mbedtls: add digest shim layer for MbedTLS

Implement digest shim layer on top of MbedTLS crypto library.
Introduce <alg>_MBEDTLS kconfig for MbedTLS crypto implementations.

Signed-off-by: Raymond Mao <raymond.mao@linaro.org>

1 files changed, 99 insertions, 0 deletions

diff --git a/lib/mbedtls/sha1.c b/lib/mbedtls/sha1.c
new file mode 100644
index 00000000000..2aee5037795
--- /dev/null
+++ b/lib/mbedtls/sha1.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Hash shim layer on MbedTLS Crypto library
+ *
+ * Copyright (c) 2024 Linaro Limited
+ * Author: Raymond Mao <raymond.mao@linaro.org>
+ */
+#ifndef USE_HOSTCC
+#include <cyclic.h>
+#endif /* USE_HOSTCC */
+#include <string.h>
+#include <u-boot/sha1.h>
+
+const u8 sha1_der_prefix[SHA1_DER_LEN] = {
+	0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e,
+	0x03, 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14
+};
+
+void sha1_starts(sha1_context *ctx)
+{
+	mbedtls_sha1_init(ctx);
+	mbedtls_sha1_starts(ctx);
+}
+
+void sha1_update(sha1_context *ctx, const unsigned char *input,
+		 unsigned int length)
+{
+	mbedtls_sha1_update(ctx, input, length);
+}
+
+void sha1_finish(sha1_context *ctx, unsigned char output[SHA1_SUM_LEN])
+{
+	mbedtls_sha1_finish(ctx, output);
+	mbedtls_sha1_free(ctx);
+}
+
+void sha1_csum_wd(const unsigned char *input, unsigned int ilen,
+		  unsigned char *output, unsigned int chunk_sz)
+{
+	sha1_context ctx;
+
+	sha1_starts(&ctx);
+
+	if (IS_ENABLED(CONFIG_HW_WATCHDOG) || IS_ENABLED(CONFIG_WATCHDOG)) {
+		const unsigned char *curr = input;
+		const unsigned char *end = input + ilen;
+		int chunk;
+
+		while (curr < end) {
+			chunk = end - curr;
+			if (chunk > chunk_sz)
+				chunk = chunk_sz;
+			sha1_update(&ctx, curr, chunk);
+			curr += chunk;
+			schedule();
+		}
+	} else {
+		sha1_update(&ctx, input, ilen);
+	}
+
+	sha1_finish(&ctx, output);
+}
+
+void sha1_hmac(const unsigned char *key, int keylen,
+	       const unsigned char *input, unsigned int ilen,
+	       unsigned char *output)
+{
+	int i;
+	sha1_context ctx;
+	unsigned char k_ipad[K_PAD_LEN];
+	unsigned char k_opad[K_PAD_LEN];
+	unsigned char tmpbuf[20];
+
+	if (keylen > K_PAD_LEN)
+		return;
+
+	memset(k_ipad, K_IPAD_VAL, sizeof(k_ipad));
+	memset(k_opad, K_OPAD_VAL, sizeof(k_opad));
+
+	for (i = 0; i < keylen; i++) {
+		k_ipad[i] ^= key[i];
+		k_opad[i] ^= key[i];
+	}
+
+	sha1_starts(&ctx);
+	sha1_update(&ctx, k_ipad, sizeof(k_ipad));
+	sha1_update(&ctx, input, ilen);
+	sha1_finish(&ctx, tmpbuf);
+
+	sha1_starts(&ctx);
+	sha1_update(&ctx, k_opad, sizeof(k_opad));
+	sha1_update(&ctx, tmpbuf, sizeof(tmpbuf));
+	sha1_finish(&ctx, output);
+
+	memset(k_ipad, 0, sizeof(k_ipad));
+	memset(k_opad, 0, sizeof(k_opad));
+	memset(tmpbuf, 0, sizeof(tmpbuf));
+	memset(&ctx, 0, sizeof(sha1_context));
+}