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- #include "sdk_common.h"
- #if NRF_MODULE_ENABLED(NRF_CRYPTO)
- #include "nrf_crypto_error.h"
- #include "sdk_config.h"
- #include "nrf_crypto_types.h"
- ret_code_t padding_pkcs7_add(uint8_t * p_padding_buff,
- uint8_t * p_message_buff,
- uint8_t msg_ending_len)
- {
- uint8_t padding_count;
- if ((p_padding_buff == NULL) || (p_message_buff == NULL))
- {
- return NRF_ERROR_CRYPTO_INPUT_NULL;
- }
- if (msg_ending_len >= NRF_CRYPTO_AES_BLOCK_SIZE)
- {
- return NRF_ERROR_CRYPTO_INVALID_PARAM;
- }
-
-
- memcpy(p_padding_buff, p_message_buff, msg_ending_len);
-
- padding_count = NRF_CRYPTO_AES_BLOCK_SIZE - msg_ending_len;
- p_padding_buff += msg_ending_len;
- for (size_t i = 0; i < padding_count; i++)
- {
- p_padding_buff[i] = padding_count;
- }
- return NRF_SUCCESS;
- }
- ret_code_t padding_pkcs7_remove(uint8_t * p_padded_message,
- size_t * p_message_len)
- {
- if (p_padded_message == NULL)
- {
- return NRF_ERROR_CRYPTO_INPUT_NULL;
- }
- if (p_message_len == NULL)
- {
- return NRF_ERROR_CRYPTO_OUTPUT_NULL;
- }
-
- if ((*p_message_len == 0) || ((*p_message_len & 0x0F) != 0))
- {
- return NRF_ERROR_CRYPTO_INVALID_PARAM;
- }
- size_t padded_bytes = p_padded_message[*p_message_len - 1];
- if ((padded_bytes == 0) || (padded_bytes > NRF_CRYPTO_AES_BLOCK_SIZE))
- {
- return NRF_ERROR_CRYPTO_AES_INVALID_PADDING;
- }
-
- for (size_t i = 2; i < padded_bytes; i++)
- {
- if (p_padded_message[*p_message_len - i] != padded_bytes)
- {
- return NRF_ERROR_CRYPTO_AES_INVALID_PADDING;
- }
- }
- *p_message_len -= padded_bytes;
- return NRF_SUCCESS;
- }
- #endif
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