[openssl-users] Openssl api for signature verification using digest
Viktor Dukhovni
openssl-users at dukhovni.org
Wed Aug 29 06:00:07 UTC 2018
> On Aug 29, 2018, at 1:05 AM, Linta Maria <lintamaria194 at gmail.com> wrote:
>
> Still its not working.
The code is working correctly. The real problem is that the PEM
format 2048-bit RSA key you posted:
> ----BEGIN PUBLIC KEY-----
> MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAzMjyWZfVfBpmNKmIm9HH
> FnrhDLZaCmQvZz57uJHhBLwLk/UAJ+kLKV9Lox8eKfimzisPFBad/TUfwPUaQmji
> bPKCp+or2EHvPFooOnPWjSd57zPCohDdo0nOLw7iTUOMCvoqvJcdor+t1zBb8MQK
> yNTycuoGlT19lr8msJFtR+ulfKucj/zk5w/jr0SsxysqFsvtEfa62Wu/wSDYIfsq
> lKlRGLTlqJNtQybtTVv2Uu2KFrbe0C8+FBkxgtBS+0MkhzpJ37/02J+mHFx1bsgN
> 09QnQY+T05te+6/mmlsHP3PYRqXqJOLl9AkLd/9kiMhSFshowFehKmls9PYt1xGf
> 5QIDAQAB
> -----END PUBLIC KEY-----
is NOT the key that was used to generate the below signature, or
the signature was subsequently altered.
> Signature={ 0x24,0xb8,0xec,0xb4,0x4f,0x31,0xa6,0x8,0x72,0x61,0xc9,0xd3,0x1c,0xd0,0x9b,0xee,0x26,0x2d,0x3d,0xef,0xff,0x2c,0x5,0x78,0x4,0xd3,0xa3,0xff,0xdc,0x97,0x53,0xe6,0x6e,0x85,0x41,0x1b,0xb2,0x2c,0xed,0xbd,0xa6,0x5d,0x6f,0xac,0xbb,0xd5,0xb8,0xa0,0x9,0x2b,0xf1,0xf5,0xb6,0xce,0xdd,0x70,0x8a,0x1a,0xa1,0x20,0x11,0x2b,0xf0,0x17,0x41,0x83,0x80,0xf6,0x61,0xd4,0x6d,0x53,0x8f,0xf1,0x8c,0x19,0x42,0x93,0x96,0xa9,0xb6,0xf2,0x8f,0x27,0x9c,0x66,0x17,0xc5,0xca,0x3d,0xa9,0x3f,0xc5,0x76,0x5f,0x1b,0x31,0xf2,0xd3,0xe,0x78,0x53,0x97,0xcb,0x9d,0xc4,0xe6,0x41,0x61,0x58,0x44,0x5c,0xf5,0xc4,0x67,0x69,0x8,0xa,0x92,0xd5,0x7e,0x9c,0xb9,0x7e,0x54,0x8b,0x8a,0xb,0xa1,0x9a,0x63,0xbf,0xcc,0xed,0x63,0x2c,0xf8,0x14,0x25,0x6,0xa2,0x2,0x0,0x7,0x2e,0x1c,0xc1,0xeb,0x16,0x89,0xaa,0x69,0xe2,0x75,0x57,0x39,0x71,0x68,0xe,0xf,0xa4,0x7a,0xc5,0x14,0x97,0x88,0x67,0xd1,0x36,0x91,0x3b,0x49,0xe7,0xb4,0xf3,0xcb,0xca,0xf6,0xe9,0xb1,0x22,0xe9,0x85,0x89,0xab,0x2,0x4,0x3c,0x2e,0xbd,0x56,0x3,0x8a,0x8b,0x54,0xc6,0xe6,0xed,0x5b,0x4c,0xa4,0x9e,0x1b,0xaa,0x90,0xc6,0xb,0x27,0x54,0xc0,0x50,0x5f,0x58,0x97,0xc,0x99,0x5c,0x2,0x74,0xfc,0x9f,0x4c,0x78,0x4e,0xc3,0xb4,0x6d,0x14,0xa1,0xdc,0x62,0xc5,0xfe,0x27,0xb8,0x7d,0x98,0x79,0x82,0x50,0x3a,0xbe,0x6f,0x83,0x79,0xd,0x8a,0xb8,0x3e,0xac,0xa,0xeb,0x62,0xd5,0x5e,0x95}
$ od -tx1 < /tmp/sig
0000000 24 b8 ec b4 4f 31 a6 08 72 61 c9 d3 1c d0 9b ee
0000020 26 2d 3d ef ff 2c 05 78 04 d3 a3 ff dc 97 53 e6
0000040 6e 85 41 1b b2 2c ed bd a6 5d 6f ac bb d5 b8 a0
0000060 09 2b f1 f5 b6 ce dd 70 8a 1a a1 20 11 2b f0 17
0000100 41 83 80 f6 61 d4 6d 53 8f f1 8c 19 42 93 96 a9
0000120 b6 f2 8f 27 9c 66 17 c5 ca 3d a9 3f c5 76 5f 1b
0000140 31 f2 d3 0e 78 53 97 cb 9d c4 e6 41 61 58 44 5c
0000160 f5 c4 67 69 08 0a 92 d5 7e 9c b9 7e 54 8b 8a 0b
0000200 a1 9a 63 bf cc ed 63 2c f8 14 25 06 a2 02 00 07
0000220 2e 1c c1 eb 16 89 aa 69 e2 75 57 39 71 68 0e 0f
0000240 a4 7a c5 14 97 88 67 d1 36 91 3b 49 e7 b4 f3 cb
0000260 ca f6 e9 b1 22 e9 85 89 ab 02 04 3c 2e bd 56 03
0000300 8a 8b 54 c6 e6 ed 5b 4c a4 9e 1b aa 90 c6 0b 27
0000320 54 c0 50 5f 58 97 0c 99 5c 02 74 fc 9f 4c 78 4e
0000340 c3 b4 6d 14 a1 dc 62 c5 fe 27 b8 7d 98 79 82 50
0000360 3a be 6f 83 79 0d 8a b8 3e ac 0a eb 62 d5 5e 95
$ openssl rsa -pubin -in /tmp/key
writing RSA key
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAzMjyWZfVfBpmNKmIm9HH
FnrhDLZaCmQvZz57uJHhBLwLk/UAJ+kLKV9Lox8eKfimzisPFBad/TUfwPUaQmji
bPKCp+or2EHvPFooOnPWjSd57zPCohDdo0nOLw7iTUOMCvoqvJcdor+t1zBb8MQK
yNTycuoGlT19lr8msJFtR+ulfKucj/zk5w/jr0SsxysqFsvtEfa62Wu/wSDYIfsq
lKlRGLTlqJNtQybtTVv2Uu2KFrbe0C8+FBkxgtBS+0MkhzpJ37/02J+mHFx1bsgN
09QnQY+T05te+6/mmlsHP3PYRqXqJOLl9AkLd/9kiMhSFshowFehKmls9PYt1xGf
5QIDAQAB
-----END PUBLIC KEY-----
Which match your post, but raw public key encryption of the signature
data does not yield a PKCS1 padded message:
$ openssl rsautl -encrypt -pubin -inkey /tmp/key -raw -in /tmp/sig | od -tx1
0000000 95 ca 3c b7 cf d3 19 3d 1d 4a 29 61 67 59 21 d1
0000020 61 47 9f 09 69 23 cc 05 77 21 e6 5c 12 9b ed 39
0000040 06 7c 23 51 5f e3 3f 48 45 df 41 89 2e d6 92 4a
0000060 bd b2 e8 36 e6 83 2a 1e 71 5e 5b 97 52 f2 bc 18
0000100 63 3b 45 e0 c1 0a ec 48 ae 42 a3 e5 46 dc 80 77
0000120 87 19 a0 29 94 e7 33 2a 77 2b bb 54 39 06 92 ca
0000140 df b2 21 04 98 d7 cb 16 a6 a0 5b ac c3 d8 20 df
0000160 ac 8f 3a 6d b9 20 7c cb 52 5e 7f f8 69 fc 39 7f
0000200 8b db c1 16 4c df ca ba d7 33 5f 8e 21 87 6b ae
0000220 a8 e1 20 1b e5 1f 8c 3f 18 2d b4 c0 0d 66 ec 1e
0000240 f2 7b 78 ab ad 3c 8c da 80 24 25 3d c8 19 ad 48
0000260 b3 21 ca 90 40 ce dd 22 85 6d 8b 6f ed da 77 be
0000300 81 02 d3 d5 5a ec fd 9f 6e 4a 52 f1 18 31 d4 e1
0000320 14 43 17 02 ff 74 f8 ee cf 2c 09 bc 60 d8 65 e3
0000340 3c c2 e1 a9 09 5e 21 42 d2 0f 4f aa d5 75 47 69
0000360 51 f0 87 98 bd 7f 99 83 e1 22 33 56 0b 13 8e 37
0000400
By way of contrast:
$ openssl genrsa -out /tmp/key2.pem 2048 2>/dev/null
$ echo foobar | openssl dgst -sha256 -sign /tmp/key2.pem -out /tmp/sig2
$ openssl rsa -in /tmp/key2.pem -pubout > /tmp/pub2.pem 2>/dev/null
$ openssl rsautl -encrypt -pubin -inkey /tmp/pub2.pem -raw -in /tmp/sig2 | od -vtx1
0000000 00 01 ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0000020 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0000040 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0000060 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0000100 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0000120 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0000140 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0000160 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0000200 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0000220 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0000240 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0000260 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0000300 ff ff ff ff ff ff ff ff ff ff ff ff 00 30 31 30
0000320 0d 06 09 60 86 48 01 65 03 04 02 01 05 00 04 20
0000340 ae c0 70 64 5f e5 3e e3 b3 76 30 59 37 61 34 f0
0000360 58 cc 33 72 47 c9 78 ad d1 78 b6 cc df b0 01 9f
0000400
Above you see that using the same key for a raw public encrypt as was used
for signing, yields content that is PKCS1-padded as expected.
--
Viktor.
More information about the openssl-users
mailing list