introduce getPeerCertificates, fixes #13299 (#13650)

* make i2d_X509 and d2i_X509 always available

i2d_X509 and d2i_X509 have been available in all versions of OpenSSL, so
make them available even if nimDisableCertificateValidation is set.

* introduce getPeerCertificates, fixes #13299

getPeerCertificates retrieves the verified certificate chain of the peer
we are connected to through an SSL-wrapped Socket/AsyncSocket. This
introduces the new type Certificate which stores a DER-encoded X509 certificate.
This commit is contained in:
Christian Ulrich 2020-03-22 21:00:37 +01:00 • committed by GitHub
commit 0ac9c7bb64
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
4 changed files with 82 additions and 22 deletions

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@ -91,6 +91,7 @@ type
PSslPtr* = ptr SslPtr
SslCtx* = SslPtr
PSSL_METHOD* = SslPtr
PSTACK* = SslPtr
PX509* = SslPtr
PX509_NAME* = SslPtr
PEVP_MD* = SslPtr
@ -359,6 +360,8 @@ proc SSL_new*(context: SslCtx): SslPtr{.cdecl, dynlib: DLLSSLName, importc.}
proc SSL_free*(ssl: SslPtr){.cdecl, dynlib: DLLSSLName, importc.}
proc SSL_get_SSL_CTX*(ssl: SslPtr): SslCtx {.cdecl, dynlib: DLLSSLName, importc.}
proc SSL_set_SSL_CTX*(ssl: SslPtr, ctx: SslCtx): SslCtx {.cdecl, dynlib: DLLSSLName, importc.}
proc SSL_get0_verified_chain*(ssl: SslPtr): PSTACK {.cdecl, dynlib: DLLSSLName,
importc.}
proc SSL_CTX_new*(meth: PSSL_METHOD): SslCtx{.cdecl,
dynlib: DLLSSLName, importc.}
proc SSL_CTX_load_verify_locations*(ctx: SslCtx, CAfile: cstring,
@ -426,6 +429,35 @@ proc ERR_peek_last_error*(): cint{.cdecl, dynlib: DLLUtilName, importc.}
proc OPENSSL_config*(configName: cstring){.cdecl, dynlib: DLLSSLName, importc.}
proc OPENSSL_sk_num*(stack: PSTACK): int {.cdecl, dynlib: DLLSSLName, importc.}
proc OPENSSL_sk_value*(stack: PSTACK, index: int): pointer {.cdecl,
dynlib: DLLSSLName, importc.}
proc d2i_X509*(px: ptr PX509, i: ptr ptr cuchar, len: cint): PX509 {.cdecl,
dynlib: DLLSSLName, importc.}
proc i2d_X509*(cert: PX509; o: ptr ptr cuchar): cint {.cdecl,
dynlib: DLLSSLName, importc.}
proc d2i_X509*(b: string): PX509 =
## decode DER/BER bytestring into X.509 certificate struct
var bb = b.cstring
let i = cast[ptr ptr cuchar](addr bb)
let ret = d2i_X509(addr result, i, b.len.cint)
if ret.isNil:
raise newException(Exception, "X.509 certificate decoding failed")
proc i2d_X509*(cert: PX509): string =
## encode `cert` to DER string
let encoded_length = i2d_X509(cert, nil)
result = newString(encoded_length)
var q = result.cstring
let o = cast[ptr ptr cuchar](addr q)
let length = i2d_X509(cert, o)
if length.int <= 0:
raise newException(Exception, "X.509 certificate encoding failed")
when not useWinVersion and not defined(macosx) and not defined(android) and not defined(nimNoAllocForSSL):
proc CRYPTO_set_mem_functions(a,b,c: pointer){.cdecl,
dynlib: DLLUtilName, importc.}
@ -688,30 +720,8 @@ when not defined(nimDisableCertificateValidation) and not defined(windows):
proc X509_STORE_set_trust*(ctx: PX509_STORE; trust: cint): cint
proc X509_STORE_add_cert*(ctx: PX509_STORE; x: PX509): cint
proc d2i_X509*(px: ptr PX509, i: ptr ptr cuchar, len: cint): PX509
proc i2d_X509*(cert: PX509; o: ptr ptr cuchar): cint
{.pop.}
proc d2i_X509*(b: string): PX509 =
## decode DER/BER bytestring into X.509 certificate struct
var bb = b.cstring
let i = cast[ptr ptr cuchar](addr bb)
let ret = d2i_X509(addr result, i, b.len.cint)
if ret.isNil:
raise newException(Exception, "X.509 certificate decoding failed")
proc i2d_X509*(cert: PX509): string =
## encode `cert` to DER string
let encoded_length = i2d_X509(cert, nil)
result = newString(encoded_length)
var q = result.cstring
let o = cast[ptr ptr cuchar](addr q)
let length = i2d_X509(cert, o)
if length.int <= 0:
raise newException(Exception, "X.509 certificate encoding failed")
when isMainModule:
# A simple certificate test
let certbytes = readFile("certificate.der")