Extend scope of ERR_RSA_UNSUPPORTED_OPERATION error code
diff --git a/include/mbedtls/rsa.h b/include/mbedtls/rsa.h
index 2ffb7ab..562395f 100644
--- a/include/mbedtls/rsa.h
+++ b/include/mbedtls/rsa.h
@@ -48,7 +48,8 @@
#define MBEDTLS_ERR_RSA_VERIFY_FAILED -0x4380 /**< The PKCS#1 verification failed. */
#define MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE -0x4400 /**< The output buffer for decryption is not large enough. */
#define MBEDTLS_ERR_RSA_RNG_FAILED -0x4480 /**< The random generator failed to generate non-zeros. */
-#define MBEDTLS_ERR_RSA_UNSUPPORTED_OPERATION -0x4500 /**< The implementation doesn't provide the requested operation. */
+#define MBEDTLS_ERR_RSA_UNSUPPORTED_OPERATION -0x4500 /**< The implementation doesn't offer the requested operation,
+ e.g. because of security violations or lack of functionality */
/*
* RSA constants