Adds the support of the hmac based on sha256. This implementation is based on rfc2104.
Signed-off-by: Philippe Reynes philippe.reynes@softathome.com --- include/u-boot/sha256.h | 4 ++++ lib/mbedtls/sha256.c | 15 ++++++++++++ lib/sha256.c | 51 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 70 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..c2e77c854b9 100644 --- a/lib/sha256.c +++ b/lib/sha256.c @@ -264,3 +264,54 @@ 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 { + memset(keybuf, 0, sizeof(keybuf)); + memcpy(keybuf, key, keylen); + keybuf_len = keylen; + } + + 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; +}