Actually not only keychain, but any other apps that request it in any way.
The problem first appeared when Adium asked me about untrusted certificates, I selected "Always trust" in system "view certificate" window, and it hung. Then I killed adium, and since then no app can access keychain.
After killing any hung app we can see the following stacktrace:
Date/Time: 2013-06-23 15:06:13 +0300
OS Version: 10.7.5 (Build 11G63b)
Architecture: x86_64
Report Version: 9
Command: Keychain Access
Path: /Applications/Utilities/Keychain Access.app/Contents/MacOS/Keychain Access
Version: 5.4 (55120.6)
Build Version: 54
Project Name: KeychainAccess
Source Version: 55120006000000000
Parent: launchd [281]
PID: 87327
Event: hang
Duration: 1.06s
Steps: 11 (100ms sampling interval)
Pageins: 13
Pageouts: 0
Process: Keychain Access [87327]
Path: /Applications/Utilities/Keychain Access.app/Contents/MacOS/Keychain Access
Architecture: x86_64
UID: 501
Thread 0x217de6 DispatchQueue 1
User stack:
11 ??? (in Keychain Access) [0x1028125e4]
11 NSApplicationMain + 867 (in AppKit) [0x7fff8c525eac]
11 -[NSApplication run] + 470 (in AppKit) [0x7fff8c2a99b9]
11 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 135 (in AppKit) [0x7fff8c2ad07d]
11 _DPSNextEvent + 1247 (in AppKit) [0x7fff8c2ad9c5]
11 AEProcessAppleEvent + 102 (in HIToolbox) [0x7fff8bf88b69]
11 aeProcessAppleEvent + 250 (in AE) [0x7fff9848a9f7]
11 _ZL25dispatchEventAndSendReplyPK6AEDescPS_ + 38 (in AE) [0x7fff9848ab03]
11 aeDispatchAppleEvent(AEDesc const*, AEDesc*, unsigned int, unsigned char*) + 200 (in AE) [0x7fff9848ac25]
11 _NSAppleEventManagerGenericHandler + 105 (in Foundation) [0x7fff98ccd5dc]
11 -[NSAppleEventManager dispatchRawAppleEvent:withRawReply:handlerRefCon:] + 283 (in Foundation) [0x7fff98ccd74e]
11 __-[NSAppleEventManager setEventHandler:andSelector:forEventClass:andEventID:]_block_invoke_1 + 101 (in Foundation) [0x7fff98cce7c7]
11 -[NSObject performSelector:withObject:withObject:] + 65 (in CoreFoundation) [0x7fff92e3a541]
11 -[NSApplication(NSAppleEventHandling) _handleCoreEvent:withReplyEvent:] + 330 (in AppKit) [0x7fff8c2b05b9]
11 -[NSApplication(NSAppleEventHandling) _handleAEOpenEvent:] + 242 (in AppKit) [0x7fff8c2b0858]
11 -[NSApplication _sendFinishLaunchingNotification] + 78 (in AppKit) [0x7fff8c2b1b91]
11 -[NSApplication _postDidFinishNotification] + 212 (in AppKit) [0x7fff8c2b1e2b]
11 ??? (in Keychain Access) [0x102826c60]
11 -[NSNotificationCenter postNotificationName:object:userInfo:] + 65 (in Foundation) [0x7fff98c97fc3]
11 _CFXNotificationPost + 2634 (in CoreFoundation) [0x7fff92df07ba]
11 __-[NSNotificationCenter addObserver:selector:name:object:]_block_invoke_1 + 47 (in Foundation) [0x7fff98cabd0e]
11 ??? (in Keychain Access) [0x1028219de]
11 ??? (in Keychain Access) [0x10281ee53]
11 ??? (in Keychain Access) [0x102844138]
11 ??? (in Keychain Access) [0x10284431c]
11 -[NSTableView _doSelectIndexes:byExtendingSelection:indexType:funnelThroughSingleIndexVersion:] + 2915 (in AppKit) [0x7fff8c415eb5]
11 -[NSTableView _enableSelectionPostingAndPost] + 425 (in AppKit) [0x7fff8c3edb0a]
11 -[NSTableView _sendSelectionChangedNotificationForRows:columns:] + 203 (in AppKit) [0x7fff8c417049]
11 ??? (in Keychain Access) [0x102826be2]
11 ??? (in Keychain Access) [0x102826c60]
11 -[NSNotificationCenter postNotificationName:object:userInfo:] + 65 (in Foundation) [0x7fff98c97fc3]
11 _CFXNotificationPost + 2634 (in CoreFoundation) [0x7fff92df07ba]
11 __-[NSNotificationCenter addObserver:selector:name:object:]_block_invoke_1 + 47 (in Foundation) [0x7fff98cabd0e]
11 ??? (in Keychain Access) [0x102843fbe]
11 ??? (in Keychain Access) [0x1028197e5]
11 ??? (in Keychain Access) [0x10281970e]
11 ??? (in Keychain Access) [0x1028198ed]
11 ??? (in Keychain Access) [0x102823ee9]
11 ??? (in Keychain Access) [0x10282de5c]
11 ??? (in Keychain Access) [0x10282e18b]
11 ??? (in Keychain Access) [0x10282ca56]
11 ??? (in Keychain Access) [0x10282d259]
11 +[SFCertificateView attributedCertificateName:showsStatus:showsIssuer:selected:prefix:] + 426 (in SecurityInterface) [0x7fff908f7ca6]
11 -[SFCertificateData statusString] + 46 (in SecurityFoundation) [0x7fff92373838]
11 -[SFCertificateData evaluateStatus] + 136 (in SecurityFoundation) [0x7fff923738ee]
11 -[SFCertificateData certStatusFromDomainTrustSettings:isMixed:hasBasic:names:] + 115 (in SecurityFoundation) [0x7fff92374c86]
11 SecTrustSettingsCopyTrustSettings + 34 (in Security) [0x7fff8e1ae138]
11 _ZL19tsCopyTrustSettingsP23OpaqueSecCertificateRefjPPK9__CFArrayPPK8__CFDate + 49 (in Security) [0x7fff8e1adfe6]
11 Security::KeychainCore::TrustSettings::CreateTrustSettings(unsigned int, bool, bool, Security::KeychainCore::TrustSettings*&) + 365 (in Security) [0x7fff8e130369]
11 ocspdTrustSettingsRead + 111 (in Security) [0x7fff8e13055a]
11 ocsp_client_trustSettingsRead + 141 (in Security) [0x7fff8e1307c9]
11 mach_msg_trap + 10 (in libsystem_kernel.dylib) [0x7fff9781267a]
Kernel stack:
11 hndl_mach_scall64 + 19 (in mach_kernel) [0xffffff80002daec3]
11 thread_set_child + 336 (in mach_kernel) [0xffffff80002aef10]
11 mach_msg_overwrite_trap + 184 (in mach_kernel) [0xffffff800021bbd8]
11 ipc_kmsg_send + 416 (in mach_kernel) [0xffffff80002149e0]
11 ipc_mqueue_send + 306 (in mach_kernel) [0xffffff8000215d72]
11 thread_block_reason + 299 (in mach_kernel) [0xffffff800022f42b]
11 thread_continue + 1661 (in mach_kernel) [0xffffff800022f1ad]
11 machine_switch_context + 361 (in mach_kernel) [0xffffff80002c2939]
... some lines of code stripped, full version here http://pastebin.com/HMS38f1g
I found some other reports on the internet, but all of them said 'after that everything began to fail so we've reinstalled Lion'. But I don't like this option, there should be some way to manually delete a failing certificate.
sudo pkill SecurityAgent