Hi Raymond,
Le 17/12/2024 à 15:54, Raymond Mao a écrit :
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Hi Philippe,
On Tue, 17 Dec 2024 at 03:32, Philippe Reynes
<philippe.rey...@softathome.com> wrote:
Adds the support of the hmac based on sha256.
This implementation is based on rfc2104.
Signed-off-by: Philippe Reynes <philippe.rey...@softathome.com>
---
include/u-boot/sha256.h | 4 ++++
lib/mbedtls/sha256.c | 15 +++++++++++++
lib/sha256.c | 50
+++++++++++++++++++++++++++++++++++++++++
3 files changed, 69 insertions(+)
diff --git a/include/u-boot/sha256.h b/include/u-boot/sha256.h
index 44a9b528b48..99cf78e204c 100644
--- a/include/u-boot/sha256.h
+++ b/include/u-boot/sha256.h
@@ -45,4 +45,8 @@ void sha256_finish(sha256_context * ctx, uint8_t
digest[SHA256_SUM_LEN]);
void sha256_csum_wd(const unsigned char *input, unsigned int ilen,
unsigned char *output, unsigned int chunk_sz);
+int sha256_hmac(const unsigned char *key, int keylen,
+ const unsigned char *input, unsigned int ilen,
+ unsigned char *output);
+
#endif /* _SHA256_H */
diff --git a/lib/mbedtls/sha256.c b/lib/mbedtls/sha256.c
index 2128e598834..7d456a82017 100644
--- a/lib/mbedtls/sha256.c
+++ b/lib/mbedtls/sha256.c
@@ -10,6 +10,8 @@
#endif /* USE_HOSTCC */
#include <u-boot/sha256.h>
+#include <mbedtls/md.h>
+
const u8 sha256_der_prefix[SHA256_DER_LEN] = {
0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86,
0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05,
@@ -33,3 +35,16 @@ void sha256_finish(sha256_context *ctx, uint8_t
digest[SHA256_SUM_LEN])
mbedtls_sha256_finish(ctx, digest);
mbedtls_sha256_free(ctx);
}
+
+int sha256_hmac(const unsigned char *key, int keylen,
+ const unsigned char *input, unsigned int ilen,
+ unsigned char *output)
+{
+ const mbedtls_md_info_t *md;
+
+ md = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256);
+ if (!md)
+ return MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE;
+
+ return mbedtls_md_hmac(md, key, keylen, input, ilen, output);
+}
diff --git a/lib/sha256.c b/lib/sha256.c
index 827bd9a872b..a18aec3928b 100644
--- a/lib/sha256.c
+++ b/lib/sha256.c
@@ -264,3 +264,53 @@ void sha256_finish(sha256_context * ctx,
uint8_t digest[32])
PUT_UINT32_BE(ctx->state[6], digest, 24);
PUT_UINT32_BE(ctx->state[7], digest, 28);
}
+
+int sha256_hmac(const unsigned char *key, int keylen,
+ const unsigned char *input, unsigned int ilen,
+ unsigned char *output)
+{
+ int i;
+ sha256_context ctx;
+ unsigned char keybuf[64];
+ unsigned char k_ipad[64];
+ unsigned char k_opad[64];
+ unsigned char tmpbuf[32];
+ int keybuf_len;
+
+ if (keylen > 64) {
+ sha256_starts(&ctx);
+ sha256_update(&ctx, key, keylen);
+ sha256_finish(&ctx, keybuf);
+
+ keybuf_len = 32;
+ } else {
+ memcpy(keybuf, key, keylen);
+ keybuf_len = keylen;
All looks fine but keys shorter than 64 bytes are copied as is,
without explicit zero-padding, this might be an issue.
You're right, I have fixed that in v6.
+ }
+
+ memset(k_ipad, 0x36, 64);
+ memset(k_opad, 0x5C, 64);
+
+ for (i = 0; i < keybuf_len; i++) {
+ k_ipad[i] ^= keybuf[i];
+ k_opad[i] ^= keybuf[i];
+ }
+
+ sha256_starts(&ctx);
+ sha256_update(&ctx, k_ipad, sizeof(k_ipad));
+ sha256_update(&ctx, input, ilen);
+ sha256_finish(&ctx, tmpbuf);
+
+ sha256_starts(&ctx);
+ sha256_update(&ctx, k_opad, sizeof(k_opad));
+ sha256_update(&ctx, tmpbuf, sizeof(tmpbuf));
+ sha256_finish(&ctx, output);
+
+ memset(k_ipad, 0, sizeof(k_ipad));
+ memset(k_opad, 0, sizeof(k_opad));
+ memset(tmpbuf, 0, sizeof(tmpbuf));
+ memset(keybuf, 0, sizeof(keybuf));
+ memset(&ctx, 0, sizeof(sha256_context));
+
+ return 0;
+}
--
2.25.1
Regards,
Raymond
Regards,
Philippe
