ssl_c_sha256

[allentc]

Output of haproxy -vv and uname -a

Re haproxy -vv: N/A - not using haproxy in part due to not having this feature

Linux ip-172-31-23-135.ec2.internal 4.14.121-109.96.amzn2.x86_64 #1 SMP Wed May 22 16:54:10 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

What should haproxy do differently? Which functionality do you think we should add?

Extend layer 5 sample fetch methods; add ssl_c_sha256 as an alternative to ssl_c_sha1. The ever greater weakness of SHA1 should make the need for this self explanatory.

What are you trying to do?

Check client certificates in a proxied application using the DER hash value. Presently using nginx which also can only provide the SHA1 hash value of the client certificate. So I forward the entire client certificate, which is often a rather large and awkward chunk of data to be passing around using headers. Since haproxy can do no better I am not compelled to convert.

[TimWolla]

This adds a converter for the SHA-2 family, supporting SHA-224, SHA-256 SHA-384 and SHA-512. The converter relies on the OpenSSL implementation, thus only being available when HAProxy is compiled with USE_OPENSSL. See GitHub issue #123. The hypothetical `ssl_?_sha256` fetch can then be simulated using `ssl_?_der,sha2(256)`: http-response set-header Server-Cert-FP %[ssl_f_der,sha2(256),hex] --- doc/configuration.txt | 12 ++++++- reg-tests/converter/sha2.vtc | 60 ++++++++++++++++++++++++++++++++ src/sample.c | 67 ++++++++++++++++++++++++++++++++++++ 3 files changed, 138 insertions(+), 1 deletion(-) create mode 100644 reg-tests/converter/sha2.vtc diff --git a/doc/configuration.txt b/doc/configuration.txt index 3e402fb92..2a09bab61 100644 --- a/doc/configuration.txt +++ b/doc/configuration.txt @@ -14086,9 +14086,19 @@ set-var(<var name>) contain characters 'a-z', 'A-Z', '0-9', '.' and '_'. sha1 - Converts a binary input sample to a SHA1 digest. The result is a binary + Converts a binary input sample to a SHA-1 digest. The result is a binary sample with length of 20 bytes. +sha2([<bits>]) + Converts a binary input sample to a digest in the SHA-2 family. The result + is a binary sample with length of <bits>/8 bytes. + + Valid values for <bits> are 224, 256, 384, 512, each corresponding to + SHA-<bits>. The default value is 256. + + Please note that this converter is only available when haproxy has been + compiled with USE_OPENSSL. + strcmp(<var>) Compares the contents of <var> with the input value of type string. Returns the result as a signed integer compatible with strcmp(3): 0 if both strings diff --git a/reg-tests/converter/sha2.vtc b/reg-tests/converter/sha2.vtc new file mode 100644 index 000000000..0354b0a20 --- /dev/null +++ b/reg-tests/converter/sha2.vtc @@ -0,0 +1,60 @@ +varnishtest "sha2 converter Test" + +#REQUIRE_VERSION=2.1 +#REQUIRE_OPTION=OPENSSL + +feature ignore_unknown_macro + +server s1 { + rxreq + txresp +} -repeat 3 -start + +haproxy h1 -conf { + defaults + mode http + timeout connect 1s + timeout client 1s + timeout server 1s + + frontend fe + bind "fd@${fe}" + + #### requests + http-request set-var(txn.hash) req.hdr(hash) + + http-response set-header SHA2 "%[var(txn.hash),sha2,hex,lower]" + http-response set-header SHA2-224 "%[var(txn.hash),sha2(224),hex,lower]" + http-response set-header SHA2-256 "%[var(txn.hash),sha2(256),hex,lower]" + http-response set-header SHA2-384 "%[var(txn.hash),sha2(384),hex,lower]" + http-response set-header SHA2-512 "%[var(txn.hash),sha2(512),hex,lower]" + http-response set-header SHA2-invalid "%[var(txn.hash),sha2(1),hex,lower]" + + default_backend be + + backend be + server s1 ${s1_addr}:${s1_port} +} -start + +client c1 -connect ${h1_fe_sock} { + txreq -url "/" \ + -hdr "Hash: 1" + rxresp + expect resp.status == 200 + expect resp.http.sha2 == "6b86b273ff34fce19d6b804eff5a3f5747ada4eaa22f1d49c01e52ddb7875b4b" + expect resp.http.sha2-224 == "e25388fde8290dc286a6164fa2d97e551b53498dcbf7bc378eb1f178" + expect resp.http.sha2-256 == "6b86b273ff34fce19d6b804eff5a3f5747ada4eaa22f1d49c01e52ddb7875b4b" + expect resp.http.sha2-384 == "47f05d367b0c32e438fb63e6cf4a5f35c2aa2f90dc7543f8a41a0f95ce8a40a313ab5cf36134a2068c4c969cb50db776" + expect resp.http.sha2-512 == "4dff4ea340f0a823f15d3f4f01ab62eae0e5da579ccb851f8db9dfe84c58b2b37b89903a740e1ee172da793a6e79d560e5f7f9bd058a12a280433ed6fa46510a" + expect resp.http.sha2-invalid == "" + txreq -url "/" \ + -hdr "Hash: 2" + rxresp + expect resp.status == 200 + expect resp.http.sha2 == "d4735e3a265e16eee03f59718b9b5d03019c07d8b6c51f90da3a666eec13ab35" + expect resp.http.sha2-224 == "58b2aaa0bfae7acc021b3260e941117b529b2e69de878fd7d45c61a9" + expect resp.http.sha2-256 == "d4735e3a265e16eee03f59718b9b5d03019c07d8b6c51f90da3a666eec13ab35" + expect resp.http.sha2-384 == "d063457705d66d6f016e4cdd747db3af8d70ebfd36badd63de6c8ca4a9d8bfb5d874e7fbd750aa804dcaddae7eeef51e" + expect resp.http.sha2-512 == "40b244112641dd78dd4f93b6c9190dd46e0099194d5a44257b7efad6ef9ff4683da1eda0244448cb343aa688f5d3efd7314dafe580ac0bcbf115aeca9e8dc114" + expect resp.http.sha2-invalid == "" +} -run diff --git a/src/sample.c b/src/sample.c index 67f59e844..96102504b 100644 --- a/src/sample.c +++ b/src/sample.c @@ -1537,6 +1537,70 @@ static int sample_conv_sha1(const struct arg *arg_p, struct sample *smp, void *p return 1; } +#ifdef USE_OPENSSL +static int sample_conv_sha2(const struct arg *arg_p, struct sample *smp, void *private) +{ + struct buffer *trash = get_trash_chunk(); + int bits = 256; + if (arg_p && arg_p->data.sint) + bits = arg_p->data.sint; + + switch (bits) { + case 224: { + SHA256_CTX ctx; + + memset(&ctx, 0, sizeof(ctx)); + + SHA224_Init(&ctx); + SHA224_Update(&ctx, smp->data.u.str.area, smp->data.u.str.data); + SHA224_Final((unsigned char *) trash->area, &ctx); + trash->data = SHA224_DIGEST_LENGTH; + break; + } + case 256: { + SHA256_CTX ctx; + + memset(&ctx, 0, sizeof(ctx)); + + SHA256_Init(&ctx); + SHA256_Update(&ctx, smp->data.u.str.area, smp->data.u.str.data); + SHA256_Final((unsigned char *) trash->area, &ctx); + trash->data = SHA256_DIGEST_LENGTH; + break; + } + case 384: { + SHA512_CTX ctx; + + memset(&ctx, 0, sizeof(ctx)); + + SHA384_Init(&ctx); + SHA384_Update(&ctx, smp->data.u.str.area, smp->data.u.str.data); + SHA384_Final((unsigned char *) trash->area, &ctx); + trash->data = SHA384_DIGEST_LENGTH; + break; + } + case 512: { + SHA512_CTX ctx; + + memset(&ctx, 0, sizeof(ctx)); + + SHA512_Init(&ctx); + SHA512_Update(&ctx, smp->data.u.str.area, smp->data.u.str.data); + SHA512_Final((unsigned char *) trash->area, &ctx); + trash->data = SHA512_DIGEST_LENGTH; + break; + } + default: + return 0; + } + + smp->data.u.str = *trash; + smp->data.type = SMP_T_BIN; + smp->flags &= ~SMP_F_CONST; + return 1; +} +#endif + static int sample_conv_bin2hex(const struct arg *arg_p, struct sample *smp, void *private) { struct buffer *trash = get_trash_chunk(); @@ -3203,6 +3267,9 @@ static struct sample_conv_kw_list sample_conv_kws = {ILH, { { "word", sample_conv_word, ARG3(2,SINT,STR,SINT), sample_conv_field_check, SMP_T_STR, SMP_T_STR }, { "regsub", sample_conv_regsub, ARG3(2,REG,STR,STR), sample_conv_regsub_check, SMP_T_STR, SMP_T_STR }, { "sha1", sample_conv_sha1, 0, NULL, SMP_T_BIN, SMP_T_BIN }, +#ifdef USE_OPENSSL + { "sha2", sample_conv_sha2, ARG1(0, SINT), NULL, SMP_T_BIN, SMP_T_BIN }, +#endif { "concat", sample_conv_concat, ARG3(1,STR,STR,STR), smp_check_concat, SMP_T_STR, SMP_T_STR }, { "strcmp", sample_conv_strcmp, ARG1(1,STR), smp_check_strcmp, SMP_T_STR, SMP_T_SINT },

…

-- 2.21.0

[TimWolla]

I had expected that email in the collapsed comment to look better. Anyway @allentc I've proposed a patch to add a converter for the SHA-2 family on the mailing list: https://www.mail-archive.com/haproxy@formilux.org/msg34217.html

Using this converter you would be able to achieve your desired use-case using: http-request set-header Client-Cert %[ssl_c_der,sha2(256),hex].

[TimWolla]

The patch will be included in HAProxy 2.1. I guess it can be trivially applied to 2.0 if you are willing to compile your own HAProxy.

[allentc]

One more haproxy convert! Thank you.

[jeswant]

Can't find documentation related to ssl_c_sha2 in here: https://cbonte.github.io/haproxy-dconv/2.3/configuration.html
in 2.2 configuration documentation. If missing, can we have the fix documented please? Thanks!

[wlallemand]

That's because "ssl_c_sha2" doesn't exist. You have to use ssl_c_der and the sha2 converter like explained by Tim.

https://cbonte.github.io/haproxy-dconv/2.3/configuration.html#ssl_c_der
https://cbonte.github.io/haproxy-dconv/2.3/configuration.html#sha2

[capflam]

Because this sample fetch does not exist. But there is a sha2 converter.