Switch error code to more appropriate value

Since we are internal rather than user-facing,
PSA_ERROR_CORRUPTION_DETECTED makes more sense than
PSA_ERROR_BUFFER_TOO_SMALL. Whilst it really is a buffer that is too
small, this error code is intended to indicate that a user-supplied
buffer is too small, not an internal one.

Signed-off-by: David Horstmann <david.horstmann@arm.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 33068af..09180b3 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -8446,7 +8446,7 @@
                                    uint8_t *input_copy, size_t input_copy_len)
 {
     if (input_len > input_copy_len) {
-        return PSA_ERROR_BUFFER_TOO_SMALL;
+        return PSA_ERROR_CORRUPTION_DETECTED;
     }
 
     memcpy(input_copy, input, input_len);
@@ -8458,7 +8458,7 @@
                                     uint8_t *output, size_t output_len)
 {
     if (output_len < output_copy_len) {
-        return PSA_ERROR_BUFFER_TOO_SMALL;
+        return PSA_ERROR_CORRUPTION_DETECTED;
     }
     memcpy(output, output_copy, output_copy_len);
     return PSA_SUCCESS;
diff --git a/library/psa_crypto_core.h b/library/psa_crypto_core.h
index 78550f8..00d9e9e 100644
--- a/library/psa_crypto_core.h
+++ b/library/psa_crypto_core.h
@@ -862,8 +862,8 @@
  * \param[out] input_copy_len   Length of the local copy buffer.
  * \return                      #PSA_SUCCESS, if the buffer was successfully
  *                              copied.
- * \return                      #PSA_ERROR_BUFFER_TOO_SMALL, if the local copy
- *                              is too small to hold contents of the
+ * \return                      #PSA_ERROR_CORRUPTION_DETECTED, if the local
+ *                              copy is too small to hold contents of the
  *                              input buffer.
  */
 psa_status_t psa_crypto_copy_input(const uint8_t *input, size_t input_len,
@@ -877,7 +877,7 @@
  * \param[out] output_len       Length of the user-supplied output buffer.
  * \return                      #PSA_SUCCESS, if the buffer was successfully
  *                              copied.
- * \return                      #PSA_ERROR_BUFFER_TOO_SMALL, if the
+ * \return                      #PSA_ERROR_CORRUPTION_DETECTED, if the
  *                              user-supplied output buffer is too small to
  *                              hold the contents of the local buffer.
  */