Commit adad6eaa authored by Niels Möller's avatar Niels Möller

Changes to pkcs1_signature_prefix interface.

parent 05898658
2012-06-03 Niels Möller <nisse@lysator.liu.se>
* testsuite/pkcs1-test.c (test_main): Include leading zero in
expected result.
* pkcs1.c (pkcs1_signature_prefix): Return pointer to where the
digest should be written. Let the size input be the key size in
octets, rather then key size - 1.
* pkcs1-rsa-*.c: Updated for above.
* rsa-*-sign.c, rsa-*-verify.c: Pass key->size, not key->size - 1.
2012-05-18 Niels Möller <nisse@lysator.liu.se>
* pkcs1-encrypt.c (pkcs1_encrypt): New file and function.
......
......@@ -62,18 +62,20 @@ md5_prefix[] =
};
int
pkcs1_rsa_md5_encode(mpz_t m, unsigned size, struct md5_ctx *hash)
pkcs1_rsa_md5_encode(mpz_t m, unsigned key_size, struct md5_ctx *hash)
{
uint8_t *p;
TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
TMP_ALLOC(em, size);
TMP_ALLOC(em, key_size);
if (pkcs1_signature_prefix(size, em,
p = pkcs1_signature_prefix(key_size, em,
sizeof(md5_prefix),
md5_prefix,
MD5_DIGEST_SIZE))
MD5_DIGEST_SIZE);
if (p)
{
md5_digest(hash, MD5_DIGEST_SIZE, em + size - MD5_DIGEST_SIZE);
nettle_mpz_set_str_256_u(m, size, em);
md5_digest(hash, MD5_DIGEST_SIZE, p);
nettle_mpz_set_str_256_u(m, key_size, em);
return 1;
}
else
......@@ -81,18 +83,20 @@ pkcs1_rsa_md5_encode(mpz_t m, unsigned size, struct md5_ctx *hash)
}
int
pkcs1_rsa_md5_encode_digest(mpz_t m, unsigned size, const uint8_t *digest)
pkcs1_rsa_md5_encode_digest(mpz_t m, unsigned key_size, const uint8_t *digest)
{
uint8_t *p;
TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
TMP_ALLOC(em, size);
TMP_ALLOC(em, key_size);
if (pkcs1_signature_prefix(size, em,
p = pkcs1_signature_prefix(key_size, em,
sizeof(md5_prefix),
md5_prefix,
MD5_DIGEST_SIZE))
MD5_DIGEST_SIZE);
if (p)
{
memcpy(em + size - MD5_DIGEST_SIZE, digest, MD5_DIGEST_SIZE);
nettle_mpz_set_str_256_u(m, size, em);
memcpy(p, digest, MD5_DIGEST_SIZE);
nettle_mpz_set_str_256_u(m, key_size, em);
return 1;
}
else
......
......@@ -62,18 +62,20 @@ sha1_prefix[] =
};
int
pkcs1_rsa_sha1_encode(mpz_t m, unsigned size, struct sha1_ctx *hash)
pkcs1_rsa_sha1_encode(mpz_t m, unsigned key_size, struct sha1_ctx *hash)
{
uint8_t *p;
TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
TMP_ALLOC(em, size);
TMP_ALLOC(em, key_size);
if (pkcs1_signature_prefix(size, em,
p = pkcs1_signature_prefix(key_size, em,
sizeof(sha1_prefix),
sha1_prefix,
SHA1_DIGEST_SIZE))
SHA1_DIGEST_SIZE);
if (p)
{
sha1_digest(hash, SHA1_DIGEST_SIZE, em + size - SHA1_DIGEST_SIZE);
nettle_mpz_set_str_256_u(m, size, em);
sha1_digest(hash, SHA1_DIGEST_SIZE, p);
nettle_mpz_set_str_256_u(m, key_size, em);
return 1;
}
else
......@@ -81,18 +83,20 @@ pkcs1_rsa_sha1_encode(mpz_t m, unsigned size, struct sha1_ctx *hash)
}
int
pkcs1_rsa_sha1_encode_digest(mpz_t m, unsigned size, const uint8_t *digest)
pkcs1_rsa_sha1_encode_digest(mpz_t m, unsigned key_size, const uint8_t *digest)
{
uint8_t *p;
TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
TMP_ALLOC(em, size);
TMP_ALLOC(em, key_size);
if (pkcs1_signature_prefix(size, em,
p = pkcs1_signature_prefix(key_size, em,
sizeof(sha1_prefix),
sha1_prefix,
SHA1_DIGEST_SIZE))
SHA1_DIGEST_SIZE);
if (p)
{
memcpy(em + size - SHA1_DIGEST_SIZE, digest, SHA1_DIGEST_SIZE);
nettle_mpz_set_str_256_u(m, size, em);
memcpy(p, digest, SHA1_DIGEST_SIZE);
nettle_mpz_set_str_256_u(m, key_size, em);
return 1;
}
else
......
......@@ -60,18 +60,20 @@ sha256_prefix[] =
};
int
pkcs1_rsa_sha256_encode(mpz_t m, unsigned size, struct sha256_ctx *hash)
pkcs1_rsa_sha256_encode(mpz_t m, unsigned key_size, struct sha256_ctx *hash)
{
uint8_t *p;
TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
TMP_ALLOC(em, size);
TMP_ALLOC(em, key_size);
if (pkcs1_signature_prefix(size, em,
p = pkcs1_signature_prefix(key_size, em,
sizeof(sha256_prefix),
sha256_prefix,
SHA256_DIGEST_SIZE))
SHA256_DIGEST_SIZE);
if (p)
{
sha256_digest(hash, SHA256_DIGEST_SIZE, em + size - SHA256_DIGEST_SIZE);
nettle_mpz_set_str_256_u(m, size, em);
sha256_digest(hash, SHA256_DIGEST_SIZE, p);
nettle_mpz_set_str_256_u(m, key_size, em);
return 1;
}
else
......@@ -79,18 +81,20 @@ pkcs1_rsa_sha256_encode(mpz_t m, unsigned size, struct sha256_ctx *hash)
}
int
pkcs1_rsa_sha256_encode_digest(mpz_t m, unsigned size, const uint8_t *digest)
pkcs1_rsa_sha256_encode_digest(mpz_t m, unsigned key_size, const uint8_t *digest)
{
uint8_t *p;
TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
TMP_ALLOC(em, size);
TMP_ALLOC(em, key_size);
if (pkcs1_signature_prefix(size, em,
p = pkcs1_signature_prefix(key_size, em,
sizeof(sha256_prefix),
sha256_prefix,
SHA256_DIGEST_SIZE))
SHA256_DIGEST_SIZE);
if (p)
{
memcpy(em + size - SHA256_DIGEST_SIZE, digest, SHA256_DIGEST_SIZE);
nettle_mpz_set_str_256_u(m, size, em);
memcpy(p, digest, SHA256_DIGEST_SIZE);
nettle_mpz_set_str_256_u(m, key_size, em);
return 1;
}
else
......
......@@ -60,19 +60,20 @@ sha512_prefix[] =
};
int
pkcs1_rsa_sha512_encode(mpz_t m, unsigned size, struct sha512_ctx *hash)
pkcs1_rsa_sha512_encode(mpz_t m, unsigned key_size, struct sha512_ctx *hash)
{
uint8_t *p;
TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
TMP_ALLOC(em, size);
TMP_ALLOC(em, key_size);
if (pkcs1_signature_prefix(size, em,
p = pkcs1_signature_prefix(key_size, em,
sizeof(sha512_prefix),
sha512_prefix,
SHA512_DIGEST_SIZE))
SHA512_DIGEST_SIZE);
if (p)
{
sha512_digest(hash, SHA512_DIGEST_SIZE,
em + size - SHA512_DIGEST_SIZE);
nettle_mpz_set_str_256_u(m, size, em);
sha512_digest(hash, SHA512_DIGEST_SIZE, p);
nettle_mpz_set_str_256_u(m, key_size, em);
return 1;
}
else
......@@ -80,18 +81,20 @@ pkcs1_rsa_sha512_encode(mpz_t m, unsigned size, struct sha512_ctx *hash)
}
int
pkcs1_rsa_sha512_encode_digest(mpz_t m, unsigned size, const uint8_t *digest)
pkcs1_rsa_sha512_encode_digest(mpz_t m, unsigned key_size, const uint8_t *digest)
{
uint8_t *p;
TMP_DECL(em, uint8_t, NETTLE_MAX_BIGNUM_SIZE);
TMP_ALLOC(em, size);
TMP_ALLOC(em, key_size);
if (pkcs1_signature_prefix(size, em,
p = pkcs1_signature_prefix(key_size, em,
sizeof(sha512_prefix),
sha512_prefix,
SHA512_DIGEST_SIZE))
SHA512_DIGEST_SIZE);
if (p)
{
memcpy(em + size - SHA512_DIGEST_SIZE, digest, SHA512_DIGEST_SIZE);
nettle_mpz_set_str_256_u(m, size, em);
memcpy(p, digest, SHA512_DIGEST_SIZE);
nettle_mpz_set_str_256_u(m, key_size, em);
return 1;
}
else
......
......@@ -34,13 +34,13 @@
/* Formats the PKCS#1 padding, of the form
*
* 0x01 0xff ... 0xff 0x00 id ...digest...
* 0x00 0x01 0xff ... 0xff 0x00 id ...digest...
*
* where the 0xff ... 0xff part consists of at least 8 octets. The
* total size should be one less than the octet size of n.
* total size equals the octet size of n.
*/
int
pkcs1_signature_prefix(unsigned size,
uint8_t *
pkcs1_signature_prefix(unsigned key_size,
uint8_t *buffer,
unsigned id_size,
const uint8_t *id,
......@@ -48,17 +48,18 @@ pkcs1_signature_prefix(unsigned size,
{
unsigned j;
if (size < 10 + id_size + digest_size)
return 0;
if (key_size < 11 + id_size + digest_size)
return NULL;
j = size - digest_size - id_size;
j = key_size - digest_size - id_size;
memcpy (buffer + j, id, id_size);
buffer[0] = 1;
buffer[--j] = 0;
buffer[0] = 0;
buffer[1] = 1;
buffer[j-1] = 0;
assert(j >= 9);
memset(buffer + 1, 0xff, j - 1);
assert(j >= 11);
memset(buffer + 2, 0xff, j - 3);
return 1;
return buffer + j + id_size;
}
......@@ -51,8 +51,8 @@ struct sha1_ctx;
struct sha256_ctx;
struct sha512_ctx;
int
pkcs1_signature_prefix(unsigned size,
uint8_t *
pkcs1_signature_prefix(unsigned key_size,
uint8_t *buffer,
unsigned id_size,
const uint8_t *id,
......
......@@ -39,9 +39,7 @@ rsa_md5_sign(const struct rsa_private_key *key,
struct md5_ctx *hash,
mpz_t s)
{
assert(key->size > 0);
if (pkcs1_rsa_md5_encode(s, key->size - 1, hash))
if (pkcs1_rsa_md5_encode(s, key->size, hash))
{
rsa_compute_root(key, s, s);
return 1;
......@@ -58,9 +56,7 @@ rsa_md5_sign_digest(const struct rsa_private_key *key,
const uint8_t *digest,
mpz_t s)
{
assert(key->size > 0);
if (pkcs1_rsa_md5_encode_digest(s, key->size - 1, digest))
if (pkcs1_rsa_md5_encode_digest(s, key->size, digest))
{
rsa_compute_root(key, s, s);
return 1;
......
......@@ -42,10 +42,9 @@ rsa_md5_verify(const struct rsa_public_key *key,
int res;
mpz_t m;
assert(key->size > 0);
mpz_init(m);
res = (pkcs1_rsa_md5_encode(m, key->size - 1, hash)
res = (pkcs1_rsa_md5_encode(m, key->size, hash)
&& _rsa_verify(key, m, s));
mpz_clear(m);
......@@ -61,10 +60,9 @@ rsa_md5_verify_digest(const struct rsa_public_key *key,
int res;
mpz_t m;
assert(key->size > 0);
mpz_init(m);
res = (pkcs1_rsa_md5_encode_digest(m, key->size - 1, digest)
res = (pkcs1_rsa_md5_encode_digest(m, key->size, digest)
&& _rsa_verify(key, m, s));
mpz_clear(m);
......
......@@ -39,9 +39,7 @@ rsa_sha1_sign(const struct rsa_private_key *key,
struct sha1_ctx *hash,
mpz_t s)
{
assert(key->size > 0);
if (pkcs1_rsa_sha1_encode(s, key->size - 1, hash))
if (pkcs1_rsa_sha1_encode(s, key->size, hash))
{
rsa_compute_root(key, s, s);
return 1;
......@@ -58,9 +56,7 @@ rsa_sha1_sign_digest(const struct rsa_private_key *key,
const uint8_t *digest,
mpz_t s)
{
assert(key->size > 0);
if (pkcs1_rsa_sha1_encode_digest(s, key->size - 1, digest))
if (pkcs1_rsa_sha1_encode_digest(s, key->size, digest))
{
rsa_compute_root(key, s, s);
return 1;
......
......@@ -42,10 +42,9 @@ rsa_sha1_verify(const struct rsa_public_key *key,
int res;
mpz_t m;
assert(key->size > 0);
mpz_init(m);
res = (pkcs1_rsa_sha1_encode(m, key->size - 1, hash)
res = (pkcs1_rsa_sha1_encode(m, key->size, hash)
&& _rsa_verify(key, m, s));
mpz_clear(m);
......@@ -61,10 +60,9 @@ rsa_sha1_verify_digest(const struct rsa_public_key *key,
int res;
mpz_t m;
assert(key->size > 0);
mpz_init(m);
res = (pkcs1_rsa_sha1_encode_digest(m, key->size - 1, digest)
res = (pkcs1_rsa_sha1_encode_digest(m, key->size, digest)
&& _rsa_verify(key, m, s));
mpz_clear(m);
......
......@@ -39,9 +39,7 @@ rsa_sha256_sign(const struct rsa_private_key *key,
struct sha256_ctx *hash,
mpz_t s)
{
assert(key->size > 0);
if (pkcs1_rsa_sha256_encode(s, key->size - 1, hash))
if (pkcs1_rsa_sha256_encode(s, key->size, hash))
{
rsa_compute_root(key, s, s);
return 1;
......@@ -58,9 +56,7 @@ rsa_sha256_sign_digest(const struct rsa_private_key *key,
const uint8_t *digest,
mpz_t s)
{
assert(key->size > 0);
if (pkcs1_rsa_sha256_encode_digest(s, key->size - 1, digest))
if (pkcs1_rsa_sha256_encode_digest(s, key->size, digest))
{
rsa_compute_root(key, s, s);
return 1;
......
......@@ -42,10 +42,9 @@ rsa_sha256_verify(const struct rsa_public_key *key,
int res;
mpz_t m;
assert(key->size > 0);
mpz_init(m);
res = (pkcs1_rsa_sha256_encode(m, key->size - 1, hash)
res = (pkcs1_rsa_sha256_encode(m, key->size, hash)
&&_rsa_verify(key, m, s));
mpz_clear(m);
......@@ -61,10 +60,9 @@ rsa_sha256_verify_digest(const struct rsa_public_key *key,
int res;
mpz_t m;
assert(key->size > 0);
mpz_init(m);
res = (pkcs1_rsa_sha256_encode_digest(m, key->size - 1, digest)
res = (pkcs1_rsa_sha256_encode_digest(m, key->size, digest)
&& _rsa_verify(key, m, s));
mpz_clear(m);
......
......@@ -39,9 +39,7 @@ rsa_sha512_sign(const struct rsa_private_key *key,
struct sha512_ctx *hash,
mpz_t s)
{
assert(key->size > 0);
if (pkcs1_rsa_sha512_encode(s, key->size - 1, hash))
if (pkcs1_rsa_sha512_encode(s, key->size, hash))
{
rsa_compute_root(key, s, s);
return 1;
......@@ -58,9 +56,7 @@ rsa_sha512_sign_digest(const struct rsa_private_key *key,
const uint8_t *digest,
mpz_t s)
{
assert(key->size > 0);
if (pkcs1_rsa_sha512_encode_digest(s, key->size - 1, digest))
if (pkcs1_rsa_sha512_encode_digest(s, key->size, digest))
{
rsa_compute_root(key, s, s);
return 1;
......
......@@ -42,10 +42,9 @@ rsa_sha512_verify(const struct rsa_public_key *key,
int res;
mpz_t m;
assert(key->size > 0);
mpz_init(m);
res = (pkcs1_rsa_sha512_encode(m, key->size - 1, hash)
res = (pkcs1_rsa_sha512_encode(m, key->size, hash)
&& _rsa_verify(key, m, s));
mpz_clear(m);
......@@ -61,10 +60,9 @@ rsa_sha512_verify_digest(const struct rsa_public_key *key,
int res;
mpz_t m;
assert(key->size > 0);
mpz_init(m);
res = (pkcs1_rsa_sha512_encode_digest(m, key->size - 1, digest)
res = (pkcs1_rsa_sha512_encode_digest(m, key->size, digest)
&& _rsa_verify(key, m, s));
mpz_clear(m);
......
......@@ -6,7 +6,7 @@ int
test_main(void)
{
uint8_t buffer[16];
uint8_t expected[16] = { 1, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
uint8_t expected[16] = { 0, 1, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0, 'a', 'b', 'c' };
pkcs1_signature_prefix(sizeof(buffer), buffer,
......
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