0 || src_size % block_size != 0)
+ return aesni_error_missing_padding(err_details);
*dest_size = src_size;
*max_padding_size = block_size;
@@ -449,6 +499,53 @@ static AesNI_StatusCode aesni_box_decrypt_buffer_block(
return status;
}
+static AesNI_StatusCode aesni_box_decrypt_buffer_partial_block(
+ AesNI_Box* box,
+ const void* src,
+ size_t src_size,
+ void* dest,
+ AesNI_ErrorDetails* err_details)
+{
+ AesNI_StatusCode status = AESNI_SUCCESS;
+
+ if (src_size == 0)
+ return status;
+
+ size_t block_size;
+
+ if (aesni_is_error(status = box->algorithm->get_block_size(
+ &block_size, err_details)))
+ return status;
+
+ void* ciphertext_buf = malloc(block_size);
+ if (ciphertext_buf == NULL)
+ return status = aesni_error_memory_allocation(err_details);
+
+ memset(ciphertext_buf, 0x00, block_size);
+ memcpy(ciphertext_buf, src, src_size);
+
+ void* plaintext_buf = malloc(block_size);
+ if (plaintext_buf == NULL)
+ {
+ status = aesni_error_memory_allocation(err_details);
+ goto FREE_CIPHERTEXT_BUF;
+ }
+
+ if (aesni_is_error(status = aesni_box_decrypt_buffer_block(
+ box, ciphertext_buf, plaintext_buf, err_details)))
+ goto FREE_PLAINTEXT_BUF;
+
+ memcpy(dest, plaintext_buf, src_size);
+
+FREE_PLAINTEXT_BUF:
+ free(plaintext_buf);
+
+FREE_CIPHERTEXT_BUF:
+ free(ciphertext_buf);
+
+ return status;
+}
+
AesNI_StatusCode aesni_box_decrypt_buffer(
AesNI_Box* box,
const void* src,
@@ -463,10 +560,10 @@ AesNI_StatusCode aesni_box_decrypt_buffer(
return aesni_error_null_argument(err_details, "dest_size");
AesNI_StatusCode status = AESNI_SUCCESS;
- size_t padding_size = 0;
+ size_t max_padding_size = 0;
if (aesni_is_error(status = aesni_box_get_decrypted_buffer_size(
- box, src_size, dest_size, &padding_size, err_details)))
+ box, src_size, dest_size, &max_padding_size, err_details)))
return status;
if (dest == NULL)
@@ -487,42 +584,24 @@ AesNI_StatusCode aesni_box_decrypt_buffer(
box, src, dest, err_details)))
return status;
- if (padding_size == 0)
+ if (max_padding_size == 0)
{
- const size_t partial_block_size = src_size % block_size;
-
- if (partial_block_size != 0)
- {
- AesNI_BoxBlock ciphertext;
-
- if (aesni_is_error(status = box->algorithm->load_partial_block(
- &ciphertext, src, partial_block_size, err_details)))
- return status;
-
- AesNI_BoxBlock plaintext;
-
- if (aesni_is_error(status = aesni_box_decrypt_block(
- box, &ciphertext, &plaintext, err_details)))
- return status;
-
- if (aesni_is_error(status = box->algorithm->store_partial_block(
- dest, &plaintext, partial_block_size, err_details)))
- return status;
- }
+ return aesni_box_decrypt_buffer_partial_block(
+ box, src, src_size % block_size, dest, err_details);
}
else
{
- padding_size = ((unsigned char*) dest)[-1];
-
- if (padding_size > block_size)
- return aesni_error_invalid_pkcs7_padding(err_details);
-
- for (size_t i = 1; i < padding_size; ++i)
- if (((unsigned char*) dest)[-1 - i] != padding_size)
- return aesni_error_invalid_pkcs7_padding(err_details);
+ size_t padding_size;
+
+ if (aesni_is_error(status = aesni_extract_padding_size(
+ AESNI_PADDING_PKCS7,
+ (char*) dest - block_size,
+ block_size,
+ &padding_size,
+ err_details)))
+ return status;
*dest_size -= padding_size;
+ return status;
}
-
- return status;
}
diff --git a/src/box_aes.c b/src/box_aes.c
index 49c5326..470e39b 100644
--- a/src/box_aes.c
+++ b/src/box_aes.c
@@ -92,18 +92,6 @@ static AesNI_StatusCode aesni_box_store_block_aes(
return AESNI_SUCCESS;
}
-static AesNI_StatusCode aesni_box_store_partial_block_aes(
- void* dest,
- const AesNI_BoxBlock* src,
- size_t src_size,
- AesNI_ErrorDetails* err_details)
-{
- __declspec(align(16)) unsigned char buf[16];
- aesni_store_block128(buf, src->aes_block);
- memcpy(dest, buf, src_size);
- return AESNI_SUCCESS;
-}
-
static AesNI_StatusCode aesni_box_load_block_aes(
AesNI_BoxBlock* dest,
const void* src,
@@ -113,32 +101,6 @@ static AesNI_StatusCode aesni_box_load_block_aes(
return AESNI_SUCCESS;
}
-static AesNI_StatusCode aesni_box_load_partial_block_aes(
- AesNI_BoxBlock* dest,
- const void* src,
- size_t src_size,
- AesNI_ErrorDetails* err_details)
-{
- __declspec(align(16)) unsigned char buf[16];
- memset(buf, 0x00, 16);
- memcpy(buf, src, src_size);
- dest->aes_block = aesni_load_block128_aligned(buf);
- return AESNI_SUCCESS;
-}
-
-static AesNI_StatusCode aesni_box_load_block_with_padding_aes(
- AesNI_BoxBlock* dest,
- const void* src,
- size_t src_size,
- AesNI_ErrorDetails* err_details)
-{
- __declspec(align(16)) unsigned char padding[16];
- memset(padding + src_size, 16 - src_size, 16 - src_size);
- memcpy(padding, src, src_size);
- dest->aes_block = aesni_load_block128_aligned(padding);
- return AESNI_SUCCESS;
-}
-
static AesNI_StatusCode aesni_box_encrypt_block_aes128(
const AesNI_BoxBlock* input,
const AesNI_BoxEncryptionParams* params,
@@ -220,10 +182,7 @@ AesNI_BoxAlgorithmInterface aesni_box_algorithm_aes128 =
&aesni_box_next_counter_aes,
&aesni_box_get_block_size_aes,
&aesni_box_store_block_aes,
- &aesni_box_store_partial_block_aes,
&aesni_box_load_block_aes,
- &aesni_box_load_partial_block_aes,
- &aesni_box_load_block_with_padding_aes,
};
AesNI_BoxAlgorithmInterface aesni_box_algorithm_aes192 =
@@ -235,10 +194,7 @@ AesNI_BoxAlgorithmInterface aesni_box_algorithm_aes192 =
&aesni_box_next_counter_aes,
&aesni_box_get_block_size_aes,
&aesni_box_store_block_aes,
- &aesni_box_store_partial_block_aes,
&aesni_box_load_block_aes,
- &aesni_box_load_partial_block_aes,
- &aesni_box_load_block_with_padding_aes,
};
AesNI_BoxAlgorithmInterface aesni_box_algorithm_aes256 =
@@ -250,8 +206,5 @@ AesNI_BoxAlgorithmInterface aesni_box_algorithm_aes256 =
&aesni_box_next_counter_aes,
&aesni_box_get_block_size_aes,
&aesni_box_store_block_aes,
- &aesni_box_store_partial_block_aes,
&aesni_box_load_block_aes,
- &aesni_box_load_partial_block_aes,
- &aesni_box_load_block_with_padding_aes,
};
diff --git a/src/error.c b/src/error.c
index fd9136a..10550f3 100644
--- a/src/error.c
+++ b/src/error.c
@@ -26,7 +26,8 @@ static const char* aesni_strerror_messages[] =
"Couldn't parse",
"Invalid PKCS7 padding (wrong key?)",
"Not implemented",
- "Invalid plaintext length",
+ "Missing padding",
+ "Couldn't allocate memory",
};
const char* aesni_strerror(AesNI_StatusCode ec)
@@ -105,6 +106,7 @@ static AesNI_ErrorFormatter err_formatters[] =
&aesni_format_error_strerror,
&aesni_format_not_implemented_error,
&aesni_format_error_strerror,
+ &aesni_format_error_strerror,
};
size_t aesni_format_error(
@@ -204,8 +206,14 @@ AesNI_StatusCode aesni_error_not_implemented(
return status;
}
-AesNI_StatusCode aesni_error_invalid_plaintext_length(
+AesNI_StatusCode aesni_error_missing_padding(
+ AesNI_ErrorDetails* err_details)
+{
+ return aesni_make_error(err_details, AESNI_MISSING_PADDING_ERROR);
+}
+
+AesNI_StatusCode aesni_error_memory_allocation(
AesNI_ErrorDetails* err_details)
{
- return aesni_make_error(err_details, AESNI_INVALID_PLAINTEXT_LENGTH_ERROR);
+ return aesni_make_error(err_details, AESNI_MEMORY_ALLOCATION_ERROR);
}
diff --git a/src/padding.c b/src/padding.c
new file mode 100644
index 0000000..08cafb1
--- /dev/null
+++ b/src/padding.c
@@ -0,0 +1,87 @@
+/**
+ * \file
+ * \author Egor Tensin <Egor.Tensin@gmail.com>
+ * \date 2015
+ * \copyright This file is licensed under the terms of the MIT License.
+ * See LICENSE.txt for details.
+ */
+
+#include <aesni/all.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+static AesNI_StatusCode aesni_extract_padding_size_pkcs7(
+ const void* src,
+ size_t src_size,
+ size_t* padding_size,
+ AesNI_ErrorDetails* err_details)
+{
+ const unsigned char* cursor = (const unsigned char*) src + src_size - 1;
+ *padding_size = *cursor;
+
+ for (size_t i = 1; i < *padding_size; ++i)
+ if (cursor[0 - i] != *padding_size)
+ return aesni_error_invalid_pkcs7_padding(err_details);
+
+ return AESNI_SUCCESS;
+}
+
+AesNI_StatusCode aesni_extract_padding_size(
+ AesNI_PaddingMethod method,
+ const void* src,
+ size_t src_size,
+ size_t* padding_size,
+ AesNI_ErrorDetails* err_details)
+{
+ assert(src);
+ assert(padding_size);
+
+ if (src == NULL)
+ return aesni_error_null_argument(err_details, "src");
+ if (padding_size == NULL)
+ return aesni_error_null_argument(err_details, "padding_size");
+
+ switch (method)
+ {
+ case AESNI_PADDING_PKCS7:
+ return aesni_extract_padding_size_pkcs7(
+ src, src_size, padding_size, err_details);
+
+ default:
+ return aesni_error_not_implemented(
+ err_details, "unsupported padding method");
+ }
+}
+
+static AesNI_StatusCode aesni_fill_with_padding_pkcs7(
+ void* dest,
+ size_t padding_size,
+ AesNI_ErrorDetails* err_details)
+{
+ memset(dest, padding_size, padding_size);
+ return AESNI_SUCCESS;
+}
+
+AesNI_StatusCode aesni_fill_with_padding(
+ AesNI_PaddingMethod method,
+ void* dest,
+ size_t padding_size,
+ AesNI_ErrorDetails* err_details)
+{
+ assert(dest);
+
+ if (dest == NULL)
+ return aesni_error_null_argument(err_details, "dest");
+
+ switch (method)
+ {
+ case AESNI_PADDING_PKCS7:
+ return aesni_fill_with_padding_pkcs7(
+ dest, padding_size, err_details);
+
+ default:
+ return aesni_error_not_implemented(
+ err_details, "unsupported padding method");
+ }
+}