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authorHeiko Schocher <hs@denx.de>2014-03-03 12:19:26 +0100
committerTom Rini <trini@ti.com>2014-03-21 16:39:34 -0400
commit646257d1f4004855d486024527a4784bf57c4c4d (patch)
treea16c9627f823bcb68606b621fe9ff2fe493f90ed /lib/rsa/rsa-verify.c
parent2842c1c24269a05142802d25520e7cb9035e456c (diff)
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rsa: add sha256-rsa2048 algorithm
based on patch from andreas@oetken.name: http://patchwork.ozlabs.org/patch/294318/ commit message: I currently need support for rsa-sha256 signatures in u-boot and found out that the code for signatures is not very generic. Thus adding of different hash-algorithms for rsa-signatures is not easy to do without copy-pasting the rsa-code. I attached a patch for how I think it could be better and included support for rsa-sha256. This is a fast first shot. aditionally work: - removed checkpatch warnings - removed compiler warnings - rebased against current head Signed-off-by: Heiko Schocher <hs@denx.de> Cc: andreas@oetken.name Cc: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'lib/rsa/rsa-verify.c')
-rw-r--r--lib/rsa/rsa-verify.c83
1 files changed, 24 insertions, 59 deletions
diff --git a/lib/rsa/rsa-verify.c b/lib/rsa/rsa-verify.c
index 02cc4e3..b3573a8 100644
--- a/lib/rsa/rsa-verify.c
+++ b/lib/rsa/rsa-verify.c
@@ -8,23 +8,11 @@
#include <fdtdec.h>
#include <rsa.h>
#include <sha1.h>
+#include <sha256.h>
#include <asm/byteorder.h>
#include <asm/errno.h>
#include <asm/unaligned.h>
-/**
- * struct rsa_public_key - holder for a public key
- *
- * An RSA public key consists of a modulus (typically called N), the inverse
- * and R^2, where R is 2^(# key bits).
- */
-struct rsa_public_key {
- uint len; /* Length of modulus[] in number of uint32_t */
- uint32_t n0inv; /* -1 / modulus[0] mod 2^32 */
- uint32_t *modulus; /* modulus as little endian array */
- uint32_t *rr; /* R^2 as little endian array */
-};
-
#define UINT64_MULT32(v, multby) (((uint64_t)(v)) * ((uint32_t)(multby)))
#define RSA2048_BYTES (2048 / 8)
@@ -36,39 +24,6 @@ struct rsa_public_key {
/* This is the maximum signature length that we support, in bits */
#define RSA_MAX_SIG_BITS 2048
-static const uint8_t padding_sha1_rsa2048[RSA2048_BYTES - SHA1_SUM_LEN] = {
- 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
- 0xff, 0xff, 0xff, 0xff, 0x00, 0x30, 0x21, 0x30,
- 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a,
- 0x05, 0x00, 0x04, 0x14
-};
-
/**
* subtract_modulus() - subtract modulus from the given value
*
@@ -209,13 +164,14 @@ static int pow_mod(const struct rsa_public_key *key, uint32_t *inout)
}
static int rsa_verify_key(const struct rsa_public_key *key, const uint8_t *sig,
- const uint32_t sig_len, const uint8_t *hash)
+ const uint32_t sig_len, const uint8_t *hash,
+ struct checksum_algo *algo)
{
const uint8_t *padding;
int pad_len;
int ret;
- if (!key || !sig || !hash)
+ if (!key || !sig || !hash || !algo)
return -EIO;
if (sig_len != (key->len * sizeof(uint32_t))) {
@@ -223,6 +179,8 @@ static int rsa_verify_key(const struct rsa_public_key *key, const uint8_t *sig,
return -EINVAL;
}
+ debug("Checksum algorithm: %s", algo->name);
+
/* Sanity check for stack size */
if (sig_len > RSA_MAX_SIG_BITS / 8) {
debug("Signature length %u exceeds maximum %d\n", sig_len,
@@ -238,9 +196,8 @@ static int rsa_verify_key(const struct rsa_public_key *key, const uint8_t *sig,
if (ret)
return ret;
- /* Determine padding to use depending on the signature type. */
- padding = padding_sha1_rsa2048;
- pad_len = RSA2048_BYTES - SHA1_SUM_LEN;
+ padding = algo->rsa_padding;
+ pad_len = RSA2048_BYTES - algo->checksum_len;
/* Check pkcs1.5 padding bytes. */
if (memcmp(buf, padding, pad_len)) {
@@ -309,7 +266,7 @@ static int rsa_verify_with_keynode(struct image_sign_info *info,
}
debug("key length %d\n", key.len);
- ret = rsa_verify_key(&key, sig, sig_len, hash);
+ ret = rsa_verify_key(&key, sig, sig_len, hash, info->algo->checksum);
if (ret) {
printf("%s: RSA failed to verify: %d\n", __func__, ret);
return ret;
@@ -323,12 +280,22 @@ int rsa_verify(struct image_sign_info *info,
uint8_t *sig, uint sig_len)
{
const void *blob = info->fdt_blob;
- uint8_t hash[SHA1_SUM_LEN];
+ /* Reserve memory for maximum checksum-length */
+ uint8_t hash[RSA2048_BYTES];
int ndepth, noffset;
int sig_node, node;
char name[100];
- sha1_context ctx;
- int ret, i;
+ int ret;
+
+ /*
+ * Verify that the checksum-length does not exceed the
+ * rsa-signature-length
+ */
+ if (info->algo->checksum->checksum_len > RSA2048_BYTES) {
+ debug("%s: invlaid checksum-algorithm %s for RSA2048\n",
+ __func__, info->algo->checksum->name);
+ return -EINVAL;
+ }
sig_node = fdt_subnode_offset(blob, 0, FIT_SIG_NODENAME);
if (sig_node < 0) {
@@ -336,10 +303,8 @@ int rsa_verify(struct image_sign_info *info,
return -ENOENT;
}
- sha1_starts(&ctx);
- for (i = 0; i < region_count; i++)
- sha1_update(&ctx, region[i].data, region[i].size);
- sha1_finish(&ctx, hash);
+ /* Calculate checksum with checksum-algorithm */
+ info->algo->checksum->calculate(region, region_count, hash);
/* See if we must use a particular key */
if (info->required_keynode != -1) {