commit f90e3019dd35da3e9979a337d30c7a14d1be6be7
author Fredrik Strupe <fredrik.strupe@silabs.com> Mon Sep 28 16:11:33 2020 +0200
committer Fredrik Strupe <fredrik.strupe@silabs.com> Wed Sep 30 12:26:58 2020 +0200
tree 7fe7b409da7f2bcb5eaa42e0dba5a451b1d067f9
parent 7829748cd49f64c4bfdf534b452268aeab828498

Use PSA_ERROR_INVALID_ARGUMENT for invalid cipher input sizes

... as opposed to PSA_ERROR_BAD_STATE.

The spec on psa_cipher_finish() states that PSA_ERROR_INVALID_ARGUMENT
should be returned when:

"The total input size passed to this operation is not valid for this
particular algorithm. For example, the algorithm is a based on block
cipher and requires a whole number of blocks, but the total input size
is not a multiple of the block size."

Currently, there is a distinction between encryption and decryption
on whether INVALID_ARGUMENT or BAD_STATE is returned, but this is not
a part of the spec.

This fix ensures that PSA_ERROR_INVALID_ARGUMENT is returned
consistently on invalid cipher input sizes.

Signed-off-by: Fredrik Strupe <fredrik.strupe@silabs.com>

library/psa_crypto.c

diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 931e2e9..08b89d0 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -199,7 +199,7 @@
         case MBEDTLS_ERR_CIPHER_INVALID_PADDING:
             return( PSA_ERROR_INVALID_PADDING );
         case MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED:
-            return( PSA_ERROR_BAD_STATE );
+            return( PSA_ERROR_INVALID_ARGUMENT );
         case MBEDTLS_ERR_CIPHER_AUTH_FAILED:
             return( PSA_ERROR_INVALID_SIGNATURE );
         case MBEDTLS_ERR_CIPHER_INVALID_CONTEXT:
@@ -4473,8 +4473,7 @@
     if( operation->ctx.cipher.unprocessed_len != 0 )
     {
         if( operation->alg == PSA_ALG_ECB_NO_PADDING ||
-            ( operation->alg == PSA_ALG_CBC_NO_PADDING &&
-              operation->ctx.cipher.operation == MBEDTLS_ENCRYPT ) )
+            operation->alg == PSA_ALG_CBC_NO_PADDING )
         {
             status = PSA_ERROR_INVALID_ARGUMENT;
             goto exit;

tests/suites/test_suite_psa_crypto.data

diff --git a/tests/suites/test_suite_psa_crypto.data b/tests/suites/test_suite_psa_crypto.data
index 2c6924a..8bdc64f 100644
--- a/tests/suites/test_suite_psa_crypto.data
+++ b/tests/suites/test_suite_psa_crypto.data
@@ -1240,7 +1240,7 @@
 
 PSA symmetric decrypt: AES-CBC-PKCS#7, input too short (15 bytes)
 depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_CBC
-cipher_decrypt:PSA_ALG_CBC_PKCS7:PSA_KEY_TYPE_AES:"2b7e151628aed2a6abf7158809cf4f3c":"2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a":"6bc1bee22e409f96e93d7e11739317":"49e4e66c89a86b67758df89db9ad6955":PSA_ERROR_BAD_STATE
+cipher_decrypt:PSA_ALG_CBC_PKCS7:PSA_KEY_TYPE_AES:"2b7e151628aed2a6abf7158809cf4f3c":"2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a":"6bc1bee22e409f96e93d7e11739317":"49e4e66c89a86b67758df89db9ad6955":PSA_ERROR_INVALID_ARGUMENT
 
 PSA symmetric decrypt: AES-CTR, 16 bytes, good
 depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_CBC:MBEDTLS_CIPHER_MODE_CTR
@@ -1252,7 +1252,7 @@
 
 PSA symmetric decrypt: AES-CBC-nopad, input too short (5 bytes)
 depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_CBC
-cipher_decrypt:PSA_ALG_CBC_NO_PADDING:PSA_KEY_TYPE_AES:"2b7e151628aed2a6abf7158809cf4f3c":"2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a":"6bc1bee223":"6bc1bee223":PSA_ERROR_BAD_STATE
+cipher_decrypt:PSA_ALG_CBC_NO_PADDING:PSA_KEY_TYPE_AES:"2b7e151628aed2a6abf7158809cf4f3c":"2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a2a":"6bc1bee223":"6bc1bee223":PSA_ERROR_INVALID_ARGUMENT
 
 PSA symmetric decrypt: DES-CBC-nopad, 8 bytes, good
 depends_on:MBEDTLS_DES_C:MBEDTLS_CIPHER_MODE_CBC