From bf93a1217ce3cc336d75a3b0cb0c1a7ed6a05cb3 Mon Sep 17 00:00:00 2001 From: Thomas Glanzmann Date: Wed, 6 Jan 2016 07:00:11 +0100 Subject: [PATCH] mbedtls: implement CURLOPT_PINNEDPUBLICKEY --- docs/libcurl/opts/CURLOPT_PINNEDPUBLICKEY.3 | 5 +- lib/vtls/mbedtls.c | 53 ++++++++++++++++++++- lib/vtls/mbedtls.h | 2 + 3 files changed, 57 insertions(+), 3 deletions(-) diff --git a/docs/libcurl/opts/CURLOPT_PINNEDPUBLICKEY.3 b/docs/libcurl/opts/CURLOPT_PINNEDPUBLICKEY.3 index 80397f716..bae1eaa72 100644 --- a/docs/libcurl/opts/CURLOPT_PINNEDPUBLICKEY.3 +++ b/docs/libcurl/opts/CURLOPT_PINNEDPUBLICKEY.3 @@ -91,8 +91,9 @@ footer: .fi .SH AVAILABILITY Added in 7.39.0 for OpenSSL, GnuTLS and GSKit. Added in 7.43.0 for -NSS and wolfSSL/CyaSSL. sha256 support added in 7.44.0 for OpenSSL, -GnuTLS, NSS and wolfSSL/CyaSSL. Other SSL backends not supported. +NSS and wolfSSL/CyaSSL. Added for mbedtls in 7.47.0, sha256 support +added in 7.44.0 for OpenSSL, GnuTLS, NSS and wolfSSL/CyaSSL. Other +SSL backends not supported. .SH RETURN VALUE Returns CURLE_OK if TLS enabled, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space. diff --git a/lib/vtls/mbedtls.c b/lib/vtls/mbedtls.c index cfebedf53..05af46212 100644 --- a/lib/vtls/mbedtls.c +++ b/lib/vtls/mbedtls.c @@ -6,7 +6,7 @@ * \___|\___/|_| \_\_____| * * Copyright (C) 2010 - 2011, Hoi-Ho Chan, - * Copyright (C) 2012 - 2015, Daniel Stenberg, , et al. + * Copyright (C) 2012 - 2016, Daniel Stenberg, , et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms @@ -141,6 +141,53 @@ const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_fr = 1024, /* RSA min key len */ }; +/* See https://tls.mbed.org/discussions/generic/ + howto-determine-exact-buffer-len-for-mbedtls_pk_write_pubkey_der +*/ +#define RSA_PUB_DER_MAX_BYTES (38 + 2 * MBEDTLS_MPI_MAX_SIZE) +#define ECP_PUB_DER_MAX_BYTES (30 + 2 * MBEDTLS_ECP_MAX_BYTES) + +#define PUB_DER_MAX_BYTES (RSA_PUB_DER_MAX_BYTES > ECP_PUB_DER_MAX_BYTES ? \ + RSA_PUB_DER_MAX_BYTES : ECP_PUB_DER_MAX_BYTES) + +static int +mbedtls_verify_pinned_crt(void *p, mbedtls_x509_crt *crt, + int depth, unsigned int *flags) +{ + struct SessionHandle *data = p; + unsigned char pubkey[PUB_DER_MAX_BYTES]; + int ret; + int size; + char *pinned_cert = data->set.str[STRING_SSL_PINNEDPUBLICKEY]; + + /* Skip intermediate and root certificates */ + if(depth) { + return 0; + } + + if(pinned_cert == NULL || crt == NULL) { + *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED; + return 1; + } + + /* Extract pubkey */ + size = mbedtls_pk_write_pubkey_der(&crt->pk, pubkey, PUB_DER_MAX_BYTES); + if(size <= 0) { + *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED; + return 1; + } + + /* mbedtls_pk_write_pubkey_der writes data at the end of the buffer. */ + ret = Curl_pin_peer_pubkey(data, pinned_cert, + &pubkey[PUB_DER_MAX_BYTES - size], size); + if(ret == CURLE_OK) { + return 0; + } + + *flags |= MBEDTLS_X509_BADCERT_NOT_TRUSTED; + return 1; +} + static Curl_recv mbedtls_recv; static Curl_send mbedtls_send; @@ -636,6 +683,10 @@ mbedtls_connect_common(struct connectdata *conn, long timeout_ms; int what; + if(data->set.str[STRING_SSL_PINNEDPUBLICKEY]) { + mbedtls_ssl_conf_verify(&connssl->config, mbedtls_verify_pinned_crt, data); + } + /* check if the connection has already been established */ if(ssl_connection_complete == connssl->state) { *done = TRUE; diff --git a/lib/vtls/mbedtls.h b/lib/vtls/mbedtls.h index b930c1000..de386285d 100644 --- a/lib/vtls/mbedtls.h +++ b/lib/vtls/mbedtls.h @@ -7,6 +7,7 @@ * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * + * Copyright (C) 2012 - 2016, Daniel Stenberg, , et al. * Copyright (C) 2010, Hoi-Ho Chan, * * This software is licensed as described in the file COPYING, which @@ -63,6 +64,7 @@ int Curl_mbedtls_shutdown(struct connectdata *conn, int sockindex); #define curlssl_check_cxn(x) (x=x, -1) #define curlssl_data_pending(x,y) (x=x, y=y, 0) #define CURL_SSL_BACKEND CURLSSLBACKEND_MBEDTLS +#define curlssl_sha256sum(a,b,c,d) mbedtls_sha256(a,b,c,0) /* This might cause libcurl to use a weeker random! TODO: implement proper use of Polarssl's CTR-DRBG or HMAC-DRBG and use that