/* * PSA AEAD entry points */ /* * Copyright The Mbed TLS Contributors * SPDX-License-Identifier: Apache-2.0 * * Licensed under the Apache License, Version 2.0 (the "License"); you may * not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "common.h" #if defined(MBEDTLS_PSA_CRYPTO_C) #include "psa_crypto_aead.h" #include "psa_crypto_core.h" #include "psa_crypto_cipher.h" #include #include "mbedtls/platform.h" #include "mbedtls/ccm.h" #include "mbedtls/chachapoly.h" #include "mbedtls/cipher.h" #include "mbedtls/gcm.h" #include "mbedtls/error.h" static psa_status_t psa_aead_setup( mbedtls_psa_aead_operation_t *operation, const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; size_t key_bits; const mbedtls_cipher_info_t *cipher_info; mbedtls_cipher_id_t cipher_id; (void) key_buffer_size; key_bits = attributes->core.bits; cipher_info = mbedtls_cipher_info_from_psa(alg, attributes->core.type, key_bits, &cipher_id); if (cipher_info == NULL) { return PSA_ERROR_NOT_SUPPORTED; } switch (PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg, 0)) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_CCM) case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CCM, 0): operation->alg = PSA_ALG_CCM; /* CCM allows the following tag lengths: 4, 6, 8, 10, 12, 14, 16. * The call to mbedtls_ccm_encrypt_and_tag or * mbedtls_ccm_auth_decrypt will validate the tag length. */ if (PSA_BLOCK_CIPHER_BLOCK_LENGTH(attributes->core.type) != 16) { return PSA_ERROR_INVALID_ARGUMENT; } mbedtls_ccm_init(&operation->ctx.ccm); status = mbedtls_to_psa_error( mbedtls_ccm_setkey(&operation->ctx.ccm, cipher_id, key_buffer, (unsigned int) key_bits)); if (status != PSA_SUCCESS) { return status; } break; #endif /* MBEDTLS_PSA_BUILTIN_ALG_CCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_GCM) case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 0): operation->alg = PSA_ALG_GCM; /* GCM allows the following tag lengths: 4, 8, 12, 13, 14, 15, 16. * The call to mbedtls_gcm_crypt_and_tag or * mbedtls_gcm_auth_decrypt will validate the tag length. */ if (PSA_BLOCK_CIPHER_BLOCK_LENGTH(attributes->core.type) != 16) { return PSA_ERROR_INVALID_ARGUMENT; } mbedtls_gcm_init(&operation->ctx.gcm); status = mbedtls_to_psa_error( mbedtls_gcm_setkey(&operation->ctx.gcm, cipher_id, key_buffer, (unsigned int) key_bits)); if (status != PSA_SUCCESS) { return status; } break; #endif /* MBEDTLS_PSA_BUILTIN_ALG_GCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305) case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CHACHA20_POLY1305, 0): operation->alg = PSA_ALG_CHACHA20_POLY1305; /* We only support the default tag length. */ if (alg != PSA_ALG_CHACHA20_POLY1305) { return PSA_ERROR_NOT_SUPPORTED; } mbedtls_chachapoly_init(&operation->ctx.chachapoly); status = mbedtls_to_psa_error( mbedtls_chachapoly_setkey(&operation->ctx.chachapoly, key_buffer)); if (status != PSA_SUCCESS) { return status; } break; #endif /* MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305 */ default: (void) status; (void) key_buffer; return PSA_ERROR_NOT_SUPPORTED; } operation->key_type = psa_get_key_type(attributes); operation->tag_length = PSA_ALG_AEAD_GET_TAG_LENGTH(alg); return PSA_SUCCESS; } psa_status_t mbedtls_psa_aead_encrypt( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg, const uint8_t *nonce, size_t nonce_length, const uint8_t *additional_data, size_t additional_data_length, const uint8_t *plaintext, size_t plaintext_length, uint8_t *ciphertext, size_t ciphertext_size, size_t *ciphertext_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; mbedtls_psa_aead_operation_t operation = MBEDTLS_PSA_AEAD_OPERATION_INIT; uint8_t *tag; status = psa_aead_setup(&operation, attributes, key_buffer, key_buffer_size, alg); if (status != PSA_SUCCESS) { goto exit; } /* For all currently supported modes, the tag is at the end of the * ciphertext. */ if (ciphertext_size < (plaintext_length + operation.tag_length)) { status = PSA_ERROR_BUFFER_TOO_SMALL; goto exit; } tag = ciphertext + plaintext_length; #if defined(MBEDTLS_PSA_BUILTIN_ALG_CCM) if (operation.alg == PSA_ALG_CCM) { status = mbedtls_to_psa_error( mbedtls_ccm_encrypt_and_tag(&operation.ctx.ccm, plaintext_length, nonce, nonce_length, additional_data, additional_data_length, plaintext, ciphertext, tag, operation.tag_length)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_CCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_GCM) if (operation.alg == PSA_ALG_GCM) { status = mbedtls_to_psa_error( mbedtls_gcm_crypt_and_tag(&operation.ctx.gcm, MBEDTLS_GCM_ENCRYPT, plaintext_length, nonce, nonce_length, additional_data, additional_data_length, plaintext, ciphertext, operation.tag_length, tag)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_GCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305) if (operation.alg == PSA_ALG_CHACHA20_POLY1305) { if (operation.tag_length != 16) { status = PSA_ERROR_NOT_SUPPORTED; goto exit; } status = mbedtls_to_psa_error( mbedtls_chachapoly_encrypt_and_tag(&operation.ctx.chachapoly, plaintext_length, nonce, additional_data, additional_data_length, plaintext, ciphertext, tag)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305 */ { (void) tag; (void) nonce; (void) nonce_length; (void) additional_data; (void) additional_data_length; (void) plaintext; return PSA_ERROR_NOT_SUPPORTED; } if (status == PSA_SUCCESS) { *ciphertext_length = plaintext_length + operation.tag_length; } exit: mbedtls_psa_aead_abort(&operation); return status; } /* Locate the tag in a ciphertext buffer containing the encrypted data * followed by the tag. Return the length of the part preceding the tag in * *plaintext_length. This is the size of the plaintext in modes where * the encrypted data has the same size as the plaintext, such as * CCM and GCM. */ static psa_status_t psa_aead_unpadded_locate_tag(size_t tag_length, const uint8_t *ciphertext, size_t ciphertext_length, size_t plaintext_size, const uint8_t **p_tag) { size_t payload_length; if (tag_length > ciphertext_length) { return PSA_ERROR_INVALID_ARGUMENT; } payload_length = ciphertext_length - tag_length; if (payload_length > plaintext_size) { return PSA_ERROR_BUFFER_TOO_SMALL; } *p_tag = ciphertext + payload_length; return PSA_SUCCESS; } psa_status_t mbedtls_psa_aead_decrypt( const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg, const uint8_t *nonce, size_t nonce_length, const uint8_t *additional_data, size_t additional_data_length, const uint8_t *ciphertext, size_t ciphertext_length, uint8_t *plaintext, size_t plaintext_size, size_t *plaintext_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; mbedtls_psa_aead_operation_t operation = MBEDTLS_PSA_AEAD_OPERATION_INIT; const uint8_t *tag = NULL; status = psa_aead_setup(&operation, attributes, key_buffer, key_buffer_size, alg); if (status != PSA_SUCCESS) { goto exit; } status = psa_aead_unpadded_locate_tag(operation.tag_length, ciphertext, ciphertext_length, plaintext_size, &tag); if (status != PSA_SUCCESS) { goto exit; } #if defined(MBEDTLS_PSA_BUILTIN_ALG_CCM) if (operation.alg == PSA_ALG_CCM) { status = mbedtls_to_psa_error( mbedtls_ccm_auth_decrypt(&operation.ctx.ccm, ciphertext_length - operation.tag_length, nonce, nonce_length, additional_data, additional_data_length, ciphertext, plaintext, tag, operation.tag_length)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_CCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_GCM) if (operation.alg == PSA_ALG_GCM) { status = mbedtls_to_psa_error( mbedtls_gcm_auth_decrypt(&operation.ctx.gcm, ciphertext_length - operation.tag_length, nonce, nonce_length, additional_data, additional_data_length, tag, operation.tag_length, ciphertext, plaintext)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_GCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305) if (operation.alg == PSA_ALG_CHACHA20_POLY1305) { if (operation.tag_length != 16) { status = PSA_ERROR_NOT_SUPPORTED; goto exit; } status = mbedtls_to_psa_error( mbedtls_chachapoly_auth_decrypt(&operation.ctx.chachapoly, ciphertext_length - operation.tag_length, nonce, additional_data, additional_data_length, tag, ciphertext, plaintext)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305 */ { (void) nonce; (void) nonce_length; (void) additional_data; (void) additional_data_length; (void) plaintext; return PSA_ERROR_NOT_SUPPORTED; } if (status == PSA_SUCCESS) { *plaintext_length = ciphertext_length - operation.tag_length; } exit: mbedtls_psa_aead_abort(&operation); if (status == PSA_SUCCESS) { *plaintext_length = ciphertext_length - operation.tag_length; } return status; } /* Set the key and algorithm for a multipart authenticated encryption * operation. */ psa_status_t mbedtls_psa_aead_encrypt_setup( mbedtls_psa_aead_operation_t *operation, const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; status = psa_aead_setup(operation, attributes, key_buffer, key_buffer_size, alg); if (status == PSA_SUCCESS) { operation->is_encrypt = 1; } return status; } /* Set the key and algorithm for a multipart authenticated decryption * operation. */ psa_status_t mbedtls_psa_aead_decrypt_setup( mbedtls_psa_aead_operation_t *operation, const psa_key_attributes_t *attributes, const uint8_t *key_buffer, size_t key_buffer_size, psa_algorithm_t alg) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; status = psa_aead_setup(operation, attributes, key_buffer, key_buffer_size, alg); if (status == PSA_SUCCESS) { operation->is_encrypt = 0; } return status; } /* Set a nonce for the multipart AEAD operation*/ psa_status_t mbedtls_psa_aead_set_nonce( mbedtls_psa_aead_operation_t *operation, const uint8_t *nonce, size_t nonce_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; #if defined(MBEDTLS_PSA_BUILTIN_ALG_GCM) if (operation->alg == PSA_ALG_GCM) { status = mbedtls_to_psa_error( mbedtls_gcm_starts(&operation->ctx.gcm, operation->is_encrypt ? MBEDTLS_GCM_ENCRYPT : MBEDTLS_GCM_DECRYPT, nonce, nonce_length)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_GCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_CCM) if (operation->alg == PSA_ALG_CCM) { status = mbedtls_to_psa_error( mbedtls_ccm_starts(&operation->ctx.ccm, operation->is_encrypt ? MBEDTLS_CCM_ENCRYPT : MBEDTLS_CCM_DECRYPT, nonce, nonce_length)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_CCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305) if (operation->alg == PSA_ALG_CHACHA20_POLY1305) { /* Note - ChaChaPoly allows an 8 byte nonce, but we would have to * allocate a buffer in the operation, copy the nonce to it and pad * it, so for now check the nonce is 12 bytes, as * mbedtls_chachapoly_starts() assumes it can read 12 bytes from the * passed in buffer. */ if (nonce_length != 12) { return PSA_ERROR_INVALID_ARGUMENT; } status = mbedtls_to_psa_error( mbedtls_chachapoly_starts(&operation->ctx.chachapoly, nonce, operation->is_encrypt ? MBEDTLS_CHACHAPOLY_ENCRYPT : MBEDTLS_CHACHAPOLY_DECRYPT)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305 */ { (void) operation; (void) nonce; (void) nonce_length; return PSA_ERROR_NOT_SUPPORTED; } return status; } /* Declare the lengths of the message and additional data for AEAD. */ psa_status_t mbedtls_psa_aead_set_lengths( mbedtls_psa_aead_operation_t *operation, size_t ad_length, size_t plaintext_length) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_CCM) if (operation->alg == PSA_ALG_CCM) { return mbedtls_to_psa_error( mbedtls_ccm_set_lengths(&operation->ctx.ccm, ad_length, plaintext_length, operation->tag_length)); } #else /* MBEDTLS_PSA_BUILTIN_ALG_CCM */ (void) operation; (void) ad_length; (void) plaintext_length; #endif /* MBEDTLS_PSA_BUILTIN_ALG_CCM */ return PSA_SUCCESS; } /* Pass additional data to an active multipart AEAD operation. */ psa_status_t mbedtls_psa_aead_update_ad( mbedtls_psa_aead_operation_t *operation, const uint8_t *input, size_t input_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; #if defined(MBEDTLS_PSA_BUILTIN_ALG_GCM) if (operation->alg == PSA_ALG_GCM) { status = mbedtls_to_psa_error( mbedtls_gcm_update_ad(&operation->ctx.gcm, input, input_length)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_GCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_CCM) if (operation->alg == PSA_ALG_CCM) { status = mbedtls_to_psa_error( mbedtls_ccm_update_ad(&operation->ctx.ccm, input, input_length)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_CCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305) if (operation->alg == PSA_ALG_CHACHA20_POLY1305) { status = mbedtls_to_psa_error( mbedtls_chachapoly_update_aad(&operation->ctx.chachapoly, input, input_length)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305 */ { (void) operation; (void) input; (void) input_length; return PSA_ERROR_NOT_SUPPORTED; } return status; } /* Encrypt or decrypt a message fragment in an active multipart AEAD * operation.*/ psa_status_t mbedtls_psa_aead_update( mbedtls_psa_aead_operation_t *operation, const uint8_t *input, size_t input_length, uint8_t *output, size_t output_size, size_t *output_length) { size_t update_output_length; psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; update_output_length = input_length; #if defined(MBEDTLS_PSA_BUILTIN_ALG_GCM) if (operation->alg == PSA_ALG_GCM) { status = mbedtls_to_psa_error( mbedtls_gcm_update(&operation->ctx.gcm, input, input_length, output, output_size, &update_output_length)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_GCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_CCM) if (operation->alg == PSA_ALG_CCM) { if (output_size < input_length) { return PSA_ERROR_BUFFER_TOO_SMALL; } status = mbedtls_to_psa_error( mbedtls_ccm_update(&operation->ctx.ccm, input, input_length, output, output_size, &update_output_length)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_CCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305) if (operation->alg == PSA_ALG_CHACHA20_POLY1305) { if (output_size < input_length) { return PSA_ERROR_BUFFER_TOO_SMALL; } status = mbedtls_to_psa_error( mbedtls_chachapoly_update(&operation->ctx.chachapoly, input_length, input, output)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305 */ { (void) operation; (void) input; (void) output; (void) output_size; return PSA_ERROR_NOT_SUPPORTED; } if (status == PSA_SUCCESS) { *output_length = update_output_length; } return status; } /* Finish encrypting a message in a multipart AEAD operation. */ psa_status_t mbedtls_psa_aead_finish( mbedtls_psa_aead_operation_t *operation, uint8_t *ciphertext, size_t ciphertext_size, size_t *ciphertext_length, uint8_t *tag, size_t tag_size, size_t *tag_length) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; size_t finish_output_size = 0; if (tag_size < operation->tag_length) { return PSA_ERROR_BUFFER_TOO_SMALL; } #if defined(MBEDTLS_PSA_BUILTIN_ALG_GCM) if (operation->alg == PSA_ALG_GCM) { status = mbedtls_to_psa_error( mbedtls_gcm_finish(&operation->ctx.gcm, ciphertext, ciphertext_size, ciphertext_length, tag, operation->tag_length)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_GCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_CCM) if (operation->alg == PSA_ALG_CCM) { /* tag must be big enough to store a tag of size passed into set * lengths. */ if (tag_size < operation->tag_length) { return PSA_ERROR_BUFFER_TOO_SMALL; } status = mbedtls_to_psa_error( mbedtls_ccm_finish(&operation->ctx.ccm, tag, operation->tag_length)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_CCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305) if (operation->alg == PSA_ALG_CHACHA20_POLY1305) { /* Belt and braces. Although the above tag_size check should have * already done this, if we later start supporting smaller tag sizes * for chachapoly, then passing a tag buffer smaller than 16 into here * could cause a buffer overflow, so better safe than sorry. */ if (tag_size < 16) { return PSA_ERROR_BUFFER_TOO_SMALL; } status = mbedtls_to_psa_error( mbedtls_chachapoly_finish(&operation->ctx.chachapoly, tag)); } else #endif /* MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305 */ { (void) ciphertext; (void) ciphertext_size; (void) ciphertext_length; (void) tag; (void) tag_size; (void) tag_length; return PSA_ERROR_NOT_SUPPORTED; } if (status == PSA_SUCCESS) { /* This will be zero for all supported algorithms currently, but left * here for future support. */ *ciphertext_length = finish_output_size; *tag_length = operation->tag_length; } return status; } /* Abort an AEAD operation */ psa_status_t mbedtls_psa_aead_abort( mbedtls_psa_aead_operation_t *operation) { switch (operation->alg) { #if defined(MBEDTLS_PSA_BUILTIN_ALG_CCM) case PSA_ALG_CCM: mbedtls_ccm_free(&operation->ctx.ccm); break; #endif /* MBEDTLS_PSA_BUILTIN_ALG_CCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_GCM) case PSA_ALG_GCM: mbedtls_gcm_free(&operation->ctx.gcm); break; #endif /* MBEDTLS_PSA_BUILTIN_ALG_GCM */ #if defined(MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305) case PSA_ALG_CHACHA20_POLY1305: mbedtls_chachapoly_free(&operation->ctx.chachapoly); break; #endif /* MBEDTLS_PSA_BUILTIN_ALG_CHACHA20_POLY1305 */ } operation->is_encrypt = 0; return PSA_SUCCESS; } #endif /* MBEDTLS_PSA_CRYPTO_C */