Limit keys to 65528 bits
65528 bits is more than any reasonable key until we start supporting
post-quantum cryptography.
This limit is chosen to allow bit-sizes to be stored in 16 bits, with
65535 left to indicate an invalid value. It's a whole number of bytes,
which facilitates some calculations, in particular allowing a key of
exactly PSA_CRYPTO_MAX_STORAGE_SIZE to be created but not one bit
more.
As a resource usage limit, this is arguably too large, but that's out
of scope of the current commit.
Test that key import, generation and derivation reject overly large
sizes.
diff --git a/tests/suites/test_suite_psa_crypto.data b/tests/suites/test_suite_psa_crypto.data
index 53f8422..a0e7f7a 100644
--- a/tests/suites/test_suite_psa_crypto.data
+++ b/tests/suites/test_suite_psa_crypto.data
@@ -314,6 +314,14 @@
depends_on:MBEDTLS_AES_C
import:"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa":PSA_KEY_TYPE_AES:128:PSA_ERROR_INVALID_ARGUMENT
+PSA import large key: raw, 65528 bits (ok)
+depends_on:HAVE_RAM_AVAILABLE_128k
+import_large_key:PSA_KEY_TYPE_RAW_DATA:8191:PSA_SUCCESS
+
+PSA import large key: raw, 65536 bits (not supported)
+depends_on:HAVE_RAM_AVAILABLE_128k
+import_large_key:PSA_KEY_TYPE_RAW_DATA:8192:PSA_ERROR_NOT_SUPPORTED
+
PSA import RSA key pair: maximum size exceeded
depends_on:MBEDTLS_PK_PARSE_C:MBEDTLS_RSA_C
import_rsa_made_up:PSA_VENDOR_RSA_MAX_KEY_BITS+8:1:PSA_ERROR_NOT_SUPPORTED
@@ -2075,6 +2083,17 @@
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C:!PSA_PRE_1_0_KEY_DERIVATION
derive_key_export:PSA_ALG_TLS12_PRF(PSA_ALG_SHA_256):"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"f0f1f2f3f4f5f6f7f8f9":1:41
+# This test assumes that PSA_MAX_KEY_BITS (currently 65536-8 bits = 8191 bytes
+# and not expected to be raised any time soon) is less than the maximum
+# output from HKDF-SHA512 (255*64 = 16320 bytes).
+PSA key derivation: largest possible key
+depends_on:MBEDTLS_MD_C:MBEDTLS_SHA512_C:!PSA_PRE_1_0_KEY_DERIVATION
+derive_large_key:PSA_ALG_HKDF(PSA_ALG_SHA_512):"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"f0f1f2f3f4f5f6f7f8f9":PSA_MAX_KEY_BITS:PSA_SUCCESS
+
+PSA key derivation: key too large
+depends_on:MBEDTLS_MD_C:MBEDTLS_SHA512_C:!PSA_PRE_1_0_KEY_DERIVATION
+derive_large_key:PSA_ALG_HKDF(PSA_ALG_SHA_512):"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":"000102030405060708090a0b0c":"f0f1f2f3f4f5f6f7f8f9":PSA_MAX_KEY_BITS + 1:PSA_ERROR_NOT_SUPPORTED
+
PSA key agreement setup: ECDH + HKDF-SHA-256: good
depends_on:MBEDTLS_PK_PARSE_C:MBEDTLS_ECP_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED:MBEDTLS_ECDH_C:MBEDTLS_MD_C:MBEDTLS_SHA256_C
key_agreement_setup:PSA_ALG_KEY_AGREEMENT(PSA_ALG_ECDH, PSA_ALG_HKDF(PSA_ALG_SHA_256)):PSA_KEY_TYPE_ECC_KEY_PAIR(PSA_ECC_CURVE_SECP256R1):"c88f01f510d9ac3f70a292daa2316de544e9aab8afe84049c62a9c57862d1433":"04d12dfb5289c8d4f81208b70270398c342296970a0bccb74c736fc7554494bf6356fbf3ca366cc23e8157854c13c58d6aac23f046ada30f8353e74f33039872ab":PSA_SUCCESS
@@ -2188,6 +2207,13 @@
PSA generate key: raw data, 8 bits
generate_key:PSA_KEY_TYPE_RAW_DATA:8:PSA_KEY_USAGE_EXPORT:0:PSA_SUCCESS
+PSA generate key: raw data, 65528 bits (ok)
+depends_on:HAVE_RAM_AVAILABLE_128k
+generate_key:PSA_KEY_TYPE_RAW_DATA:8:PSA_KEY_USAGE_EXPORT:0:PSA_SUCCESS
+
+PSA generate key: raw data, 65536 bits (not supported)
+generate_key:PSA_KEY_TYPE_RAW_DATA:65536:PSA_KEY_USAGE_EXPORT:0:PSA_ERROR_NOT_SUPPORTED
+
PSA generate key: AES, 128 bits, CTR
depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_CTR
generate_key:PSA_KEY_TYPE_AES:128:PSA_KEY_USAGE_EXPORT | PSA_KEY_USAGE_ENCRYPT | PSA_KEY_USAGE_DECRYPT:PSA_ALG_CTR:PSA_SUCCESS