| Message ID | 4f98bb7ee2e660a8b4513a94ed79f4f29d1ff379.1695921657.git.lukas@wunner.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | PCI device authentication | expand |
On Thu, 28 Sep 2023 19:32:36 +0200 Lukas Wunner <lukas@wunner.de> wrote: > Alternatively to the X9.62 encoding of ecdsa signatures, which uses > ASN.1 and is already supported by the kernel, there's another common > encoding called P1363. It stores r and s as the concatenation of two > big endian, unsigned integers. The name originates from IEEE P1363. > > The Security Protocol and Data Model (SPDM) specification prescribes > that ecdsa signatures are encoded according to P1363: > > "For ECDSA signatures, excluding SM2, in SPDM, the signature shall be > the concatenation of r and s. The size of r shall be the size of > the selected curve. Likewise, the size of s shall be the size of > the selected curve. See BaseAsymAlgo in NEGOTIATE_ALGORITHMS for > the size of r and s. The byte order for r and s shall be in big > endian order. When placing ECDSA signatures into an SPDM signature > field, r shall come first followed by s." > > (SPDM 1.2.1 margin no 44, > https://www.dmtf.org/sites/default/files/standards/documents/DSP0274_1.2.1.pdf) > > A subsequent commit introduces an SPDM library to enable PCI device > authentication, so add support for P1363 ecdsa signature verification. Ah good. The spec got updated. I remember playing guess with the format against libspdm which wasn't fun :) One trivial formatting note inline. > > Signed-off-by: Lukas Wunner <lukas@wunner.de> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > --- > crypto/asymmetric_keys/public_key.c | 8 ++++++-- > crypto/ecdsa.c | 16 +++++++++++++--- > crypto/testmgr.h | 15 +++++++++++++++ > 3 files changed, 34 insertions(+), 5 deletions(-) > > diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c > index 7f96e8e501db..84c4ed02a270 100644 > --- a/crypto/asymmetric_keys/public_key.c > +++ b/crypto/asymmetric_keys/public_key.c > @@ -105,7 +105,8 @@ software_key_determine_akcipher(const struct public_key *pkey, > return -EINVAL; > *sig = false; > } else if (strncmp(pkey->pkey_algo, "ecdsa", 5) == 0) { > - if (strcmp(encoding, "x962") != 0) > + if (strcmp(encoding, "x962") != 0 && > + strcmp(encoding, "p1363") != 0) > return -EINVAL; > /* > * ECDSA signatures are taken over a raw hash, so they don't > @@ -246,7 +247,10 @@ static int software_key_query(const struct kernel_pkey_params *params, > * which is actually 2 'key_size'-bit integers encoded in > * ASN.1. Account for the ASN.1 encoding overhead here. > */ > - info->max_sig_size = 2 * (len + 3) + 2; > + if (strcmp(params->encoding, "x962") == 0) > + info->max_sig_size = 2 * (len + 3) + 2; > + else if (strcmp(params->encoding, "p1363") == 0) > + info->max_sig_size = 2 * len; > } else { > info->max_data_size = len; > info->max_sig_size = len; > diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c > index fbd76498aba8..cc3082c6f67d 100644 > --- a/crypto/ecdsa.c > +++ b/crypto/ecdsa.c > @@ -159,10 +159,20 @@ static int ecdsa_verify(struct akcipher_request *req) > sg_nents_for_len(req->src, req->src_len + req->dst_len), > buffer, req->src_len + req->dst_len, 0); > > - ret = asn1_ber_decoder(&ecdsasignature_decoder, &sig_ctx, > - buffer, req->src_len); > - if (ret < 0) > + if (strcmp(req->enc, "x962") == 0) { > + ret = asn1_ber_decoder(&ecdsasignature_decoder, &sig_ctx, > + buffer, req->src_len); > + if (ret < 0) > + goto error; > + } else if (strcmp(req->enc, "p1363") == 0 && > + req->src_len == 2 * keylen) { > + ecc_swap_digits(buffer, sig_ctx.r, ctx->curve->g.ndigits); > + ecc_swap_digits(buffer + keylen, > + sig_ctx.s, ctx->curve->g.ndigits); Indent looks a little odd. > + } else { > + ret = -EINVAL; > goto error; > + } > > /* if the hash is shorter then we will add leading zeros to fit to ndigits */ > diff = keylen - req->dst_len; > diff --git a/crypto/testmgr.h b/crypto/testmgr.h > index ad57e7af2e14..f12f70818147 100644 > --- a/crypto/testmgr.h > +++ b/crypto/testmgr.h > @@ -674,6 +674,7 @@ static const struct akcipher_testvec ecdsa_nist_p192_tv_template[] = { > "\x68\x01\x9d\xba\xce\x83\x08\xef\x95\x52\x7b\xa0\x0f\xe4\x18\x86" > "\x80\x6f\xa5\x79\x77\xda\xd0", > .c_size = 55, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, { > @@ -698,6 +699,7 @@ static const struct akcipher_testvec ecdsa_nist_p192_tv_template[] = { > "\x4f\x53\x75\xc8\x02\x48\xeb\xc3\x92\x0f\x1e\x72\xee\xc4\xa3\xe3" > "\x5c\x99\xdb\x92\x5b\x36", > .c_size = 54, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, { > @@ -722,6 +724,7 @@ static const struct akcipher_testvec ecdsa_nist_p192_tv_template[] = { > "\x69\x43\xfd\x48\x19\x86\xcf\x32\xdd\x41\x74\x6a\x51\xc7\xd9\x7d" > "\x3a\x97\xd9\xcd\x1a\x6a\x49", > .c_size = 55, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, { > @@ -747,6 +750,7 @@ static const struct akcipher_testvec ecdsa_nist_p192_tv_template[] = { > "\xbc\x5a\x1f\x82\x96\x61\xd7\xd1\x01\x77\x44\x5d\x53\xa4\x7c\x93" > "\x12\x3b\x3b\x28\xfb\x6d\xe1", > .c_size = 55, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, { > @@ -773,6 +777,7 @@ static const struct akcipher_testvec ecdsa_nist_p192_tv_template[] = { > "\xb4\x22\x9a\x98\x73\x3c\x83\xa9\x14\x2a\x5e\xf5\xe5\xfb\x72\x28" > "\x6a\xdf\x97\xfd\x82\x76\x24", > .c_size = 55, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, > @@ -803,6 +808,7 @@ static const struct akcipher_testvec ecdsa_nist_p256_tv_template[] = { > "\x8a\xfa\x54\x93\x29\xa7\x70\x86\xf1\x03\x03\xf3\x3b\xe2\x73\xf7" > "\xfb\x9d\x8b\xde\xd4\x8d\x6f\xad", > .c_size = 72, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, { > @@ -829,6 +835,7 @@ static const struct akcipher_testvec ecdsa_nist_p256_tv_template[] = { > "\x4a\x77\x22\xec\xc8\x66\xbf\x50\x05\x58\x39\x0e\x26\x92\xce\xd5" > "\x2e\x8b\xde\x5a\x04\x0e", > .c_size = 70, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, { > @@ -855,6 +862,7 @@ static const struct akcipher_testvec ecdsa_nist_p256_tv_template[] = { > "\xa9\x81\xac\x4a\x50\xd0\x91\x0a\x6e\x1b\xc4\xaf\xe1\x83\xc3\x4f" > "\x2a\x65\x35\x23\xe3\x1d\xfa", > .c_size = 71, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, { > @@ -882,6 +890,7 @@ static const struct akcipher_testvec ecdsa_nist_p256_tv_template[] = { > "\x19\xfb\x5f\x92\xf4\xc9\x23\x37\x69\xf4\x3b\x4f\x47\xcf\x9b\x16" > "\xc0\x60\x11\x92\xdc\x17\x89\x12", > .c_size = 72, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, { > @@ -910,6 +919,7 @@ static const struct akcipher_testvec ecdsa_nist_p256_tv_template[] = { > "\x00\xdd\xab\xd4\xc0\x2b\xe6\x5c\xad\xc3\x78\x1c\xc2\xc1\x19\x76" > "\x31\x79\x4a\xe9\x81\x6a\xee", > .c_size = 71, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, > @@ -944,6 +954,7 @@ static const struct akcipher_testvec ecdsa_nist_p384_tv_template[] = { > "\x74\xa0\x0f\xbf\xaf\xc3\x36\x76\x4a\xa1\x59\xf1\x1c\xa4\x58\x26" > "\x79\x12\x2a\xb7\xc5\x15\x92\xc5", > .c_size = 104, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, { > @@ -974,6 +985,7 @@ static const struct akcipher_testvec ecdsa_nist_p384_tv_template[] = { > "\x4d\xd0\xc6\x6e\xb0\xe9\xfc\x14\x9f\x19\xd0\x42\x8b\x93\xc2\x11" > "\x88\x2b\x82\x26\x5e\x1c\xda\xfb", > .c_size = 104, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, { > @@ -1004,6 +1016,7 @@ static const struct akcipher_testvec ecdsa_nist_p384_tv_template[] = { > "\xc0\x75\x3e\x23\x5e\x36\x4f\x8d\xde\x1e\x93\x8d\x95\xbb\x10\x0e" > "\xf4\x1f\x39\xca\x4d\x43", > .c_size = 102, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, { > @@ -1035,6 +1048,7 @@ static const struct akcipher_testvec ecdsa_nist_p384_tv_template[] = { > "\x44\x92\x8c\x86\x99\x65\xb3\x97\x96\x17\x04\xc9\x05\x77\xf1\x8e" > "\xab\x8d\x4e\xde\xe6\x6d\x9b\x66", > .c_size = 104, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > }, { > @@ -1067,6 +1081,7 @@ static const struct akcipher_testvec ecdsa_nist_p384_tv_template[] = { > "\x5f\x8d\x7a\xf9\xfb\x34\xe4\x8b\x80\xa5\xb6\xda\x2c\x4e\x45\xcf" > "\x3c\x93\xff\x50\x5d", > .c_size = 101, > + .enc = "x962", > .public_key_vec = true, > .siggen_sigver_test = true, > },
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c index 7f96e8e501db..84c4ed02a270 100644 --- a/crypto/asymmetric_keys/public_key.c +++ b/crypto/asymmetric_keys/public_key.c @@ -105,7 +105,8 @@ software_key_determine_akcipher(const struct public_key *pkey, return -EINVAL; *sig = false; } else if (strncmp(pkey->pkey_algo, "ecdsa", 5) == 0) { - if (strcmp(encoding, "x962") != 0) + if (strcmp(encoding, "x962") != 0 && + strcmp(encoding, "p1363") != 0) return -EINVAL; /* * ECDSA signatures are taken over a raw hash, so they don't @@ -246,7 +247,10 @@ static int software_key_query(const struct kernel_pkey_params *params, * which is actually 2 'key_size'-bit integers encoded in * ASN.1. Account for the ASN.1 encoding overhead here. */ - info->max_sig_size = 2 * (len + 3) + 2; + if (strcmp(params->encoding, "x962") == 0) + info->max_sig_size = 2 * (len + 3) + 2; + else if (strcmp(params->encoding, "p1363") == 0) + info->max_sig_size = 2 * len; } else { info->max_data_size = len; info->max_sig_size = len; diff --git a/crypto/ecdsa.c b/crypto/ecdsa.c index fbd76498aba8..cc3082c6f67d 100644 --- a/crypto/ecdsa.c +++ b/crypto/ecdsa.c @@ -159,10 +159,20 @@ static int ecdsa_verify(struct akcipher_request *req) sg_nents_for_len(req->src, req->src_len + req->dst_len), buffer, req->src_len + req->dst_len, 0); - ret = asn1_ber_decoder(&ecdsasignature_decoder, &sig_ctx, - buffer, req->src_len); - if (ret < 0) + if (strcmp(req->enc, "x962") == 0) { + ret = asn1_ber_decoder(&ecdsasignature_decoder, &sig_ctx, + buffer, req->src_len); + if (ret < 0) + goto error; + } else if (strcmp(req->enc, "p1363") == 0 && + req->src_len == 2 * keylen) { + ecc_swap_digits(buffer, sig_ctx.r, ctx->curve->g.ndigits); + ecc_swap_digits(buffer + keylen, + sig_ctx.s, ctx->curve->g.ndigits); + } else { + ret = -EINVAL; goto error; + } /* if the hash is shorter then we will add leading zeros to fit to ndigits */ diff = keylen - req->dst_len; diff --git a/crypto/testmgr.h b/crypto/testmgr.h index ad57e7af2e14..f12f70818147 100644 --- a/crypto/testmgr.h +++ b/crypto/testmgr.h @@ -674,6 +674,7 @@ static const struct akcipher_testvec ecdsa_nist_p192_tv_template[] = { "\x68\x01\x9d\xba\xce\x83\x08\xef\x95\x52\x7b\xa0\x0f\xe4\x18\x86" "\x80\x6f\xa5\x79\x77\xda\xd0", .c_size = 55, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, { @@ -698,6 +699,7 @@ static const struct akcipher_testvec ecdsa_nist_p192_tv_template[] = { "\x4f\x53\x75\xc8\x02\x48\xeb\xc3\x92\x0f\x1e\x72\xee\xc4\xa3\xe3" "\x5c\x99\xdb\x92\x5b\x36", .c_size = 54, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, { @@ -722,6 +724,7 @@ static const struct akcipher_testvec ecdsa_nist_p192_tv_template[] = { "\x69\x43\xfd\x48\x19\x86\xcf\x32\xdd\x41\x74\x6a\x51\xc7\xd9\x7d" "\x3a\x97\xd9\xcd\x1a\x6a\x49", .c_size = 55, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, { @@ -747,6 +750,7 @@ static const struct akcipher_testvec ecdsa_nist_p192_tv_template[] = { "\xbc\x5a\x1f\x82\x96\x61\xd7\xd1\x01\x77\x44\x5d\x53\xa4\x7c\x93" "\x12\x3b\x3b\x28\xfb\x6d\xe1", .c_size = 55, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, { @@ -773,6 +777,7 @@ static const struct akcipher_testvec ecdsa_nist_p192_tv_template[] = { "\xb4\x22\x9a\x98\x73\x3c\x83\xa9\x14\x2a\x5e\xf5\xe5\xfb\x72\x28" "\x6a\xdf\x97\xfd\x82\x76\x24", .c_size = 55, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, @@ -803,6 +808,7 @@ static const struct akcipher_testvec ecdsa_nist_p256_tv_template[] = { "\x8a\xfa\x54\x93\x29\xa7\x70\x86\xf1\x03\x03\xf3\x3b\xe2\x73\xf7" "\xfb\x9d\x8b\xde\xd4\x8d\x6f\xad", .c_size = 72, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, { @@ -829,6 +835,7 @@ static const struct akcipher_testvec ecdsa_nist_p256_tv_template[] = { "\x4a\x77\x22\xec\xc8\x66\xbf\x50\x05\x58\x39\x0e\x26\x92\xce\xd5" "\x2e\x8b\xde\x5a\x04\x0e", .c_size = 70, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, { @@ -855,6 +862,7 @@ static const struct akcipher_testvec ecdsa_nist_p256_tv_template[] = { "\xa9\x81\xac\x4a\x50\xd0\x91\x0a\x6e\x1b\xc4\xaf\xe1\x83\xc3\x4f" "\x2a\x65\x35\x23\xe3\x1d\xfa", .c_size = 71, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, { @@ -882,6 +890,7 @@ static const struct akcipher_testvec ecdsa_nist_p256_tv_template[] = { "\x19\xfb\x5f\x92\xf4\xc9\x23\x37\x69\xf4\x3b\x4f\x47\xcf\x9b\x16" "\xc0\x60\x11\x92\xdc\x17\x89\x12", .c_size = 72, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, { @@ -910,6 +919,7 @@ static const struct akcipher_testvec ecdsa_nist_p256_tv_template[] = { "\x00\xdd\xab\xd4\xc0\x2b\xe6\x5c\xad\xc3\x78\x1c\xc2\xc1\x19\x76" "\x31\x79\x4a\xe9\x81\x6a\xee", .c_size = 71, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, @@ -944,6 +954,7 @@ static const struct akcipher_testvec ecdsa_nist_p384_tv_template[] = { "\x74\xa0\x0f\xbf\xaf\xc3\x36\x76\x4a\xa1\x59\xf1\x1c\xa4\x58\x26" "\x79\x12\x2a\xb7\xc5\x15\x92\xc5", .c_size = 104, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, { @@ -974,6 +985,7 @@ static const struct akcipher_testvec ecdsa_nist_p384_tv_template[] = { "\x4d\xd0\xc6\x6e\xb0\xe9\xfc\x14\x9f\x19\xd0\x42\x8b\x93\xc2\x11" "\x88\x2b\x82\x26\x5e\x1c\xda\xfb", .c_size = 104, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, { @@ -1004,6 +1016,7 @@ static const struct akcipher_testvec ecdsa_nist_p384_tv_template[] = { "\xc0\x75\x3e\x23\x5e\x36\x4f\x8d\xde\x1e\x93\x8d\x95\xbb\x10\x0e" "\xf4\x1f\x39\xca\x4d\x43", .c_size = 102, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, { @@ -1035,6 +1048,7 @@ static const struct akcipher_testvec ecdsa_nist_p384_tv_template[] = { "\x44\x92\x8c\x86\x99\x65\xb3\x97\x96\x17\x04\xc9\x05\x77\xf1\x8e" "\xab\x8d\x4e\xde\xe6\x6d\x9b\x66", .c_size = 104, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, }, { @@ -1067,6 +1081,7 @@ static const struct akcipher_testvec ecdsa_nist_p384_tv_template[] = { "\x5f\x8d\x7a\xf9\xfb\x34\xe4\x8b\x80\xa5\xb6\xda\x2c\x4e\x45\xcf" "\x3c\x93\xff\x50\x5d", .c_size = 101, + .enc = "x962", .public_key_vec = true, .siggen_sigver_test = true, },
Alternatively to the X9.62 encoding of ecdsa signatures, which uses ASN.1 and is already supported by the kernel, there's another common encoding called P1363. It stores r and s as the concatenation of two big endian, unsigned integers. The name originates from IEEE P1363. The Security Protocol and Data Model (SPDM) specification prescribes that ecdsa signatures are encoded according to P1363: "For ECDSA signatures, excluding SM2, in SPDM, the signature shall be the concatenation of r and s. The size of r shall be the size of the selected curve. Likewise, the size of s shall be the size of the selected curve. See BaseAsymAlgo in NEGOTIATE_ALGORITHMS for the size of r and s. The byte order for r and s shall be in big endian order. When placing ECDSA signatures into an SPDM signature field, r shall come first followed by s." (SPDM 1.2.1 margin no 44, https://www.dmtf.org/sites/default/files/standards/documents/DSP0274_1.2.1.pdf) A subsequent commit introduces an SPDM library to enable PCI device authentication, so add support for P1363 ecdsa signature verification. Signed-off-by: Lukas Wunner <lukas@wunner.de> --- crypto/asymmetric_keys/public_key.c | 8 ++++++-- crypto/ecdsa.c | 16 +++++++++++++--- crypto/testmgr.h | 15 +++++++++++++++ 3 files changed, 34 insertions(+), 5 deletions(-)