HKDF: be more robust if we reach the maximum ouptut length
In psa_generator_hkdf_read, return BAD_STATE if we're trying to
construct more output than the algorithm allows. This can't happen
through the API due to the capacity limit, but it could potentially
happen in an internal call.
Also add a test case that verifies that we can set up HKDF with its
maximum capacity and read up to the maximum capacity.
diff --git a/tests/suites/test_suite_psa_crypto.data b/tests/suites/test_suite_psa_crypto.data
index 43b9647..8ffaa87 100644
--- a/tests/suites/test_suite_psa_crypto.data
+++ b/tests/suites/test_suite_psa_crypto.data
@@ -853,6 +853,14 @@
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_output:PSA_ALG_HKDF(PSA_ALG_SHA_256):"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"f0f1f2f3f4f5f6f7f8f9":42:"3cb25f25faacd57a90434f64d0362f2a2d2d0a90cf1a5a4c5db02d56ecc4c5bf34007208d5b887185865ff":"ff"
+PSA key derivation: HKDF SHA-256, read maximum capacity minus 1
+depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
+derive_full:PSA_ALG_HKDF(PSA_ALG_SHA_256):"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"f0f1f2f3f4f5f6f7f8f9":255 * 32 - 1
+
+PSA key derivation: HKDF SHA-256, read maximum capacity
+depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
+derive_full:PSA_ALG_HKDF(PSA_ALG_SHA_256):"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"f0f1f2f3f4f5f6f7f8f9":255 * 32
+
PSA key derivation: HKDF SHA-256, exercise HMAC-SHA-256
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_key_exercise:PSA_ALG_HKDF(PSA_ALG_SHA_256):"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"f0f1f2f3f4f5f6f7f8f9":PSA_KEY_TYPE_HMAC:256:PSA_KEY_USAGE_SIGN:PSA_ALG_HMAC(PSA_ALG_SHA_256)